Class , . n':vv^ 
 
 Rnok r'\. ^ 
 GopyrightN^ 
 
 COPYRIGHT DEPOSIT. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
THE MACMILLAN COMPANY 
 
 NEW YORK • BOSTON • CHICAGO • DALLAS 
 ATLANTA • SAN FRANCISCO 
 
 MACMILLAN & CO., Limited 
 
 LONDON • BOMBAY • CALCUTTA 
 MELBOURNE 
 
 THE MACMILLAN CO. OF CANADA, Ltd. 
 
 TORONTO 
 
THE FUNGI WHICH CAUSE 
 PLANT DISEASE 
 
 > 
 
 BY 
 
 F. L. STEVENS, Ph. D. 
 
 PROFESSOR OF VEGETABLE PATHOLOGY AND DEAN, COLLEGE OP 
 
 AGRICULTURE AND MECHANIC ARTS, MAYAGUEZ, PORTO 
 
 RICO. FORMERLY OF THE NORTH CAROLINA 
 
 COLLEGE OF AGRICULTURE ALSO FORMERLY 
 
 PRESIDENT OF THE AMERICAN PHY- 
 
 TOPATHOLOGICAL SOCIETY 
 
 THE MACMILLAN COMPANY 
 
 1913 
 
 All rights reserved 
 

 Copyright, 1913 
 
 By the MACMILLAN COMPANY 
 
 Set up and electrotyped. Published November, 1913 
 
 <S)CI,A358112 
 
TO 
 
 MY WIFE 
 
 ADELINE CHAPMAN STEVENS 
 
 IN ACKNOWLEDGMENT 
 
 OF 
 
 HELP, ENCOURAGEMENT 
 
 AND INSPIRATION 
 
PREFACE 
 
 This volume is intended to introduce to the student the more 
 important cryptogamic parasites affecting economic plants in the 
 United States, with sufficient keys and descriptions to enable 
 their identification. Technical description of each division, order, 
 family, genus and species when important is given unless the 
 essential characters are to be clearly inferred from preceding keys 
 or text. Gross descriptions of the host as diseased, i. e., of the 
 disease itself, have been avoided since such are to be found in 
 "Diseases of Economic Plants." Effort has been made to avoid 
 duplication of matter contained in that volume. Abundant 
 citations to the more important papers are given, sufficient, it is 
 believed, to put the student in touch with the literature of the 
 subject. 
 
 While many parasites not yet known in the United States are 
 briefly mentioned, especially the more important ones or those 
 which are likely to invade America, no attempt has been made to 
 list all of these. Non-parasitic groups closely related to those that 
 are parasitic have been introduced in the keys merely to give a 
 larger perspective to the student. 
 
 Effort has been made to give at least one illustration of each 
 genus that is of importance in the United States. 
 
 The author is indebted for descriptions, keys, etc., to the 
 various standard works. Those which have been drawn upon 
 most largely are Saccardo's Sylloge Fungorum, Die Natiirlichen 
 Pflanzenfamilien of Engler & Prantl, Clinton's Ustilaginales of 
 North America, Clement's Genera of Fungi, and Minnesota 
 Mushrooms, Plowright's British Uredinese and Ustilaginese, Ar- 
 thur and Murrill each in North American Flora. 
 
 The author wishes also to express thanks for suggestions and 
 criticism of the manuscript to T. H. Macbride, who read the por- 
 tion on Myxomycetes; J. J. Davis, Phycomycetes; L. R. Jones 
 
 vii 
 
viii PREFACE 
 
 and T. J. Burrill, Bacteria; G. M. Reed, Perisporiales; G. P. Clin- 
 ton, Ustilaginales; J. L. Sheldon, Ascomycetes in part; D. Red- 
 dick, Ascomycetes in part; J. C. Arthur, Uredinales; F. D. Heald, 
 Fungi Imperfecti in part; F. C. Stewart, Fungi Imperfecti in part; 
 H. Metcalf, Basidiomycetes in part; to Mrs. Flora W. Patter- 
 son for aid in securing descriptions otherwise unobtainable; to 
 Dr. Marshall Avery Howe for assistance with the glossary; to 
 Messrs. Norton, Rosenkranz and Fawcett, for aid in proof- 
 reading and in preparation of the manuscript, though no re- 
 sponsibility for error attaches to those who have so kindly 
 aided. 
 
 It is probable, owing to the present unsatisfactory condition of 
 taxonomy of the fungi, loose and imperfect description of species, 
 disregard of generic limitation, lack of knowledge regarding the 
 limits of specific variation, influence of environment, biologic host 
 relations, etc., that many of the species treated in the text are 
 untenable. The author has, however, attempted so far as possible 
 to reflect the facts as they appear in the light of present knowledge 
 and has deemed it more useful to err on the side of* conservatism 
 than to attempt to reduce the apparent number of species by con- 
 solidation without full and complete evidence as to the real identity 
 of the species in question. 
 
 F. L. Stevens. 
 Mayaguez, Porto Rico. 
 
CONTENTS 
 
 PAGE 
 
 Introduction 1 
 
 Division I, Myxomycetes 5 
 
 Division II, Schizomycetes 13 
 
 Bibliography of Introduction, Myxomycetes and 
 
 Schizomycetes 53 
 
 Division III, Eumycetes. . 59 
 
 Class Phycomycetes 65 
 
 Bibliography of Phycomycetes 109 
 
 Class Ascomycetes 113 
 
 Bibliography of Ascomycetes 288 
 
 Class Basidiomycetes 298 
 
 Bibliography of Basidiomycetes 466 
 
 Fungi Imperfecti 475 
 
 Bibliography of Fungi Imperfecti 666 
 
 Bibliography of Books and Periodicals 678 
 
 Glossary 681 
 
 Index 697 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
INTRODUCTION 
 
 The principal non-flowering vegetable parasites which cause 
 plant diseases belong to three divisions: the Slime Molds (Myxo- 
 mycetes) ; the Bacteria (Schizomycetes) ; and the True Fungi 
 (Eumycetes including the Phycomycetes). The term fungi, in 
 the broad sense, is often used to include all three of these divisions. 
 All are devoid of chlorophyll and therefore all differ from the green 
 plants in the essential ways which result from this deficiency. 
 Transpiration, respiration, and true assimilation are the same as 
 with the green plants, but photosynthesis or starch manufacture 
 cannot be accomplished by them. Sunlight being thus useless to 
 them directly they can live in the dayk as well as the light. Having 
 no ability to elaborate their own foods from inorganic matter 
 these organisms are limited to such nutriment as they can obtain 
 from plants or animals which have elaborated it; that is, they must 
 have organic foods for their sustenance. 
 
 The fungi have acquired various food habits and adapted them- 
 selves to different methods of nutrition. Some are nearly om- 
 nivorous and can subsist upon almost any decaying tissue or upon 
 soils or solutions rich with organic debris. Others thrive only 
 upon special substances, as for example, some particular plant or 
 animal, the host, perhaps only upon some particular part of that 
 plant or animal. The organisms that prey upon living things are 
 called parasites. Those living upon dead things are sapro- 
 phytes. No hard and fast line can be drawn between these two 
 classes. An organism which is usually a saprophyte may live 
 upon a dead member of some plant, gradually encroach upon the 
 still living part and thus become partially a parasite. Again there 
 are times in the history of a plant when life ebbs so low that it is 
 difficult to tell the living from the dead. The pulp of the apple 
 
 1 
 
2 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 when ripe, a resting seed, the cells of the potato tuber in winter, 
 are undoubtedly alive, yet their activity is so little that many 
 organisms can gain a foothold upon these stages of the plant 
 that cannot do so at more vigorous periods of their exist- 
 ence. 
 
 Tubeuf ranks as hemi-parasites those organisms that usually 
 are parasites, but may sometimes become saprophytic, and as 
 hemi-saprophytes such as are usually parasitic, but may excep- 
 tionally become saprophytic. These distinctions are of little 
 import, other than to bring out clearly that each species has its 
 own limits as to food requirements. 
 
 It is hardly to be thought that these parasites and saprophytes 
 have always been dependent organisms. The true fungi for ex- 
 ample are best to be regarded as degraded descendants of algse, 
 in which ancestors they once possessed chlorophyll and could 
 prepare their own food from mineral matter by the aid of sun- 
 light. 
 
 No discussion of the general metabolic processes of the fungi is 
 here necessary further than to indicate that among the products 
 of their activity there are various excretions and secretions, which 
 bear important relations to parasitism. Thus certain fungi grow- 
 ing in artificial culture produce enzymes or organic ferments 
 capable of softening and dissolving cellulose, also toxins, poisons 
 which are capable of killing the cells of the host plant. Such 
 enzymes and toxins are numerous and their bearing upon par- 
 asitism is obvious. They enable the parasite to kill adjacent cells 
 of the host and then to effect an entrance through the cell walls 
 to the protoplasm and other nutrients contained within the 
 cell. 
 
 The presence of the parasite, or secretions produced by it, often 
 calls forth abnormal growth responses from the host. These take 
 very diverse forms, either the undergrowth or overgrowth, hyper- 
 trophy, of single cells or tissues, or even the excessive development 
 of large plant parts as in the case of the witches' brooms, and the 
 "double flowering" of the dewberry. 
 
 The probable relations of the groups under consideration to the 
 other members of the Thallophyta are suggested in the following 
 scheme. 
 

 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 'Bacteria, Schizomycetes. 
 Cyanophyce/e, Blue-green Algse. 
 
 Myxomycetes, Slime Fungi. 
 Peridine^, Dinoflagellates. 
 
 1 Conjugate, Conjugates. 
 Diatome^. 
 'Heterocont^. 
 
 ^"CHLOROPHYCEiE, Green Algse. 
 ^Charace^, Stoneworts. 
 Rhodophyce^, Red Algae. 
 ^^"^^"EuMYCETES, Fungi. 
 
 ■Phycomycetes, Alga-like Fungi. 
 ■Ph^ophyce^, Brown Algaj. 
 
 Key to the three Divisions important as plant parasites: 
 Vegetative body a multinucleate naked plasmodium 
 
 Division I. Myxomycetes, p. 5. 
 
 Vegetative body a single-walled cell, nucleus absent or not of the 
 
 form typical in the other fungi, reproduction by fission (by conidia 
 
 in a few non-parasitic forms).. .Division II. Schizomycetes, p. 13. 
 
 Not as above : Vegetative body usually filamentous, reproduction by 
 
 various means Division III. Eumycetes, p. 59. 
 
DIVISION I 
 
 MYXOMYCETES, SLIME MOLDS, SLIME 
 FUNGI"-'* (p. 3) 
 
 These are the lowest organisms considered by the botanist, and 
 partake so much of the nature of both animals and plants that 
 their position has long been debated. Their affinities are with the 
 lowest living things, on the boundary between the animal and the 
 vegetable kingdom, and sometimes more attention is accorded 
 them by the zoologist than by the botanist. 
 
 The distinctive character of this group is that the vegetative 
 condition consists either of distinct amoeboid cells or of a mass of 
 naked protoplasm, the Plasmodium, composed of numerous cell 
 units, each unwalled. The plasmodia, at the completion of the 
 free vegetative stage, produce numerous walled spores either free 
 or in sporangia of various forms. The spores upon germination 
 produce either zoospores or amoeboid bodies which multiply and 
 unite to form either new plasmodia or pseudoplasmodia. 
 
 The slime molds consist of three orders: 
 
 Key to Orders of Myxomycetes 
 
 Parasitic 1 . Plasmodiophorales, p. 5. 
 
 Saprophytic 
 
 Vegetative phase of free amoeba? 2. Acrasiales 
 
 Vegetative phase plasmodia! 3. Myxogastrales, p. 9. 
 
 The Acrasiales contain some five genera and ten species purely 
 saprophytic. 
 
 Plasmodiophorales 
 
 Intracellular parasites; vegetative stage plasmodial; spores 
 formed by the simultaneous breaking up of the Plasmodium into 
 an indefinite number of independent cells. 
 
 5 
 
6 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 The Plasmodiophorales appear to include all of the true para- 
 sites of the Myxomycetes. 
 
 Key to Genera of Plasmodiophorales 
 
 Spores free, spherical 1. Plasmodiophora, p. 6. 
 
 Spores united into groups 
 
 Spores in groups of four 2. Tetramyxa, p. 8. 
 
 Spores in larger groups 
 
 Spores forming a hollow sphere. ... 3. Sorosphaera, p. 8. 
 
 Spores forming a spongy spore-ball 4. Spongospora, p. 8. 
 
 Plasmodiophora Woronin 
 
 This genus is parasitic in the living parenchyma of the roots 
 of plants, the plasmodia filling the cells and causing galls at 
 the point of attack. There are three species of the genus in 
 Europe and America. 
 
 P. brassicae Wor.^~*' ~^^~^^' ^os ^r^^g jong been known as a parasite 
 on the crucifers generally and recent work indicates that other 
 families, as the Umbelliferse and cucurbs, are also susceptible. -^^^ 
 
 The parasitised cells especially, and the adjacent cells as well, 
 are stimulated to enormous overgrowth; this hypertrophy result- 
 ing in a characteristic root "clubbing." 
 
 Study of diseased sections shows that the medullary rays and 
 cortex are abnormally thick (hypertrophy and hyperplasia) and 
 many of their cells are parasitized. Sclerenchyma cells are sup- 
 pressed by the parasite and the xylem is reduced and phloem in- 
 creased proportionately. The amount of stored starch is much 
 less than in normal tissues. 
 
 Infection does not appear to pass from cell to cell but groups of 
 diseased cells are thought to arise from repeated division of a cell 
 after its infection. 
 
 In the enlarged host cells the protoplasm appears abnormally 
 dense and fine grained. Eventually the whole lumen of the cell is 
 occupied by the crowded, amoeboid, individuals, each uninucleate 
 and unwalled, and still distinct from the other. These individuals 
 later fuse into a Plasmodium the nuclei of which enlarge and un- 
 dergo simultaneous mitotic division. Still later the mass divides 
 into uninuclear segments each of which matures to a spore 1.6 ju 
 in diameter, covered by a thin, smooth, colorless membrane. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 7 
 
 The decay of the host liberates the spores in the soil. Their 
 germination may be readily studied upon a microscope slide 
 where in from five to twenty-four hours uninucleate zoospores 
 are produced. The zoospores are differentiated into an inner 
 
 10 11 
 
 Fig. 1. — P. brassicse: 3, cabbage cells occupied by the unicellular parasite; 5, later 
 stage, parasite many-nucleate; 10, host cell full of spores; 11, germinating 
 spores. After Lotsy. 
 
 granular part and an outer hyaline part, the hyaloplasm, which 
 may extend to form pseudopodia, thus giving the cell an amoeboid 
 movement in addition to that due to the single long cilium. In- 
 fection by these swarm spores is supposed to occur through the 
 root hairs though the mode of primary infection is not definitely 
 
8 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 known. Seedlings raised in soil inoculated with chopped roots 
 bearing the disease become badly diseased as do also seedlings 
 upon which infected water is poured. 
 
 P. humili Kirk is mentioned by Kirk ^ as the cause of club 
 root of hops in New Zealand. 
 
 P. vitis Viala & Sauvageau ; ^ P. calif ornica Viala & Sauvageau ; ® 
 P. orchidis Massee ^° and P. tomato Abbey ^^ have been reported 
 as the causes of serious diseases but their relation to the diseases 
 and even their identity as actual organisms is seriously ques- 
 tioned.12-14 
 
 Tetramyxa Goebel grows upon water plants, notably Ruppia.^ 
 
 Sorosphaera Schroter (p. 6) 
 
 Parasitic in the parenchyma of living plants; spores elliptic- 
 wedge shaped, forming a hollow, spherical spore ball. 
 
 One species is found upon Veronica f a second species has been 
 reported upon tea.^"^' 
 
 S. graminis Schwartz is reported by Schwartz ^^"^ on the roots 
 of Poa and other grasses where it caused nodules much resembling 
 those of nematodes. 
 
 Spongospora Brunchorst (p. 6) 
 
 Similar to Sorosphaera but the spores forming a spore ball 
 with open reticulations. 
 
 S. subterranea (Wallr.) Lag.^^"^^ causes the powdery scab of 
 potatoes in Great Britain, Europe and South America. It has 
 been closely studied by Osborne ^^ who shows it to appear first in 
 the tuber cells as a uninucleate myxamoeba which ultimately 
 develops into a multinucleate amoeboid Plasmodium. 
 
 Sorolpidium Nemec is a new genus with the species. 
 
 S. betae Nemec which is on beets. ^^^ 
 
 Several little known genera, kin to the above, attack algae, 
 fungi, pollen, etc. 
 
 Pseudomonas radicicola, the legume tubercle organism has been 
 by some placed in this order under the name Phytomyxa legumi- 
 nosarum. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Myxogastrales (p. 5) 
 
 This order comprises some forty-seven genera and four hun- 
 dred species of great variety and beauty. The Plasmodium, 
 which varies from a millimeter or less 
 to several decimeters in diameter, pro- ( \ ^\ 
 duces either flat encrusted masses of \ ' ' ^C- \^ •'" 
 
 spores, aethalia, or develops spores in \ '^ 
 
 sporangia which show some superficial r 
 resemblance to very small pufTballs, 
 Fig. 2. The interior of the sporan- 
 gium is often permeated by a thread- '^Tum-TSrercaTJ'arcoS'cr;^- 
 like structure, the capillitium. They tais. After Macbride. 
 are not parasites but occasionally injure plants by overgrowing 
 them. 
 
 Key to Families of Myxogastrales 
 
 Spores not enclosed in a sporangium, borne 
 
 externally upon the fruiting bodies. .. . 1. Ceratiomyxaceae. 
 Spores enclosed in a sporangium 
 
 Capillitium wanting, or very poorly de- »^ 
 veloped 
 Periderm of uniform thickness, rup- 
 turing irregularly 2. Liceaceae. 
 
 Periderm of unequal thickness 
 
 Periderm with a subapical thin line, 
 
 opening by an operculum 3. Orcadellaceae. 
 
 Periderm unequally tliick above, the 
 thin portions evanescent, leaving 
 a network formed by the thicker 
 
 portions 4. Cribrariaceae. 
 
 Capillitium well developed 
 Calcareous deposits absent, or rarely 
 present in the periderm 
 Capillitium of hollow, usually sculp- 
 tured tlireads; spores light colored 5. Trichiaceae. 
 CapiUitium of solid, smooth and 
 usually much branched threads; 
 spores dark colored 
 Fruiting bodies sethalioid or in- 
 
10 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 definite, walls poorly defined, 
 fraying out into a pseudo- 
 
 capillitium 6. Reticulariaceae. 
 
 Sporangia definite, true capilli- 
 
 tium more or less prominent 7. Brefeldiaceae. 
 Fruiting bodies separate sporangia 
 with columella and abundant 
 
 capillitium 8. Stemonitaceae. 
 
 Calcareous deposits present 
 Capillitium not calcareous 
 
 Capillitium simple 9. Didymiacese, p. 10. 
 
 Capillitium more intricate 10. Spumariaceae, p. 11. 
 
 Fructification calcareous throughout 11. Physaraceae, p. 11. 
 
 Didymiaceae 
 
 Fructification of separate sporangia or plasmodiocarps, periderm 
 simple or double, the outer calcareous; columella present or ab- 
 sent; capillitial threads thin, colorless or violet, arising from the 
 base of the sporangium or passing from the columella to the peri- 
 derm, usually without calcareous deposits, which if present are 
 very small crystals; spores in mass black, spore walls violet. 
 
 Key to Genera op Didymiaceae 
 
 Calcareous deposits in the form of stellate crys- 
 tals, frosting the surface 1. Didymium, p. 10. 
 
 Calcareous deposits not stellate, 
 
 Calcareous deposits forming a superficial crust 2. Diderma. 
 Calcareous deposits forming large superficial 
 scales 3. Lepidoderma. 
 
 Didymium Schroter 
 
 Sporangia distinct, stipitate, sessile or even plasmodiocarpous, 
 never aethalioid; the peridium thin, irregular in dehiscence, cov- 
 ered with a more or less dense coating of calcareous crystals; 
 columella more frequently present ; capillitium of delicate threads, 
 simple or sparingly branched, extending from the columella to the 
 peridial wall. 
 
 D. daedalium. B. & Br. is occasionally injurious to melons in 
 culture. ^° 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 11 
 
 Spumariaceae (p. 10) 
 
 Sporangia separate or aethalioid; calcarious deposit in the peri- 
 derm or columella, never in the capillitium; capillitium radiating 
 from various points of the columella, branching and anastomosing 
 to form a network, the ultimate branchlets of which support the 
 periderm. 
 
 Key to Genera of Spumariaceae 
 
 Fructification of ordinary sporangia 1. Diachea. 
 
 Fructification sethalioid 2. Spumaria, p. 11. 
 
 Spumaria Persoon 
 
 Fructification ffithalioid, consisting generally of large cushion- 
 shaped masses covered without by a white foam-like crust; within, 
 composed of numerous tubular sporangia, developed from a com- 
 mon hypothallus, irregularly branched, contorted and more or less 
 confluent; the peridial wall thin, delicate, frosted with stellate 
 lime crystals, which mark in section the boundaries of the several 
 sporangia; capillitium of delicate threads, generally only slightly 
 branched, terminating in the sporangial wall, marked with oc- 
 casional swellings or thickenings. 
 
 S. alba (Bui.) D. C. Like all other members of the order 
 the present species is not a parasite but its aethalia are fre- 
 quently produced upon grass, strawberries ^^ and other plants in 
 such abundance as to cause more or less serious injury. The 
 sporangia are fused into a large sethalium which is white or cream- 
 colored, from 1 to 7 cm. long and half as thick. 
 
 Physaraceae (p. 10) 
 
 Key to Genera of Physaraceae 
 
 Fructification aethalioid 1. Fuligo, p. 12. 
 
 Fructification plasmodiocarpous or of distinct 
 sporangia 
 Peridium without lime 
 
 Plasmodiocarpous 2. Cienkowskla. 
 
 Sporangia distinct 3. Leocarpus. 
 
 Peridium calcareous, more or less throughout 
 
 Capillitium calcareous throughout 4. Badhamia. 
 
12 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Capillitium in part hyaline 
 
 Sporangium vaselike, or more or less tubu- 
 lar 
 
 Opening irregularly 5. Physarella. 
 
 Opening by a lid 6. Craterium. 
 
 Sporangia various, dehiscence irregular 
 Capillitium evenly branched ; the calca- 
 reous nodes small, fusiform 7. Tilmadoche. 
 
 Capillitium intricate 8. Physarum, p. 12. 
 
 The species of Fuligo produce very large yellowish plasmodia 
 which change to yellowish or brownish aethalia. Some are credited 
 with damage similar to that of the preceding species. ^^ 
 
 Physarum Persoon 
 
 Sporangia plasmodiocarpous, sethalioid or distinct; the peridium 
 usually simple, sometimes double, irregularly dehiscent, more or 
 less definitely calcareous; capillitium a uni- 
 form irregular net, dilated and calcareous at 
 the nodes, adherent on all sides to the 
 peridial wall. 
 
 P. cinereum (Batsch), Pers., the species 
 most commonly reported as injurious, forms 
 its tiny sessile, gray sporangia in great num- 
 bers on living plants, ^°' ^^^ often smother- 
 „ „, ing them. The peridium is lime charged as 
 
 Fig. 3.— Physarum ^ ^ . . . _<i 
 
 sporangium. After are also the nodes of the . capillituim. The 
 
 Macbride. i • i j. j a 
 
 spores are brown or violet, and warty. 
 P. bivalve F. has been noted as injuring young bean plants.^^ 
 Dendrophagus globosus Toumey was reported by Toumey ^^ 
 as the probable cause of crown gall, but such relation is doubt- 
 ful (p. 36). It is said to be closely related to Physarum. 
 
DIVISION II 
 
 BACTERIA, SCHIZOMYCETES 
 
 (p. 3) 
 
 a 
 
 Fig. 4. — The three type forms of bacteria; 
 a, spheres; h, rods; c, spirals. After Conn. 
 
 Bacteria are extremely minute, unicellular organisms, which in 
 outline present three primary forms each of great simplicity, 
 
 namely the spheres (cocci), 
 
 0( 
 
 the straight rods (bacteria), 
 the curved rods (spirilli). 
 
 In addition to these forms 
 which comprise the vast 
 majority of known species 
 of bacteria there are also 
 bacteria consisting of fila- 
 mentous bodies, either sim- 
 ple or branched, attached or free. In both structure and phys- 
 iology bacteria are allied to the vegetable kingdom and in it 
 most closely to the blue green algae. 
 
 Bacteria are inconceivably small. Most of the spherical bacteria 
 fall within the limits of from 0.5 to 1.5 ju in diameter. Among 
 the rod and curved bacteria the length in most species is between 
 1 and 1.5 /t, the diameter between 0.5 and 1 /i. Among the 
 largest species is B. megatherium, 2.5 x 10 ix] Clostridium butyri- 
 cum, 3 X 10 m; and Spirillum volutans, 13 to 50 ^ long. Among 
 the smallest is Spirillum parvum 0.1-0.3 n in diameter and Pseudo- 
 monas indigofera 0.06 x 0.18 ix. 
 
 It is practically impossible to conceive these dimensions. An 
 
 illustration may aid the imagination. The paper on which these 
 
 words are printed is about 87.5 m thick. It 
 
 would therefore take about 200 bacteria of ordi- 
 
 FiG. 5.— This dot is nary size or 400 moderately small or 20 very 
 
 mm. m lameter. j^^^gg ^^^^ placed end to end to equal in length 
 
 the thickness of this paper. It would take 1571 ordinary bacteria 
 (1 X 2 /z) end to end to reach around the circumference of a dot 
 
 13 
 
14 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 1 mm. in diameter. (Fig. 5.) 500 to reach across it; and 392,700 
 placed side by side or 785,400 if placed on end to cover its area, and 
 about 500,000,000 to fill a cube the edge of which is 1 millimeter, 
 making no allowance for lost space of the interstices. Considerably 
 more than 500,000,000,000 bacteria of this size would find room 
 enough to move about in a space of one cubic centimeter. 
 
 The typical mode of increase among bacteria — the only mode 
 except among the sheath bacteria — is by fission or direct divi- 
 sion of one cell, the mother cell, into two, the daughter cells. 
 Fig. 6. The rapidity with which fission can proceed depends of 
 course upon conditions of environment, ranging from no growth 
 at all, due to cold, lack of nutriment, presence of inhibiting sub- 
 stance, to a maximum that varies with the species. For bacteria 
 
 . J 1^ , . ,.,/Lm. ,/# ^v, M yJ Vw/^ 
 
 Fig. 6. — Diagram illustrating the fission of bacteria, bacilli and cocci. 
 After Novy. 
 
 in general under very favorable surroundings, with proper tem- 
 perature and abundance of food, from 20 to 40 minutes may be 
 reckoned as a generation. In 24 hours, with the divisions once 
 each hour, the progeny of one germ will be 16,777,216; with 
 divisions each 30 minutes it will be (16,777,216)1 
 
 If cell division be in one direction only and the resulting daugh- 
 ter cells remain undisturbed, a thread-like row results. If cell 
 division be in two planes, and the resulting cells adhere in groups, 
 tablets of 8, 16, and 64 will occur frequently. If the division be 
 in three planes and their cells adhere, packets result. 
 
 The structure of the bacterium cell owing to its minuteness 
 is yet very incompletely known. The most enduring portion of 
 the vegetative cell is the cell wall. This is surrounded by a layer, 
 the capsule and bears the flagella. The number of the flagella 
 and their position varies in different species. Some species have 
 none, some one, two, or many. They may be at the ends, polar, 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 15 
 
 ^Mmnr^^mmm 
 
 Fio. 7. — Spores of bacteria showing their position 
 within the cells. After Frost & McCampbell. 
 
 or scattered over the whole surface, diffuse or peritrichiate. 
 They are the organs of locomotion. Within the wall is the pro- 
 toplast consisting of a peripheral layer, inner strands, imbedded 
 granules and vacuoles bearing cell sap. The existence of a nucleus 
 comparable to that in higher plants is a much controverted point. 
 Spores: Typically a bacterial spore consists of a highly refractive, 
 ovoid, walled body within the mother cell. This body possesses 
 high resistance to ordinary stains, a great tenacity against de- 
 colorizing if it be once 
 stained, a higher resist- 
 ance against adverse tem- 
 peratures and adverse 
 conditions generally than 
 do vegetative cells, and 
 finally the ability to ger- 
 minate and thus aid in 
 perpetuating the species. 
 While the absolute num- 
 ber of bacterial species 
 that form spores is large, comparatively they are few. They are 
 most frequently met among the rod forms, and are rare among 
 the spirilla and cocci. None are known among the important 
 plant pathogens. 
 
 In the simplest cases of spore formation, the protoplasm be- 
 comes more dense in some part of the mother cell, the remaining 
 protoplasm of the cell is drawn around the denser mass, and the 
 
 whole resulting dense region becomes 
 enclosed within a special wall. Usually 
 in this process nearly all the protoplasm 
 of the mother cell, the sporangium, is 
 used. The mother cells during spore 
 formation may remain of the normal 
 Fig. 8.— Spore formation in vegetative size and shape; they may 
 
 bacteria. After Fischer. ^^^^ ^^ (g subtilis) Or abandon (B. 
 
 megatherium) the habit of thread formation. Bacteria of many 
 species become swollen at the point where the spore develops, 
 Figs. 7 and 9; be this in one end (Vibrio rugula) or in the middle 
 (B. inflatus). The swelling at the end is very common, giving rise 
 
16 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 to the peculiar and characteristic form known as "Nail Head" or 
 "Drum Stick" bacteria. In nearly all species of the Eubacteria 
 the spores are solitary. 
 
 There are three modes of spore germination. The most com- 
 mon, polar germination, consists in a rupture of one pole of the 
 spore and the development of a normal vegetative cell through 
 the opening. The second mode, equatorial, Fig. 9, consists in a 
 rupture in the side instead of the end of the spore. The third mode, 
 
 Fig. 9. — Spores of bacteria, showing bispored cells, spore formation and spore 
 germination. After Prazmowski, De Bary and Koch. 
 
 absorption, consists in a direct development of the whole spore 
 into a vegetative cell. In suitable environment germination may 
 occur immediately after spore formation; if conditions be unsuit- 
 able it may be delayed for many years. 
 
 Under certain conditions most bacteria undergo abnormal 
 changes in form becoming elongated, branched, swollen, bulged, 
 curved, or variously, usually irregularly, distorted. Such are 
 termed involution forms. They are in most cases due to unfavor- 
 able conditions of temperature and nutriment, and the bacteria 
 resume their normal form when again in normal environment. 
 
 The branched forms found in root tubercles after the period of 
 luxuriant growth has passed, and the branched thread-like growth 
 of the bacterium of human tuberculosis upon artificial media, are 
 by many regarded as involution forms. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 17 
 
 Constancy of Species. Bacteria in nature and under artificial 
 conditions remain true to species. There may be variation from 
 generation to generation as among all other plants or animals of 
 the world, and by the slow process of evolution, a species may in 
 many generations become modified, leading eventually to new 
 races, varieties, and possibly species. That one species can change 
 directly and suddenly to another, much less a species of one genus 
 into a species of another genus, is not to be credited. Marked 
 variation is brought about in many species by change in tempera- 
 ture, food, oxygen supply, etc., changes in size, form, sporulation, 
 flagellation, virulence, chromogenesis, fermentative power, group- 
 ing, etc. These changes belong to the life cycle of the species and 
 occur as reactions to the environment. 
 
 Bacteria were discovered by Loewenhoek in 1683. That they 
 do not originate spontaneously was shown by Pasteur in 1860-4. 
 The first disease producing bacteria were recognized in anthrax by 
 PoUander & Davaine in 1849; and the first definite proof that 
 bacteria actually cause animal disease was made by Koch with 
 anthrax in 1875-1878. The first plant disease to be definitely as- 
 cribed to bacteria was the pear blight by Burrill in 1879. The 
 invention of the cotton plug, Schroeder & Dusch, 1853, the gela- 
 tine method of plating for the isolation of species, Koch, 1881, 
 and the use of stains, Weigert, 1875, were practically necessary 
 prerequisites to any considerable advance in bacteriology. For 
 long it was contended, especially by European bacteriologists, 
 that bacteria do not cause plant diseases but most convincing 
 proof to the contrary was adduced by E. F. Smith. 
 
 Entrance to the host plant is made in various ways, very often 
 through wounds, particularly wounds caused by insects,, through 
 roots, stomata, water pores, through delicate tissues as blossoms, 
 etc. Once in the tissue, bacteria may migrate rapidly by means 
 of the vessels, intercellular spaces or more slowly through cavities 
 dissolved by the aid of enzymes. 
 
 Classification. In all there are some thirty-six well recognized 
 genera embracing twelve hundred or thirteen hundred purported 
 species of bacteria. This number will doubtless be greatly de- 
 creased when the organisms have been well studied, by finding 
 that many so-called species are not really distinct. The number 
 
18 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 will also of course receive many additions of forms not as yet 
 known. 
 
 No system of classification can yet be said to have general 
 acceptance and all classifications now in vogue will undoubtedly 
 undergo minor changes and perhaps changes in fundamental 
 conception. 
 
 The system of Migula^^ meets probably with most favor. 
 With the omission of genera of little import pathologically, and 
 with the introduction of the order Myxobacteriales, it is as follows : 
 
 SCHIZOMYCETES (p. 3) 
 
 Fission plants, without phycochrome, dividing in one, two or 
 three directions of space. Reproduction by vegetative multiplica- 
 tion. Resting stages, endospores, exist in many species. Motility 
 by means of flagella in many genera. 
 
 Key to Orders, Families, and Genera of Schizomycetes 
 
 Cells without sulphur or bacterio-purpu- 
 
 rein Order I. Eubacteriales. 
 
 Cells in free condition gobular; in di- 
 vision somewhat elliptical I. Coccaceae, p. 21. 
 
 Nonflagellate 
 
 Division in only one direction, 
 
 cells single, in pairs, or chains 1. Streptococcus. 
 Division in two directions; cells 
 
 may remain in plates 2. Micrococcus, p. 21. 
 
 Division in three directions cells 
 may remain in bale-like 
 
 packets 3. Sarcina. 
 
 Flagellate 
 
 Division in two directions 4. Planococcus. 
 
 Division in three directions. . 5. Planosarcina. 
 Cells long or short, cylindrical, 
 straight, division in one direc- 
 tion II. Bacteriaceae, p. 21. 
 
 Nonflagellate 6. Bacterium, p. 21. 
 
 Flagellate 
 
 Flagella diffuse 7. Bacillus, p. 37. 
 
 Flagella polar 8. Pseudomonas, p. 22. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 19 
 
 Cells spirally curved or represent- 
 ing part of a spiral, division in 
 
 one direction III. Spirillaceae. 
 
 Cells cylindric in sheathed threads. . . IV. Chlamydobacteriaceae. 
 
 Cells with sulphur Order II, Thiobacteriales. 
 
 Motile rods in pseudoplasmodial masses 
 in a gelatinous matrix, and forming 
 highly developed cysts Order III. M3rxobacteriales. 
 
 The species of families 3 and 4 and of orders II and III, some 
 twenty-five genera in all, are so far as is known, unimportant as 
 regards plant disease. All of the known plant pathogens belong 
 to one or other of the first two families of the Eubaeteriales. Each 
 of these families contains several dangerous parasites upon ani- 
 mals, e. g., Bacillus typhosus, Spirillum cholerae-asiaticse, Bacte- 
 rium tuberculosis. 
 
 The specific characters of bacteria are chiefly chemical or 
 physiological and rest in the relation of the forms to oxygen, gel- 
 atine liquefaction, fermentation of various sugars, acid production, 
 relation to nitrogenous compounds, chromogenesis, etc.^^' ^'' "°^ 
 
 To enable brief expression of these characters the Society of 
 American Bacteriologists endorses the following numerical sys- 
 tem.* 
 
 A Numerical System of Recording the Salient Characters of an 
 Organism. (Group Number) 
 
 100. Endospores produced 
 
 200. Endospores not produced 
 
 10. Aerobic (Strict) 
 
 20. Facultative anaerobic 
 
 30. Anaerobic (Strict) 
 
 1. Gelatine liquefied 
 
 2. Gelatine not liquefied 
 
 0.1 Acid and gas from dextrose 
 
 0.2 Acid without gas from dex'trose 
 
 0.3 No acid from dextrose 
 
 0.4 No growth with dextrose 
 
 * This will be found useful as a quick method of showing close relationships 
 inside the genus, but is not a sufficient characterization of any organism. 
 
20 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 .01 
 
 Acid and gas from lactose 
 
 
 .02 
 
 Acid without gas from lactose 
 
 
 .03 
 
 No acid from lactose 
 
 
 .04 
 
 No growth with lactose 
 
 
 .001 
 
 Acid and gas from saccharose 
 
 
 .002 
 
 Acid without gas from saccharose 
 
 
 .003 
 
 No acid from saccharose 
 
 
 .004 
 
 No growth with saccharose 
 
 
 .0001 
 
 Nitrates reduced with evolution o 
 
 ■gas 
 
 .0002 
 
 Nitrates not reduced 
 
 
 .0003 
 
 Nitrates reduced without gas formation 
 
 .00001 
 
 Fluorescent 
 
 
 .00002 
 
 Violet chromogens 
 
 
 .00003 
 
 Blue 
 
 
 .00004 
 
 Green " 
 
 
 .00005 
 
 Yellow " 
 
 
 .00006 
 
 Orange " 
 
 
 .00007 
 
 Red 
 
 
 .00008 
 
 Brown " 
 
 
 .00009 
 
 Pink 
 
 
 .00000 
 
 Non-chromogenic 
 
 
 .000001 
 
 Diastasic action on potato starch, 
 
 strong 
 
 .000002 
 
 Diastasic action on potato starch, 
 
 feeble 
 
 .000003 
 
 Diastasic action on potato starch, 
 
 absent 
 
 .0000001 
 
 Acid and gas from glycerine 
 
 
 .0000002 
 
 Acid without gas from glycerine 
 
 
 .0000003 
 
 No acid from glycerine 
 
 
 .0000004 
 
 No growth with glycerine 
 
 
 The genus according to the system of Migula is given its proper ab- 
 breviation which precedes the number thus : * 
 
 Bacillus coli (Esch.) Mig. becomes B. 222.111102 
 
 Bacillus ALCALiGENES Petr. " B. 212.333102 
 
 PsEUDOMONAS CAMPESTRis (Pam.) E. F. Sm. " Ps. 211.333151 
 
 Bacterium suiciDA Mig. " Bact. 222.232203 
 
 * Incomplete group numbers are given with many of the species in suc- 
 ceeding pages. In these the known factors are given and the unknown or 
 imperfectly known are represented by dashes. These numbers were worked 
 out for the author by Mr. W. C. Norton, from the available literature. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 21 
 
 The plant pathogens as yet known, with few exceptions, belong 
 to the two genera Pseudomonas and Bacillus between which they 
 are about equally divided. 
 
 In the earlier days of bacteriology and to some extent in recent 
 days, bacteria have been seen in diseased plant tissues and have 
 been placed by their observers in one genus or another and cited 
 as the causes of the diseases in question but without actual evi- 
 dence that they cause the diseases and very often without any real 
 evidence as to the genus to which the bacteria belonged. It is 
 of course usually impossible to identify such forms and they must 
 be dropped from consideration. 
 
 Coccaceae (p. 18) 
 
 No representative of this family parasitic upon plants has yet 
 been reliably recorded in America. Micrococcus tritici Pril -'' 
 upon wheat in England is probably in reality Bacillus prodigiosus 
 and not pathogenic. Micrococcus phytophthorus Frank ^^ -^ re- 
 ported as a cause of potato rot and also associated with potato 
 black-leg is perhaps in reality identical with Bacillus phytoph- 
 thorus Appel. Micrococcus nuclei Roze, M. imperiatoris Roze, 
 M. flavidus Roze, M. albidus Roze, M. delacourianus Roze and 
 M. pellucidus Roze are assigned by Roze -' as the causes of va- 
 rious potato troubles in Europe, and M. populi Del.^^ is said to be 
 the cause of canker on Populus. 
 
 Bacteriaceae (p. 18) 
 
 Bacterium Ehrenberg (p. 18) 
 
 These non-motile forms, perhaps owing to their lack of power 
 of locomotion, are comparatively rare as plant pathogens. 
 
 Bact. briosianum Pav. is given as the cause of rotting of to- 
 mato fruit and distortion of vegetative parts in Italy. ^^° It is 
 described also on Vanilla. '"^° 
 
 Bact. montemartinii Pav. is described as the cause of a canker 
 of Wisteria. ^^- 
 
 Bact. mori B. & L. is said to cause leaf and branch spots on 
 mulberry. ^^^ 
 
22 THE FUx\GI WHICH CAUSE PLANT DISEASE 
 
 Bact. teutlium Metcalf.-^ (Group number 222.— 220— .) 
 
 A short rod with rounded ends, 1.5 x 0.8 ix, before division 
 3 X 1 ju; non-motile, no flagella seen; no spores; Gram-positive; 
 agar colonies round, thin, riot viscid, porcelaneous to transparent, 
 seldom over 0.5 ix. No liquefaction. Broth clouded, precipitate 
 thin or none, no pelhcle. Milk not coagulated. T. D. P. 45°. 
 10 min. Opt. 17°. Aerobic, no gas. 
 
 Beets diseased by this organism were honeycombed with pockets 
 filled with a viscous fluid, a practically pure bacterial culture. 
 The vascular tissue was not rotted. Inoculation by pricking the 
 bacterial exudate into healthy beets resulted in typical disease. 
 Pure cultures isolated by use of cane-sugar-agar gave similar results. 
 Three weeks after inoculation the exudate-forming pockets were 
 typically developed. Surface inoculation failed and there is no 
 evidence that the organism can infect except through wounds. 
 No rotting followed inoculation on potato, white turnip, radish, 
 tomato, or apple. 
 
 Bact. pini Vuill.^° was found in tissue of pine galls and regarded 
 as their cause. 
 
 Bact. fici Cav.^^^ is reported as the cause of a disease of figs. 
 
 Bact. scabigenum Busse & v. Faber is described as the cause 
 of scab of sugar-beets in Germany.^^ 
 
 Pseudomonas Migula (p. 18) 
 
 Short or long rods motile by polar flagella, fig. 10, whose num- 
 ber varies from one to ten but is most commonly one. Endo- 
 spores are sometimes present. The cells in some species adhere 
 to form short chains. The basis of separation into species is the 
 growth upon gelatine, character of the colonies, chromogenesis 
 and numerous other cultural characters.^'-* ^^' ^^ 
 
 Something over seventy-nine species are known, at least fifteen 
 of which cause diseases in plants, some of them very serious. 
 Many other species occur in water, soil and manure, while others 
 are suspected animal pathogens. 
 
 One prominent group of plant pathogens, ^^ the yellow Pseudo- 
 monas group, contains, according to Smith, Ps. campestris, Ps. 
 phaseoli, Ps. hyacinthi, Ps. stewarti, Ps. juglandis, Ps. vascularum, 
 Ps. dianthi, Ps. amaranti, Ps. malvacearum. These, he says, 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 23 
 
 agree in the following particulars: They are yellow rod-shaped 
 organisms of medium size, straight or slightly crooked with 
 rounded ends. The segments multiply by fission, after elongation. 
 They are generally less than 1 /x in diameter. The segments 
 occur singly, in pairs or in fours joined end to end, or in clumpy 
 masses of variable size (zoogloece), more rarely they are united 
 into long chains or into filaments in which no septa are visible. 
 Endospores have not been observed. The segments are motile by 
 means of one polar flagellum which is generally several times as 
 long as the rod, and may be wavy or straight when stained. The 
 species grow readily on all of the ordinary culture media, but so 
 far as is definitely known all are strictly aerobic. None are gas 
 producers. They do not reduce nitrates to nitrites. The yellow 
 color appears to be a lipochrome and in the different species varies 
 from deep orange and buff-yellow, through pure chrome and 
 canary-yellow, to primrose-yellow and paler tints. 
 
 Ps. aeruginosus Del. possibly identical with Ps. flourescens- 
 putridus Flugge is the cause of a leaf and stem disease of tobacco 
 in France.^' 
 
 Ps. avenae Manns, (Group number 111.2223032.) A short rod 
 with round ends, 0.5 to 1 At x 1 to 2 m- Actively motile, generally 
 by one polar flagellum, occasionally by two or three. Gram 
 negative. What seem to be endo- 
 spores are found in old cultures. On 
 agar stroke, growth very slow, fili- 
 form, rather flat, glistening; margin 
 smooth, opaque to opalescent; non- 
 chromogenic. Liquefaction occurs on 
 gelatine in seven to twelve days. 
 , Broth is slowly clouded. Agar colo- 
 nies, amorphous, round with surface 
 smooth, edges entire. No gas in 
 dextrose, saccharose, lactose, maltose, Fig. lo.— Ps. avenae. After 
 
 , . . . I'll Manns. 
 
 or glycerme. Ammonia and mdol 
 
 not formed. Nitrates reduced to nitrites. T. D. P. 10 min., 
 
 60°, Opt. 20° to 30°. 
 
 This organism was isolated and described by Manns in 1909,^^ 
 as the cause of a serious oat blight. Inoculations with it alone by 
 
24 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 hypodermic injection produced only limited lesions but similar 
 inoculations with a mixed culture of Ps. avense and Bacillus avense 
 produced typical disease. Manns, moreover, noticed that the 
 virulence of the Pseudomonas decreased when kept in culture free 
 from the Bacillus, also that in the disease as it occurs in nature 
 these two organisms are associated. His conclusion is that the 
 Pseudomonas is the active parasite and that the Bacillus is an 
 important, perhaps a necessary symbiont. 
 
 2 
 
 Fig. 11. — Showing effect of inoculation of Ps. campestris into cabbage plants. Nos. 
 1 and 2, six weeks after inoculation. No. 3, check plant uninoculated. After 
 Russell. 
 
 Infection in nature is chiefly stomatal by spattering rain. 
 Soaking of seed in suspensions of bacteria did not produce the 
 disease. Inoculations on wheat failed, though from one variety 
 of blighted wheat. Extra Square Head, the typical organism was 
 isolated. Inoculations on corn made during wet weather produced 
 lesions which spread rapidly and the organism was re-isolated. 
 Barley is said by Manns to be susceptible and what he believes to 
 be the same disease occurs on blue grass and timothy. 
 
 Ps. campestris (Pam.) E. F. Sm. (Group number 211.333151.) 
 A rod-shaped, motile, organism generally 0.7 to 3.0 x 0.4 to 0.5 f^; 
 color dull waxy-yellow to canary-yellow, occasionally brighter or 
 more pale. One polar flagellum; no spores known. Aerobic but 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 25 
 
 not a gas or acid producer, gelatine liquefied. Cavities are formed 
 around the bundles but the organism seems to be only feebly 
 destructive to cellulose. A brown pigment is produced in the 
 host plants and on steamed cruciferous substrata. Growth 
 rapid on steamed potato cylinders at room temperatures, without 
 odor or brown pigment. Growth feeble at 7°, rapid at 17 to 19°, 
 luxuriant at 21 to 26°, very feeble at 37 to 38° and ceases at 40°. 
 T. D. P., 10 min., 51°. 
 
 Fig. 12. — Ps. campestris. Section of a cabbage leaf par- 
 allel to the surface and near the margin, showing the 
 result of infection through the water-pores. After 
 Smith. 
 
 It is closely related to Ps. hyacinthi from which it differs chiefly 
 in its pathogenic properties, its duller yellow color and its higher 
 thermal death point. It is troublesome upon cabbage, turnips, 
 cauliflowers, coUards; and a very large number of cruciferous 
 hosts, both cultivated and wild are susceptible. It enters the host 
 plant through the vascular system which becomes decidedly 
 brown. 
 
 This organism was first isolated by Pammel ^^ (see also ^^) from 
 rutabagas and yellow turnips in 1892; green-house inoculations 
 with pure cultures were made in scalpel wounds, which were then 
 
26 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 sealed with wax. The plants showed rot in a few days and the 
 actual causal relation of the organism was thus established. Con- 
 firmatory evidence was gained by Russell ^^ from puncture inocula- 
 tions in cabbage and 
 cauliflower petioles. It 
 was further shown by 
 E. F. Smith ^^ that the 
 cabbage and turnip or- 
 ganisms are identical 
 and that the bacteria, 
 by solution of the cellu- 
 lose, produce pits and 
 holes through the walls 
 of the host cells re- 
 sulting eventually in 
 large cavities. 
 
 Infection was shown 
 by Russell ^^ and by 
 Smith 3«' 39 to be chiefly 
 through the water pores 
 or through wounds 
 made by insects; the 
 bacteria being air or 
 insect borne and de- 
 rived largely from in- 
 fected soil. After en- 
 tering the plant the 
 bacteria multiply rap- 
 idly, and migrate in 
 every direction by 
 means of the veins. 
 Studies of Harding, Stewart and Prucha ^° (see also) ^^ showed 
 that it can survive the winter on the seed and thus infect seedlings. 
 Ps. destructans Potter ^^ is described as an uniflagellate organism 
 causing a destructive soft rot of turnips and beets in England. 
 Doubt has been thrown upon its identity by the work of Harding 
 and Morse ^^ and of Jones ^^ who found supposedly authentic 
 cultures to bear peretrichiate rather than polar flagella. See p. 42. 
 
 Fig. 13. — Ps. campestris; cross-section of a turnip 
 root. After Smith. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 27 
 
 Ps. dianthi Arth. & Boll.^^ Though originally reported as the 
 probable cause of carnation leaf spot, this organism is now regarded 
 as a saprophyte. 
 
 Ps. fluorescens (Flugge) Mig. Straight and curved rods of 
 medium size in chains of two or several members. Cells 0.68 x 
 1.17-1.86 ji. Spores not seen. Flagella 3-6 polar. 
 
 Gelatine liquefied; surrounding medium colored greenish-yellow; 
 Gram negative. Milk not coagulated. Indol weak. Bouillon, 
 turbid, fluorescent. 
 
 This organism or two varieties of it are by Barlow ^^ held re- 
 sponsible for a decay of celery. The organism was found in large 
 numbers in the decayed tissue; was isolated and typical rot was 
 induced by inoculation of pure cultures upon sterilized celery 
 stems. 
 
 It is also credited with two distinct types of tobacco disease in 
 France, one of them on seed, the other on the growing plant. 
 Recently Griffon ^^ has claimed that both of the varieties, Ps. 
 fljorescens liquefaciens and Ps. putrida are capable of producing 
 wet rot of various vegetables, carrots, rutabagas, tobacco, toma- 
 toes, melons, and that the latter organism is identical with Ps. 
 seruginosus. It is also held that B. brassicaevorus and B. cauli- 
 vorus are forms of Ps. fluorescens. 
 
 Ps. fluorescens exitiosus v. Hall is said by van Hall ^° to cause 
 rot of Iris. 
 
 Ps. hyacinthi (Wak.) E. F. Sm., is a serious pest of hyacinths in 
 the Netherlands but has not yet been recorded in America.^® 
 It is medium sized rod with rounded ends, 
 measuring in the host 0.8-1.2 x 0.4-0.6 n; 
 actively motile by one long polar flagellum; 
 non sporiferous; liquefies gelatine slo\yly; 
 aerobic; no gas. It produces indol. Does not Fig. i4.—Ps. hyacinthi. 
 grow at 37°. Opt. 28 to 30°, T. D. P. 10 '^^*'' ®°'^*^- 
 
 min., 47.5°. It is a wound parasite which grows in the vessels 
 forming a bright yellow slime and is closely related to Ps. cam- 
 pestris and Ps. phaseoli. 
 
 Ps. iridis v. Hall ^° is described by van Hall as the cause of 
 decay of shoots and rhizomes of Iris. 
 
 Ps. juglandis Pierce. (Group number -11. 51-.) ^^ A rod 
 
28 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 1-2 X 0.5 11, with rounded ends, actively motile by one long polar 
 flagellum. Bright chrome-yellow in growth; disastatic ferment 
 present. No gas; aerobic. It was isolated from diseased nuts, 
 leaves, and twigs of English walnut in California in 1901. In- 
 oculations by spraying demonstrated its pathogenicity. The 
 organism is closely related to Ps. campestris but is distinguished 
 from it by the abundant bright yellow pigment produced upon the 
 surface of extracts of leaves of walnut, magnolia, fig, castor bean 
 and loquat. 
 
 Ps. leguminiperdus (v. Oven.) Stev.,^^ said to be distinct 
 from Ps. phaseoli, occurs on peas and other legumes. It was 
 isolated, cultivated and inoculations made. 
 
 Ps. levistici Osterw.^^ occurs on Levisticum. 
 
 Ps. maculicolum (McC.) Stev. (Group number 211.3332023.) 
 A short rod, forming long chains in some media. Ends rounded. 
 Size from leaf 1.5 to 2.4 /x by 0.8 to 0.9 /x; in 24-hour beef-agar 
 culture, 1.5 to 3 ix by 0.9 m- No spores, actively motile, one to 
 five polar flagella two to three times the length of the rod. Mo- 
 tile in most artificial media. Involution forms in alkaline beef 
 bouillon. Pseudo-zoogloeae in Uschinsky's solution. Gram nega- 
 tive. Stains readily with carbol fuchsin and with an alcoholic 
 solution of gentian violet. 
 
 Agar plate colonies visible on the second day as tiny white 
 specks, in three to four days, 1 to 3 mm. in diameter, white, 
 round, smooth, flat, shining, and translucent, edges entire, with 
 age dull to dirty white, slightly irregular, edges undulate, slightly 
 crinkled, and with indistinct radiating marginal lines. Buried 
 colonies small, lens-shaped. 
 
 Agar streak cultures white, margins slightly undulate. Beef 
 bouillon clouds in twenty-four hours. Growth best at surface 
 where a white layer, not a true pellicle, is formed. No zoogloese. 
 No rim. 
 
 Gelatine stab cultures liquefied in eight to ten days. Growth 
 from surface crateriform; slight, white, granular precipitate. Slight 
 green fluorescence. No separation into curd and whey. Indol 
 production feeble. T. D. P. 46°. Opt. 24-25°. Max. 29°. Min. 
 below 0°. 
 
 Isolated from cauliflower leaves on which it forms brownish to 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 29 
 
 purplish-gray spots 1-3 mm. in diameter. ^°^ Pathogenicity on 
 this host also on cabbage was proved by inoculation. Its entrance 
 is stomatal. 
 
 Ps. malvacearum, E. F. Sm.^"*' ^'' ^°^ This yellow organism, 
 pathogenic on cotton, much resembles Ps. campestris but its slime 
 is more translucent on potato and it 
 does not attack the cabbage. It was 
 grown in pure culture by Smith and 
 successful inoculations were made by 
 spraying a suspension of a young agar 
 culture of the organism upon cotton 
 leaves and bolls. No description has 
 been published. 
 
 Ps. medicaginis Sackett.^^ (Group 
 number 212.3332133.) A short rod, 
 1.2-2.4 X 0.5-0.8 m; filaments 20.2- 
 37.2 n long. No spores; actively 
 motile with 1^ bipolar flagella; cap- 
 sules and zooglcea none. Agar streak 
 filiform, later echinulate, glistening, 
 smooth, translucent, grayish-white; 
 no gelatine liquefaction; bouillon 
 slightly turbid, pellicle on third day, 
 sediment scant. Milk unchanged. 
 Agar colonies round, grayish-white. 
 No gas or indol. Optimum reaction 
 + 15 to +18 Fuller's scale. T. D. P. 
 49-50°, 10 min. Opt. 28-30°. Aerobic, 
 zymase, rennit or pepsin. 
 
 It occurs as a pathogen on alfalfa and issues in clouds visible to 
 the naked eye from small pieces of tissue of the diseased stem or 
 leaf when mounted in water on the shde. These clouds under the 
 high power resolve into actively motile rods, relatively short and 
 thick. The bacteria are also found in practically pure culture in 
 the exudate which oozes from the diseased tissue as a clear viscous 
 liquid and collects in drops or spreads over the stem. Sackett 
 with pure culture inoculations produced the typical disease and 
 re-isolated the organism with unchanged characters. Re-inoculated 
 
 Fig. 15. — Ps. malvacearum. 
 Early stage of stomatal infec- 
 tion in angular leaf-spot of 
 cotton. After Smith. 
 
 No diastase, invertase, 
 
30 THE FUx\GI WHICH CAUSE PLANT DISEASE 
 
 it again caused disease. More than a hundred inoculations by 
 scarification or puncture gave one hundred per cent infection. 
 Controls remained undiseased. Infection, stomatal or water pore, 
 was also secured through the apparently unbroken epidermis. 
 
 The virulence of the or- 
 ganism was retained after 
 five months on agar. It 
 is beheved that the usual 
 mode of infection is 
 through rifts in the epider- 
 mis due to frost and that 
 the germ is wind-borne 
 from infected soil. 
 
 Ps. michiganense (E. 
 F. Sm.) Stev. (Group 
 
 number -22. 252-.) 
 
 Rod short with rounded 
 ends, 0.35-0.4 x 0.8-1.0 /x. 
 
 Fig. 16.— Ps. medicagiiiis; 4S-hour agar-oulture, No motility seen from 
 showing formation of filaments. After Sackett. ^^^^^^ Flagella apparently 
 
 polar but not seen distinctly. Agar colonies pale-yellow, smooth, 
 round. Agar stab canary-yellow, opaque, viscid. Bouillon moder- 
 ately clouded, a moderate sUmy precipitate; no rim or pellicle. 
 Gelatine not liquefied. 
 
 The organism was described by Smith ^^ as the cause of a stem 
 disease of tomatoes in Michigan. No fungi were seen but bacteria 
 were present in great numbers in the bundles also in cavities in 
 the pith and bark. The organism was isolated and the disease was 
 produced both by pure culture inoculations and by crude inocula- 
 tions, using an impure inoculum. The disease caused is less rapid 
 in development than that caused by B. solanacearum and less 
 browning of the infected tissue occurs. 
 
 Ps. mori (B. & L.) Stev. (Group number 222. 202-.) Rod 
 
 with rounded ends, 1.8-4.5 x 0.9-1.3 /x, mostly 3.6 x 1.-2 /x; 
 motile by one, sometimes two polar flagella. No spores. Pseudo- 
 zoogloese present. Agar colonies round, smooth, fiat. Agar 
 streaks spreading, flat, dull-white. Gelatine stab filiform, no 
 liquefaction. Milk not coagulated. No gas. T. D. P. 51.5°. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 31 
 
 In 1894 Boyer and Lambert '°^ produced successful inoculations 
 on mulberries with an organism to which they gave the above 
 name, but without description. 
 
 In 1908 E. F. Smith. ^^ plated out, from blighted mulberry 
 leaves collected 
 in Georgia, a 
 white species 
 with which he 
 made numerous 
 infections on 
 both stems and 
 leaves of mul- 
 berry. From 
 these cultures 
 Smith supplied 
 the description 
 quoted in part 
 above. The re- 
 1 a t i o n which 
 Bacillus cuboni- 
 anus '"^ has to 
 this mulberry 
 
 rlicoQCP ic nn ^^G. 17. — Ps. medicaginis; agar colonies 7 days old, deep 
 uibedbe lb uii- ^^^ surface colonies by reflected light. After Sackett. 
 
 known. 
 
 Ps. phaseoli E. F. Sm. A short round-ended rod, wax-yellow 
 
 to chrome; motile; anaerobic. Milk coagulates, and the whey 
 
 slowly separates without acidity; gelatine liquefies slowly. Growth 
 feeble at 37°, none at 40°. T. D. P. 10 min., 
 49.5°. A starch enzyme is produced and the 
 middle lamella also dissolved. 
 
 This organism is pathogenic to beans and 
 some related legumes and is closely related to 
 Ps. hyacinthi and Ps. campestris. The bean 
 
 Fig. 18.— Ps. phaseoli. disease, occasioned by it was noted and as- 
 cribed to bacteria by Beach "^ and by Hal- 
 
 sted ^° in 1892, and the organism was described by E. F. Smith 
 
 in 1897 ^^ after it had been grown in pure culture and successful 
 
 inoculations had been made. 
 
32 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Ps. pruni, E. F. Sm. The organism resembles Ps. campestris 
 but is distinguislied from it by its feebler growth on potato and 
 by its behavior in Uschnisky's solution which it converts into a 
 viscid fluid. It consists of small rods, motile by one to several 
 polar flagella. T. D. P. 51°. Gelatine not Hquefied. Casein 
 slowly precipitated and later redissolved. No gas. 
 
 The bacteria enter through the stomata of the Japanese plum; ^^ 
 cause small watery spots on green fruit and leaves, and finally the 
 
 Fig. 19. — Earliest stage of fruit spot on green plums, due to Ps. 
 pruni. The bacteria entered through the stoma. After Smith. 
 
 death of the affected tissue. In earliest disease they are limited 
 to the substomatal space but gradually they invade more distant 
 tissue. Wounds are not necessary to infection. It seems to have 
 been seen first on the peach in 1903 by O'Gara in Georgia and in 
 the same year by Clinton in Connecticut. Rorer ^^ by numerous 
 cultures and cross inoculations proved this same organism re- 
 sponsible for a leaf, twig and fruit disease of peaches. In the twig 
 the bacteria were present in great numbers in the bast. 
 
 Ps. radicicola (Bey.) Moore.^^ The legume root-tubercle or- 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 33 
 
 ganism, by some regarded as a parasite, though beneficial, and by 
 others regarded as a mutualistic symbiont will not be discussed 
 here owing to its beneficial character. 
 
 Fig. 20. — Part of sweet-corn stem parasitized by Ps. stewarti. After Smith. 
 
 Ps. savastanoi (E. F. Sm.) Stev. A rod with rounded ends, 
 solitary or in short chains, 1.2-3 x 0.4-0.8 n; motile; aerobic; non- 
 sporing; flagella 1-several, often 2-4, polar. Standard agar, 
 surface colonies, white, small, circular, smooth 1.5-3 mm. at three 
 days, edge entire; bouillon thinly clouded, precipitate shght, white, 
 no rim or pellicle. On gelatine no liquefaction; colonies white, 
 round, erose, margin pale. 
 
34 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 From swellings known as olive tubercles on Californian olive 
 branches, E. F. Smith isolated this organism ^^ which is in part 
 Ps. oleae-tuberculosis and which may bear relation to several other 
 olive bacteria previously described in Europe. 
 
 The organism when inoculated by puncture into young olive 
 shoots produced the characteristic tubercle. Later it was re- 
 isolated from these artificially produced tubercles and used in a 
 second series of inoculations which gave a second crop of tubercles. 
 Controls showed no infection and healed promptly. The oleander 
 was not susceptible to infection. 
 
 Smith's results are not in full accord with much of the European 
 work on the olive tubercle. 
 
 Ps. sesami Malk. causes disease on sesame ^^ 
 Ps. stewarti, E. F. Sm. A medium size rod, 0.5 - 0.9 /z x 1 - 2 p., 
 with rounded ends, and 1 polar flagellum. Buff-yellow to chrome 
 or ochre color; non-liquofving; does not separate casein in milk. 
 
 T. D. P. 10 min., 53°. 
 Agar colonies subcir- 
 cular, becoming lobate; 
 bouillon rendered tur- 
 bid with yellow-white 
 precipitate. No gas. 
 
 The bacterial corn 
 blight of this organism 
 was first described by 
 Stewart in 1897 ^^ and 
 attributed to bacteria. 
 The organism was de- 
 scribed by E. F. Smith 
 in 1890 '^s from a cul- 
 ture furnished by Stew- 
 art. Definite proof by 
 inoculation of the 
 causal relation of this 
 particular organism to the disease was adduced in 1902 by 
 sprinkling bacteria upon the leaves.^^' ™ Some plants showed 
 typical constitutional symptoms during the first month, most of 
 them in two or three months when the plants were several feet 
 
 Fig. 21. — Various forms of Ps. stewarti, gr 
 potato agar; a and b are typical forms 
 Stewart. 
 
 Aftc 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 35 
 
 
 7 
 
 V 
 
 X/ 
 
 high. In these plants the vessels become plugged with pure cul- 
 tures of Ps. stewarti from tip to base. Small holes filled with 
 yellow slime appeared later in the parenchyma. Wounds were en- 
 tirely unnecessary to infection, though the vessels are the primary 
 seat of disease. 
 
 Ps. syringae v. Hall "^ causes disease of Syringa and other plants. 
 
 Ps. tumefaciens (S. & T.) Stev.^-"^^ (Group number 
 212.2822023.) Vegetative cells taken directly from a gall usually 
 0.6 to 1.0 M X 1.2 to 1.5 IX. 
 
 When grown on agar for two days 2.5 to 3 /x x 0.7 to 0.8 y. or 
 occasionally wider. Endospores not observed. Motile by means 
 of one, sometimes two or three terminal flagella; viscid on agar 
 but capsules not demonstrated. Readily stained in ordinary basic 
 anilin stains; Gram negative. Agar surface colonies usually come 
 up in from four to six days at 25°, 
 white, smooth, circular; margin even, 
 shining, semi-transparent, maximum 
 size 2 to 4 mm. Agar streak; growth 
 moderate, filiform. On sterile potato 
 cylinders growth more rapid, in one 
 or two days covering the entire surface 
 of the cylinder; smooth wet-glisten- 
 ing, slimy to viscid, odorless; potato 
 cylinder grayish, darker with age, 
 never yellow. Gelatine colonies dense, 
 white, circular, small, non-liquefying, 
 medium not stained. In beef broth 
 clouding often absent or inconspicuous, rim of gelatinous threads 
 present, also more or less of peUicle; in young cultures very deli- 
 cate suspended short filaments, best seen on shaking. Milk coagu- 
 lation delayed; extrusion of whey begins only after several days; 
 litmus milk gradually blued, then reduced. Cohn's solution, 
 growth scanty or absent, medium non-fluorescent. 
 
 No gas produced; organism aerobic in its tendencies; nitrates 
 not reduced. Indol produced in small quantity, slowly. Slight 
 toleration for citric, malic, and acetic acids. Toleration for alkali 
 slight. Optimum reaction between +12 and +24, Fuller's 
 scale. T. D. P. 51°. Opt. between 25° and 28° Max. ±37°. Growth 
 
 Fig. 22. 
 
 Flagella of Ps. tumefa- 
 ciens, various stains. After 
 Smith. 
 
36 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 occurs at 0°. Milk, bouillon, dextrose peptone water with calcium 
 carbonate are the best media for long continued growth. 
 
 The following are recommended as quick tests for differential 
 purposes. Time of appearance of colonies on +15 agar plates 
 made from the tumors; young agar stroke cultures; behavior in 
 milk and litmus milk; growth on potato; behavior in Cohn's 
 solution; stringy ring and suspended filaments in peptonized beef 
 bouillon; inoculations into young, rapidly growing daisy shoots 
 or into growing sugar-beet roots. 
 
 The organism is readily plated from young sound galls, i. e., 
 those not fissured or decayed. 
 
 In galls on the Paris daisy (Chrysanthemum frutescens) these 
 bacteria were found in small numbers. By plating they were 
 obtained in pure culture and puncture inoculations repeatedly 
 resulted in the characteristic gall. From these the organism was 
 reisolated and the disease again produced, thus giving conclusive 
 evidence that the organism is the actual cause of the gall. Swell- 
 ings began four or five days after inoculation and in a month they 
 were well developed though they continued to enlarge for several 
 months, reaching a size of 2-5 cm. in diameter. 
 
 Tumor-producing Schizomycetes have also been isolated from 
 over-growths on plants belonging to many widely separated 
 families (Compositae to Salicacese). Natural galls have been 
 studied on Chrysanthemum, peach, apple, rose, quince, honey- 
 suckle, Arbutus, cotton, poplar, chestnut, alfalfa, grape, hop, beet, 
 salsify, turnip, parsnip, lettuce, and willow. The organisms from 
 these sources are closely alike on various culture media, and many 
 of them are readily cross-inoculable, e. g., daisy to peach, radish, 
 grape, sugar-beet, hop; peach to daisy, apple. Pelargonium, 
 sugar-beet, poplar; hop to daisy, tomato, sugar-beet; grape to 
 almond, sugar-beet; poplar to cactus, oleander, sugar-beet; willow 
 to daisy. With eight of these organisms tumors have been pro- 
 duced on sound specimens of the species from which obtained. 
 Some cross-inoculate more readily than others, and there are also 
 slight cultural differences. Thus, it is probable that there are 
 several races of the gall-forming organisms varying more or less 
 in amount of virulence and in adaptability to various hosts. In 
 general it is said that all plants susceptible to crown galls, i. e., 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 37 
 
 those on which the galls have been found in nature, are susceptible 
 to artificial cross inoculation. Hard gall, hairy root, and soft gall 
 are also all due to infectious bacteria. 
 
 As tentative hypotheses Smith assumes either: (1) That the 
 hairy root organism while resembling the crown gall organism is 
 not identical with it; or (2) That they are the same, and that if 
 infection takes place in a certain group of cells an ordinary gall 
 will develop, while if other special groups of cells are first invaded, 
 i. e., the root aniagc, then a cluster of the fleshy roots will develop. 
 Some of his inoculation experiments point to the latter conclusion. 
 
 Ps. vascularum (Cobb) E. F. Sm. ^^' ^^' " is parasitic on sugar 
 cane, filling the bundles with a yellow slime. It has not been re- 
 ported in America. 
 
 Ps. sp. indet. A short rod, 2-4 x 1-1.5 m,- actively motile by 
 1-3 polar flagella, was isolated from diseased spots on the larger 
 veins and petioles of beet leaves by Brown."^ The organism was 
 successfully inoculated in pure culture, disease produced, and the 
 organism reisolated. It is infective as well for lettuce, sweet 
 pepper, nasturtium, egg plant and bean. Agar colonies are creamy 
 white, thin, circular, turning the surrounding agar yellow-green 
 in three days. Gelatine is liquefied; litmus milk turns blue; 
 bouillon is clouded. Opt. 28°. 
 
 Ps. sp. indet. A short rod, 2^ n long, motile by 1-3 polar 
 flagella was isolated from diseased nasturtiums (Tropeolum) 
 leaves by Jamiesson.^° Pure culture inoculations induced typical 
 disease. The organism clouds bouillon; produces on agar small, 
 round, bluish- white colonies; liquefies gelatine and does not pro- 
 duce gas. Opt. 25°. T. D. P. 49-50°, 10 min. It is pathogenic 
 also for sweet-pea, lettuce, pepper, sugar-beet and bean. 
 
 Bacillus Cohn. (p. 18.) 
 
 This genus differs from Pseudomonas only in its peritrichiate, 
 not polar, flagella. Endospores are often present. Of the four 
 hundred and fifty or more species nineteen at least are known to 
 be plant pathogens. Numerous animal pathogens also belong to 
 this genus, notably B. typhosus, B. pes'is. 
 
 B. ampelopsorae Trev. is said to cause grape galls in Europe, 
 but the evidence is by no means conclusive. Cf. B. uvae. 
 
38 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Fig. 23. — B. amylo- 
 V o r u s, multiply- 
 ing by fission. 
 After W h e t z e 1 
 and Stewart. 
 
 B. amylovorus (Burr.) De Toni. (Group number 221. — .) 
 
 Bacillus in broth, 0.9-1.5 x 0.7-1.0 y., longer when older. 
 Gram positive; no capsule; flagella several; no spores; broth 
 clouded, pellicle slight. Gelatine shows slow, crateriform lique- 
 faction. Agar, buried colonies white, surface 
 colonies elevated, circular wet-shining, margin 
 irregular. Milk coagulated in three-fourths of 
 a day, later digested to a pasty condition. 
 Opt. 25-30°. T. D. P. 43.7°, 10 min. Faculta- 
 tive anaerobe. Indol produced; no gas; no pig- 
 ment. 
 
 Bacteria were noted in blighted pear twigs by 
 Burrill in 1877.8-' ^^ In 1880 he ^^ demonstrated 
 the communicability of the disease by intro- 
 ducing the bacterial exudate into healthy pear 
 trees as well as into apple and quince trees. 
 This constitutes the first case of plant disease definitely at- 
 tributed to bacteria. Burrill's results were confirmed by Arthur 
 in 1884 8^ by one hundred and twenty-one puncture 
 inoculations, using the exudate, also a bacterial 
 suspension from diseased twigs. He further demon- 
 strated the susceptibility of Juneberry and haw- 
 thorn. Usually the disease appeared about a 
 week after inoculation. Attempted raspberry and 
 grape inoculations failed. 
 
 Arthur placed the whole matter on a firm foun- 
 dation by passing the bacteria through a long 
 series of artificial cultures and then by inocula- 
 tions, showing that they were capable of causing 
 the blight.8^' ^"^ He further demonstrated that the 
 bacterial exudate from the tree, when freed of 
 bacteria by filtration, could not produce disease. 
 The results of an extensive study of the bacteria on 
 various media; of their morphology and stain 
 reactions were published by Arthur in 1886.^^ Bacteria were 
 shown to penetrate twigs 3-4 dm. beyond their area of visible 
 effect. 207 
 
 In 1902 Jones ^^ isolated an organism from blighted plum trees. 
 
 Fig 
 
 24.— Claw 
 from bee's foot 
 with blight 
 bacteria on 
 and about it 
 showing the 
 relative size. 
 After Whct- 
 zel and Stew- 
 art. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 39 
 
 This he demonstrated by culture and cross inoculation in fruits to 
 be identical with the pear blight organism, though inoculations in 
 plum twigs did not give disease, presumably due to the high re- 
 sistance of this plant. Similarly Paddock has shown this organism 
 to attack the apricot.^° Detmers has reported what she regarded 
 as this blight caused by this Bacillus on blackberries.^^ 
 
 Other hosts are hawthorn, shad bush, mountain ash. 
 
 By inoculations with pure cultures of the apple body-blight 
 bacteria, blight upon twigs and blossoms was produced by Whetzel 
 in 1906,^" thus proving the identity of these two forms of disease, 
 an identity asserted first by Burrill.^^ 
 
 Fig. 25. — B. aroideae. After Townsend. 
 
 B. apii (Brizi.) Mig.^'* is reported as the cause of a celery rot, 
 which is possibly identical with a bacterial rot reported earlier 
 by Halsted.*^^ 
 
 B. araliavorous Uyeda, described on Ginseng in Korea is per- 
 haps also the cause of soft rot of Ginseng in America.^^ The 
 organism was isolated and studied by Uyeda who made inocula- 
 tions. 
 
 Pseudomonas araliae and Bacillus koraiensis were also com- 
 monly present in the Oriental disease.^^ 
 
 B. aroideae Town. (Group Number 221.2223022.) =^=^ 
 
 This organism was described in 1904 as the cause of soft rot of 
 calla ^^ corms and leaves. The bacteria were present in almost 
 pure culture in affected tissue and by puncture inoculation in pure 
 culture produced the typical disease in a few days. 
 
 Townsend regarded the organism as distinct from B. carotov- 
 orus, B. oleracese, B. hyacinthi septicus and Pseudomonas de- 
 
40 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 structans. Harding and Morse, however, believe it specifically 
 identical with B. carotovorus. See p. 42. 
 
 B. atrosepticus v. Hall,^^ was isolated from ducts of potatoes 
 affected with black leg. 
 
 B. avenae, Manns.^^ This is the symbiont of Pseudomonas 
 avense. See p. 23. 
 
 (Group number 222.2223532.) A very actively motile bacillus, 
 short, rod-shaped with rounded ends, 0.75 to 1 x 1.5 to 2 /i. 
 
 Fig. 26. — Plate culture of B. avenae, on nutrient glucose agar, 
 four days at SCC. After Manns. 
 
 Gram negative; endospores not observed; flagella many, diffuse, 
 long, undulate; growth on agar stroke rapid, filiform, white, 
 glistening, later somewhat dull, margin smooth, growth rather 
 opaque, turning yellow third day; gelatine not liquefied; broth 
 clouded and on the second day showing heavy yellow precipitate; 
 milk coagulated at end of two weeks with extrusion of whey; 
 agar colonies round, entire, surface smooth, slightly raised. No 
 gas in dextrose, saccharose, lactose, maltose, or glycerins. Indol 
 production moderate; nitrates reduced to nitrites. T. D. P. 10 
 min., 60°; Opt. 20-30°. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 41 
 
 B. betas Mig. is reported as the cause of gummosis of beet.^"*^ 
 B. brassicaevorus Del, isolated from diseased cabbage ^°^ is per- 
 haps identical with Pseudomonas fluorescens. See page 27. 
 
 B. carotovorus Jones. (Group number 221.1113022.) From 
 agar 1-2 days old as 
 short or long rods, in 
 short or long chains. 
 0.7-1.0 X 1.5-5 n, com- 
 monly 0.8 X 2 ju; ends 
 rounded. No spore; 
 flagella 2-10, peritri- 
 chiate; no capsule; 
 Gram negative. White 
 on all media. Agar 
 slope filiform to spread- 
 ing, glistening, opaque 
 to opalescent. In gela- 
 tine stab; liquefaction 
 crateriform to infun- 
 dibuliform. Broth 
 clouded, peUicle thin 
 to absent, sediment 
 flocculent; milk coagu- 
 lated. Agar colonies, 
 round, smooth, entire 
 to undulate, amor- 
 phous or granular. Fig. 27. — B. cmotovuruis wedging apart cells of the 
 . carrot. After Smith. 
 
 bome gas m dextrose, 
 
 lactose and saccharose, nitrates reduced to nitrites; indol feeble. 
 
 T. D. P. 48-50°. Opt. 25-30°. 
 
 A considerable number of cultivated plants suffer soft rot from 
 the attacks of a non-chromogenic liquefying bacillus. Among the 
 plants so affected are cabbage, turnips and other crucifers; parsnip, 
 carrot, mangel, sugar-beet, potato, celery, tomato, Jerusalem 
 artichoke, asparagus, rhubarb, onion and iris. 
 
 In 1901, Jones reported an organism isolated from rotting carrots 
 which he named B. carotovorus. ^°-' ^°^ It disorganized tissue 
 by solution of the middle lamella; and infection into wounds led 
 
42 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 to decay of roots of carrot, parsnip, turnip, radish, salsify, of 
 onion bulbs, hyacinth corms, cabbage heads, celery stalks and 
 fruits of tomato, pepper and egg plant. Jones found no decay pro- 
 duced in young carrot or parsnip plants, fruits of orange, banana, 
 apple, pear, cauliflower head,* Irish potato tuber, beet root or 
 
 tomato stems. ^°^ Infection 
 v. ^J ^__^ did not occur unless the 
 -^ "* "^ epidermis was broken. The 
 
 rotten mass was always 
 soft, wet, and exuded a 
 liquid clouded with bac- 
 teria. 
 
 Jones ^^ in 1909 made an 
 . , , extensive study of the cyto- 
 
 biG. 2S. — B. carotovorus. Alter Jones. . . 
 
 litic enzyme of this germ. 
 This enzyme was separated by heat, filtration, formalin, phenol, 
 thymol, chloroform, diffusion, alcohol, and its conditions of pro- 
 duction and action investigated. Heating the enzyme to 60° in- 
 hibited its activity to a marked degree; higher than 63° inhibited 
 it entirely; chloroform, thymol and phenol did not retard its ac- 
 tion. No loss was suffered through alcoholic precipitation and 
 resolution. The dried enzyme remained active for fully two 
 years. Its effect was greatest at 42°, less at 32° and 48°. No 
 diastatic action was observable. 
 
 In 1909 Harding and Morse, ^^ from an extended study of some 
 12,000 cultures of non-chromogenic, liquefying soft-rot bacilli 
 of some forty-three pathogenic strains (including B. carotovorus, 
 B. oleraceae, B. omnivorus, B. aroideae and what Potter regarded 
 as Pseudomonas destructans), from six different vegetables, con- 
 clude that unless later studies of the pathogenicity of these cul- 
 tures shall offer a basis for subdividing them, there is no apparent 
 reason why they should not all be considered as somewhat variant 
 members of a single botanical species. 
 
 This conception would lead to the abandonment of the supposed 
 species mentioned above and the recognition of all of them under 
 their oldest described form, B. carotovorus Jones, which in our 
 
 * Harding and Stewart later showed that it is capable of rotting cauli- 
 flower. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 43 
 
 present knowledge seems certainly to be the most wide spread, 
 common and destructive of the soft rot bacteria. Some, perhaps 
 much, of the rot of crucifers generally thought to be due to Pseudo- 
 monas campestris is probably caused by B. carotovorus. See 
 Harding & Morse.^^ 
 
 B. caulivorus, Pril. & Del. has been reported as the cause of 
 spots on grapes under glass, also as a parasite on a large number 
 of other plants among them Pelargonium, potato, begonia, clem- 
 atis. It is later stated that this is probably really a variety of 
 Ps. putrifaciens liquefaciens. 
 
 B. cepivorus Del. (possibly a Bacterium) is recorded on onion 
 bulbs.^i 
 
 B. coli (Esch.) Mig. or an organism indistinguishable from it is 
 held by Johnston ^^^ capable of causing rot of soft tissues of the 
 cocoanut plant and is perhaps responsible for cocoanut bud 
 rot. 
 
 B. cubonianus Mace, was originally described as the cause of 
 mulberry disease (cf. Ps. mori). This organism, or at least one 
 that was regarded as indistinguishable from it, has been men- 
 tioned as the cause of a disease of hemp.^*^^ 
 
 B. cypripedii Hori is a medium sized slender, non-sporulating 
 form with four flagella.-'^^ 
 
 B. delphini E. F. Sm. This is a motile, gray-white, nitrate- 
 reducing, non-liquefying organism. On agar young colonies small, 
 circular, wrinkled. Grows well at 30°, not at all at 37.5°. T. D. 
 P. 48^9.1°. 
 
 The cause of stomatal infection of larkspur resulting in sunken 
 black spots on leaves and stems. ^''^ 
 
 B. elegans Hegyi is reported on lupine. ^"'^ 
 
 B. dahliae Hori & Bakis is on dahUa.^^^ 
 
 B. gossypini Stedman was reported by Stedman ^°^ as the 
 cause of cotton-boll soft rot in Alabama; much doubt, however, 
 remains as to its actual identity and causal relation. It was de- 
 scribed as a short, straight, spore-forming motile bacillus; 1 .5 x 
 .75 fx; aerobic; non-liquefying (?). 
 
 B. gummis Comes, has by some been held responsible for gum- 
 mosis or inal nero of the grape vine ^"^ though others discredit this 
 idea. 
 
44 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 B. haria Hori & Miy. is a parasite of the Japanese basket 
 willow. '^^ 
 
 B. hyacinthi septicus Heinz, ^-^ is recorded as the cause of a soft 
 white rot of the hyacinth. 
 
 B. iactucae Vogl. is said to cauee a lettuce disease. ^^^ 
 B. lycopersici Hegyi has been described as the cause of a rot 
 of tomatoes. ^^- 
 
 B. maculicola Del. is regarded as the cause of a tobacco leaf 
 spot.^^^ 
 
 B. melanogenus P. & M.^^^is recorded in England on potatoes. 
 B. melonis Giddings.^^^ 
 
 An actively motile bacillus, 0.6-0.9 x 1-1.7 fx; flagella 4-6 
 peritrichiate; no spores. Gram negative. Broth strongly clouded, 
 
 no pellicle or ring, 
 slight sedim.ent. Agar 
 stroke slimy, glistening 
 translucent; colonies 
 round or amoeboid. In 
 gelatine stab liquefac- 
 tion infundibuliform in 
 two days. Milk co- 
 agulated with abun- 
 dant gas. Nitrite pro- 
 duction abundant ; indol 
 slight. T. D. P. 49- 
 50°. Opt. 30°. The 
 vegetables rotted were 
 muskmelon, citron, car- 
 rot, potato, beet, cu- 
 cumber and turnip. 
 
 In the soft rot caused 
 by this organism in 
 muskmelons, motile 
 bacteria were observed in abundance by Giddings in 1907. Plating 
 gave pure cultures which by inoculation tests were shown to be 
 those of the causal organism of the rot. Decay is produced by 
 solution of the middle lamella by enzymic action, the remainder 
 of the walls withstanding the attack. The bacteria are thus 
 
 Fig. 29. — Photomicrograph of B. melonis. a, show- 
 ing living organisms in agar hanging block cul- 
 ture; b, with flagella stained by Lowitz method. 
 After Giddings. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 45 
 
 strictly intercellular. Wound inoculations in muskmelon generally 
 gave complete decay in from three to seven days. Similar inocula- 
 tion of citron and cucumbers resulted in decay, though inoculation 
 into squash did not. No decay of musk- 
 melon followed applications of the bacteria 
 to unbroken surfaces. 
 
 B. mycoides Fliigge. (Group number 
 -22.1 8-.) 
 
 Rods thick, 0.95 x 1.6-2.4 ^u, usually in 
 long threads, sporiferous. Spores elliptical, 
 1.3-1.48 X 0.7-0.9 mm. Gelatine colonies 
 white with mycelium-like outgrowths; gela- 
 tine liquefied. Pellicle formed in broth. 
 Gram positive. 
 
 This common soil organism has been held 
 responsible for a disease of beets. ^^^ 
 
 B. nicotianae Uyeda is ascribed as the 
 cause of a tobacco wilt in Japan ^^'^' ^^^ which 
 closely resembles that caused by B. sola- 
 nacearum in America. 
 
 The bacillus is 1-1.2 x 0.5-0.7 ix with 
 rounded ends, actively motile by peritri- 
 chiate flagella. Spores are produced. A 
 complete physiological study is to be found 
 in the articles above cited. 
 
 Bacillus oleae (Arc.) Trev. (Group num- 
 ber -22.333-0—.) C. 0. Smith describes 
 the organism as a motile rod with rounded 
 ends, 1.5-2.5 x 0.5-0.6 ix. On agar slant 
 growth thin, gray-white, spreading; colonies 
 circular, whitish. On gelatine no liquefac- 
 tion. Milk not coagulated. Distribution of 
 flagella not stated. 
 
 In oleander tubercles on leaves and twigs, 
 and in oUve tubercles C. O. Smith ^^^ found 
 bacteria which he regards as this species. Upon puncture inocu- 
 lation in both olive and oleander, tubercles were produced. Con- 
 trols were not diseased. The organism was reisolated from the 
 
 Fig. 30.— Cultures of B. 
 melonis on silicate jelly 
 slants, 12 da3^s' growth, 
 (30° C.) After Gid- 
 
 dings. 
 
46 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 artificially produced knot with unchanged characters. E. F. 
 Smith's results ®^ do not agree with those of C. O. Smith. (See 
 Pseudomonas savanastoi.) 
 
 B. oleraceae Harr. (Group number 221.1113022.) 120-122 
 
 This organism was studied by Harrison in 1901 in Canada where 
 it was found associated with a soft rot of cauliflower, cabbages and 
 turnips. In the rotting tissue it was always present; it was iso- 
 lated, and upon inoculation and cross inoculation characteristic 
 infection followed. The organism was reisolated in unchanged 
 character. The chemical products of the bacillus, secured by 
 filtration, also produced the characteristic tissue changes. Sec- 
 tions of diseased tissue showed the bacteria in the intercellular 
 spaces, occupying the position of the middle lamella which was 
 softened and eventually dissolved by the bacterial enzymes. 
 
 Harding and Morse ^^ from their extensive studies conclude 
 that this form is identical with B. carotovorus. See p. 42. 
 
 B. omnivorus v. Hall is described by van Hall ^^^ as the cause of 
 a soft rot of iris shoots and rhizomes. According to Harding & 
 Morse ^^ it does not present characters sufficient to distinguish it 
 from B. carotovorus. See p. 42. 
 
 A species closely related to B. omnivorus is described by Uyeda ^^'^ 
 as the cause of a disease of Zingiber. The organism was isolated and 
 studied and the disease produced by inoculation with pure culture. 
 
 B. oncidii (Pegl.) Stev. is mentioned ^^^ as the cause of an 
 orchid leaf spot. 
 
 B. oryzae Vogl. has been mentioned as the possible cause of 
 brusone ^"^ of rice. 
 
 B. phytophthorus Appel. (Group number 221.21230—.) A 
 non-sporiferous rod, 0.6-0.8 x 1.5-2.5 fx, actively motile by per- 
 itrichiate flagella. Gram negative. It rots potatoes, cucumbers, 
 etc.; is aerobic or a facultative anaerobe; grayish white on agar; 
 surface colonies round, smooth; gelatine liquefaction moderate; 
 bouillon clouded; no indol; no gas. Nitrate changed to nitrite. 
 Milk coagulated and casein precipitated. Opt. 28-30°. T. D. P. 47°. 
 
 It was described by Appel ^-'^ of Berlin as the chief cause of 
 potato black-leg. The description given above is by E. F. Smith ^'^ 
 and was made from Appel's organism. Smith also isolated it from 
 potatoes grown in Maine and in Virginia. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 47 
 
 It is closely related to but is not identical with B. solanisaprus 
 and B. atrosepticus.^-^ 
 
 B. populi Brizi is said to cause galls on the poplar ^-^. 
 
 B. pseudarabinus R. G. Sm.^'^'^ is capable of producing on inocu- 
 lation a crimson-red gum in the vessels of sugar cane and is per- 
 haps responsible for a disease showing this symptom. 
 
 B. rosarum Scalia is the name given to a very imperfectly 
 described organism said, on scant evidence, to be the cause of rose 
 tumors or crown galls /^ 
 
 B. sesami Malk.^^ Malkoff in infection experiments caused a 
 disease of sesame with this organism. 
 
 B. solanacearum E. F. Sm. (Group number 212.333-8—.) 
 A medium sized, easily stained, strictly aerobic bacillus with 
 rounded ends; about lJ^-3 times longer than broad; 0.5 x 1.5 /x. 
 Motile, sluggish or active; flagella long, diffuse. Spores not 
 known. Zoogloea occur in liquid media as small, white flecks or 
 as surface rings. It grows well at 20-30°. Milk is saponified with 
 no casein precipitation or acidity. Gelatine not liquefied. Agar 
 surface colonies, dirty-white. Agar streaks first dirty- white, later 
 yellowish to brownish-white, then brown. On potato as on agar, 
 but darker, with substratum and fluid browned. No gas from 
 cane sugar, lactose, maltose or dextrose. 
 
 The disease caused by this bacillus upon tomato and other 
 plants was early studied by Halsted i^i-iss qj^^ perhaps by Bur- 
 rill. ^^'^'^^^ Halsted made inoculations which produced the disease 
 but he did not use pure cultures. The first complete account of 
 the causal organism was given by E. F. Smith ^^^' ^^^ in 1896. 
 
 In its hosts the bacillus is found in the pith, in the xylem which 
 is browned, and more rarely in the bark. From the cut ends of in- 
 fected ducts bacteria exude as a viscid ooze and the diseased ducts 
 may be traced to great distances through the plant, even from root 
 to leaf. From the bundles the organism later invades other tissues. 
 
 Needle prick inoculations in tomatoes and potatoes with pure 
 cultures, were followed after several weeks (tomato) by typical 
 disease. Inoculations in Irish potato resulted similarly, though in 
 this host the parenchyma and bark were eventually invaded, and 
 the tuber was reached through its stem end and rotted. In South 
 Carolina, Smith noted the disease on egg plants and crude cross 
 
48 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 inoculations were made to tomato. Smith demonstrated experi- 
 mentally the efficiency of the potato beetle in transmitting the 
 disease. 
 
 The disease was described for tobacco by Stevens ^^^ and Stevens 
 and Sackett.139 
 
 Successful inoculations were reported upon tobacco by E. F. 
 Smith in 1909 ^'° though in his earlier trials tobacco and pepper 
 gave negative results when inoculated with this bacillus. In addi- 
 tion to the above hosts it is known to grow upon Datura, Solanum 
 nigrum, Physalis and Petunia. 
 
 B. solanicola Del. was reported as the cause of a potato stem 
 disease. ^^^ 
 
 B. solaniperda Mig. (Group number 121. 0--.) A rod, 
 
 2.5-4 X 0.7-0.8 li, with rounded ends, often in long chains; actively 
 motile ; spores present. Agar colonies dirty-white ; gelatine liquefied. 
 This was shown by Kramer in 1890 ^^^ to be the cause of soft rot 
 
 of potatoes. The organism 
 was grown in pure culture 
 and inoculated on potatoes 
 producing the characteris- 
 tic decay. The germs enter 
 through the lenticels, con- 
 sume the sugar, then at- 
 tack the intercellular sub- 
 stances and the cell wall. 
 Later the albuminous sub- 
 stances are destroyed. 
 
 B. solanisaprus Harr. 
 (Group number 221.212-0- 
 
 _ \ 143 
 
 Fig. 31.— Surface colonies of B. solanisaprus. A bacillus with rounded 
 
 After Harrison. , ^ ^ . ^ „ 
 
 ends, 1.5-4 x 0.6-0.9 n, 
 variable in culture; no capsule; actively motile by 5-15+ peritri- 
 chiate flagella; no spores seen. Gram negative. Gelatine colonies, 
 punctiform 0.25 mm. at two days ; gelatine stab filiform. Liquefac- 
 tion noticeable on the thirty-fifth day. Agar colonies punctiform 
 at two days, 1-5 mm., gray-white, slimy, flat. Bouillon turbid 
 with fine sediment; ring, and thin band present; milk curdled. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 49 
 
 Gas only in mannite and lactose. Nitrate reduced to nitrite. 
 Opt. 25-28°. T. D. P. 54°, 10 min. 
 
 It was found constantly associated with a type of potato disease 
 which Harrison regarded as distinct from black-leg and from the 
 disease caused by B. 
 solanacearum. It was 
 repeatedly isolated 
 from diseased tubers, 
 stems and leaf veins 
 and occurred in prac- 
 tically pure culture in 
 freshly infected tissue. 
 
 The organisms first 
 appeared in the ducts 
 and thence invaded 
 the surrounding tis- 
 sue, dissolving the 
 middle lamellse and 
 producing cavities. 
 Inoculations of pure 
 
 cultures into healthy Fig. 32.— B. solanisaprus, from agar 24 hours. 
 . , After Harrison. 
 
 plants produced char- 
 acteristic lesions and the organism was reisolated. Characteristic 
 enzymic action was observed on placing precipitated enzyme on 
 slices of potato. 
 
 B. sorghi Burr."4 Rods 0.5-1 (usually 0.7) x 1-3 (usually 
 1.5) fi, cylindrical or oval, motile, spore-bearing, non-liquefying. 
 Colonies on agar, white to pearly. In broth with a white smooth 
 membrane. 
 
 The bacillus was recognized as the cause of a sorghum blight 
 by Burrill and this view was confirmed by Kellerman & Swingle 
 through ^^'^ inoculation experiments. 
 
 B. spongiosus A. & R. ^^^ causes gummosis of cherry in Ger- 
 many. 
 
 B. subtilis (Ehr.) Cohn. 
 
 Straight rods, often united in threads, 0.7 x 2-8 jj,. Sporiferous. 
 Spores central or lying near one pole; germination equatorial. 
 Flagella, 6-8, peritrichiate; gelatine liquefied; gelatine colonies 
 
50 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 bordered by numerous fine filamentous outgrowths. Growth on 
 slant agar gray. It is reported as the cause of vegetable rot.-^''^ 
 
 B. tabacivorus Del. is recorded on tobacco stems. 
 B. tabificans Del.^'^ which perhaps belongs to the genus Bac- 
 terium is reported as the cause of a beet disease in France. 
 B. tracheiphilus, E. F. Sm. (Group number 222. 03-.) 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 51 
 
 Bacillus 1.2-2.5 x 0.5-0.7 n, variable, actively motile in young 
 cultures. Capsulated, no spores, peritrichiate. No gelatine 
 liquefaction. On agar thin, smooth, milk-white. No gas, aerobic 
 or facultative anaerobic. Milk not curdled. T. D. P. 43°, 10 min. 
 
 This pathogen was first reported by E. F. Smith without de- 
 scription in 1893 ^^^ and more fully in 1895.^^° It is found filling 
 the vessels of cucurbits, (musk melons and cucumbers) affected 
 with wilt. Smith produced the disease artificially by puncture 
 inoculations on the blades of leaves with the white sticky fluid 
 from infected veins. The inoculated plants showed symptoms of 
 wilt after four days and sixteen days later the ducts of the vine 
 were found to be plugged with bacteria. The organism was then 
 isolated from this artificially infected plant. The cultures thus 
 obtained were carried by transfers over winter and in December 
 were used successfully to 
 infect cucumber plants. 
 Control plants were never 
 diseased. The ready 
 growth of the organism in 
 the vessels is attributed to 
 the alkalinity of the latter; 
 the failure to grow in the 
 parenchyma is attributed 
 to its acidity. 
 
 B. uvae Cug. & Mac. is ''j^^*"C'l. ^' . C'V"**- 
 reported as causmg mjury ^j*, t** ^ s, "jl C* * *'\r' 
 to young grape clusters.'' 
 It is perhaps identical with 
 B. ampelopsorae. m>^ >•" ^'' ** »r*', '*' '^'^i 
 
 B. vulgatus (Flugge) -J >. ^''^^^^ "'^'. /. .>-/ ' 
 Mig. This organism is *"' A ' " V,." X -/ ^x^l/,0 ' 
 
 found as small thick rods ^^^ ^^_^ tracheiphilus. ^Ifter Smith. 
 
 with rounded ends, or is 
 
 often paired or in chains of four; sporiferous. Gelatine colonies 
 
 round, hquefaction rapid. Growth on agar dirty-white. 
 
 It has been shown capable of causing rot of various vegetables. ^^' 
 B. zeae Burr, is the name applied to a bacillus isolated from 
 
 diseased corn plants by Burrill in 1887-1889.^^''* ^^^ It is often 
 
 ury .^, tj. a, ^ir^:-' \\r . 
 
 ,151 - . ^3»,'A * >^n«''w\<V' • ' 
 
52 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 cited as the cause of a bacterial corn disease but the evidence of 
 causal relation as well as the identity of the germ are not clear. 
 
 B. zinzgiberi Uyeda causes a disease of Zinzibar,-°*^ B. sac- 
 chari and B. glangae are on sugar cane as the possible cause of 
 
 , 58 
 
 sereh. 
 
 An organism called Clostridium persicae-tuberculosis by 
 Cavara ^^^ is mentioned as cause of knot on peach trees. 
 
 Less known bacterial plant diseases. The literature abounds 
 in references to what are regarded as cases of plant bacteriose, 
 cases which as yet rest upon very incomplete evidence. In many 
 of these bacteria are found in abundance in the diseased tissue 
 but pathogenicity has not been proved by inoculation nor pure 
 cultures made. Among such incompletely studied diseases may 
 be mentioned those of geranium; I'^^-iss celery /^^ onion, ' 
 cucumber, ^^^ orchard grass, ^^^ lettuce, ' (one lettuce disease 
 is due to a motile rod-shaped organism cultured and inoculated 
 but not named, ^^^) strawberries, ^^^"^^^ mulberry, ^^^ hemp,^^" calceo- 
 laria.^^^ 
 
 There are also several obscure bacterial beet diseases; another 
 cabbage rot due to Pseudomonas; ^^^ a decay of apples said by 
 Prillieux to be due to a Bacillus; ^^^ the blossom-end-rot of tomatoes 
 which is perhaps bacterial; ^^"^ a cyclamen leaf spot; ^^^ a juniper dis- 
 ease; ^'^ a pine gall; ^^" an ash bark disease; ^^^ and an ash canker; ^^^ 
 an ivy canker; ^^° a grape disease; a salsify rot; ^^^ a carnation 
 spot; ^^^ and a banana disease; ^^^ a gummosis of tobacco; ^^^ a 
 disease of tobacco seedlings; ^^^ also perhaps the serious widespread 
 mosaic disease of tobacco and an orchid gummosis. ^^ 
 
BIBLIOGRAPHY OF INTRODUCTION 
 MYXOMYCETES AND BACTERIA * (pp. 1 to 53) 
 
 1 Eycleshymer, A. C, Journ. Myc. 7; 79, 1892. 
 
 2 Nawaschin, S., Flora 86: 404, 1890. 
 
 > Woronin, M., Jahrb. f. wiss. Bot. 11: 548, 1878. 
 
 * Rowazek, S., Arb. d. Kais. Gesund. Berlin S2: 396, 1905. 
 » Maire, R., & Tison, A., Ann. Myc. 7: 226, 1909. 
 
 ' Idem., 9: 226, 1911. 
 
 ' Kirk, T. W., D. Agr. R., N. Zeal., 365, 1906. 
 8 Viala & Sauvageau, C. R. 11 4: 1892 and 120. 
 ^Idem., C. R., 115: 67, 1892. 
 
 10 Massee, G., Ann. Bot. 9: 95. 
 
 11 Abbey, Jour. Hort. Soc. London, 1895. 
 
 12 Debray, Rev. d. Viticulture, 85, 1894. 
 
 1' Behrens, J., Weinbau u. Weinhandel, 33, 1899. 
 
 '^ Ducomet, V., C. R. Ass. Fr. Avanc. Sc. Angers, Pt. 2: 697, 1903. 
 
 15 Maublanc, C., Agr. Prat. Pays Chauds. S.- 91, 1908. 
 
 i» Osborne, T. G. B., Ann. Bot. 25: 271, 1911. 
 
 " Lagerheim, Jour. Myc. 7: 103, 1892. 
 
 18 Johnson, Sci. Proc. Roy. Dublin Soc. N. S. 12: 165, 1909. 
 
 * In the bibhographies the usual abbreviations for the states followed by 
 B. or R. indicate respectively Bulletin or Report of the State Agricultural 
 Experiment Station, B. P. I. or V. P. P. of the Bureau of Plant Industry or 
 Division of Vegetable Physiology and Pathology of the United States De- 
 partment of Agriculture, respectively. 
 
 Zeit.=Zeitschrift flir Pflanzenkrankheiten. 
 Sc."= Science New Series. 
 E. S. R.=Experiment Station Record. 
 Ann. Myc. = Annales Mycologici. 
 Soc. M. rr.=Societe Mycologique de France. 
 Y. B. = Yearbook, U. S. Department of Agriculture. 
 C. R. = Compt. Rendu. 
 
 C. Bak. = Centralblatt f. Bakt. Par. u. Inf. Ab. II. 
 Other abbreviations are those usually employed or readily understood. 
 All bold face references,®**" will be found in the book bibliography, page 678. 
 
 53 
 
54 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 '9 Johnson, Econ. Proc. Roy. Dublin Soc. 1, pt. 12, 1908. 
 
 20 Wulff, T., Zeit. 16: 203, 1906. 
 
 21 Mangin, L., Rev. Hort. Paris 81: 568. 
 
 22 Zeit. 13: 267, 1903. 
 
 23 Toumey, Ariz. B. 33. 
 
 2" Prillieux, E., Ann. Sc. Nat, 6 ser. 7: 248, 1879. 
 25 Frank, Ber. d. Deut. Bot. Gas. 16: 237, 1898. 
 20 Frank, C. Bak. 5: 98, 1899. 
 
 27 Roze, E., C. R. 1S2: 543, 1896 and 1S3: 1323. 
 
 28 Delacroix, G., Maladies d. PI. Cult. 19, 1909. 
 23 Metcalf, H., Neb. R. 17: 69, 1904. 
 
 • 30 Vuillamen, C. R. 107: 874, 1888. 
 
 31 Busse, W. & V. Faber, F. C., Mit. K. Biol. Anst Land u Forst, 
 18, 1907. 
 
 32 Jones, L. R., N. Y. (Geneva) T. B. 11: 1909. 
 
 33 Harding, H. A., and Morse, W. J., N. Y. (Geneva) T. B. 11: 1909. 
 3« Smith, E. F., V. P. P. 38: 1901. 
 
 3fi Manns, T. F., 0. B. SIO: 1909. 
 
 36 Pammel, L. H., la. B. 27: 1895. 
 
 37 Russell, H. L., Wis. B. 65: 1898. 
 
 38 Smith, 'E. F., B. P. I. 29: 1903. 
 
 39 Smith, E. F., C. Bak. 3: 284, 485, 1897. 
 
 « Harding, H. A., Stewart, Y. C, and Prucha, M. S., N. Y. (Geneva) 
 B.251: 1904. 
 
 *i Garman, H., Ky. R. 3: 43, 1890. 
 
 *2 Harding, H. A., C. Bak. 6: 305, 1900. 
 
 " Potter, M. C., C. Bak. 7: 282, 1901. 
 
 " Jones, L. R., C. Bak. U: 257, 1905. 
 
 « Arthur, J. C. & BoUey, H. L., Ind. B. 59: 17, 1896. 
 
 ^6 Barlow, B. B., Ont. Ag. Co. B. 136: 1904. 
 
 « Griffon, E., C. R. Acad. Sci. Paris 149: 50, 1909. 
 
 *^ Scalia, Agricolt Calabro-Siculo, 1903. 
 
 « Smith, E. F., V. P. P. 26: 1901. 
 
 5" van Hall, C. J. J., Zeit. 13: 129, 1903. 
 
 51 Pierce, N. B., Bot. Gaz. 31: 272, 1901. 
 
 " von Oven, E., C. Bak. 16: 1907. 
 
 " Osterwalder, A., Cent. Bak. 25: 260, 1910. 
 
 54 Sackett, W. G., Colo. B. 158: 1910. 
 
 55 Smith, E. F., Sc. 31: 794, 1910. 
 
 59 Boyer & Lambert, C. R., Paris 117: 342, 1893. 
 57 Smith, E. F., Sc. N. S. 31: 792, 1910. 
 
BIBLIOGRAPHY OF INTRODUCTION 55 
 
 "*« Macchiati, L., Malpighia 5: 289, 1892. 
 
 ^^ Beach, S. A., N. Y. (Geneva) B. 48: 331, 1892. 
 
 60 Halsted, B. D., N. J. R. 13: 283, 1892. 
 
 «i Smith, E. F., Proc. A. A. A. S. 288: 1897. 
 
 «" Smith, E. F., Sc. 17: 456, 1903. 
 
 63 Rorer, J. B., Mycoligia 1: 23, 1909. 
 
 " Pierce, G. P., Proc. Cal. Acad. Sc. 3rd Ser. Bot. 2: 295, 1902. 
 
 65 Smith, E. F., B. P. I. 131: 25, 1908. 
 
 66 Malkoff, K., C. Bak. 16: 664, 1906. 
 
 67 Stewart, F. C, N. Y. (Geneva) B. 130: and R. 16: 401, 1897. 
 
 68 Smith, E. F., Proc. A. A. A. S. 422: 1898. 
 
 69 Smith, E. F., C. Bak. 10: 745, 1903. 
 ^° Smith, E. F., Sc. 17: 458, 1903. 
 
 71 van Hall, C. J. J., Bij. t. Kenn. Bak. Plonet 142, 1902. 
 
 72 Smith, E. F., and Townsend, C. 0., Sc. 25: 672, 1907. 
 7' C. Bak. 20: 89. 
 
 7" Townsend, C. 0., Sc. 29: 273, 1909. 
 
 76 Smith, E. F., Phytopathology 1: 7, 1911. 
 
 76 Smith, E. F., Brown, N. A., and Townsend, C. 0., B. P. I. 213, 1911. 
 
 77 Cobb, N. A., New So. Wales, Dept. Agr. 1893. 
 
 78 Smith, E. F., C. Bak. 13: 726, 1905. 
 '^ Brown, Nellie A., Sc. 29: 914, 1909. 
 
 8" Jamiesson, Clara 0., Sc. 29: 915, 1909. 
 
 81 Delacroix, G., Ann. Inst. Nat. Agi-on. 2, Ser, 5: 353, 1906. 
 
 82 Burrill, T. J., Trans. 111. Hort. Soc. 114, 1877. 
 8» Idem, 80, 1878. 
 
 8" Burrill, T. J., Proc. A. A. A. S. 29: 583 and Am. Nat. 15: 527. 
 
 85 Arthur, J. C, N. Y. (Geneva) R. 3: 1884. 
 
 86 Arthur, J. C, Proc. A. A. A. S. 34: 1885. 
 
 87 Arthur, J. C, Bot. Gaz. 10: 343, 1885. 
 
 88 Arthur, J. C, Proc. Phila. Acad. Science 331, 1886. 
 
 89 Jones, L. R., C. Bak. 9: 835, 1902. 
 9« Paddock, W., Col. B. 84. 
 
 » Detmers, F., 0. B. Ser., IV: No. 6, 129, 1891. 
 »2 Whetzel, H. H., N. Y. (Cornell) B. 236, 1906. 
 93 Burrill, T. J., Trans. 111. Hort. Soc. 147, 1881. 
 9^ Brizi, U., C. Bak. 3: 575, 1897. 
 
 95 Halsted, B. D., N. J. B. Q: 1892. 
 
 96 Rankin, W. H., Special Crops. N. S. 9: 94, 356. 
 "7 Uyeda, Y., see 96. 
 
 98 Townsend, C. 0., B. P. I. 60: 1904. 
 
56 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 99 van Hall, C. J. J., Diss. 1902. 
 o" Busse, W., Zeit. 7; 65, 1897. 
 " Delacroix, C. R. l^O: 1356, 1905. 
 02 Jones, L. R., C. Bak. 7: 12, 1901. 
 0' Jones, L. R., Vt. R. 13: 299, 1901. 
 »* Harding & Stewart, Sc. i^; 314, 1902. 
 05 Peglion, v., Zeit. 7; 81. 
 0" Smith, E. F., Sc. 19: 416, 1904. 
 0' Hegyi, Kizer Kozlem 1: 232, 1899. 
 
 08 Stedman, J. M., Ala. B. 55: 1894. 
 
 09 Prillieux & Delacroix, Rev. Int. d. Vit. D'Oenol, 1894. 
 
 10 Heinz, Cent. f. Bakt. 5: 535, 1889. 
 
 11 Voglino, P., An. R. Ac. d. Agr. d. Torino ^6: 1903. 
 
 12 Hegyi, D., Kiser. Kozlem 2: 1899, No. 5235. 
 
 13 C. R. HO: 678, 1905. 
 1* Pethybridge, & Murphy, P. A., Nature (London, 1910), 296, 
 
 No. 2148. 
 
 16 Giddings, N. J., Vt. B. I48: 1910. 
 
 i« Linhart I., Zeit. 10: 116, 1900. 
 
 " Uyeda, Y., Bull. Imp. Centr. Agric. Sta. 1: 39, Dec, 1905. 
 
 18 Uyeda, Y., C. Bak. 13: 327, 1904. 
 
 19 Smith, C. 0., Bot. Gaz. 42: 302, 1906. ■ 
 
 20 Harrison, F. C., C. Bak. 13: 46, 1904. 
 
 21 Harrison, F. C., Sc. 16: 152, 1902. 
 
 22 Harrison, F. C, Ont. B. 137: 1904. 
 
 23 van Hall, C. J. J. Zeit. 13: 129, 1903. 
 2^ Uyeda, Y., Bot. Cent. 17: 383, 1907. 
 25 Voglino, P., Bot. Cent. 274, 1893. 
 29 C. Bak. 5: 33, 1899. 
 
 27 Appel, 0. Arb. aus. Biol. Abt. Kaisel Gesundtheilamt 3: 364, 1903. 
 
 28 Smith, E. F., Sc. 31: 748, 1910. 
 
 29 Brizi, U., Atte. Cong. Nat. Ital. Milan, 1907. 
 '0 Smith, R. G., Proc. Lin. Soc. N. S. Wales 29: 449. 
 
 31 Halsted, B. D., N. J. R. 12. 
 
 32 Halsted, B. D., N. J. R. J^: 267, 1891. 
 
 33 Halsted, B. D., Miss. B. 19: 1892. 
 
 34 Burrill, T. J., Proc. 11th Ann. Meeting Soc. Prom. Agr. Sci. 21, 1890. 
 
 35 Ibid. 29, 1891. 
 
 36 Smith, E. F., V. P. P. 12: 109, 1896. 
 
 37 Smith, E. F., Proc. A. A. A. S. 191, 1895. 
 
 38 Stevens, F. L., Press Bull. N. C. 11: Aug. 1903. 
 
BIBLIOGRAPHY OF INTRODUCTION 57 
 
 "9 Stevens, F. L. and Sackett, W. G., N. C. B. 188: 1903. 
 i« Smith, E. F., B. P. I. 141, Pt. II, 1909. 
 '" Delacroix, G., C. R. 133: 417, 1030, 1901. 
 1^2 Kramer, E., Oest. land. Cent. 1: 11, 1891. 
 1" Harrison, C. Bak. 17: 34, 1907. 
 '^^ Burrill, T. J., Proc. Am. Soc. Mic. 1888. 
 i« Kellerman, W. A. and Swingle, Kan. R. 1: 1888. 
 i^" Aderhold and Ruhland, Arb. d. Kais. Biol. Anst f. Land. u. Forst. 
 5: 1907. 
 
 1" van Hall, C. J. J. C. Bak. 9: 642. 
 
 i« Delacroix, C. R. 37: 871, 1903. 
 
 i« Smith, E. F., Bot. Gaz. 18: 339, 1893. '' 
 
 15" Smith, E. F., C. Bak. 1: 364, 1895. 
 
 1^' Macchiati, L., Rev. inter d. Vit. et D'Oenol. 1: 129, 1894. 
 
 152 van Hall, C. J. J. C. Bak. 9: 642, 1902. 
 
 153 Burrill, T. J., Billings, the corn stalk disease in cattle investigation 
 3: 163, 1889. 
 
 15" Burrill, T. J., 111. B. 6: 1889. 
 
 1" Sta. Sperim Agr. Itat. 30: 482, 1897, also Zeit. 8: 37. 
 
 156 Stone, G. E., and Smith, R. E., R. Mass. (Hatch) 12: 57, 1900. 
 
 1" Stone, G. E., and Monahan, N. F., R. Mass. Sta. 19: 164, 1907. 
 
 158 Galloway, B. T., J. Myc. 6: 114. 
 
 159 Stewart, F. C., N. Y. (Geneva) B. 164, 1889. 
 i"" Halsted, B. D., N. J. R. 11: 1890. 
 
 "1 Stone, G. E., and Monahan, N. F., R. Mass. Sta. 19: 161, 1907. 
 
 i«- Rathay, E., Sitz, K. A. K. Wiss. Wien 597, 1899. 
 
 i«3 Jones, L. R., Vt. R. 6: 1892. 
 
 1" Fawcett, H. S., Fla. R. 1908, 80. 
 
 105 Detmers, 0., B. 4: 1891. 
 
 196 Voligno, P., Zeit. 11: 150. 
 
 1" Stone & Smith, Mass. R. 1896. 
 
 188 Smith, R. E., Mass. R. 9: 59, 1897. 
 
 189 Cavara, Sta. Spm. Agr. ital. 30: 482, 1897. 
 1'" Peglion, Zeit. 7: 81, 1897. 
 
 1" Halsted, B. D., N. J. R. 430, 1893. 
 
 1" Spieckermann, Land. Jahr. 31: 155, 1902. 
 
 1" Prillieux, B. Soc. Bot. d. France 33: 600, 1896. 
 
 "■• Earle, F. S., Ala. B. 108: 19, 1896. 
 
 1" Prillieux, E. & Delacroix, G., C. R. 118: 668, 1894. 
 
 1" Cavara, B. Soc. Bot. Ital. 241, 1898. 
 
 1" Tubeuf, Nat. Zeit. Forst und Land. 9: 25, 1911. 
 
58 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 "8 Jour. Bd. Agr. London, 17: 478. 
 "9 Noack, F., Zeit. 3: 191, 1893. 
 i8"Lindau, Zeit. J^: I, 1894. 
 
 181 Halsted, B. D., N. J. R. 11: 351, 1890. 
 
 182 Woods, A. F., Sc. 18: 537, 1903. 
 
 183 Rorer, J. B., Proc. Agr. Soc. Trinidad and Tol^ago, 10: No. 4. 
 18^ Honing, J. A., Med. Deli. Medan 5: 24. 
 
 185 Comes, O. Atti. d. R. Inst. d'Incor. d. Napolo, 4; 6, 1893. 
 
 186 Potter, Card. Chron. Mch. 6, 145, 1909. 
 
 187 Schwartz, E. J., Ann. Bot. 25: 791, 1911. 
 
 188 Nemec B., Ber. d. deut. Bot. Gez. 29: 48, 1911. 
 
 189 Johnston, J. R,, Phytop. /.- 97, 1911. 
 
 ISO Pavarino, G. L., Atti R. Acad. Lincei CI. Sci. Fis. Mat. e. Nat. 
 5.- 355, 1911. 
 
 1" Boyer & Lambert, C. R. 128: 342, 1893. 
 
 i92Pavarino, L., Riv. d. Pat. Veg. 5: 65, 1911. 
 
 193 Halsted, B. D., N. J. B. Q., also R. 1891, 558. 
 
 19^ Cavara, B. Soc. Bot. Ital. 241, 1898. 
 
 196 Stevens, F. L., N. C. R. 31: 74, 1908. 
 
 i96Hori, S., C. Bak. 31: 85, 1911. 
 
 i97Hori, S., B. Imp. Cent. Ag. Ex. Sta. Nishigahara, 1910. 
 
 i^^Idem., 11, 1911. 
 
 199 Marchand, E. F. L., C. R., heb. d. scans, d. I'ac. d. Sc. 150: 1348. 
 
 200 Stewart, F. C, N. Y. (Geneva) R. U: 525, 1895. 
 
 201 Kirk, N. Zeal. R. 13: 427. 
 
 202 Jones, L. R., Vt. B. 66: 1898. 
 
 203 Halsted, B. D., N. J. R. 306, 1896. 
 
 204 McCulloch, L., B. P. I. 225: 1911. 
 
 205 Orton, W. A., Farm B. 41: 309, 1907. 
 
 206 Uyeda, Y., C. Bak. 17: 383, see also extensive Japanese publica- 
 tion later by Uyeda. 
 
 20'Sackett W. G., Col. B. 177: 1911. 
 
 208 Bull. No. 2, 1896, p. 76, Torr. Bot. CI. 
 
 209 Jour. Am. Pub. H. Assn., Jan. 1898: 60; Recommendation for the 
 study of Bacteria. See also Rept. Soc. Am. Bact. Meeting of 1907. 
 
 210 Pavarino, L., Rend. d. r. Ac. d. Lincei, Classe Scienze, 20: 161, 1911. 
 
DIVISION III 
 
 EUMYCETES. TRUE FUNGI (p. 3) 
 
 1-17. 19. 22. 23. 29. 45-63 
 
 The Vegetative Body is devoid of chlorophyll and typically 
 consists of a more or less branched filament of apical growth, the 
 mycelium. This mycelium may be cut into cells by partitions 
 (septa) or may be continuous, i. e., without septa. The cells of 
 the septate mycelium do not differ essentially from typical plant 
 cells except in the absence of chlorophyll. They consist of masses 
 of protoplasm, the protoplasts, bearing vacuoles and are more or 
 
 less rich in oils, acids, 
 
 gums, alkaloids, sug- 
 ars, resins, coloring 
 matter, etc., varying 
 in amount and kind 
 with the particular 
 species and condition 
 of the fungus. The 
 protoplast is covered 
 by a cell wall which 
 consists of cellulose 
 though often of a 
 special quality known 
 as fungous cellulose. 
 The protoplast bears 
 one or in some fungi 
 two or more nuclei. 
 The vacuolation of the protoplasm, the mode of branching of the 
 cells, their color, dimensions, etc., are in some cases quite charac- 
 teristic. 
 
 In one class, the Phycomycetes, the active vegetative mycelium 
 possesses no septa except such as serve to cut off the sexual or 
 other reproductive organs or such as are found in senility. The 
 
 59 
 
 Fig. 35.- 
 
 -Showing a septate mycelium within host 
 cells. After Stevens and Hall. 
 
60 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 protoplasm is therefore continuous throughout the whole plant 
 body and may be regarded as constituting one cell though it may 
 be of great extent and bear very numerous nuclei. Such multi- 
 nucleate cells, coenocytes, may be regarded as cell complexes with 
 the walls omitted. 
 
 In one comparatively small order, the Chytridiales, there is 
 often no filamentous mycelium and the vegetative body consists 
 merely of a globular, irregularly spherical or amoeboid cell. Such 
 forms are thought by some mycologists to be degenerate, to have 
 in remote time possessed a mycelium which has been lost owing to 
 the present simple mode of life of the fungus, the needs of which 
 no longer call for a filamentous body, while others ^ find here 
 primitive forms of Phycomycetes, and trace their phylogenetic 
 connection with the higher orders of the class. 
 Reproduction. 
 
 Vegetative. Most mycelia, if cut in bits and placed in suitable 
 environment, continue to grow, soon equaling the parent mycelium 
 in size if abundant nourishment obtains. Bits 
 of diseased tissue, bearing mycelium, thus con- 
 stitute ready means of multiplication and dis- 
 persal. 
 
 Asexual Spores. A spore is a special cell set 
 aside to reproduce the plant. An asexual spore 
 is a spore not produced by a sexual process. 
 Manifold forms of asexual spores exist among 
 the fungi. In some of the simplest cases, bud- 
 like out-growths (gemmae) appear on the myce- 
 lium; or portions of the mycelium itself are cut 
 off by partitions and the protoplasm inside 
 gathers into a mass and protects itself by a 
 firmer wall than that of the mycelium, chla- 
 mydospores. In other cases special branches, 
 Fig. 36.— One form hyphas, are Set apart for the purpose of bearing 
 Oidium. After spores. If the spores are cut off from the tip of 
 Biolotti. ^j^g branch they are known as conidia or conidio- 
 
 spores, and the branch bearing them is a conidiophore. Conidia 
 may be borne singly or in false clusters caused by the youngest 
 pushing the older conidia aside; frequently they are produced in 
 
THE FUxXGI WHICH CAUSE PLANT DISEASE 61 
 
 chains, catenulate, Fig. 36, owing to tiie development of one spore 
 below another before the elder spore is shed. Conidia may be 
 either simple, composed of one cell, or compound, composed of two 
 or more cells. In compound spores each cell is at least potentially 
 a spore and can germinate under favorable conditions and per- 
 petuate the species. In many compound spores the germinating 
 function is sacrificed by one or more of their component cells. 
 
 Conidiophores may consist of loosely branching, rather long 
 hyphse, or they may be short, innate, and in close clusters forming 
 distinct spore bearing 
 spots. Fig. 371. Such 
 sporiferous spots when 
 naked are called acer- 
 vuli. Often the conid- 
 iophores are roofed over 
 with a net-work of 
 woven fungous threads 
 thus constituting a 
 special spore-bearing 
 structure, the pycnidium. 
 Figs. 37, 335. Conidio- 
 phores may be solitary 
 or grow together in bun- 
 dles or branch loosely as 
 in Fig. 383. 
 
 The basidium, Fig. 38, 
 is a special kind of sporo- 
 
 phore bearing at its Fig. 37. — Conidia borne in a pycnidium. After 
 „ p Quaintance and Shear. 
 
 apex usually tour, or 
 
 two, small projections, sterigmata, each of which produces one 
 
 spore, for distinction called a basidiospore. 
 
 Some fungi bear the spores loose inside of the swollen tips of 
 sporophores as in Fig. 68. The spore bearing structure is then 
 called a sporangium and its stalk a sporangiophore. The ascus 
 is another spore bearing structure. In it the spores are borne very 
 much as they are in the sporangium but usually of definite num- 
 ber, 1, 2, 4, 8, 16, etc., eight being the most common number. 
 Asci may be naked or covered, scattered or collected in groups. 
 
62 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 When covered, the chamber in which they are borne is called a 
 perithecium, Fig. 39; when on an open disk the disk is called an 
 apothecium, Fig. 101. 
 
 According to their length of life spores are classed as: 1. rest- 
 ing spores whose function is to tide over unfavorable conditions, 
 
 ^ hence the common name 
 ^^^^f^ "winter spore," and 
 
 in contradistinction: 2. 
 "Summer spores" which 
 are produced in abun- 
 dance in warm weather, 
 germinate immediately, 
 and can ordinarily live 
 but a short time. 
 
 In some species the 
 spores that are to func- 
 tion in water possess cilia, 
 and the power of motion. 
 These are zoospores or 
 swarm spores, Fig. 44. 
 At sporing time many kinds of fungi produce special structures 
 for the bearing of spores. The fungous threads interweave to 
 form a firm, or even a densely solid, mass and constitute a false 
 parenchyma. Such are the stalks and caps of the mushrooms and 
 of the shelving toadstools, the skin of the puff ball, etc. A cross 
 section of such a structure appears much as a true parenchyma, a 
 longitudinal section shows it to be merely a mass of interwoven 
 fungous threads. 
 
 Sexual Spores are formed by the union of sexual elements, 
 gametes. They are most conspicuous among the Oomycetes 
 where the antheridium carries the sperms into the oogonium, 
 fertilizes the obsphere and produces an oospore. Figs. 53-55. 
 
 As a rule the sexual spores are produced toward the end of the 
 vegetative period of the fungus. The asexual spores are produced 
 earlier and for a longer period. Sexual spores are commonly 
 resting spores. 
 
 Germination of spores. Under suitable environment mature 
 spores germinate and eventually give rise to vegetative bodies 
 
 Fig. 38.— Basidia of various ages. After Schenck. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 63 
 
 similar to that of the parent. The most usual mode is for the 
 mycelium to rise directly from the spore. In other instances the 
 spores produce zoospores which migrate, come to rest, then develop 
 a mycelium. In still other cases a short mycelium, promycelium, 
 is formed and from this small conidia, sporidia, are made. 
 Figs, 217, 240. These conidia give direct rise to the mycelium. 
 Spores of some species may by gemmation lead a more or less 
 prolonged existence without return to the mycelial stage. 
 
 Heat and Moisture Relation. Like all living things these 
 organisms cannot develop without heat and moisture. The 
 necessary degree of each varies with different species. Some 
 
 ascospore 
 
 germinafion 
 
 Fig. 39. — A porithecium with asci. After Reddick. 
 
 species are strictly aquatic, and must be surrounded with water; 
 others can grow in comparatively dry situations. Generally 
 speaking, however, dampness favors fungous development, and 
 the growth of most fungi is more vigorous in a damp atmosphere 
 than in a drier one. Similarly moderate warmth, as that of summer 
 heat, favors fungous growth. Humidity and warmth combined 
 are proverbial as producers of mold and mildew. So conspicuous 
 is the coincidence of these conditions with fungous growth, that 
 in the minds of many a warm damp air is the cause rather than the 
 condition of fungous development. 
 
 Respiration with the fungi as with other plants and animals 
 consists in oxidation, involving intake and consumption of oxygen 
 accompanied by the giving off of carbon dioxide and water, and 
 
64 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 since no photosynthesis occurs, this process is never masked as it 
 is in the case of the chlorophyll-bearing plants. 
 
 In nutrition requirements there is great diversity; but in all 
 cases carbon must be taken from some organic source. Starch, 
 sugar, cellulose and kindred compounds are frequent sources of 
 the carbon food supply. Nitrogenous foods are, generally speaking, 
 not required in such abundance by the Eumycetes as by the 
 bacteria and advantage may frequently be taken of this fact in 
 isolating the fungi from bacteria by growing them on media poor 
 in nitrogen, in which case the fungi often outgrow the bacteria. 
 
 The color of the fungi is determined largely by the constitution 
 of the media upon which they grow.-' ^' "*' ^ 
 
 Many fungi exhibit a peculiar heteroecism, that is, part of their 
 life cycle is passed through upon one host, part of it upon another 
 host, even of very distant botanical kinship. Thus among the 
 rusts; in one instance part of the life cycle is upon the apple, the 
 remainder upon the cedar tree. Fungi also exhibit polymor- 
 phism, i. e., in one stage they exhibit one spore form and in an- 
 other stage another spore form totally different. In this way 
 several apparently quite distinct types of spores and sporiferous 
 structures may belong to the same species. 
 
 Classification of Fungi.®' ''' ^^' "' ^^' ^^ The true fungi in them- 
 selves constitute a very large group made up of diverse forms, many 
 of which are as yet little known. Any satisfactory system of classi- 
 fication is impossible until much more knowledge is gotten regard- 
 ing their morphology, cytology, life histories and especially their re- 
 lations to their hosts. According to present knowledge they com- 
 prise very numerous species distributed in three classes as follows : 
 
 Key to Classes of Eumycetes 
 Mycelium continuous in vegetative 
 
 stage Class 1 . Phy corny cetes, p. 65. 
 
 Mycelium septate 
 
 Spores in asci Class 2. Ascomycetes, p. 113. 
 
 Spores on basidia* Class 3. Basidiomycetes, p. 298. 
 
 Not as above; spores on conidio- 
 phores, naked, or in pycnidia; 
 
 or spores quite unknown Fungi Imperfecti, p. 475. 
 
 * In the rusts and smuts the promyceUum is regarded as a basidium. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 65 
 
 Class I. Phycomycetes, Alga-like Fungi (p. 64) 
 
 The Phycomycetes are characterized by the absence of septa in 
 the mycelium except in sporing branches, where they occur to 
 cut off the spore-bearing cells or the gametangia, and in old fila- 
 ments. The body is multi-nucleate and sexual spores as well as 
 asexual ones are usually, though not always, produced. Some of 
 the Phycomycetes live in water and possess zoospores, others are 
 parasitic on land plants and bear conidia or sporangia. These 
 may germinate either by germ tubes or by zoospores. The char- 
 acteristic fertilization consists of a union of two gametes which 
 may be like in character (isogamy) or unlike (heterogamy). If 
 the sexual organs are unlike the receptacle which bears the sexual 
 spores is called the oogonium, its eggs before fertilization oospheres, 
 and the spores oospores. The receptacle bearing the fertiliz- 
 ing gamete is the antheridium, and the fertilizing elements 
 are the sperms. The sperms may be motile and swim or creep 
 into the oogonium or the antheridium may develop a tube leading 
 into the oogonium through which the fertilizing nuclei pass. In 
 some forms which, by their sexual or asexual spores, show relation 
 to the Phycomycetes the mycelium is wanting and the vegetative 
 body is reduced to a single spherical or amoeboid cell, which fre- 
 quently lives in a purely parasitic manner entirely imbedded in 
 the protoplasts of its host. This mode of life constitutes the 
 strictest kind of parasitism inasmuch as the fungus derives its 
 nourishment from the still living host cell. 
 
 Key to Orders of Phycomycetes 
 
 Sexual spores when present heteroga- 
 
 mous Subclass I. Obmycetes, p. 66. 
 
 Conidia absent; sexual spores and zoo- 
 sporangia only 
 Mycelium poorly developed, frequently 
 reduced to a single cell 
 Fruiting mycelium a single cell, or a 
 group of cells in a sorus, forming 
 either asexual resting spores or 
 sporangia from the entire proto- 
 plasmic mass 1. Chytridiales, p. 66. 
 
66 THE FUNGI WHICH CAUSE PLAxNT DISEASE 
 
 Fruiting mycelium multicellular, 
 some cells forming sporangia, 
 others producing gametes and 
 
 oospores 2. Ancylistidiales. 
 
 Mycelium well developed 
 Fertilization by motile sperms. ... 3. Monoblepharidiales. 
 Fertilization through an anther- 
 
 idial tube 4. Saprolegniales, p. 74. 
 
 Conidia present 5. Peronosporales, p. 77. 
 
 Sexual spores isogamous, formed by the 
 
 union of similar gametes . .Subclass II. Zygomycetes, p. 101. 
 Asexual spores several, in sporangia ... 6. Mucorales, p. 102. 
 Asexual spores solitary, conidia 7. Entomophthorales,p. 107. 
 
 Of these orders the Ancylistidiales which are parasitic upon 
 Algae, and the Monoblepharidiales which are saprophytic will not 
 be considered further. 
 
 Subclass Oomycetes (p. 65) 
 
 In the Oomycetes there is pronounced difference between the 
 male and female sexual organs. The oogonium is comparatively 
 large, and contains one or more large passive eggs (oospheres), 
 which are fertilized by sperms, differentiated or not, which either 
 swim to the oogonium by cilia, creep to it, or are carried to it by 
 a fertilizing tube. Oospores are in some species produced fre- 
 quently and abundantly while in others they are entirely unknown. 
 The asexual reproduction is by either conidia or sporangia. 
 
 Chytridiales (p. 65) 
 
 The members of this order are the simplest of any of the Phy- 
 comycetes. Many of them are single, more or less globose, undif- 
 ferentiated cells, others have a more or less prominent haustoria- 
 like mycelium, while but few have any approach to a true myce- 
 lial development. Most are intracellular parasites; a few of the 
 more highly developed genera are intercellular parasites. With 
 few exceptions reproduction is entirely asexual, all spores being 
 formed directly from the vegetative cell. Zoosporangia and thick- 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 67 
 
 walled resting spores are produced. The zoospores have either 
 one or two cilia. There are over forty genera and two hundred 
 species. The majority of the species are inconspicuous parasites 
 of algse and infusoria; but some genera, like Synchytrium and 
 Urophlyctis, produce conspicuous sori and even cause hyper- 
 trophy of land plants. 
 
 Key to Families of Chytridiales 
 
 Spores all asexual, or rarely formed by the 
 union of free-swimming gametes 
 Mycelium none 
 
 Sporangia solitary 1. Olpidiaceae, jx 67. 
 
 Sporangia grouped into sori 2. Synchytriaceae, \). 69. 
 
 Mycelium present 
 
 Mycelium of delicate, evanescent haus- 
 toria-like strands 
 Mycelium limited, sporangia ter- 
 minal 3. Rhizidiaceae. 
 
 Mycelium extended, sporangia ter- 
 minal or intercalary 4. Cladochytriaceae, p. 72. 
 
 Mycelium of permanent hyphse 5. Hypochytriaceae. 
 
 Spores both sexual and asexual 
 
 Gametes hetrogamous 6. Oochytriaceae, p. 73. 
 
 Gametes isogamous 7. Zygochytriaceae. 
 
 Four only of these families have parasitic representatives on 
 higher plants in America, the others being chiefly parasitic on 
 algae and infusoria. 
 
 Olpidiaceae 
 
 This family which contains the simplest members of the order 
 has no mycelium; the entire plant body consists of a single more 
 or less globular or elliptic cell which never divides, but at maturity 
 forms either a zoosporangium or an asexual resting spore which 
 after a period of rest gives rise to swarm spores. All the species 
 are endobiotic. The family contains some forty species but few 
 of which are of economic importance. 
 
68 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Key to Genera of Olpidiaceae 
 
 Vegetative body amoeboid 
 
 Vegetative body of definite form 
 Sporangia free in the cells of the host 
 Sporangial membrane very delicate, 
 
 evanescent 
 
 Sporangial membrane firm, swarm 
 spores escaping by a definite open- 
 ing 
 Sporangium globular or eUipsoid 
 Sporangium with only one or two 
 openings 
 Swarm spores uniciliate 
 Vegetative cells globose or sub- 
 globose 
 Vegetative cells stellate 
 Swarm spores biciliate 
 Sporangium with several openings 
 
 Sporangium elongate 
 
 Sporangial membrane vmited to the wall of 
 the host cell 
 
 1. Reessia. 
 
 2. Sphaerita. 
 
 3. Olpidium, p. 68. 
 
 4. Asterocystis, p. 69. 
 
 5. Olpidiopsis. 
 
 6. Pleotrachelus. 
 
 7. Ectrogella. 
 
 8. Pleolpidium. 
 
 Olpidium A Braun 
 
 In this genus a single swarm spore invades the cell of the host 
 
 and develops in its pro- 
 toplasm. Later a cell 
 wall forms and the vege- 
 tative body changes into 
 a zoosporangium which 
 develops a neck. This 
 reaches to the outside 
 of the host even though 
 the fungus be developed 
 several cells below the 
 surface. The uniciliate 
 zoospores pass out 
 through this neck to 
 Thick-walled resting spores are also formed. 
 
 Fig. 40. — O. brassicoe; right, three sporangia in 
 a cell; left, resting spores. After Woronin. 
 
 make their escape. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 69 
 
 There are some twenty-five species most of which five as para- 
 sites on alga?, worms, pollen grains, etc. 
 
 O. brassicae (Wor.) Dang.^ is parasitic on quite young cabbage 
 seedlings, sometimes infecting cells deeply seated in the host. 
 The same or a nearly related species also attacks tobacco and 
 several weeds. 
 
 Sporangia solitary or several in each infected host cell, globular ; 
 zoospores numerous, globose, uniciliate; resting spores globose, 
 with a wrinkled epispore which gives them more or less of a star- 
 like appearance. Fig. 40. 
 
 Asterocystis de Wildeman (p. 68) 
 
 There is a single species, A. radicis d. Wild.^ which differs from 
 Olpidium in its stellate vegetative cell and the absence of the tube 
 for the escape of the zoospores, this being accomplished by the 
 breaking away of the tissues of the host. The fungus attacks the 
 roots of various plants, notably flax, Brassica and other crucifers, 
 Plantago, Veronica and numerous grasses, producing chlorosis. 
 It has not been reported from America. 
 
 A Chytridiaceous fungus of unknown genus thought to stand 
 near the Olpidiacese and Synchytriacese has been described by 
 Home ^ as the cause of an Irish potato disease. 
 
 Synchytriaceae (p. 67) 
 
 The infecting zoospore invades the host cell and becomes 
 parasitic upon the still living protoplasm. Hypertrophy of this and 
 adjacent host cells is usually induced, resulting in the formation of 
 a small gall around the infected cell. This gall is often colored 
 and bears a superficial resemblance to a rust sorus. The parasite 
 enlarges until it occupies nearly the whole of the host cell. In 
 Synchytrium the one nucleus then enlarges and divides to produce 
 very numerous nuclei. ^' ^°' ^^' ^- The whole mass then divides 
 into segments regarded as sporangia, and each sporangium divides 
 into numerous uninucleate parts, each of which develops into a 
 zoospore. In some species development is arrested before the 
 division of the primary nucleus and the protoplast becomes 
 spherical, invests itself with a thick wall and becomes a resting 
 
70 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 spore. (Fig. 42.) After a more or less protracted period of rest 
 this produces zoospores. 
 
 The family includes some fifty species, all of which, except two 
 small genera, are parasitic upon land plants. 
 
 Key to Genera of Synchytriaceae 
 
 Zoosporangia formed by direct division of 
 
 the entire plasma of the young fruiting 
 
 body. 
 
 Swarm sporangia completely filling the 
 
 host cell, membrane united to the 
 
 wall of the host cell 1. Rozella. 
 
 Swarm sporangia lying free in the host cell 
 
 Parasitic on algae 2. Woronina. 
 
 Parasitic on land plants 3. Woroniella. 
 
 Zoosporangia formed by division of an ini- 
 tial cell to forma sorus of sporangial cells. 
 Sporangia formed directly from the full- 
 grown plant body 4. Synchytrium, p. 70. 
 
 Sporangia formed by the division of a thin- 
 walled mother cell after its escape 
 from the plant body 5. Pycnochytrium, p. 72. 
 
 Synchytrium de Bary & Woronin 
 Upon reaching maturity the plant body develops directly into 
 a sporangial sorus. Both zoosporangia and winter spores present. 
 
 I'lG. 41. — Showing nucleus in Synchytrium. After Stevens. 
 
 S. endobioticum (Schilb.) Perc, the cause of a very serious wart 
 disease of the potato, was originally described as Chrysophlyctis 
 endobioticum by Schilberszky ^^ and transferred to Synchytrium 
 by Percival.^^ It invaded America about 1909.^^^ It was reported 
 from Africa by Zimmermann.^^ 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 71 
 
 A B 
 
 Fig. 42. — A, section showing sporangia or 
 sporocysts; B, zoospores, ciliated and 
 amoeboid. After Percival. 
 
 In summer the resting spores which average about 52 fi in diam- 
 eter are found in abundance in the host cells near the surface, few 
 
 in the outer layer, more below 
 down to the sixth or eighth 
 row of cells. Each resting 
 spore contains several hun- 
 dred roundish zoospores which 
 measure 2-2.5 ^i. In spring 
 the resting spores germinate, 
 freeing numerous pear-shaped 
 uniciliate zoospores, which at 
 first swim with a jerky motion 
 but soon become amoeboid. 
 The summer sporangia may 
 germinate without protracted 
 rest, and also give rise to zoospores. Another type of sporangium 
 consists of thin sacs, produced singly or two to five in a sorus, 
 each bearing numerous zoospores somewhat smaller than those 
 from the first type of sporangia. 
 
 The zoospores, says Percival, enter the potato apparently in 
 the amoeboid state in bud tissue of rhizomes and in the "eyes" of 
 young tubers. Usually only one zoospore enters each cell but 
 occasionally more may do so. Crushed sporangia produced 
 characteristic warts in three to four days when placed on suscep- 
 tible parts. Successful inoculations were also made by Salmon and 
 Crompton.^® The cytology has been studied by Percival. ^^ The 
 full grown tumors vary in size from that of a 
 pea to a hen's egg, and represent metamor- 
 phosed branch systems. 
 
 S. vaccinii Thomas ^^"^^ is the cause of a 
 disease of the cranberry and related hosts. It 
 forms numerous, small, reddish galls in which, 
 deeply embedded, are the sori. 
 
 S. papillatum Farl."° occurs on Alfilaria in 
 California. 
 
 Other species of Synchytrium are found upon 
 dandelion, ffinothera, Geranium, Amphicarpa, Ornithogalum, clo- 
 ver, elm, etc., but as yet are not of economic importance in America. 
 
 Fig. 43.— GaU of S. 
 vaccinii. After 
 Shear. 
 
72 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Pycnochytrium Schroter (p. 70) 
 
 Only resting spores are known. In germination their proto- 
 plasmic contents emerges and forms a sporangial sorus. 
 
 P. anemones (D. C.) Schr. is common on various species of 
 Anemone; P. globosum (Schr.) Schr. on the violet, blackberry, 
 maple, etc. None of the species are of any considerable economic 
 importance. 
 
 Cladochytriaceae (p. 67) 
 
 A branching mycelium runs through or between the cells of 
 the host drawing nourishment from many cells. Sporangia are 
 either apical or intercalary and contain uniciliate zoospores. 
 Resting spores are also produced. There are about a half dozen 
 genera and some thirty species. 
 
 Key to Genera of Cladochytriaceae 
 
 Resting spores only known 1. Physoderma. 
 
 Swarm spores only known 
 Intracellular and endo])hytic 
 
 Swarm spores at first ciliate, becoming 
 
 amoeboid 2. Cladochytrium, p. 72. 
 
 Swarm spores not becoming amoeboid 3. Pyroctonium, p. 73. 
 Living free among the hosts 
 
 Sporangia opening by a pore 4. Amcebochytrium. 
 
 Sporangia opening by a lid 5. Nowakowskiella. 
 
 Cladochytrium Nowakowski-^ 
 
 The genus contains about ten species of intercellular parasites 
 with branched mycelial threads. The zoosporangium is globose, 
 and opens by a distinct mouth which develops a tube for the 
 escape of the zoospores much as does Olpidium. Resting spores 
 are not known. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 73 
 
 The most important species are C. tenue Nowak. on Acorus 
 and Iris; C. graminis Busg. on various grasses, C. violae Berlese 
 on violets.-" 
 
 C. viticulum Pru.^ and C. mori Pru.^^ have been described on 
 grape and mulberry _, but further study is very desirable. 
 
 C. brassicae E. & B.'-"" is described from dead leaves of cab- 
 bage. 
 
 C. csespitis G. & M.-^ occurs in France on Lolium. 
 
 Pyroctonium sphaericum Pru.-^ was reported in 1894 as the 
 cause of wheat disease in France but has not since been 
 found. 
 
 Odchytriaceae (p. 67) 
 
 The plant body is either an undifferentiated cell or a well de- 
 veloped mycelium; reproduction by means of asexual swarm 
 spores and sexual resting spores. Of the three genera only one 
 is of economic importance. 
 
 Key to Genera of Oochytriaceae 
 
 Mycelium entirely lacking 1. Diplophysa. 
 
 Mycelium present 
 
 Mycelium producing a single gametan- 
 
 gium 2. Polyphagus. 
 
 Mycelium producing several gametangia 3. Urophlyctis, p. 73. 
 
 Urophlyctis Schroter 
 
 Mycelium endophytic, producing zoosporangia on the surface 
 of the host and thick- walled oospores within the tissues; zoospores 
 uniciliate. The genus contains some half dozen species all of 
 which are parasitic on higher plants. 
 
 U. leperoides (Sacc. & Trab.) Magnus -^' -^ causes "beet root 
 tumor," in North Africa and Western Europe. The rootlets of 
 the upper portion of the root are attacked and develop tumorous 
 growths, sometimes as large as a walnut. The infection is super- 
 
74 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 ficial and does not extend to the fleshy tap root. The develop- 
 ment of the spores is the typical method for the genus, the an- 
 theridium persisting at the base of the oogonium and retaining its 
 hyphal connection, while the oogonium becomes free just before 
 
 conjugation. The oospores are 
 subglobose, depressed on one side, 
 smooth, brown, 45-50 x 30 /i. 
 
 U. pulposa (Wallr.) Schr., a 
 closely related species occurs on 
 the aerial portions of Chenopo- 
 dium and Atriplex. 
 
 U. alfalfse Mag.^"' '^'^ ''^' '''' ^^^ 
 causes a crown gall of alfalfa in 
 America and Europe. The dis- 
 ease is quite similar to that de- 
 
 FiG. 44.— Urophlyctis pulposa. a, zoo- scribed abovc for the beet. 
 
 sporangium; h, zoospores; c, oospore 
 formation ; d, mature oospores. After 
 Schroter. 
 
 U. trifolii (Pass.), Mag., a 
 closely related species, forms 
 small, glassy, globose pustules on the leaves and petioles of 
 various species of clover in Europe. 
 
 U. hemispherica (Speg.) Syd.^^ in South America, U. krieger- 
 iana Mag.^^ in Europe and U. pluriannulata (B. & C.) Farl.^'^ 
 in America form Synchytrium-like galls on various umbelliferous 
 genera. All may belong to the same species. U. major Schr. and 
 U. rubsaameri Mag. infect respectively the leaves and the roots of 
 Rumex. 
 
 Saprolegniales (p. 66) 
 
 Asexual reproduction is mainly by biciliated spores formed in 
 large numbers in sporangia of various shapes. Sexual spores, 
 often apogamous, are produced in most genera, much after the 
 fashion of those of the Peronosporales except that more than one 
 oospore is frequently formed in one oogonium. ^^^ 
 
 The order consists of fifty or more species, mostly parasites 
 or saprophytes upon aquatic organisms. One species of the genus 
 Achlya causes serious disease in young fish. 
 
 There are three families: 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 75 
 
 Key to Families of Saprolegniales 
 
 Vegetative mycelium of tiiick tubular hy- 
 phse; aquatic; zoosporangia cylindrical 
 not much thicker than the mycelium 
 
 Filaments uniform, not constricted 1. Saprolegniaceae. 
 
 Filaments constricted regularly 2. Leptomitaceae. 
 
 Vegetative mycelium of thin hyphse, mostly 
 parasitic or saprophytic on plant tis- 
 sues; zoosporangia much broader than 
 the mycelium, mostly globular 3. Pythiaceae, p. 75. 
 
 Dictyuchus Leitgeb. 
 
 This genus of the Saprolegniaceae contains the only parasite 
 genus in the first two families. 
 
 Sporangia cylindric or clavate, swarm-spores becoming walled 
 within the sporangium and emerging singly through its lateral 
 walls. The genus is usually saprophytic but, D. monosporus 
 Leit. is said by Halsted to be a serious hyacinth enemy. ^^^ 
 
 The other members are mainly on dead or diseased insects or 
 other animals that are in water or are on diseased algse or in water- 
 slime. 
 
 Pythiaceae ^^^ 
 
 This family shows affinity with both the Peronosporales and 
 the Saprolegniales and is sometimes classed with the one, some- 
 times with the other. It consists of three genera and about twenty 
 species characterized by a mycelium of very delicate hyphse which 
 show no differentiation into sterile and fertile regions. The 
 species are either aquatic or terrestial; in the latter case they are 
 soil fungi that grow to maturity upon seedlings. When of aerial 
 habit the sporangia become conidial in character, that is, they are 
 detached from the hypha before the discharge of the zoospores. 
 
 Zoosporangia elongate 1. Nematosporangium. 
 
 Zoosporangia spherical or oval, not linear 
 Zoospores formed outside of the zoospo- 
 rangia 2. Pythium, p. 76. 
 
 Zoospores formed within the zoospo- 
 rangia 3. Pythiacystis, p. 77. 
 
76 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Pythium Pringsheim ^^ (p. 75) 
 
 The mycelium is found in abundance in and about the infected 
 tissue as fine, branched continuous threads. These, in the terrestial 
 
 Fig. 45. — Cucumber seedlings. Pots 5, 6, and 8 inoculated with Pythium. Pot 7, 
 Control. After Atkinson. 
 
 species, bear conidia on branches which are of the same character 
 as the mycelium itself. The conidia germinate either by a rupture 
 
 of the wall or by the formation of a 
 beak-like process through which the 
 protoplasm is extruded, after which it 
 becomes differentiated into zoospores. 
 Gemmae, very like the conidia in ap- 
 pearance, are also produced. 
 
 The oogonia are quite like the conidia 
 and gemmae in structure but develop 
 oospores within. The oogonium is at 
 first multinucleate but as the oosphere 
 matures all of the nuclei except one 
 migrate toward the periphery, the peri- 
 plasm, or degenerate in the ooplasm, re- 
 sulting at maturity in an uninucleate egg. This is fertilized by 
 one nucleus from the antheridium. No sperm is differentiated, 
 
 Fig. 46. — Fertilization ii 
 
 thium, showing oogonium, 
 antheridium, oospore, peri- 
 plasm and the c? and Q 
 nuclei. After Miyaki. 
 
THE PTINGI WHICH CAUSE PLANT DISEASE 
 
 77 
 
 and the contents of the antheridium are carried over to the egg 
 by a fertilizing tube. Members of the 
 genus are aggressively parasitic only under 
 most favorable environmental conditions 
 of heat and moisture. 
 
 Some sixteen species are known. 
 
 P. de baryanum Hesse, is most com- 
 j^Qj^ 33-37 g^g ^Y\e cause of "Damping Off." 
 
 Zoosporangia or "conidia" globose to 
 elliptic, usually papillate, 20-25 n; gemmaj 
 similar in form and size; oospores globose, 
 hyaline, smooth, 15-18 fx. 
 
 P. intermedium de Bary, causes a 
 "damping off" of fern prothalia,^^ P. 
 gracile Schenck, a rot of ginger; ^^ P. 
 palmivorum Butler, a palm disease in India. ^''' 
 
 Fig. 47. — P. citriophora; de- 
 velopment of swarnispores 
 from sporangia. After 
 Smith and Smith. 
 
 Pithiacystis, Smith & Smith (p. 75) 
 
 The sporangiophore is delicate; septate; and bears numerous 
 sporangia sympodially. These produce many biciliate zoospores 
 
 internally. No oospores have been 
 seen. Only one species is known. 
 P. citriophora Sm. & Sm.^^' '^ 
 Parasitic on lemons, the sterile 
 mycelium inhabiting the rind; 
 spores normally formed in the soil 
 near infected fruits; sporangia ovate 
 or lemon-shaped, papillate, 20-60 x 
 
 Fig. 48.— Sporangiophores and spo- Qnqn ,, Qvprnmns- 35 X 50 u borne 
 rangia of Pythiacystis. After '^^ ^" ^' ^Veragmg OO X OU /X, uorne 
 
 Smith and Smith. sympodially; zoospores 10-16 n, 
 
 at first elongate, becoming rounded and bearing two lateral cilia. 
 
 This was first noted by Smith and Smith ^^' ^° on rotting lemons 
 in California. Infection by pure cultures proved that the fungus 
 was the true cause of the rot. 
 
 Peronosporales (p. 66) 
 
 These fungi constitute an order characterized by a richly 
 developed, branching, non-septate, usually coarse, mycelium of 
 
78 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 strictly parasitic habit. The mycelial threads in most genera 
 wander between the host cells and draw nutriment from them by 
 short branches, sucking organs (haustoria), (Fig. 49) of various 
 forms, which penetrate into the victimized cell. In one genus 
 only, Phytophthora, does the mycelium grow directly through cells. 
 Two kinds of spores are produced, sexual and asexual. The 
 sexual spores result from the union of two 
 unlike gametes, the egg (oosphere) and 
 sperm, borne respectively in the oogonium 
 and antheridium. Each oogonium bears a 
 solitary oosphere. Fertilization is accom- 
 plished by means of a tube from the anther- 
 idium and penetrating into the oogonium. 
 The sexual spores are thick walled, re- 
 
 FiG. 49. — Haustoria of a . , . . , • . 
 
 Peronospora. After sistant, and usually require a long time to 
 ^^ reach maturity. They are, therefore, often 
 
 called "resting spores." In germinating the sexual spores pro- 
 duce either germ tubes or develop directly into zoosporangia. 
 The asexual spores are conidia. They are borne on conidio- 
 phores which arise from the mycelium and which may be short 
 or long, simple or branched, subepidermal or superficial accord- 
 ing to the habit of the species. The conidia in various genera 
 germinate by three methods, (1) a germ tube is sent out by 
 the conidium, (2) the entire protoplasmic contents of the spore 
 passes outside the spore wall and then forms a germ tube, or 
 (3) the conidium by internal division breaks up into zoospores. 
 
 Key to Families of Peronosporales 
 
 Conidiophores, short, thick, subepidermal, 
 
 conidia catenulate 1. Albuginaceae, p. 78. 
 
 Conidiophores, longer, superficial, simple or 
 
 branched, conidia not catenulate 2. Peronosporaceae, p. 82. 
 
 Albuginaceae 
 
 There is a single genus. Albugo (Persoon) Roussell. This genus 
 of about fifteen species is entirely parasitic upon flowering plants. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 79 
 
 causing the "white rusts." The conidia are borne in white 
 bhster-Uke sori under the raised and finally ruptured epidermis 
 of the host. The conidiophores are short, club-shaped, arranged 
 
 Fig. 50. — Albugo. A, section through a sorus showing epidermis, conidia, 
 conidiophores and myceUum; B, conidiophores and conidia; C, myce- 
 lium and haustoria. After Bergen and Davis. 
 
 in clusters; the spores are borne in basipetal succession and 
 remain attached in rather long chains unless disturbed. 
 
 The mycelium is very fine, intercellular and penetrates the cells 
 by globular haustoria. The rudimentary oogonium is multi- 
 nucleate and filled with uniform proto- 
 plasm. As the oogonium grows older 
 the protoplasm within differentiates 
 into two parts, the inner part of dense 
 protoplasm, the oosphere, and the 
 outer part less dense, the periplasm. ^^ 
 Figs. 51, 53, 54. During this process 
 the nuclei enlarge, undergo one or two 
 mitoses, Fig. 54, and in some species 
 all the nuclei except one pass to the 
 
 periplasm. In other species the Fig. 5 1.— Multiple fertilization 
 ... . ,,. , , . , •, inA. bliti. Antheridial tube 
 
 oosphere is multmucleate at maturity. discharging sperms. After 
 
 The latter type is fertilized by nu- Stevens. 
 
 merous nuclei from the antheridium, the former by a single nu- 
 
 cleus.^^'^^' ^^ After fertilization the oosphere matures to an 
 
 oospore. 
 
80 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 The globular oospores fall into two classes; '^^ first tuber- 
 culate or ridged; second, reticulated. These are illustrated in 
 Fig. 52. 
 
 Fig. 52. — Oospores of Albugo. 1. A. oandida. 2. A. tropica. 3. A. ipomoea;- 
 panduranse. 4. A. Icpigoni. 5. A. swertiie. 6. A. tragopogonis. 7. A. bliti. 8. A. 
 platensis. 9. A. occidentalis. 10. A. portulacse. After Wilson. 
 
 The conidia in germination usually produce several ovate 
 zoospores with two unequal, lateral cilia. After a brief period of 
 motility they became walled and produced germ tubes capable of 
 infecting susceptible hosts. The oospores after a period of rest 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 81 
 
 germinate in a similar manner. Conidia germinate freely only if 
 they are chilled/" 
 
 A. Candida (Pers.) Roussel/^ Sori on all parts of the host except 
 the roots, white or rarely light-yellow, prominent and rather deep- 
 seated, variable in size and shape, often confluent and frequently 
 producing marked distortion of the host; conidiophores hyaline, 
 clavate, about 35-40 x 15-17 m; conidia, globular, hyaline, with 
 uniformly thin walls, 15-18 ix; oospores, much less common than 
 conidia, usually confined to stems and fruits, chocolate-colored. 
 
 Fig. 53. — A. bliti, young oogo- 
 nium and antheridium show- 
 ing nuclei. After Stevens. 
 
 Fig. 54.— a. bliti, 
 showing differ- 
 entiation of 
 ooplasm and 
 periplasm, the 
 nuclei in mito- 
 sis. After 
 Stevens. 
 
 Fig. 55. — A. bliti, an- 
 theridium showing 
 the multinucleate 
 tube. After Ste- 
 
 40-55 ix; epispore thick, verrucose, or with low blunt ridges 
 which are often confluent and irregularly branched. 
 
 This is the most widely distributed and most common species 
 of the genus. It occurs throughout the world on a large number 
 of cruciferous hosts, and often gives rise to very pronounced 
 hypertrophy. Practically all cultivated crucifers, cabbage, 
 radish, turnip, etc., are subject to attacks of this fungus. In 
 Europe the caper and mignonette are attacked by the same 
 species. It has been reported in New York on Tropoeolum.'*^ 
 
 A. ipomoeae-panduranaB (Schw.) Sw.^^' ^^° Sori amphigenous or 
 caulicolous, white or light yellow, prominent, superficial, 0.5- 
 20 mm., rounded, often confluent and frequently producing 
 marked distortions of the host; conidiophores hyaline, clavate. 
 
82 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 unequally curved at base, 15 x 30 /x; conidia hyaline; short- 
 cylindric, all alike or the terminal more rounded, 14-20 x 12-18 /x; 
 the membrane with an equatorial thickening, usually very pro- 
 nounced. Oosporic sori separate from the conidial, caulicolous, 
 rarely on petioles, 1-2 x 5-6 cm. or even more, causing marked 
 distortion; oospores light yellowish-brown, 25-55 (jl; epispore 
 papillate or with irregular, curved ridges. 
 
 Common throughout the world on various species of Convol- 
 vulaceae, morning glory, moon flower, sweet potato, etc., although 
 causing but little damage. 
 
 A. occidentalis G. W. W., reported by Pammel '"^ on the beet 
 has been collected but once. 
 
 A. portulaceae (D. C.) Kze. on purslane ^^ and A. bliti (Biv.) 
 Kze.^- occur on Amaranthus and related plants. 
 
 A. tragopogonis (D. C.) S. F. G.^^' ^^ Sori hypophyllous or 
 caulicolous, prominent, deep-seated, white or yellowish, pul- 
 verulent, rounded or elongate, 1-3 x 1-8 mm; conidiophores 
 hyaline, clavate, about 12-15 x 40-50 fx; conidia, 12-15 x 18-22 /x; 
 light yellow or hyaline, short-cylindric, the terminal larger and 
 less angular than the others, membrane with an equatorial thick- 
 ening; oospores produced in stems and leaves, dark brown or 
 almost black at maturity, opaque, 44-68 /x, epispore reticulate, 
 areolae 2 /x; wing bearing papillate tubercles at its angles. 
 
 A cosmopolitan species of less economic importance in America 
 than in Europe attacking a wide range of hosts of the Compositse. 
 Salsify is the chief economic host. 
 
 Peronosporaceae (p. 78) 
 
 The members of this family, producing the diseases commonly 
 known as the "downy mildews," have been long known and much 
 studied. They contain many important plant pathogens. The 
 globular oospores are in general indistinguishable from those of 
 the Aibuginaceae but the conidiophores are quite different from 
 those of that family, being aerial instead of subepidemal. In 
 most cases they are branching and tree-like, Fig. 63, but in a 
 few genera they are short. The oospore in such genera as have 
 been studied (Peronospora ^^ Sclerospora ''^) is formed as in Albugo 
 resulting when mature in an uninucleate egg surrounded by a 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 83 
 
 periplasm bearing the degenerate supernumerary nuclei. Fer- 
 tilization is as in the Albugos that have an uninucleate 
 eea; ^^' ^^' ^^' ^^ 
 
 The family has suffered many revisions of classification and 
 much renaming of genera. Plasmopara and Peronospora are 
 especially rich in a masquerade of names. ^^' ^^"'^^* 
 
 Key to Genera op Peronosporaceae 
 
 Conidiophores scorpioid-cymosely branched ; 
 
 conidia germinating by zoospores 1. Phytophthora, p. 84. 
 
 Conidiophores simple, monopodially or 
 
 dichotomously branched. 
 
 Conidiophores simple or monopodially 
 
 branched; conidia germinating by 
 
 zoospores or by a plasma 
 
 Conidiophores simple or irregularly 
 
 branched 2. Kawakamia, p. 89. 
 
 Conidiophores regularly branched 
 Conidiophores with the main a.xis 
 indurate, the lateral branches 
 
 reduced and basidia-like 3. Basidiophora, p. 89. 
 
 Conidiophores with the main 
 
 axis not indurate, the lateral 
 
 branches developed normally. 
 
 Conidiophores fugacious, stout, 
 
 sparingly branched; oospore 
 
 permanently united to the 
 
 wall of the oogonium 4. Sclerospora, p. 89. 
 
 Conidiophores persistent, slender, 
 usually freely branched; oo- 
 spore free from the wall of 
 the oogonium 
 Branches of the conidiophore 
 
 apically obtuse 5. Plasmopara, p. 90. 
 
 Branches of the conidiophore 
 
 apically acute 6. Peronoplasmopara,p.93. 
 
 Conidiophores dichotomously branched; 
 conidia germinating by a germ tube. 
 Conidiophores with subapical disk-like 
 enlargements from which the ul- 
 
84 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 timate branchlets arise radially; 
 germ tube produced from the apex 
 
 of the conidia 7. Bremia, p. 95. 
 
 Conidiophores without subapical en- 
 largements; conidia germinating 
 from the side 8. Peronospora, p. 95. 
 
 Phytophthora de Bary (p. 83) 
 
 This genus is of especial interest on account of its one exceed- 
 ingly destructive representative, P. infestans, which occupies an 
 historic position in phytopathology as one of the earliest of para- 
 sitic fungi to receive study in any way complete or adequate; 
 study moreover which did much to turn attention and interest 
 toward plant pathology. 
 
 A distinctive character is that the conidiophores have irregular 
 thickenings below the apparently lateral conidia. The conidio- 
 phore is at first simple and bears a single apical conidium, after 
 the production of which a lateral branch arises below the conidium 
 and grows on in such a way as to give the first conidium a lateral 
 appearance. This process is, in some species, repeated until a 
 large scorpioid cyme is produced. The genus 
 contains seven or eight species, all parasitic. 
 The mycelium is much branched, non-septate, 
 hyaline; the conidiophores arise singly or in 
 groups from the stomata, or break through 
 the epidermis; conidia oval, papillate; zoo- 
 spores oval, biciliate, escaping by rupture of 
 the papilla; oospores, when present, with the 
 epispore more or less ridged. 
 
 P. phaseoli Thax.^^"^^ Mycelium well de- 
 veloped, intracellular; conidiophores single or 
 in clusters from the stomata, simple or 
 branched below, apparently simple above 
 but really one to many times cymosely 
 branched; conidia oval or elliptic, papillate, 35-50 x 20-24 /x; 
 germination by about fifteen zoospores. Oogonia in the seed 
 coats or cotyledons of seeds, rarely in the pods, thin walled, 
 slightly folded; subspherical 23-28 fi; oospores spherical or 
 
 Fig. 56. — Structural de- 
 tails of P. phaseoli. 
 After Thaxter. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 85 
 
86 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 subspherical with smooth, moderately thick walls, hj^aline or 
 light yellow, 18-26 /x. It was described on lima beans in 1889. 
 The methods of infection were studied by Sturgis ^'- who showed 
 that spores are carried to the basal portion of the style and ovary 
 by visiting insects. Oospores were described and extensive arti- 
 ficial culture experiments made by Clinton ^^ who first grew the 
 fungus successfully in pure culture on corn-meal-agar, and other 
 media, on which oospores were produced in abundance. 
 
 The species is unique within the genus on account of the single 
 conidia which are borne at the apex of apparently simple conidio- 
 phores but subtended by several enlargements of the kind so 
 characteristic of the genus. 
 P. infestans (Mont.) de Bary.^^' '''- ''''^'^ 
 
 Mycelium well developed, probably perennial; conidiophores 
 single or in groups of 2-4 from the stomata; scorpiose-cymosely 
 branched; conidia 27-30 x 15-20 fj,, ovoid, germinating by about 
 six to sixteen zoospores. 
 
 On diseased solanaceous hosts, particularly the potato and 
 tomato,^^ this species is very destructive. It was first described 
 
 in 1845 as a Botrytis and 
 has since been the subject 
 of many extensive papers. 
 
 The conidiophores are 
 abundant on the lower sides 
 of infected leaves near the 
 invasion line. The myce- 
 lium migrates between the 
 cells piercing them with 
 haustoria. 
 
 The existence of oospores 
 is a much controverted 
 point; the structures re- 
 ported by Smith ^''"^'' as oospores probably belonged to some other 
 fungus. Recently Jones ^^ found peculiar thick-walled bodies, 
 somewhat resembling oospores, in undoubtedly pure cultures of 
 P. infestans. Whether they are oospores is not known. Clinton 
 has recently announced ^^ that he, in pure cultures, has obtained 
 "absolutely perfect oogonia, antheridia and even oospores." The 
 
 Fig 
 
 58. — Young and mature 
 P. phaseoli. After Clinton, 
 
 oospores 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 87 
 
 oval, flattened biciliate zoospores which emerge from the conidia, 
 swim about, come to rest, develop a wall, then produce a germ 
 tube. Direct germination by a germ tube also occurs rarely. In- 
 
 FlG. 
 
 59. — P. infestans; 1, section showing conidiophores and conidia- 
 formation; 5, germination of a conidia. After Scribner. 
 
 fection is brought about by the germ tube, either by penetrating 
 through stomata or directly through the epidermis. 
 
 The walls and contents of parasitized cells are browned. When 
 this fungus is alone on the tubers dry rot is induced, but invasion 
 of numerous saprophytic fungi and bacteria usually turns this 
 into a disagreeable wet rot. Tuber infection occurs largely from 
 
88 
 
 THE FUxNGl WHICH CAUSE PLANT DISEASE 
 
 conidia washed into the soil by rain; possibly sometimes by the 
 mycelium migrating by way of the stem. 
 
 The fungus was extensively studied by Jones in pure culture and 
 a decided difference in luxuriance of growth was observed on blocks 
 cut from different varieties of potatoes, Fig. 57. 
 
 The mode of hibernation is not thoroughly known but undoubt- 
 edly hibernation occurs in part in live mycelium in infected 
 tubers.™ The conidia are short-lived, especially when dry. 
 
 P. omnivora de Bary. Conidiophores simple or branched; 
 conidia ovoid or lemon-shaped, 50-60 or even 90 x 35-40 fx, ger- 
 minating by as many as fiftj^ zoospores; oospores smoothish or 
 wrinkled, light-brown, transparent, 24-30 /jl. This species which 
 includes forms previously described as P. cactorum (Lebert & 
 Cohn) Schr., P. fagi Hartig, and P. sempervivi Schenk is found 
 upon seedlings of some fifteen families ranging from Pinacse to the 
 higher Angiosperms. It is of considerable economic importance 
 in Europe especially in the seed beds of the forester. Recently it 
 
 has been found on ginseng in 
 Japan and the United States.^^ 
 The same fungus is credited with 
 destructive rotting of apples ^^ 
 and pears ^^ in Europe and with 
 causing two wide-spread tropical 
 diseases, the cocoa pod rot and a 
 palm disease. From the studies 
 of de Bary ^^ and from the nature 
 of the more recent outbreaks cred- 
 ited to this fungus it appears that 
 P. omnivora is a composite species 
 which will eventually be segre- 
 gated. Indeed segregation has 
 already been begun. Coleman ^^ has described the palm in- 
 fecting fungus of India as P. omnivora var. arecae while Maub- 
 lanc ^^ has gone further and described the cocoa disease as P. 
 faberi. See also "''> '^^^ 
 
 P. sjrringae recently described by Klebahn is a closely related 
 species, which is very destructive in the propagating beds of the 
 lilac in Germany. 
 
 Fig. 60. — Formation of swarm-spore 
 of Phytophthora. After Smith. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 89 
 
 P. agaves C{an.'^^ occurs on the Agave in Mexico. 
 
 P. nicotiana v. B. d H.^*' is also closely related to P. omnivora, 
 but culture work shows it to be rather fastidious in its choice of 
 host as it attacks only tobacco seedlings. 
 
 P. calocasiae Rac. occurs on Calocasia antiquorum in the Orient. 
 An undescribed species on Castor is also reported.^^ 
 
 Kawakamia Miyabi (p. 83) 
 
 Mycelium slender, copiously branched; conidiophores single or 
 in groups of 2-5 or more from the stomata, simple or sometimes 
 irregularly branched, but branches never arising near the conidia. 
 Conidia usually upon a slender pedicel cell, lemon-shaped, ob- 
 tusely tipped, contents and wall colorless, germination normally 
 by zoospores; zoospores oval, flattened and laterally biciliate; 
 oospores spherical, smooth. 
 
 A single species, K. cyperi (M. & I.) Miyabe,^^ which was intro- 
 duced from Japan into Texas in imported plants of a sedge, 
 Cyperus tegetiformis. The species is very destructive in Japan. 
 Both conidia and oospores were produced in the Texan material.^^ 
 
 Basidiophora Roze & Cornu (p. 83) 
 
 B. entospora R. & C. occurs on species of Erigeron and culti- 
 vated aster in Europe and America. 
 
 Sclerospora Schroter (p. 83) 
 
 This genus differs from all other Peronosporales in the pre- 
 ponderance of its oospores; these are the conspicuous stage, while 
 the conidiophores and conidia are few, small and evanescent. 
 There are about five species. 
 
 Mycelium much branched, with small vesicular haustoria; 
 conidiophores erect, solitary or in groups of two or three, 
 fugaceous, low and stocky, sparsely branched, the branches 
 also stocky; conidia elliptic or globose-elliptic, hyaline, smooth; 
 oospores globose, intramycelial, the epispore brown, irregularly 
 wrinkled, permanently united to the persistent wall of the oogo- 
 nium. 
 
90 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 S. graminicola (Sacc.) Sehr.,''-' ''^ infects leaves and inflorescences, 
 the oospores causing marked distortion of the latter and rapid 
 disintegration of the former; conidiophores 100 x 10-12 /x, conidia 
 20 X 15-18 IX] oogonium wall thick, 4-12 n, at maturitj^ 30-60 n 
 in diameter, reddish-brown; oospore pale-brown, 26-36 ii. 
 
 The conidial phase is not prominent, while the oospores by their 
 disintegrating effect upon the leaves of the host, render the plants 
 quite conspicuous and closely simulate the habit of a brown smut. 
 
 Fig. 61. — S. graminicola. 
 Conidiophores and co- 
 n i d i a ; germinating 
 conidia and zoo- 
 spores. After Butler. 
 
 Fig. 62. — S. graminicola, oo- 
 gonium, oospore and an- 
 theridium in section. Af- 
 ter Stevens. 
 
 On millet (Setaria italica), pearl millet, fox tail and corn; in India 
 of considerable economic importance.^^ 
 
 S. macrospora Sacc. has been reported in com tassels and on 
 wheat in Italy and the United States.^'^* ^^ Conidia unknown; 
 oogonia embedded firmly in the tissue of the host, not causing 
 disintegration as in S. graminicola; oospores light yellow, smooth, 
 60-65 /i. 
 
 Plasmopara. Schroter (p. 83) ^^^ 
 
 The tree-like, branching conidiophores, Fig. 63, are common to 
 this genus, Peronospora, Peronoplasmopara and Bremia, and 
 unlike the conidiophores of Phytophthora they are completely 
 formed before they begin to bear spores. 
 
 Mycelium branched; haustoria simple; conidiophores erect. 
 
THE FUxNGI WHICH CAUSE PLANT DISEASE 91 
 
 solitary or fasciculate, from the stomata of the host, monopodi- 
 ally branched, the branches arising at right angles to the main 
 axis, as do also the secondary branches (at least never appearing 
 truly dichotomous) the ultimate branches apically obtuse; conidia 
 globose to ovoid, hyaline or smoky, germinating by zoospores or 
 the entire protoplasmic mass escaping and then sending out a 
 germ tube; oospore globose yellowish-brown, the epispore va- 
 riously wrinkled sometimes appearing somewhat reticulate; oogo- 
 nium persistent, but free from the oospore. 
 
 P. viticola (B. & C.).B. & d T,''- ''' "^' "'• ''' first collected in 
 1834 by Schweinitz and regarded as a Botrytis was first published 
 in 18515 
 
 Hypophyllous, caulicolous, or on young fruits, covering the 
 infected areas with a white downy growth; on the leaves epiphyl- 
 lous discoloration yellowish ; on the fruit often causing a brown rot 
 without producing conidia; conidiophores fasciculate, 250-850 x 
 5-8 n, 4-5 times branched, the ultimate branchlets about 8 fj, long; 
 conidia ovate-elliptic, very variable in size, 9-12 x 12-30 n; 
 oospores 30-35 n, epispore brown, wrinkled, or almost smooth; 
 oogonium thin-walled, hyaline or light yellowish-brown. 
 
 The mycelium is found in all diseased tissues except the xylem. 
 The conidiophores issue from stomata. The conidia germinate 
 readily in water, producing in about three-fourths of an hour 
 biciliate zoospores. These after fifteen to twenty minutes activity 
 cease motion, round off, become walled, then germinate by a tube. 
 This bores through the epidermis and develops into the internal 
 mycelium. Infection is almost exclusively from the lower side of 
 the leaf .^^ Oospores are much more rare than conidia but are often 
 found in autumn, sometimes two hundred to a square millimeter of 
 leaf surface. Though hibernation is doubtless chiefly by oospores 
 it has been shown that the mycelium can perennate in old wood, 
 and even form oospores therein. The fungus is dependent on 
 abundant moisture. 
 
 P. nivea (Ung.) Schr. attacks various species of umbellifers in- 
 cluding the parsnip and carrot. It has been reported in America 
 only from the region of San Francisco. 
 
 P. halstedii (Farl.) B. & d T. 
 
 This form is quite variable and should perhaps be separated 
 
92 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 into several distinct species. It is limited to the Compositse, 
 Helianthus and Madia being the only hosts of economic impor- 
 tance. 
 
 Hypophyllous; conidiophores fasciculate, slender, 300-750 fx, 
 3-5 times branched, ultimate branchlets 8-15 ju long, verticillate 
 
 Fig. 63. — P. viticola. A, section of a leaf with conitliophores emerg- 
 ing from a stoma; C, formation of swarm spores; D, formation 
 of oospores. After Millardet. 
 
 below the apex of the branching axis which is frequently swollen 
 and ganghon-like ; conidia oval or elliptic, 18-30 x 14-25 /jl; 
 oospores 30-32 n, epispore yellowish-brown, somewhat wrinkled. 
 
 P. ribicola (Schr.) Schr. grows on various species of currants in 
 Europe and America but is probably of but slight economic 
 importance. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 93 
 
 P. obducens (Schr.) Schr. occurs on Impatiens, both wild and 
 cultivated, in North America, Europe and Asia. 
 
 P. pygmea (Ung.) Schr. on various Ranunculacese, including 
 Aconitum in Europe and cultivated Hepaticas in America,'''^ is 
 of little economic importance. 
 
 Peronoplasmopara (Berlese) Clinton (p. 83) 
 
 There are three species which have been variously designated 
 as Peronospora, Plasmopara, Pscudoplasmopara and Peronoplas- 
 mopara. The genus combines colored conidia and zoosporic germi- 
 nation with a type of conidiophores intermediate between those of 
 Peronospora and Plasmopara. 
 
 Mycelium much branched, haustoria small, usually simple; 
 conidiophores pseudo-monopodially branched, the ultimate branch- 
 lets acute, the primary arising at acute angles; conidia colored, 
 elliptic, conspicuously papillate both apically and basally; oospores 
 thin- walled, smooth or roughened; oogonium thin-walled. 
 
 P. celtidis (Waite) Cl.^^ is unique in the family as the only 
 species infecting dicotyledonous trees. It occurs on hackberry in 
 the region about Chesapeake Bay, also in Japan. 
 
 P. humuli Miy, & Taka ^" causes a serious hop disease in Japan. 
 It has recently been found by Davis ^^ on wild hops in Wisconsin. 
 
 P. cubensis (B. & C), CV'-'''' '°^ 
 
 Hypophyllous, rarely amphigenous; discoloration of the host 
 yellowish, or water-soaked; conidiophores 1-2 rarely more from a 
 stoma, 180-400 x 5-9 fi, 3-4, rarely 2-5 times branched, the ulti- 
 mate branchlets recurved; apically acute, 5-20 /x long; conidia 
 gray, brownish or smoky, ovoid to ellipsoid, papillate, 20-40 x 
 14-25 fi; oospores spherical, yellowish, warty-papillate, 30-43 fi, 
 maturing in the decajdng leaves. 
 
 The mycelium abounds in the spongy parenchyma. The 
 conidiophores emerge through stomata, or rarely directly through 
 the cuticle, near the invasion line of the fungus. Fresh conidia 
 germinate in water in two to four hours forming fiattish zoospores 
 with one anterior and one posterior cilium. The zoospores later 
 become spherical, walled and develop a germ tube. These germ 
 tubes enter the host through the stomata or directly through the 
 cuticle from either above or below. Moist weather is favorable to 
 
94 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 the fungus in that conidia are produced more abundantly and 
 retain their power of germination longer when moist. Disease 
 spots appear two or three days after infection; conidia same nine 
 or ten days after infection. 
 
 The species is perennial in Florida ^'^ and spreads northward as 
 the season advances, reaching Ohio and New York by late summer 
 
 Fig. 64. — P. cubensis: 3. Conidiophore with young and 
 old conidia. 5. Conidium. 6. Conidium germinating. 
 11. Zoospores. 18. Infection through a stoma. 
 After Clinton. 
 
 or early autumn.^^ For a series of years after its discovery it was 
 not well known even scientifically, its first serious outbreak being 
 about 1889.^^ It appeared in Japan about the same time ^°° and 
 is now known to be almost cosmopolitan. The oospores have 
 been found only by Rostewzew and have not been seen in America. 
 A wide range of wild and cultivated cucurbits is infected, among 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 95 
 
 them the pumpkin, squash, cucumber, muskmelon, watermelon, 
 gourd, in fact according to the work of Selby ^^^ any cucurbit ap- 
 pears liable to attack. Clinton infected muskmelons with spores 
 produced on cucumber. The fungus is especially prevalent on 
 cucumbers raised under glass. 
 
 Bremia Kegel (p. 84) 
 
 As in Peronospora except that just below the ends of the conidio- 
 phore branches there are pronounced swellings from which spring 
 radially a number of short branches each 
 bearing an ovate, papillate conidium. The 
 conidia germinate by apical germ tubes. 
 There is only one species. 
 
 B. lactucae Kegel is found on lettuce and 
 several other Compositae.^"^ It is more in- 
 jurious in Europe than in America. 
 
 Hypophyllous or amphigenous, causing 
 
 discoloration, then wilting of the host; conid- fig. 65. B.lactucEe. 
 
 iophores produced singly but in great abun- After Tubeuf. 
 dance, much branched; conidia ovate, 16-22 x 15-20 /x; oospores 
 small, 26-35 n, light brown, the epispore wrinkled. 
 
 Peronospora Corda (p. 84) ^- 
 
 This genus of some sixty species contains several aggressive 
 parasites. Its conidiophores are much like those of Plasmospara 
 but with more tendency to dichotomous branching and to more 
 graceful habit; the apices are acute. 
 
 Mycehum well developed, haustoria filiform, simple or 
 branched; conidiophores dichotomously 2-10 times branched at 
 acute angles, ultimate branchlets acute, more or less reflexed; 
 conidia hyaline or colored, papillate, germinating directly by lateral 
 germ tubes; oospores globose, reticulate, tuberculate, wrinkled or 
 smooth. 
 
 P. parasitica (Pers.) De Bary.^^ This is often associated with 
 Albugo Candida, giving it the appearance of a parasite on that 
 fungus. Almost all species of Cruciferae are subject to attack, 
 among them cabbage, cauliflower, radish, coUards, turnips, horse- 
 
96 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 radish, and others of minor economic importance. It is cos- 
 mopohtan in distribution. 
 
 The fungus covers any green part of the host with a dense white 
 growth, often causing hypertrophy especially in oospore forma- 
 tion; conidiophores 200-300 x 10-12 /i, bushy branched, stout, 
 deliquescent, with 5-8 main branches, each from 3-7 times 
 branched, ultimate branchlets slender, more or less curved, 
 usually arising at acute angles, about 12-15 x 2-3 /x; conidia 
 broadly elliptic, bluntish, often becoming globose, about 12-22 x 
 24-27 IX, hyaline or very light; oospore 
 globose, yellow-brown, 26-45 }x, epispore 
 smooth or wrinkled; oogonium thick, color- 
 less. 
 
 P. effusa (Grev.) Rab. causes a serious 
 disease of spinach. ^°^ It also occurs on a 
 wide range of weeds of the Chenopodiacese. 
 The species was formerly made to include 
 all the effusse forms of the genus so that 
 literature abounds with references to it on 
 Viola, Plantago, Polygonum, etc. 
 
 Hypophyllous, causing yellowish or brown- 
 ish discolorations, the mass of conidiophores 
 of a violet cast; conidiophores 150-400 x 
 7-9 IX, much branched, the ultimate branches 
 at right angles, usually recurved, 8-15 x 
 3^ IX', conidia ellipsoid to globose 17-18 x 
 22-24 IX, violet or smoky; oospores globose, 
 30-40 IX, epispore light brown, more or 
 less regularly wrinkled; oogonium thin, 
 brown. 
 
 P. schleideni Ung.^*^^ was first described as aBotrytis in 1841. 
 It was noted in America in 1872 by Taylor, ^°^ later by Trelease ^°^ 
 and by many others. ^°^ A very complete description was given 
 by Whetzel ^°^ in 1904 under the name P. schleideniana. 
 
 The conidia in mass present a purplish tint. The conidio- 
 phores usually emerge singly through the stomata. The slender, 
 branched haustoria abound in the parasitized part often with 
 their ends wrapped around the nuclei. In water the conidia 
 
 Fig. 66.— P 
 spinach, 
 sted. 
 
 effusa on 
 After Hal- 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 97 
 
 germinate directly to form an infective tube (Fig. 07) which 
 grows into the stomata. According to Whetzel conidia retain 
 their germinating power only a few hours. Shipley believed them 
 viable for a much longer time.^"^ Fertilization occurs much as in 
 P. parasitica (Fig. 67) and the sexual spores, which abound, 
 serve for hibernation. They may live several years. 
 
 It is found on onion, garlic, etc. (Allium sps.) everywhere, 
 covering leaves with a dense growth; conidiophores, 3-6 femes 
 branched, 300-700 x 12-15 /x; branches 2-5, scattered, ultimate 
 branchlets subulate, 15-20 /jl, more or less recurved; conidia large, 
 obovate to pyriform, basally papillate, 45-58 x 20-25 [jl, the 
 membrane violet; oospore globose, light-brown, about 30 ju, 
 epispore smooth or slightly wrinkled. 
 
 P. sparsa Berk, is parasitic on roses ^^ and constitutes a serious 
 pest in Europe, though not so common in America. 
 
 Hypophyllous, with a whitish growth; conidiophores about 
 9 times branched, the ultimate branchlets reflexed; conidia sub- 
 elliptic, pale gray. 
 
 P. trifoliorum de Bary. Hypophyllous, forming a dense grayish 
 or dirty- white growth over the host; conidiophores slender, 360- 
 600 X 9-11 M, 6-8 times branched at acute angles, the primary 
 branches rather erect, the secondary more spreading, flexuose, more 
 or less recurved, ultimate branchlets at right or obtuse angles, 
 straight, subulate, 7-12 x 7-3 /x; conidia globose to broadly elliptic, 
 15-20 X 18-36 iJL, violet; oospores globose, 24-30 n, epispore light 
 brown, smooth. 
 
 It causes serious loss to clover in Europe. Species of related 
 genera also suffer. Recently it has assumed a role of importance 
 in America by its attacks upon Alfalfa ^^° on which it occurs from 
 New York to California. 
 
 It differs from P. vicise in the branching of the conidiophores, 
 the lighter color of the spot and fungus, and the smooth oospores. 
 
 P. viciae Berk. Hypophyllous or cauHcolous, covering the host 
 with a grayish-violet growth, epiphyllous discolorations yellowish 
 or inconspicuous; conidiophores fasciculate, 300-700 x 9-11 fi, 
 5-8 times branched, the main branches arising at acute angles, 
 erect, the ultimate subequal, slightly flexuose, arising at right or 
 obtuse angles, the lateral recurved, 10-17 x 2-3 n; conidia elliptic 
 
98 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 14 15 
 
 Fig. 67. — P. schlcideni. 11. Mycelial threads between the large conductive cells of 
 the leaf; (a) the mycelial thread; (b, b) branched or coiled haustoria; (c) branched 
 haustorium wrapped about the nucleus. 13. Young eonidiophores, (a, a) turn- 
 ing toward the stoma, (b); (c) haustorium wrapped about the nucleus of the 
 epidermal cell. 14. Mature conidiophore (a) with mature conidia, (c, c); 
 (d) germ tube of conidium entering stoma. 15. Oospores, (a) mature oospore 
 with old antheridium, (d) still attached; (b) mature oospore still inclosed in the 
 old wall of the oogonium. After Whetzel. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 99 
 
 or obovoid, 15-20 x 21-28 /x, light-violet; oospores small, 25-30 fx, 
 epispore yellowish-brown, with low, broad reticulations, areola? 
 about 8 n; oogonium thin, fugaceous, 32-40 /x. 
 
 This fungus on Mcia and related genera is sometimes quite 
 
 A 
 
 Fig. 68. — A sporangium with a columella (Mucor). 
 After Sachs. 
 
 serious, particularly on vetch and peas in Europe, Asia and 
 America. 
 
 P. violae de Bary ; on cultivated violets and the pansy in Europe 
 and America, ^^ forming discolored spots; foUicolous or caulicolous, 
 with a pale violet growth, conidiophores fasciculate, short, 2-7 
 times dichotomously branched; ultimate branchlets short, sub- 
 ulate, reflexed; conidia elliptic, short, apiculate, 20-22 x 15-18 /x, 
 violet. 
 
100 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 P. dipsaci Tul. on teasel and Scabiosa in Europe and America and 
 P. violacea Berk, on the flowers of species of Scabiosa in Europe 
 are quite distinct from the preceding; P. schachtii Fcl. on beets 
 kills seedlings in Europe. P. linariae Fcl. is on digitalis; P. cytisi 
 
 Fig. 69. — Sporophores in the Zygomycetes. After De Bary, 
 Brefeld, Cunningham, Schrotor. 
 
 Rost."^' ^^- on species of Cytisus in Europe; P. arborescens (Berk.) 
 de Bary on poppies, especially garden seedlings, in Europe and 
 Asia. 
 
 Species of less importance are: 
 
 P. rubi Rab. on various species of Rubus in Europe and 
 America; P. fragariae R. & C, usually cited as a synonym of 
 P. potentillse de Bary, on the strawberry in France and America; 
 P. trichomata Mas.^^''' ^^^ the cause of a root rot of Colocasia 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 101 
 
 Fig 
 
 foMiuition. 
 
 in the West Indies; P. Candida Fcl. on the primrose in Europe 
 and upon non-economic Primulaceae in America; P. maydis Rac.^^^ 
 the cause of a disease of corn in Java. [Its identity with Sclero- 
 spora graminicola is suggested by the recent studies of that species 
 by Butler.] P. vincae Schr. on Vinca minor in Europe; P. myoso- 
 tidis de Bary on several species 
 of forget-me-not and related 
 genera in Europe and America; 
 P. cannabina Otth. on hemp in 
 Europe and Japan; P. con- 
 glomerata Fcl. upon alfilaria 
 in Europe; P. ficariaB Tul. on 
 various species of Ranunculus 
 both in the old and the new 
 world; P. antirrhini Schr. on 
 the snapdragon and related 
 hosts in Europe; P. nicotianae 
 Speg.-^^^ on various ornamental 
 species of Nicotiana in South 
 America and California; P. Va- 
 leria mellae Fcl. in Europe on Valerianella; P. Valerianae Trail on 
 Valerian; P. dianthi de Bary on species of Dianthus in Europe; 
 P. corallae Tranz. on Campanula in Europe; P. jaapiana ^^" on 
 rhubarb in Europe; P. phoenixae Tap. on Phoenix ^^^ and an un- 
 determined species on Para rubber. 
 
 Mycelophagus castaneae Man."^ is an imperfectly described 
 form which may belong either to the present group or to the 
 Chytridiales. A serious disease of the chestnut in France is 
 charged to it. 
 
 Zygomycetes (p. 66) 
 
 This group of fungi is readily distinguished from the Oomycetes 
 by its isogamous sexual organs, when these are present. In the 
 absence of sexual organs the general type of sporangium is usually 
 sufficient mark of distinction for those who are even but slightly 
 acquainted with the two groups. The mycelium, if young, serves 
 to indicate relationship to the Phycomycetes. Older mycelium is 
 often septate and would lead the unwary into errors of classification. 
 
 -Mucor: zygospore 
 After Brefeld. 
 
102 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Asexual spores are either in sporangia or are borne as conidia. 
 The sporangium is usually with a columella. The spore-bearing 
 stalks exhibit the widest diversity in shape and form of branch- 
 ing, Fig. 69. 
 
 Sexual spores (zygotes) are produced through the union of two 
 like gametangia. (Fig. 70.) Though the cytology of zygote 
 formation has not been completely studied it seems clear that the 
 fertilization is multi -nucleate ^^'^ as in Albugo bliti and that the 
 two uniting elements are coenogametes. 
 
 Key to Orders of Zygomycetes 
 
 Asexual spores borne in sporangia which 
 
 in some genera are reduced to 
 
 conidia-like bodies 1. Mucorales, p. 102. 
 
 Asexual spores true conidia borne singly 
 
 at the apex of the conidiophores . ... 2. Entomophthorales, p. 107. 
 
 Mucorales (p. 66) 
 
 This order is comprised mainly of saprophytes, about twenty 
 genera and one hundred fifty species; but includes a few forms 
 
 which prey upon vegetation in a very 
 low ebb of life, as cells of ripe fruit, 
 tubers, etc., and a few species which 
 are of especial interest as they grow 
 upon other fungi. The sporangial 
 stage is exceedingly common; the 
 zygosporic much less so, very rare in 
 the case of some species. Blakeslee ^-° 
 has shown that in some species, 
 though the two uniting sexual organs 
 Fig. 71.— Phyroinycctos showing are to all appearances alike, the plants 
 
 zygosporic lines at regions of . ,. ,. . 
 
 contact between + and — are in reality dioecious; that a branch 
 
 strains. After Blakeslee. c i j. j. i i 
 
 from one plant cannot produce sexual 
 organs that will unite with other sexual organs produced upon 
 the same plant. Moreover, there appears to be a differentia- 
 tion of sex in that one plant, which may provisionally be re- 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 103 
 
 garded as the male, unites freely with another plant, provisionally 
 the female, but this male plant refuses to unite with any other 
 plant which is capable of uniting with the female and all plants 
 that can unite with the male refuse to unite with the females. In 
 some species the plants of one sex show a more luxuriant vegeta- 
 tive growth than do plants of the other sex. 
 
 Key to Families of Mucorales. 
 
 Asexual spores in typical sporangia, although 
 in some genera few-spored 
 Sporangium with columella;- zygospores 
 naked or tliinly covered with out- 
 growths of the suspensor 1. Mucoraceae, p. 103. 
 
 Sporangium without a columella; zygo- 
 spores closely covered by hyphae ... 2. Mortierellaceae. 
 Asexual sporangia monosporic and conidia- 
 like, sometimes accompanied by larger 
 polysporic sporangia 
 Sporangia of two kinds, polysporic and 
 
 monosporic. 3. Choanephoraceae, p. 106. 
 
 Sporangia all monosporic; parasitic on 
 
 other genera of Mucorales 4. Chaetocladiaceae. 
 
 Sporangia simulating chains of conidia. . 5. Piptocephalidaceae. 
 
 Of these families the second and fifth are pure saprophytes, 
 while the fourth is parasitic upon other members of the order. 
 
 Mucoraceae 
 
 Mycelial threads all alike or of two kinds, one aerial, the other 
 buried in the substratum, coenocytic during growth but septate 
 at maturity; reproduction by asexual spores borne in sporangia 
 and by zygospores formed by the union of equal gametes; spor- 
 angiophores, simple or branched; sporangia variable, typically 
 with a columella, and many spores but in some genera some of 
 the sporangia are few-spored and without columellas; zygospores 
 variable, smooth or spiny, borne on short branches of the myce- 
 lium. 
 
104 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Key to Subfamilies and Genera of Mucoracese 
 
 Sporangial membrane cuticularized and per- 
 manent above, thin and fugaceous be- 
 low Subfamily I. Paoboleae. 
 
 Sporangiopliore of equal size throughout; 
 
 spore mass not forcibly discharged . . . Pilaira. 
 Sporangiopliore swollen beneath the spo- 
 rangium; spore mass forcibly dis- 
 charged at maturity Pilobolus, p. 105. 
 
 Sporangial membrane thin and fugaceous 
 throughout 
 
 Sporangia all similar Subfamily II. Mucoreae. 
 
 Mycelium differentiated into a colorless 
 vegetative and a colored aerial re- 
 gion 
 Aerial mycelium stoloniferous, zygo- 
 spores formed in the substratum 
 Sporangiophores arising from the 
 
 nodes 1. Rhizopus, p. 105. 
 
 Sporangiophores arising from the 
 
 internodes 2. Absidia. 
 
 Aerial mycelium not stoloniferous; 
 zygospores aerial 
 
 Sporangiophores simple 3. Spinellus. 
 
 Sporangiophores dichotomously 
 
 branched 4. Syzygites. 
 
 Mycelium undifferentiated 
 
 Mycelium gray or brown; suspensors 
 smooth 
 
 Sporangiophores simple 5. Mucor, p. 106. 
 
 Sporangiophores variously branched 
 
 Sporangia borne apically on the 
 
 sporangiophore and its 
 
 branches 
 
 Zygospores formed from equal 
 
 gametes 6. Calyptromyces. 
 
 Zygospores formed from un- 
 equal gametes 7. Zygorhynchus. 
 
 Sporangia borne only on the 
 lateral, circinate branches of 
 the sporangiophore 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 105 
 
 Sporangia globular; columella 
 
 not constricted 8. Circinella. 
 
 Sporangia pear-shaped ; colu- 
 mella constricted 9. Pirella. 
 
 Mycelium metallic; suspensors spiny 10. Phycomyces. 
 Sporangia of two kinds, the primary 
 many-spored; the secondary few- 
 spored Subfamily III. Thamnidieae. 
 
 Pilobolus crystallinus (Wigg.) Tode, a form with beautiful 
 crystalline sporangia on yellowish, evanescent sporangiophores has 
 been frequently noted as injuring or smudging chrysanthemum, 
 rose and other leaves 121-122 j^y j^g profuse discharge of spo- 
 rangia. It is not, however, a parasite. 
 
 Of the other genera the only ones of interest regarding plant 
 disease are Rhizopus and Mucor. The others are saprophytes found 
 on a great variety of substances, manure, fungi, and many other 
 kinds of organic matter. 
 
 Rhizopus Ehrenberg (p. 104) 
 
 The sporangium wall is not cutinized, and falls away. The 
 sporangia are all of one kind and with columellas. The sporan- 
 giophore is never dichoto- 
 mous; zygotes are found in the 
 mycelium. The suspensor is 
 without outgrowths. Twelve 
 or fifteen species, chiefly sap- 
 rophytes. 
 
 R. nigricans Ehr. Aerial 
 mycelium at maturity choco- ,, „„ ^, . -^. 
 
 . . riG. 72. — Rhizopus. Diagram showing 
 
 late-colored; rhlZOlds numer- mycelium and sporophores. After Coul- 
 
 1 r • ter, Barnes and Cowles. 
 
 ous; sporangiophores fascicu- 
 late, erect, aseptate; sporangia globose, blackish-olive, granular; 
 columella hemispheric; spores gray to brown, subglobose or irregu- 
 lar, 11-14 /x; zygospore 150-200 n, epispore with rounded warts, 
 black. This is the cause of soft rot of stored vegetables, particu- 
 larly of sweet potatoes,^^^also of Irish potatoes, ^^^ apples and pears; 
 it causes death of squash blossoms ^^'^ and is destructive to barley 
 
106 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 during malting. It is distinctly a wound parasite and is unable 
 to force entrance through a sound epidermis. 
 
 The richly branched mycelium which varies from very thin and 
 hyaline to thick, coarse and slightly fuscous, is found throughout 
 the rotten portion of the host. After a period of luxuriant vegeta- 
 tive growth hyphae protrude to the air, first through existing 
 ruptures in the epidermis, later by rifts forced by the fungus 
 itself. Sporangiophores then form in dense bush-like growths, 
 each sporangiophore bearing one terminal sporangium. The 
 sporangia are at first white, later black and contain very numerous 
 spores. Spore formation has been closely studied by Swingle. ^^^ 
 Aerial stolon-like hyphae reach out in various directions and at 
 their points of contact with some solid develop holdfasts (Fig. 72) 
 and a new cluster of sporangiophores. 
 
 Zygotes are produced by union of two mycelial tips as is shown 
 in Fig. 70. 
 
 Orton ^-^ inoculated pure cultures of this fungus on sterile raw 
 Irish potato and induced typical decay. He also noted that there 
 was a difference in the rate of decay produced by strains of Rhizo- 
 pus derived from different sources and that the most rapid decay 
 of potatoes was caused by strains taken from rotting potatoes. 
 
 R. necans Mas.^^^ causes decay of lily bulbs in Japan. 
 
 R. schizans Mas. is cited as the cause of split-stone in peach. ^^^ 
 
 Mucor Linnaeus (p. 104) 
 
 Mycelium all of one kind, buried in the substratum or grow- 
 ing over its surface; sporangiophores scattered or not, simple 
 or branched; sporangia globose; columella cylindric, pyriform or 
 clavate; spores numerous, variable; zygospores globose, smooth or 
 warty. 
 
 Some thirty species, chiefly saprophytes. 
 
 M. mucedo L. is destructive to beech nuts in winter. 
 
 M. pyriformis Fisch and M. racemosus Fes. cause decay of 
 fruits. 
 
 Choanephoraceae (p. 103) 
 
 Mycelium parasitic on living plants; sporangia of two kinds; 
 macrosporangia globose, columella small, spiny, spores few, on 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 107 
 
 simple or branched, erect sporangiophores ; microsporangia clavate, 
 one-spored simulating conidia and borne in heads on the enlarged 
 apices of umbellately branched sporangiophores; zygospores as 
 in Mucoracae. 
 
 A single genus, with three species. 
 
 Choanephora infundibulifera (Curry) Sacc. and C. americana 
 A. Moll occur on blossoms in India and South America. 
 
 A third species, C. cucurbitarum (B. & Br.) Thaxter, is the 
 cause of decay of cucurbits especially pumpkins, in the eastern 
 and southern states. ^-^ 
 
 Entomophthorales (p. 66) 
 
 This order is predominately one parasitic on insects. Some 
 fifty species are known, only four of which are plant parasites. 
 Asexual reproduction is chiefly by conidia, apically borne and for 
 the most part forcibly ejected from their stalks at maturity. 
 
 Key to Families of Entomophthorales 
 
 Endozoic parasites (Insecta, Arachnoidea) . 1. Entomophthoraceae. 
 Endophytic or saprophytic 2. Basidiobolaceae, p. 107. 
 
 Basidiobolaceae 
 
 This family is characterized chiefly by its habitat. Septa are 
 numerous in the vegetative mycelium. 
 
 Key to Genera op Basidiobolaceae 
 
 Intracellular parasites, the mycelium greatly 
 
 reduced 1. Completoria, p. 108. 
 
 Saprophytes, or parasites on higher fungi, 
 the mycelium well developed. 
 Conidia produced directly from an un- 
 swoUen conidiophore. Parasites on 
 
 higher fungi 2. Conidiobolus. 
 
 Conidia cut off from the apex of a swelling 
 
 of the conidiophore. Saprophytic. . . 3. Basidiobolus. 
 
108 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 With the exception of the one species given below these are not 
 
 parasitic on higher plants. 
 
 Completoria complens Lohde is parasitic upon fern prothallia,^^'^ 
 Vegetative body compact, of oval or curved branches in a single 
 
 host cell, extending to other cells by slender tubes. Resting spores 
 
 10 to 20, formed in the host cell. Propagation by non-motile 
 
 conidia, 15-25 fx, in diameter. 
 
BIBLIOGRAPHY OF PHYCOMYCETES * 
 
 (pp. 59-108) 
 
 1 Atkinson, G. F., Ann. Myc. 7: 441, 1909. 
 
 2 Stevens, F. L. and Hall, J. G., Bot. Gaz. ^8: 1, 1909. 
 
 3 Bessey, Ernst, Diss, Halle, 1904. 
 
 4 Smith, E. F., B. P. I. B. 17: 13, 1899. 
 
 6 Milburn, Thomas, C. Bak. 13: 129, 257, 1904. 
 8 Woronin, Jahrb. Wiss. Bot. 11: 556, 1878. 
 
 7 Home, A., Ann. Myc. 7: 286. 
 
 8 de Wildeman, E., Mem. Roy. Belg. Soc. Micr. 21, 1893. 
 
 9 Stevens, F. L., Bot. Gaz. 35: 405, 1903. 
 " Stevens, F. L., Ann. Myc. 5: 480, 1907. 
 
 11 Griggs, R. F., Bot. Gaz. 48: 339, 1909. 
 
 12 Kusano, C. Bact. 19: 558, 1907. 
 " Percival, C. Bak. 25: 440, 1910. 
 
 1" Schilberszky, Ber. Deut. Bot. Gez. V^: 36, 1896. 
 15 Zimmermann, E., Nat. Zeit f. Forst u. Land. 8: 320, 1910. 
 i« Salmon, E. S. & Crompton, T. E., Wye Ag. Coll. R. Ec. Myc. 109, 
 1908. 
 
 17 Thomas, Insect Life 1: 279, 1884. 
 
 18 Halsted, B. D., N. J. B. 6^: 4, 1889. 
 " Shear, C. L., B. P. I. 110: 37, 1907. 
 
 20 Farlow, W. G., Bull. Bussey Inst. 2: 233, also Bot. Gaz. 10: 239, 1885. 
 
 21 Nowakowski Beitrag. Kennt, Chytrid. 1876. 
 
 22 Berlese, A. N., Riv. Path. Veg. 7: 167, 1901. 
 
 23 C. R. 119: 572, 1894. 
 2" C. R. 120: 222, 1894. 
 
 25 Ellis and Barthohnew, Trans. Kan. Acad. Sci. 16: 167, 1899. 
 
 2" B. My. d. Fr. 26: 
 
 27 C. R. 119: 108, 1894. 
 
 2s Magnus P. Ann. Bot. 11: 92, 1897. 
 
 23 Massee, Bull. Kew Garden, 1906. 
 
 3» Magnus, P. Ber. Deutsch. Bot. Ges. 20: 291, 1902. 
 
 '1 Sydow. Ann. Myc. 1: 517, 1904. 
 
 '2 Farlow, W. G., Rhodora 10: 9, 1908. 
 
 *See footnote, page 53. 
 109 
 
no THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 33 Atkinson, G. F., N. Y. (Cornell) B. 94, 1895. 
 
 3* Mass. Agr. Exp. Sta. R. 8: 220, 1890. 
 
 35 Miyaki, Ann. Bot. 15: 653, 1901. 
 
 38 Butler, E. J., Mem. Dept. Agric. India, Botan. Ser. 15: 86-91, 1907. 
 
 37 Halsted, B. D., N. J. R. 13. 
 
 38 Butler, E. J., R. Pusa. 10: 44, 1909. 
 
 ^' Smith, E. H. & Smith, R. E., Bot. Gaz. 42: 215, 1909. 
 
 « Smith, R. E., Cal. B. 190. 
 
 "1 Stevens, F. L., Bot. Gaz. 32: 77, 1901. 
 
 « Stevens, F. L., Bot. Gaz. 28: 149, 1899. 
 
 « Davis, B. M., Bot. Gaz. 29: 297, 1900. 
 
 " Wager, H., Ann. Bot. 10: 295, 1896. 
 
 45 Wilson, G. W., Torr. Bull. 34: 61, 1907. 
 
 « Melhus, I. E., Sc. 33: 156, 1911. 
 
 « Halsted, B. D., N. J. R. 11: 350, 1890. 
 
 48 Stewart, F. C., N. Y. (Geneva) B. 328, 1910. 
 
 « Halsted, B. D., N. J. B. 76: 1890. 
 
 M Pammell, L. H., la. B. 15: 236, 1891. 
 
 " Halsted, B. D., N. J. R. 15: 355, 1894. 
 
 62 Ruhland, Diss., 1903. 
 
 53 Stevens, F. L., Bot. Gaz. 34: 420, 1902. 
 
 54 Wilson, G. W., Torr. Bull. 34: 387, 1907. 
 
 55 J. Myc. 13: 205, 1907. 
 
 5" Clinton, G. P., Ct. R. 329, 1904. 
 
 57 Berlese, A. N., Riv. d. Pat. Veg. 9: 1, 1900; 10: 185, 1902. 
 
 58 Thaxter, R., Bot. Gaz. U: 273, 1889. 
 
 59 Thaxter, R., Ct. R. (State) Sta. 167, 1899, 1890. 
 6" Scribner, F. L., D. Agr. R. 337, 1888. 
 
 61 Lodeman, E. G., N. Y. (Cornell) Bui. 113: 249, 1896. 
 
 62 Sturgis, Bot. Gaz. 25: 191, 1898. 
 «3 Clinton, G. P., Ct. R. 278, 1905. 
 
 64 Smith, R. E., Cal. B. 175, 1906. 
 
 65 Smith, W. G., Card. Chron. 1875. 
 
 66 Smith, W. G., Quar. Jour. Mic. Sc. 15: 1875. 
 
 67 Smith, W. G., Diseases of Crops, 1884. 
 
 68 Jones, L. R., Sc. 29: 271, 1909. 
 
 69 Clinton, G. P., Sc. 33: 746, 1911. 
 
 '« Clinton, G. P., Ct. R. 362, 1904; also R. 304, 1905. 
 
 71 Whetzel, H. H., Sc. 31: 790, 1910. 
 
 72 Osterwaldc, A., C. Bak. 15: 434, 1906. 
 
 73 Bubak, Fr., Zeit. 20: 257, 1910. 
 
BIBLIOGRAPHY OF PHYCOMYCETES 111 
 
 '* de Bary, A., Bot. Zeit. 587, 1881. 
 
 " Coleman, L. C, Mycol. Bull. 2: Dept. Agric. Mysore State, 1910. 
 
 ™ Maublanc, L'Agr. Prat. d. Pays Chauds 79: 315, 1909. 
 
 " Ridley, H. N., Agr. B. Straits & Fed. Maley Sts. 10: 70, 1911. 
 
 '8 Petch, T., Circ. and Agr. J. Roy. Bot. Gard. Ceylon 5: 143, 1910. 
 
 " Gandary, G., Mem. Y. Rev. Soc. Cient "Antonio Alzate" 25: 293, 
 1909. 
 
 «o Meded, Lands. Plant. Batavia IS: 189G. 
 
 81 Butler, E. J., Rept. Agr. Research Inst. Pusa 10: 45, 1909-1910. 
 
 8= Patterson, F. and Charles V. K., B. P. I. 171: 1910. 
 
 8^ Kawakamia, a new genus belonging to Peronosporacea? on Cyperus 
 tegetiformis. With a postscript by Dr. Khigo Miyabe, 1904. 
 
 " Butler, E. J., Mem. Dept. Agric. India, 2: No. 1, 1907. 
 
 85 Cugini, G. and Traverso, G. B., Staz. sperim. Agr. Ital. 35: 46, 1903. 
 
 86 Peglion, C. Bak. 28: 580, 1910. 
 
 " Berkeley, J., Hort. Soc. Lond. 6: 289, 1851. 
 
 88 Dept. Agr. R. 96, 1886. 
 
 89 Appel & Riehm, Ber d. Kais. Biol Ans. f . L. u. F. Heft, 8, 1908. 
 
 90 Stewart, F. C, N. Y. (Geneva) B. 32S: 352. 
 
 91 Waite, M. B., Journ. Myc. 7: 105, 1902. 
 
 92 Miyabe, K., Trans. Sappora Acad. Sci. 1: 1909. 
 
 93 Davis, J. J., Science, 31: 752, 1910. 
 
 9" Clinton, G. P., Ct. R. 336: 1904, 1905. 
 
 95 Rostewzew, Ann. Inst. Agron. Moscow, 9: 47 and Flora 92: 405, 1903. 
 
 9« Clmton, G. P., Ct. R. 23: 277, 1899. 
 
 9' Hume, H. H., Fla. R. 30, 1900. 
 
 98 Orton & Garrison, S. C. B. 116: 7, 1905. 
 
 99 Halsted, B. D., Bot. Gaz. U: 149, 1889. 
 
 100 Farlow, W. G., Bot. Gaz. 14: 187, 1889. 
 "1 Selby, A. D., Bot. Gaz. 27: 67, 1909. 
 
 102 Stewart, F. C, N. Y. (Geneva) B. 119: 158. 1897. 
 
 103 Arthur, J. C, N. Y. (Geneva) R. 4: 253, 1885. 
 10^ Halsted, B. D., N. J. B. 70. 
 
 105 Whetzel, H. H., N. Y. (Cornell) B. 21S: 1904. 
 108 Taylor, T. R., D. Agr. 193, 1872. 
 
 107 Trelease, Wm., Trans. Wis. Acad. Sc. 6: 7, 1881-1884. 
 
 108 Wis. R. 16: 34, 1883. 
 
 109 Shipley, A., B. 19: Miss. Kew. 1887. 
 
 110 Stewart, F. C, French, G. T., & Wilson, T. K., B. N. Y. (Geneva) 
 305: 394, 1908. 
 
 111 Rostrup, Zeit. 2: 1, 1892. 
 
112 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 112 Magnus, P., Hedw. 149, 1892. 
 
 1" Massee, G., Jour. Linn. Soc. Bot. 24: 48, 1887. 
 
 114 Barrett, O. W., R. Porto Rico 398, 1904. 
 
 115 Raciborski, M., Ber. d. Deut. Bot. Ges. 15: 475, 1897. 
 11° Spegazzini, C., Rev. Argent. Hist. Nat. 1: 36, 1891. 
 
 1" Magnus, P., Ber. d. Deut. Bot. Ges. 28: 250, 1910. 
 
 118 Taplin, W. H., Amer. Florist 21: 587. 
 
 115 C. R. Acad. Sci. Paris, 136: 472, 1906. 
 
 120 Blakeslee, A. F., Proc. Acad. Art. & Sci. 40: 1904. 
 
 "1 Halsted, B. D., Amer. Flor. 13: 117. 
 
 122 Stewart, F. C., N. Y. (Geneva) B. 328: 342. 
 
 123 Halsted, B. D., N. J. B. 76': 1890. 
 12* Orton, W. A., Sc. 29: 916, 1909. 
 
 125 Kirk, T. W., N. Zeal. D. Agr. R. 77: 1909. 
 
 126 Swingle, D. B., B. P. I. 37: 1903. 
 
 127 Kew Bull. 871, 1897. 
 
 128 Rept. Mic. Vio., N. S. Wales, 1909. 
 123 Thaxter, R., Rhodora 99: 1903. 
 
 i3« Atkinson, G. F., N. Y. (Cornell) B. 94: 252: 1895, also Bot. Gaz. 
 19: 47, 1894. 
 
 131 Gussow, Ottawa B. 63, 1909. 
 
 "2 Trow, A. H., Ann. Bot. 18: 541, 1904. 
 
 133 Idem, 15: 269, 1901. 
 
 13" Rosenberg, 0., Bihand till K. Svens Vet. Akad. Handl. 28: 10, 1903. 
 
 135 Gruber E., Ber. d. Deut. Bot. Gaz. 19: 51, 1901. 
 
 136 Edgerton, C. W., La. B. 126: 1911. 
 13' Smith, E. G., Sc. 30: 211, 1909. 
 
 138 McCallum, W. B., Ariz. R. 583, 1909. 
 
 139 Halsted, B. D., N. J. R. 1893, 393. 
 
 i« Stevens, F. L., Bot. Gaz. 38: 300, 1904. 
 
 1" Bubak, Fr., C. B. 8: 817, 1902. 
 
 "2 Magnus, P., C'. Bak. 9: 895, 1902. 
 
 1" Farlow, W. G., Bus. Inst. 1: 415, 1871. 
 
 14" Scribner, F. L., D. Agr. R. 96, 1886 and 88, 1887. 
 
 i« Stewart, F. C., Eustace, H. J. & Sirrine, F. A., N. Y. (Geneva) B. 
 241: 1903. 
 
 i"6 Morse, W. J., Me. B. 169: 1909. 
 
 i« Jones, L. R., Vt. B. 72: 1899. 
 
 i"8 Stewart, F. C., Eustace, H. J. and Sirrine, F. A., N. Y. (Geneva) B. 
 264: 1904. 
 
 i« Fariow, W. G. B. Bussey, Inst. 415, 1876. 
 
ASCOMYCETES (p. 64) ^' ''• "• ^^' "' "• "• *^ 
 
 The distinguishing mark of this group is the ascus. This in its 
 typical form is shown in Fig. 73, as a long, slender or club-shaped 
 sac in which the spores are borne. The number of spores in the 
 ascus is usually definite and is commonly of the series, 1, 2, 4, 8, 
 16, 32, 64, etc., the most common number being 8. The spores 
 vary in size, color, shape, markings and septation. The asci 
 in most genera are arranged in a definite group, a layer, con- 
 stituting the hymenium which may be either 
 concave, convex, or flat. Between the asci in the 
 hymenium are often found slender hyphal threads 
 of various form, the paraphyses, Fig. 73. 
 
 The hymenium may be borne in or upon a 
 firm substratum of woven threads, the stroma, 
 or upon a very tenuous substratum, the subicu- 
 lum, or without any definite subascal structure. 
 The stromata vary widely in character, size, tex- 
 ture, color, surface, form, etc. 
 
 The mycelium is usually abundant, branched 
 and septate, the septation readily distinguishing 
 this group from the Phycomycetes. In many 
 species the mycelium weaves together into a false 
 parenchyma and constitutes relatively large -p^^ -3 _ portion 
 spore-bearing structures. Fig. 74. 0/ a hymenium 
 
 . showing asci and 
 
 ihe ascigerous organ, ascocarp, or ascoma, paraphyses. Af- 
 if saucer-shaped and open is an apothecium, ^""'^ Chamberlain. 
 Fig. 92; if closed a perithecium, Fig. 144. In other cases, the 
 ascigerous layer covers the exterior surface. Fig. 74. 
 
 On the boundary lines between the Ascomycetes and other groups 
 are fungi which do not present the typical Ascomycete picture 
 but which are regarded as probably belonging to the group, i. e., 
 transition forms between this and other groups. Among such are 
 
 113 
 
114 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 forms in which the asci are without either stroma or covering, 
 (Protodiscales, p. 125) ; others in which the asci are not even in 
 groups but are scattered irregularly throughout the ascocarp 
 (Aspergillales, p. 164); and still others with the asci neither in 
 regular groups nor covered (Protoascomycetes, p. 119). One 
 further deviation from the typical form occurs in the Hemiascomy- 
 
 FiG. 74. — The large ascocarp of the morel. After Freeman. 
 
 cetes which possess a sporangium-like structure resembling that 
 of the typical Zygomycete; but a mycelium like that of the typical 
 Ascomycetes. This is by many regarded as the transition form 
 bridging the gap between and indicating the kinship of these two 
 groups; a view strongly supported by the existence of very similar 
 sexual processes in the two groups. 
 
 Besides the ascus the Ascomycetes possess many other kinds of 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 115 
 
 reproductive structures in the form of conidia. These may be 
 borne singly or in rows on simple or branched conidiophores. 
 
 The conidiophores may be single or variously grouped in columns 
 or layers. Figs. 352, 378, 382. In some instances they are very 
 
 ,an 
 
 H 
 
 Fiu. 75. — Sphaerotheca castagnei. Fertilization and de- 
 velopment of the perithecium. Og= oogonium, an = 
 antheridium, st= stalk-cell. 6 as the ascogonium 
 derived from the oogonium. After Harper. 
 
 short, innate; again they are long, loose or floccose. They may 
 emerge through stomata singly or in tufts or they may form sporo- 
 genous cushions below the epidermis or again they may be borne 
 inside of a hollow structure, the pycnidium, which covers them. 
 Chlamydospores are also found. 
 One or several distinct types of 
 sporification may belong to one 
 species of Ascomycete. These dif- 
 ferent forms of spores may appear 
 simultaneously on the same myce- 
 lium or they may follow in definite 
 succession regulated by the changes 
 in environment, or again one or 
 more of the spore forms belonging to the life history of the fun- 
 gus may be omitted for long intervals to appear only as the 
 result of stimuli of which little is yet known. 
 
 The conidia and chlamydospores are asexual spores. Sexuality 
 
 u 
 
 Fig. 76. — Boudiera. Six sets of 
 sexual organs. After Claussen. 
 
116 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 ■-PxH 
 
 in the great majority of Ascomy- 
 
 cetes has not been investigated; 
 
 but in some species fertilization is 
 
 / 7^ known to occur ; in many species, 
 
 at least in form similar to that 
 shown by the Phycomycetes, it is 
 absent, probably having been lost 
 by degeneration or else very much 
 modified. 
 
 In some of the Discomycetes 
 ^ „^ T . - . u • • there is one or more carpogonia 
 
 Fig. 77. — Later stage showing asci ... . . 
 
 and ascophores. After Claussen. and fertilization is through a tri- 
 chogyne by spermatia; a mode often met among the lichens. 
 
 In Pyronema,^ Fig. 78, the carpogonium is multi-nucleate and it is 
 fertilized by a multi-nucleate antheridium through a trichogyne. Fu- 
 
 C--: 
 
 / <^ 
 
 YrmJM 
 
 
 J? ^ B . . 
 
 Fig. 78. — Pyronema eonfluens. A. the sex organs, og = oogonium, t= trichogyne. 
 B. fertilization stage in section through young apothecium, asc=asci, asf=a8- 
 cogenous filament. After Harper. 
 
 sion of nuclei is probably in pairs as in Albugo bliti of the Phycomy- 
 cetes. In Boudiera" a very similar relation is found. Figs. 76, 77. 
 
 In some Perisporiales ^ an uninucleate oogonium is fertilized by 
 an uninucleate antheridium. Fig. 75. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 117 
 
 The oogonium after fertilization gives rise to a more or less 
 complicated system of ascogenous hyphae, very simple in the 
 Erysiphacese, very complex in some Discomycetes, which produces 
 the asci. The sterile parts of the ascocarp, the paraphyses and 
 enveloping structures, arise from parts below the oogonium and 
 antheridium. 
 
 The very young ascus usually receives two nuclei from the parent 
 strand of the ascogenous hypha. These nuclei unite giving the 
 
 Fig. 79. — Tip of ascus 
 of Erysiphe showing 
 delimitation of asco- 
 spore from asco- 
 plasm by astral 
 rays. After Harper. 
 
 Fig. >sU.— Later .sta^o than 
 fig. 79, showing well de- 
 fined spore-wall. After 
 Harper. 
 
 primary-ascus-nucleus. This by successive mitoses affords the 
 single spore-nuclei. The spores are cut out from the protoplasm 
 of the ascus in a most peculiar manner by reflexion of and union 
 of astral rays which emanate from a centrosome-like organ at the 
 beak of the prolonged nucleus. Figs. 79, 80. 
 
 The significance of two nuclear fusions in the life cycle of these 
 fungi, one following the union of the antheridium with the oogo- 
 nium, the other later, in the asci, is a puzzling phenomenon, the 
 real significance of which is not clear. 
 
 Key to Subclasses of Ascomycetes 
 Asci with varying number of spores, 
 
 usually numerous 1. Hemiascomycetes, p. 118. 
 
 Asci with definite number of spores 
 
 > Asci separate or scattered 2. Protoascomycetes, p. 119. 
 
 Asci approximate, usually forming a 
 
 hymenium 3. Euascomycetes, p. 123. 
 
118 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Hemiascomycetes (p. 117) 
 
 There is a single order, the Protomycetales, which contains about 
 twenty-five species. Mycehum filamentous, branched, septate; 
 conidia present; asci sporangia-like, containing numerous spores, 
 terminal, naked or covered with a hyphal felt; in some species 
 known to originate from the fertilization of an oogonium. 
 
 Protomycetales 
 
 Key to Families of Protomycetales 
 
 Asci naked 
 
 Asci long, tubular 1. Ascoideaceae. 
 
 Asci elliptic or globular 2. Protomycetaceae, p. 118. 
 
 Asci more or less covered by hyphse 3. Monascaceae. 
 
 Of these families the first is found in slime flux; the last is sap- 
 rophytic. 
 
 Protomycetaceae 
 
 Mycelium prominent; asci intercalary or terminal, large, de- 
 velopment arrested before spores are formed; a process which is 
 completed only after a period of rest. 
 
 Key to Genera of Protomycetaceae 
 
 Parasitic, intercellular in living plants 1. Protomyces, p. 118. 
 
 Saprophytic, building hemispheric sporing 
 
 masses 2. Endogone. 
 
 Protomyces linger 
 
 Asci thick walled; after a long period of rest forming a large 
 mass of elliptic spores which conjugate in pairs, then germinate 
 immediately by a germ tube. 
 
 This genus is sometimes placed with the Phy corny cetes.^* 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 119 
 
 P. macrosporus Ung. 
 
 Asci globose to elliptic, 40-80 x 35-60 m; membrane yellowish, 
 up to 5 M in thickness, contents colorless; spores elongate-ellipsoid, 
 2-3 X 1 At. 
 
 It produces small galls, which are at first watery looking, then 
 
 Fig. 81. — Protomyces. .-1, mycelium and 
 young ascus; E, ascus with mature spores. 
 
 After De Bary. 
 
 brown, upon the leaves and stems of various economic and non- 
 economic Umbelliferae. 
 
 P. pachydermus Thiim. affects carrots and dandelions. P. 
 rhizobius Trail, grows on Poa annua in Scotland. Several other 
 species are found on wild plants. 
 
 Subclass Protoascomycetes (p. 117) 
 
 There is a single order, the Saccharomycetales, with about 
 seventy species. 
 
 Mycelium often undeveloped ; asci isolated or formed at different 
 points on the mycelium, mainly 4-spored; spores unicellular; 
 asexual reproduction by gemmation or by conidia. 
 
120 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Key to Families of Saccharomycetales 
 
 Vegetative cells single or loosely 
 attached in irregular colonies, 
 mycelium not usually developed, 
 asci isolated, not differentiated 
 from vegetative cells 
 
 Vegetative cells forming a mycelium, 
 asci terminal, or intercalary, 
 differentiated from mycelium. . 
 
 1. Saccharomycetaceae, p. 120. 
 
 2. Endomycetaceae, p. 122. 
 
 The first family, the yeasts, to vi^hich belong the majority of the 
 species of the order, is of prime importance in fermentation. A 
 
 Fig. 82. — Yeast plant-bodies, showing 
 budding and sporulation. After 
 Coulter and Rees. 
 
 few species are known to cause animal diseases; others are found 
 associated with the slime fluxes. 
 
 Saccharomycetaceae 
 
 Vegetative cells separate or few together, never truly filamen- 
 tous, propagating by buds; asci globose to elliptic, 1 to 8-spored; 
 growing typically in sugary or starchy materials. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 121 
 
 Key to Genera of Saccharomycetaceae 
 
 Vegetative cells globose, ovoid, pyriform, etc. 
 Vegetative cells increasing by budding; 
 asci typically 3 to 4 spored. 
 Spores globose or ovoid. 
 
 Spores upon germination forming 
 typical yeast cells. 
 Ascus formation preceded by the 
 
 conjugation of like gametes. . 1. Zygosaccharomyces. 
 Ascus formation not preceded by 
 the conjugation of gametes. 
 
 Spore membrane single 2. Saccharomyces, p. 121. 
 
 Spore membrane double 3. Saccharomycopsis. 
 
 Spores upon germination forming a 
 
 poorly developed promycelium. 4. Saccharomycodes. 
 Spores pileiform or limoniform, costate 5. Willia. 
 Spores hemispheric, angular or irregular 
 in form, upon germination forming 
 
 an extended promycelium 6. Pichia. 
 
 Vegetative cells increasing by fission; asci 
 
 8-spored 7. Schizosaccharomyces. 
 
 Vegetative cells elongate, cylindric; spores 
 filiform, 
 
 Asci 1-spored 8. Monospora. 
 
 Asci 8-spored 9. Nematospora, p. 122, 
 
 Saccharomyces Meyen 
 
 Vegetative cells globose, ellipsoid, ovate, pyriform, etc., repro- 
 ducing by budding and remaining attached in short, simple or 
 branched pseudo-mycelial groups, at length separating; asci 
 globose, ellipsoid, or cylindric, 1 to 4-spored (typically 3 to 4- 
 spored), single or in chains; spores globose to ellipsoid, continuous. 
 
 Many species, chiefly saprophytes. 
 
 S. croci Roze is described as the cause of a crocus disease.^ 
 
 From sorghum plants suffering from blight a yeast was isolated 
 by Radais.^ This when inoculated in pure culture into healthy 
 plants produced the characteristic lesions and effects. 
 
122 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Nematospora Peglion (p. 121) 
 
 Colonies (in culture) disciform; cells elongate; asci cylindric, 
 8-spored; spores filiform, continuous, long-ciliate, hyaline, 
 
 Monotypic. 
 
 N. coryli Pegl.,^ the cause of malformation of the hazel nut in 
 Italy, is a peculiar fungus with what appears to be asci contain- 
 ing eight long slender flagellated spores. 
 
 Endomycetaceae (p. 120) 
 
 Mycelium usually well developed, often producing a luxuriant 
 growth, multiseptate; asci borne singly on branches, or inter- 
 calary, 4 to 8-spored; spores one-celled; conidia produced apically, 
 unicellular. 
 
 Key to Genera of Endomycetaceae 
 
 Mycelium poorly developed, parasitic on 
 
 Mucorales 1. Podocapsa. 
 
 Mycelium well developed 
 Asci formed after conjugation of a pair of 
 
 spirally entwined branches 2. Eremascus. 
 
 Asci formed asexually, produced termi- 
 nally, rarely intercalary. 
 
 Asci 4-spored 3. Endomyces, p. 122, 
 
 Asci 8-spored 4. Oleina. 
 
 Endomyces Rees 
 
 Mycelium well developed, byssoid; asci 
 borne singly on the ends of short lateral 
 l)ranches, globose to pyriform, 4-spored, 
 spores continuous. 
 
 The members of this genus are of ques- 
 tionable importance as parasites. Some 
 //CS^^ are commonly found in sap exuding from 
 ^"aes'of'i'^n^Sres t^^e wounds" where they, together with 
 later form in these, other fungi present, set up a fermentation 
 the products of which prevent the wound 
 from healing and result in injury. One species has been re- 
 ported in America as an active parasite on apples. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 123 
 
 E. mali Lewis ^ 
 
 Mycelium well developed, multiseptate; conidia formed on 
 short conidiophores or on the ends of short germ tubes, averag- 
 ing 3 X 8 m; no yeast-like budding; asci usually 
 on short lateral branches, 11-14 n in diameter; 
 ascospores sphaeroidal, slightly elongate, 4.5 x 
 5.5 fi with thickened places on the walls, brown 
 when mature. Figs. 83, 84. ^J 'g^ _j^ ^^j. 
 
 Lewis isolated the fungus from decayed spots Typical manner 
 
 , , , , ,, T 1 i- 1 of bearing conidia 
 
 on apples by plate cultures. Inoculations proved on agar. After 
 that it is capable of causing a slow decay with- *^^^^" 
 out the aid of other fungi. An extensive cultural study as well as 
 a considerable cytological study was made. 
 
 E. decipiens (Tul.) Rees is parasitic on Armillaria; E. parasitica 
 Fayod on Tricholoma."' " 
 
 Euascomycetes (p. 117) 
 
 This is an extraordinarily large group comprising some 16,000 
 species, with great variety of size, color and shape of plant body. 
 Most of them are saprophytes, still many are parasites either in 
 their ascigerous or their conidial stages of development. 
 
 The twelve orders may be recognized by the following key. 
 
 Key to Orders of Euascomycetes 
 
 Asci approximate in an indefinite hyme- 
 
 nium, no ascoma 1. Protodiscales, p. 125. 
 
 Asci grouped in a definite ascoma 
 
 Asci collected in a flattened, concave or 
 
 closed ascoma, often bordered by a 
 
 distinct layer 
 
 Ascoma at maturity open and more or 
 
 less cup-like. Discomycetes 
 
 Ascoma open from the first, clavate or 
 
 convex, pitted, or gyrose 2. Helvellales, p. 130, 
 
 Ascoma at first closed, opening early, 
 without special covering, more 
 or less fleshy 3. Pezizales, p. 133. 
 
124 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Ascoma opening tardily, enclosed by 
 a tough covering which becomes 
 torn open at the maturity of the 
 spores 
 Ascoma roundish, opening by stel- 
 late or radiating fissures 4. Phacidiales, p. 154. 
 
 Ascoma elongate, opening by a 
 
 longitudinal fissure 5. Hysteriales, p. 159. 
 
 Ascoma at maturity closed and tuber- 
 like, subterranean, 6. Tuberales. 
 
 Asci collected in a cj'lindric or globose 
 
 perithecium 
 
 Perithecia sessile, solitary and free, or 
 
 united and embedded in a stroma 
 
 Asci arranged at different levels in 
 
 the perithecium 7. Aspergillales, p. 164. 
 
 Asci arising from a common level 
 
 Mycelium superficial, perithecia 
 
 scattered, globose and without 
 
 apparent ostiole, or flattened 
 
 and ostiolate 8. Perisporiales, p. 170. 
 
 Mycelium nearly superficial, peri- 
 thecia ostiolate 
 Perithecia and stroma (if pres- 
 ent) fleshy or membranous, 
 
 bright colored 9. Hypocreales, p. 195. 
 
 Perithecia and stroma (if pres- 
 ent) hardened, rarely mem- 
 branous, dark colored 
 Wall of perithecia scarcely 
 distinguishable from the 
 
 stroma 10. Dothidiales, p. 215. 
 
 Perithecia with distinct wall, 
 free or embedded in the 
 
 stroma 11. Sphaeriales, p. 221. 
 
 Perithecium borne on a short pedicel; 
 microscopic fungi parasitic on 
 insects 12. Laboulbeniales. 
 
 Of these all contain plant parasites with two exceptions; the 
 Tuberales, which bear underground tuber-like ascocarps, some of 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 125 
 
 these prized as table delicacies, and the Laboulbeniales, an order 
 rich in species which are all parasitic upon insects. 
 
 Protodiscales (p. 123) 
 
 The 4-8 to many-spored asci form a flat palisade-like hymenium 
 which arises directly from the mycelium; paraphyses none; spores, 
 one-celled, elliptical or round. 
 
 Key to Families of Protodiscales 
 
 Parasitic 1. Exoascaceae, p. 125. 
 
 Saprophytic 2. Ascocorticiaceae. 
 
 Of these families the second contains only one genus and two 
 species found in bark. The first family is aggressively parasitic. 
 
 Exoascaceae 
 
 8-10. 292, 327 
 
 This is the most simple of the parasitic Ascomycetes, definitely 
 recognizable as such, and is comparable with the Exobasidiales 
 among the Basidiomycetes. All the 
 species are parasitic and many of 
 them very injurious. The mycelium, 
 which can be distinguished from 
 that of other fungi by its cells of 
 very irregular size and shape, wan- 
 ders between the host cells (intra- 
 cellular in one species), or is some- 
 times limited to the region just Fig. 85.-Exoascus showing myce- 
 below the cuticle. The asci develop Hum and asci. After Atkinson. 
 
 in a palisade form on a mycelial network under the epidermis, or 
 the cuticle, or on the ends of hyphse arising from below the epi- 
 dermal cells. They are exposed by the rupture of the cuticle or 
 epidermis and contain four to eight hyaline, oval, one-celled 
 spores. These by budding, while still in the ascus, may pro- 
 duce numerous secondary spores, conidia, which give the im- 
 pression of a many-spored ascus. The ascospores also bud freely 
 in nutritive solutions. The primary-ascus-nucleus arises from 
 
128 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 
 fusion of two nuclei as is general among the Ascomycetes. The 
 spore-nuclei arise by repeated mitoses of the primary nucleus. 
 
 Affected leaves, fruit and twigs become swollen and much dis- 
 torted; wrinkled, curled, arched, puckered. In woody twigs the 
 
 mycelium often induces 
 unnatural, profuse, 
 tufted branching result- 
 ing in "witches brooms" 
 though such structures 
 often arise from irrita- 
 tion due to other causes. 
 Many attempts have 
 TT cp T u • x. ■ -^ ■ ^.u been made to arrange the 
 
 fiG. 8b. — 1 aphrina showing mitoses in the young _ _ ° 
 
 ascus leading to the development of spore- species in natural genera; 
 
 nuclei. After Ikeno. , , , , 
 
 some based on the num- 
 ber of ascospores, ' others largely on the biologic grounds of an- 
 nual or perennial mycelium.^ Giesenhagen ^^ whose classification 
 is followed here, recognizes two genera, Exoascus being merged 
 into Taphrina. 
 
 Key to Genera of Ezoascaceae 
 
 Asci cylindric, clavate or abbreviate-cylin- 
 
 dric, produced above the epidermis of 
 
 the host 1. Taphrina, p. 126. 
 
 Asci saccate, in epidermis 2. Magnusiella. 
 
 Taphrina Fries 
 
 Mycelium annual or perennial; asci 4 to 8-spored, or by germina- 
 tion of the ascospores, multispored, borne on the surface of blisters 
 and other hypertrophied areas, cylindric to clavate, or a modifica- 
 tion thereof. Of this genus Giesenhagen ^^ recognizes four series 
 of species which are arranged in three subgenera. 
 
 Subgenus 1. Taphrinopsis, — one series (Filicina) 
 
 The asci are slender clavate, narrowed at each end, rounded 
 above, broadest in the upper fourth. Parasitic on ferns. None of 
 the five species is of economic importance. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 127 
 
 Subgenus. 2. Eutaphrina, — one series (Betula) 
 
 Asci broadly cylindric, rarely contracted at the base or from 
 the middle down, truncate above and sometimes in-sunken. On 
 Amentacese, chiefly Betula, Alnus, Ostrya, Carpinus, Quercus, 
 Populus. Of the twenty-four species of this series but few are 
 of importance. 
 
 T. coerulescens (D. & M.) Tul.^^ Annual, producing blisters 
 on the leaves of oak, the sporing surface bluish; asci elongate, 
 broadl}^ cylindric, 55-78 x 18-24 /x; spores breaking up into 
 conidia. 
 
 On various species of Quercus in Europe and America. 
 
 T. ulmi (Fcl.) Joh., on the elm; T. aurea (Pers.) Fries on the 
 leaves of Populus and T. johonsonii Sad. on the fertile aments of 
 the aspen are among the more important remaining species of the 
 series. 
 
 Subgenus 3. Exoascus, — two series 
 
 Asci clavate, normally cylindric or more or less abbreviated. 
 
 (1) Prunus series on Rosacese. Asci slender, clavate, narrowed 
 below, broadest in their upper fourth, varying through all inter- 
 mediate forms to narrowly cylindric. 
 
 (2) iEsculus series, on Sapindacae, Anacardiacese, etc. — Asci 
 broadly cylindric, short, rounded or truncate. 
 
 The more important economic species of the genus belong to 
 the Prunus series. 
 
 T. deformans (Fcl.) Tul.^- '-' '^ 
 
 The irregular vegetative mycelium devoid of haustoria grows 
 in the leaf parenchyma and petiole and in the cortex of branches. 
 A distributive mycelium lies close beneath the epidermal cells of 
 twigs and in the pith and extends some distance through the twig. 
 Fig. 87. Branches arise from the vegetative mycelium, penetrate 
 between the epidermal cells to the cuticle and then branch freely 
 to form a network of short distended cells beneath the cuticle. 
 This is the hymenium, a layer of ascogenous cells. These cells 
 elongate perpendicularly to the host's surface, Fig. 85, rupture 
 the cuticle, and form a plush-like layer. The protoplasmic con- 
 
128 
 
 THE FUNGI WHICH CAUSE PLAxNT DISEASE 
 
 tents crowds toward the tips of these cells and a basal septum cuts 
 off the ascus proper from the stalk cell, Fig. 88. The spores then 
 form within the ascus. The ascospores may bud either before 
 
 or after extrusion 
 from the ascus, pro- 
 ducing conidia, which 
 may themselves bud 
 indefinitely, producing 
 secondary, tertiary, 
 etc., crops. In this 
 condition the conidia 
 strongly resemble 
 yeast cells. On the 
 host plant ascospores 
 germinate by germ 
 tubes, which are ca- 
 p a b 1 e of infecting 
 proper hosts. No 
 success has rewarded 
 attempts to secure 
 germ tubes from co- 
 nidia. Leaf infection 
 is chiefly external; 
 rarely internal from 
 mycelium perennating 
 in the twigs. It oc- 
 curs when the leaf is 
 very young. Infected 
 leaves are thickened 
 and broadened and 
 the tissues are stiff 
 and coriaceous. The 
 palisade cells increase in size and .number and lose their chloro- 
 phyll. Blistering and reddening of the leaves follows. 
 
 Asci clavate, 25-40 x 8-11 ^; spores 8, subglobose or oval, 
 3-4 IX. On the peach in Europe, North America, China, Japan, 
 Algeria and South Africa. 
 
 T. pruni (Fcl.) Tul.^' ^^ j^. f^^nd in Europe and North America 
 
 
 Fiu. 87. — T. deformans 5, distributive hj'pha, 
 1, vegetative hyphse; 9, sponferous hyphae. After 
 Pierce. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 129 
 
 on plum and wild cherry, causing "plum pockets." The ovary is 
 the seat of attack. The mycelium after bud infection pervades 
 the mesocarp which hypertrophies and alone produces a much 
 enlarged fruit, usually with entire sacrifice of the other fruit parts. 
 Asci are formed over the diseased surface much as in the last 
 species. The mycelium is perennial in the bast and grows out into 
 the new shoots and 
 buds each spring. In- 
 fection also reaches 
 other shoots and trees 
 by means of the spores. 
 
 Ascus elongate-cylin- 
 dric, 30-60 x 8-15 tx; 
 spores 8, globose 4-5 ix. 
 Perennial. 
 
 T.cerasi(Fcl.)Sad.8'i^ 
 produces the witches 
 broom effect upon culti- 
 vated and wild cherries. 
 It is common in Eu- 
 rope, rare in America. 
 Perennial ; asci clavate 
 30-50 X 7-10 m; spores 
 8, forming conidia in 
 the ascus, oval, 6-9 x 
 5-7 II. 
 
 On Prunus avium, P. cerasus, etc. in North America and 
 Europe. 
 
 T. mirabilis (Atk.) Gies.^' ^^ grows on leaf buds and twigs of 
 Prunus angustifolia, P. hortulana, P. americana in North America. 
 
 Perennial ; sporing on the fruits and tips of branches of the host ; 
 asci subcylindric, blunt above, 25-45 x 8-10 /x; spores 8, ovate. 
 , T. longipes (Atk.) Gies. is on Prunus americana in North 
 America, causing plum pockets.^ 
 
 Perennial; sporing on young fruits; asci cylindric, truncate or 
 not, 30-40 X 7-10 ix; spores 8, globose or ovate, 3-4 ju. 
 
 T. rhizipes (Atk.) Gies. Known only in North America, caus- 
 ing pockets on Japanese plums ; ^ probably of wider distribution. 
 
 T^-CTl 
 
 Fig. 88. — T. deformans. Young and old asci. 
 After Pierce. 
 
130 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Perennial; asci cylindric, or club-shaped, 30-40 x 8-10 n, 
 appearing to have basal rhizoids; spores 8, globose. 
 
 T. communis (Sad.) Gies.^ Perennial in branches; sporing on 
 immature fruits; asci clavate, 24-45 x 6-10 ix; spores 8, elliptic, 
 5 X 3-4 n, often producing conidia. 
 
 On Prunus americana, P. maritima, P. nigra, and P. pmnila, in 
 North America. 
 
 T. institiae (Sad.) Joh. Forming witches brooms on Prunus 
 institia, P. domestica, and P. pennsylvanica in Europe and 
 America.^ 
 
 Perennial; sporing on the under side of the leaf; asci clavate to 
 cylindric, 25-30 x 8-10 jn; spores 8, not rarely producing conidia, 
 globose, 3.5 jjl. 
 
 T. decipiens (Atk.) Gies. On Prunus americana in North 
 America.^ 
 
 Perennial; sporing on under surfaces of leaves; asci irregularly 
 clavate, often almost cylindric, 20-40 x 10 /i; spores breaking up 
 into conidia. 
 
 T. buUata (Fcl.) Tul. On pear and Japanese quince. 
 
 Annual; asci clavate, 36-40 x 8-9 /i; spores 8, often forming 
 conidia, globose, about 5 jx. 
 
 T. farlowii (Sad.) Gies.^ is found on Prunus serotina in America; 
 T. minor Sad. on leaves of Prunus chamaecerasus and P. cerasus, 
 in Germany and England. It has recently caused considerable 
 damage in South England. 
 
 T. bassei Fab. causes witches broom of cacao in Kamerun. 
 
 T. rostrupiana (Sad.) Gies. is on Prunus spinosa; 
 
 T. crataegi (Fcl.) Sad. on Crataegus oxycantha. 
 
 T. maculans Butler is reported on Tumeric and Zinzibar by 
 Butler.-^^ T. theobromae Ritzema Bos. is reported as injurious to 
 the cacao tree. 
 
 Many other species of Taphrina of minor importance occur upon 
 alder, poplar (Populus), Carpinus, birch, elm, maple, hawthorn, 
 oak and numerous other hosts. 
 
 Helvellales (p. 123) 
 
 Ascoma fleshy, separable into a definite hymenium of asci and 
 paraphyses and a stroma which is usually large and stalk-like; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 131 
 
 fertile portion more or less cap-like; hymenium free from the first 
 or covered with a thin, evanescent veil; '^ asci cylindric, opening 
 by an apical pore; spores ellipsoid, colorless or light yellow, smooth, 
 or in one genus echinulate. 
 
 Key to Families of Helvellales 
 
 Ascocarp stalked 
 
 Fertile portion clavatc or capitate; asci 
 
 opening by an irregular slit 1. Geoglossaceae, p. 131. 
 
 Fertile portion pileate; asci opening by a lid. 2. Helvellaceae. 
 Ascocarp sessile 3. Rhizinaceae, p. 132. 
 
 The majority of the species of this order are saprophytes, the 
 only parasites being of the first and third families. Of the second 
 family many of the species are edible and some are very large. 
 
 Geoglossaceae 
 
 Key to Tribes and Genera of Geoglossaceae 
 
 Ascoma clavate or spatulate, ascigerous 
 portion usually more or less com- 
 pressed, rarely subglobose . . . . Tribe I. Geoglosseae. 
 Ascoma clavate, fertile portion at most 
 only slightly decurrent 
 Spores small, elliptic, cylindric or 
 fusiform, continuous ; plants 
 
 bright colored 1. Mitrula, p. 132. 
 
 Spores long, elliptic to cylindric, 3 to 
 many-septate at maturity 
 
 Hymenium bright colored 2. Microglossum. 
 
 Hj^menium black or blackish 
 
 Spores hyaline 3. Corynetes. 
 
 Spores brown 4. Geoglossum. 
 
 Ascoma spatulate or fan-shaped, as- 
 cigerous portion decurrent on the stipe 
 Ascigerous only on one side of the 
 
 stem 5. Hemiglossum. 
 
 Ascigerous on both sides the stem 
 
 Spores globose 6. Neolecta. 
 
 Spores elongate 7. Spathularia. 
 
 Ascoma stalked, capitate or pileate, in one 
 
 genus sessile II. Cudonieae. 
 
132 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Fig. 89. — Mitrul 
 sketch; F, asci 
 
 Mitrula sclerotiorum Rost.^^ 
 which causes a disease of alfalfa in 
 Denmark is the only pathogen of 
 the family. The infected plants die 
 and later the roots and stems be- 
 come filled with black sclerotia 
 which lie dormant about a year. 
 
 B, habit Upon resuming growth they be- 
 After Schroter. , , ^■ ^ . ^ ^ 
 
 come covered by light red eleva- 
 
 tions, which bear small light red ascocarps. 
 
 Rhizinaceae (p. 131) 
 Key to Genera of Rhizinaceae 
 
 Spores elliptic or spindle-shaped 
 
 Without rhizoid-like structures 1. Psilopezia. 
 
 With rhizoid-like structures 2. Rhizina, p. 132. 
 
 Spores globose 3. Sphaerosoma. 
 
 Only one genus, Rhizina, causes 
 disease. 
 
 Rhizina Fries with some eight 
 species is recognized by its crust- 
 formed, sessile, flat ascophore with 
 root-like outgrowths from the lower 
 side. Fig. 90. Asci cylindrical, 8- 
 spored, opening by a lid; spores one- 
 celled, hyaline; paraphyses many. It 
 is often purely saprophytic, growing 
 in burned-over spots in forests. 
 
 R. inflata (Schaff) Quel.'^' ^* is 
 counted as the cause of serious root 
 diseases of forest trees, especially 
 conifers, in Europe. The fungus also 
 occurs in Asia and America. 
 
 R. undulata causes death of fir seedlings. -^^ 
 
 Fig. 90. — Rhizina inflata. B, asco- 
 carp from below; C, asci and 
 paraphyses. After Schroter and 
 Tulasne. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 133 
 
 Pezizales (p. 123) 
 
 In this order unlike the last, the hymenium is at first enclosed 
 but soon becomes exposed. The apothecia at maturity are typi- 
 cally disc or saucer-shaped (Fig. 101) or sometimes deeper, as 
 cup, beaker or pitcher-shaped. They vary from a size barely 
 visible up to 8-10 cm. in diameter. Some are stalked, more often 
 they are sessile. In consistency they vary from fleshy or even 
 gelatinous to horny. Paraphyses are present and may unite over 
 the asci to form a covering, the epithecium. The apothecium may 
 be differentiated into two layers; the upper bearing the asci is the 
 hypothecium, the lower the peridium. In some cases sclerotia 
 are formed. Many species possess conidiospores as well as asco- 
 spores, borne either on hyphae or in pycnidia. The great majority 
 are saprophytes, a few are parasitic. There are some three thou- 
 sand species. 
 
 Key to Families of Pezizales 
 
 No lichenoid thallus and no algal cells 
 Ascocarps free, solitary or cespitose 
 Ascocarps fleshy or waxy, rarely gelati- 
 nous; ends of paraphyses free 
 Peridium and hj^pothecium without 
 distinct lines of junction 
 Ascoma open from the beginning, 
 convex; peridium wanting or 
 
 poorly developed 1. Pyronemaceae. 
 
 Ascoma concave at first; a fleshy 
 peridium present. 
 » Asci forming a uniform stratum, 
 
 at maturity not projecting. 2. Pezizaceae. 
 Asci projecting from the ascoma 
 
 at maturity 3. Ascobolaceae. 
 
 Peridium forming a more or less dif- 
 ferentiated membrane. 
 Peridium of elongate, parallel 
 pseudo-parenchymatous, hya- 
 line, thin-walled cells 4. Helotiaceae, p. 134. 
 
134 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Peridium firm, of roundish or angu- 
 lar, pesudo-parenchymatous, 
 
 mostly dark, thick-walled cells 5. MoUisiacese, p. 146. 
 Ascocarps leathery, horny or cartilagi- 
 nous ; ends of the paraphyses united 
 into an epithecium 
 Peridium wanting or poorly devel- 
 oped 6. Celidiaceae. 
 
 Peridium well developed, mostly 
 leathery or horny 
 Ascccarps free from the beginning, 
 dish or plate-shaped, never en- 
 closed by a membrane 7. Patellariacese. 
 
 Ascocarps at first embedded in a 
 matrix, then erumpent, urceo- 
 late or cup-shaped, at first en- 
 closed in a membrane which 
 
 disappears later 8. CenangiaceaD, p. 150. 
 
 Ascocarps borne on a highly developed 
 stringy or globoid stroma 
 Ascocarps at the ends of the branches 
 
 of a cord-like stroma 9. Cordieritidaceae. 
 
 Ascocarps embedded in the upper por- 
 tion of a globoid stroma 10. Cyttariaceae. 
 
 Lichenoid thallus more or less prominent, 
 algal cells typically present, asci disap- 
 pearing early, disk with a mazsedium. . 11. Caliciaceae, p. 153. 
 
 The Pyronemacese, Peziacese, and Ascobolacese are pure sapro- 
 phytes on organic matter in the ground or on rotting wood. The 
 Patellariacese are largely, and the Celidiaceae are nearly all, para- 
 sitic on lichens. The Cordieritidaceae of four species, possessing 
 a stony stroma, are unimportant. The Cyttariacese, of one genus, 
 and some six species, are limited to the southern hemisphere where 
 they grow on branches of the beech. 
 
 Helotiaceae (p. 133) 
 
 In members of this family there is a distinctly differentiated 
 
 peridium. The apothecia are usually fleshy or waxy, superficial, 
 
 first closed, later opening; the paraphyses form no epithecium. 
 
 Asci 8-spored. Spores round to thread-shaped, one to 8-celled, 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 135 
 
 hyaline. Some of the genera are among the most serious of 
 plant pathogens. About one thousand species. 
 
 Key to Genera of Helotiaceae 
 
 Ascocarps fleshy, fleshy-waxy, thick ormem- 
 branous 
 Ascocarps fleshy-waxy, brittle when fresh, 
 
 leathery when dry I. Sarcoscypheae. 
 
 Ascocarps felty hairy externally 1. Sarcoscypha. 
 
 Ascocarps covered with bristle-like hairs 
 
 externally 2. Pilocratera. 
 
 Ascocarps naked 
 
 Ascocarps springing from a sclero- 
 
 tium 3. Sclerotinia, p. 136. 
 
 Ascocarps not springing from a 
 sclerotium 
 Spores 1-celled 
 
 Substratum green 4. Chlorosplenium, p. 144. 
 
 Substratum uncolored 5. Ciboria. 
 
 Spores at length 2 to 4-celled .... 6. Rutstroemia. 
 Ascocarps waxy, thick, tough or mem- 
 branous 
 
 Ascocarps externally hairy II. Trichopezizeae. 
 
 Ascocarps resting on an extended 
 arachnoid mycelium 
 
 Spores 1-celled 7. Eriopeziza. 
 
 Spores becoming several-celled. . . 8. Arachnopeziza. 
 Ascocarps without arachnoid my- 
 celium 
 
 Spores globose 9. Lachnellula. 
 
 Spores ellipsoid or elongate 
 
 Disk surrounded by black hairs. 10. Desmazierella. 
 Disk smooth 
 Paraphyses obtuse at the apex 
 Walls of ascoma delicate; 
 spores mostly 1-celled, 
 rarely 2-celled at ma- 
 turity 11. Dasyscypha, p. 144. 
 
 Walls of ascoma thick; 
 spores 2-celled at ma- 
 turity 12. Lachnella, p. 145. 
 
136. THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Paraphyses lancet-shaped at 
 apex 
 
 Spores 1 -celled 13. Lachnum. 
 
 Spores at length several- 
 celled 14. Erinella. 
 
 Ascocarps naked III. Helotieae. 
 
 Spores globose 15. Pitya. 
 
 Spores ellipsoid or fusiform 
 Spores 1-celled 
 
 Border of disk smooth 16. Hymenoscypha, p. 146. 
 
 Border of disk toothed 17. Cyathicula. 
 
 Spores at length 2 to 4-celled 
 Ascocarps sessile, rarely com- 
 pressed at base 18. Belonium. 
 
 Ascocarps stalked, or at least 
 compressed like a stalk 
 Walls of ascoma waxy; stem 
 
 short and dehcate 19. Belonioscypha. 
 
 Walls of ascoma waxy, thick; 
 
 stem thick 20. Helotium. 
 
 Spores filiform 
 
 Ascocarps sessile 21. Gorgoniceps. 
 
 Ascocarps stalked 22. Pocillum. 
 
 Ascocarps gelatinous gristly, horny when 
 
 dry IV. Ombrophileae. 
 
 Of these genera only the five given below have parasitic represen- 
 tatives of economic importance, while only one to two others are 
 parasitic. The rest grow as saprophytes on rotting wood and 
 organic debris in the soil. 
 
 Sclerotinia Fuckel (p. 135) 
 
 This genus contains several very important pathogens, some 
 of them preying upon a wide range of hosts and causing great loss. 
 A striking feature of the genus is the sclerotium which is black and 
 borne within the host tissue or upon its surface. From the sclerotia 
 after a more or less protracted period the apothecia develop. These 
 are disc-shaped and stalked. The asci are 8-spored ; spores elliptical 
 or fusiform, unicellular, hyaline, straight or curved. Some species 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 137 
 
 Fig. 91. — S. urnula, 
 moniliform conidia 
 with disjunctors. 
 After Woronin. 
 
 possess Botrytis forms (see pp. 141 and 578), others Monilia (see 
 
 pp. 139 and 558) forms of conidial fructification. In addition to 
 
 these there may be gonidia, which appear to be 
 
 degenerate, f unctionless conidia. In some species 
 
 there is no known spore form except that in the 
 
 ascus. 
 
 S. ledi Now. is of especial interest as the one 
 fungus outside of the Uredinales that exhibits 
 heteroecism.^^" 
 
 Many forms found upon separate hosts and 
 presenting shght differences under the micro- 
 scope, often even no microscopic differences, 
 have been named as separate species. Only 
 long careful culture studies and inoculation ex- 
 periments will determine which of these species 
 are valid, where more segregation, where more 
 aggregation is needed. 
 
 The mere association of Botrytis or Monilia 
 conidial forms with Sclerotinia, in the same host, 
 has repeatedly led to the assumption that such forms were genetic- 
 ally connected. Such assumptions are not warranted. Only the most 
 careful study and most complete evidence justify such conclusions. 
 
 The genus contains some fifty species which are divided into two 
 subgenera; Stromatinia Boud., forming sclerotia in the fruits of 
 the host; Eusclerotinia Rehm forming sclerotia in or on stems 
 and leaves of the host. 
 
 When conidia are known those of Stromatinia are of the Monilia 
 tj'pe and those of Eusclerotinia of the Botrytis type. Each group 
 contains important economic species. 
 
 S. fructigena, S. cinerea and S. laxa.'-°' -^' -^' -^i-^ss 
 
 These forms are perpetuated chiefly by their conidia. The 
 ascus-forms are much less often seen. 
 
 When the conidia. fall upon the peach, the mycelium develops 
 and penetrates even the sound skin; then rapidly induces a brown 
 rot. The mycelium within the tissue is septate, much branched, 
 and light brown in color. It soon proceeds to form a subepidermal 
 layer and from this the hyphie arise in dusty tufts of Monilia-form 
 conidiophores and conidia (Fig. 92) . The earlier conidia are thin- 
 
138 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 walled and short lived, the later ones thicker walled and more 
 enduring. 
 
 After some weeks these tufts cease forming and disappear. The 
 mycelium within the fruit persists, turns olivaceous and forms 
 large irregular sclerotioid masses which on the following spring 
 may produce fresh conidia. 
 
 These sclerotioid (mummified) fruits under suitable conditions 
 
 Fig. 92. — Sclerotinia on plum, a, section showing a spore pustule and chains 
 of conidia; b, part of a spore-chain; c, spores germinating; d, a mummy 
 plum and ascophores; e, an ascophore; /, ascus; g, mature spores. After 
 Longyear. 
 
 in nature, usually at blossom time of the host, can also produce 
 apothecia, a fact first demonstrated by Norton. ^^ 
 
 These apothecia develop in large numbers from old fruits half 
 buried in soil, and send forth ascospores to aid in infection. The 
 ascospores germinate readily in water and it was proved by Norton 
 that they give rise to a mycelium which produces the characteristic 
 Monilia. Inoculation of ascospores on fruit and leaves also gave 
 positive results in two or three days. The flowers, and through 
 them the twigs, are also invaded by the mycelium which seeks 
 chiefly the cambium and bast. Shot-hole effect is produced on 
 leaves of peach and cherry (Whetzel ^^). Infection is frequently 
 through minute wounds.^* 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 139 
 
 Fig. 93.— S. fuckeli- 
 ana, attachment 
 organ. After Ist- 
 vanffi. 
 
 On the apple the fungus shows two different modes of develop- 
 ment. In some cases the mycehum accumulates under the epider- 
 mis without producing spores, becomes dark colored and also 
 causes a darkening of the contents of the host cells, which results 
 in a black spot giving rise to the name black 
 rot. In other cases ^^ the mycelium produces a 
 brown rot and abundant conidial tufts, ar- 
 ranged in concentric circles around the point 
 of infection. 
 
 The form on pomaceous fruits has long been 
 regarded as identical with that on stone fruits; 
 but recently, at least in Europe, they have been 
 distinguished on cultural and morphological 
 grounds * (see also^^'^'^), as separate species, 
 the most distinctive character perhaps being 
 the color of the mass of conidia. In a similar 
 way S. laxa Ad & Ruhl. is set aside as a distinct species infecting 
 only apricots. ^-^ 
 
 American mycologists are inclined to doubt the distinctness of 
 the species on drupes and pomes in this country. 
 S. fructigena (Pers.) Schr. 
 Apothecia from sclerotia produced either 
 in or on mummied fruits, 0.5-3 cm. high, 
 stem dark brown, disk lighter, 5-8 or even 
 15 mm. in diameter; asci 125-215 x 7-10 /z; 
 spores ellipsoidal, 10-15 x 5-8 /i. 
 
 Conidia (=Monilia fructigena Pers.). Co- 
 nidiophores covering the fruits of the host 
 with a dense mold-like growth of light 
 brownish-yellow or ochraceous color; spores 
 averaging 20.9 x 12.1 /x. On stone and 
 pome fruits, especially the latter. 
 S. cinerea (Bon.) Wor. 
 Apothecia and asci similar to those of 
 S. fructigena, Conidia (=Momlia cinerea 
 Bon.). Conidiophores covering the fruits 
 with a dense grayish mold-like growth; spores averaging 12.1 x 
 8.8 fjL. On stone and pome fruits, especially the former. 
 
 Fig. 94. — -Typical conid- 
 iophore and conidia 
 of the Botrytis-form 
 of S. fuckeliana. Af- 
 ter Smith. 
 
140 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 S. linhartiana P. & D.^^ is reported on quince in France. S. 
 
 mespili Schell on medlar. S. seaveri, Rehm., conidia = Monilia 
 
 seaveri, is on Prunus serotina.^^^ 
 
 S. padi Wor. is found on Prunus padus and Castanea.^^ 
 
 It possesses a Monilia-form conidial stage with typical dis- 
 
 junctors, i. e., spindle-shaped cellulose bodies between the conidia, 
 
 which easily break across to facilitate the separation of the conidia. 
 
 Fig. 95. — S. libertiana. Sclerotia produced in artificial cul- 
 ture. After Stevens and Hall. 
 
 S. oxycocci Wor. is found on cranberry. It is unique in that 
 half of the spores in each ascus are larger than the others. The 
 conidial stage is a Monilia. 
 
 S. fuckeUana (De Bary) Fcl.'-^ 
 
 Apothecia in clusters of 2-3 from sclerotia in the leaves, rarely 
 in the fruits, of the host, yellowish-brown, 0.5-4 /i across, stem 
 slender; ascospores 10-11 x 6-7 /x. 
 
 Conidia (=Botrytis cinerea Pers., B. vulgaris Fr.). Conidio- 
 phores simple or branched, forming dense gray tufts; conidia sub- 
 globose, usually minutely apiculate, almost hyaline, 10-12 n. 
 Fig. 94. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 141 
 
 It causes a rot of the grape, much dreaded in Europe, attacking 
 leaves, fruit and stem. The fungus can persist long as a sapro- 
 phyte in the conidial condition. Sclerotia are borne within the 
 affected tissues. On germination they may either produce the 
 conidia directly or form apothecia. Both ascospores and conidia 
 are capable of infecting the grape but infection is much more 
 certain from a vigorous mycelium (see S. libertiana, p. 142). 
 
 Attachment organs, c. f. Fig. 93, which consist of close branch- 
 clusters and seem to be induced by contact of a mycelial tip with 
 any hard substance are present in abundance. Both toxins and 
 digestive enzymes are produced.-^' ^^ 
 
 Botrytis douglasii on pine is perhaps identical with the conidial 
 form of the last fungus (see p. 140) as may also be the Botrytis of 
 Ward's Lily Disease; ^° the Botrytis causing disease of goose- 
 berries ^^ and many others that have been named as distinct 
 species of Botrytis. 
 
 S. galanthina Ludwig, close kin to S. fuckeliana, attacks snow- 
 drops. S. rhododendri Fisch. occurs on Rhododendron. 
 
 The former of these two is supposed to be the ascigerous form 
 of Botrytis galanthina Berk. & Br. but no conclusive proof has 
 been adduced. 
 
 S. libertiana Fcl.^- 
 
 Sclerotia from a few millimeters up to 3 cm. in length, black; 
 apothecia scattered, pale, 4-8 mm. or more broad, stem slender; 
 asci cylindric, 130-135 x 8-10 ^t, apically 
 very slightly bluish; spores ellipsoid, 
 usually minutely guttulate, 9-13 x 
 4-6.5 fx; paraphyses clavate. 
 
 This fungus affects numerous hosts. 
 Among the most important on which it 
 causes serious disease are lettuce, ^^' ^^* ^^' ^^ 
 ginseng,^^ cucumber,^^ carrot, potato, Fig. 96.— S. lii.citiana. 
 parsley, hemp, rape, various bulbs, zinnia, Ifte^sfeven^'* and Hall"''' 
 petunia, etc. The white mycelium is 
 
 found superficially and within the host, especially at places 
 where moisture is retained, as between leaves, at leaf axils, etc., 
 also within plant cavities. Microscopically it consists of long 
 cells branching in a rather characteristic way. Fig. 97. Within 
 
142 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Fig. 97. — Mycelium showing septation and 
 branching. After Stevens and Hall. 
 
 the host's tissue the hyphal threads are thicker, richer in proto- 
 plasm, more septate, and much more branched and crooked 
 than outside of the host. Aerial hyphal filaments when they 
 touch a solid repeatedly branch in close compact fashion form- 
 ing the attachment organs. 
 
 At the exhaustion of the food supply and the consequent term- 
 ination of the vegetative period the mycelium becomes very dense 
 in spots and within these clumps of mycelium the sclerotium 
 forms; at first white, later pink, finally smooth and black (Fig. 95). 
 They are often found in the leaf axils (lettuce), in the pith of 
 
 stems (carrot), etc. Under 
 some conditions, as on un- 
 suitable nutrient media, 
 gonidia are produced. 
 
 The sclerotia can ger- 
 minate at once or remain 
 dormant for one, perhaps 
 several years. On ger- 
 mination they send forth 
 from 1 to 35 ^"^ negatively geotropic sprouts which grow to the 
 soil surface unless that be more than about 5 cm. distant. On 
 reaching the light the apex of the sprout begins to thicken and 
 soon develops its apothecium; at first inverted- 
 conidial, soon flat, and finally somewhat revo- 
 lute. Changes in atmospheric humidity cause 
 the discharge of ascospores in white clouds. 
 
 The ascospores germinate readily but the re- 
 sulting mycelium is of such small vigor that it 
 is incapable of parasitism. If the ascospore 
 germinates where it can maintain a saprophytic Fig. 98.— S. liber- 
 life until a vigorous mycelium is developed then paraphyses^.'^^ After 
 the mycelium may become parasitic. Stevens and Hall. 
 
 Both ascospores and mycelium are comparatively short-lived. 
 The mycelium can migrate but a short distance over soil. No 
 form of conidia except the apparently functionless gonidia is 
 produced. The fungus may be cultivated easily upon almost any 
 medium, corn-meal-agar is especially suitable. 
 
 It has been repeatedly claimed that this fungus possesses a 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 143 
 
 Botrytis conidial stage l)iit the results of much careful work deny 
 this.34' 40 
 
 Recent tests by Westerdijk ^'^ indicate the absence of such 
 biologic specialization in regard to hosts as 
 is found in the Erysiphe and elsewhere. 
 
 S. nicotianae Oud. & Kon.^^' "^^ parasitize;; 
 the leaves and stems of tobacco. It is 
 possibly identical with S. libertiana. 
 S. trifoliorum Erik.^^"^^ 
 In general this resembles S. libertiana 
 with which it is by some regarded as iden- 
 tical; sufficient evidence has, however, not 
 been adduced to prove them the same. 
 The sclerotia, varying in size from that of 
 a mustard seed to a pea, are found in the de- 
 cayed tissue, or as larger flat surface sclero- 
 tia. No conidia except 
 the functionless gonidia. 
 Unknown on clover. 
 
 S. bulborum (Wak.) 
 Rehm "^^ which is very 
 similar to S. trifoliorum 
 
 and without known conidia grows on hyacinth, 
 crocus, scilla and tulip. Cross infections be- 
 tween hyacinth and clover have not, however, 
 been successful and the species may be dis- 
 tinct. A sterile form, Sclerotium tuliparum, 
 found on the tulip may also belong here. 
 
 S. tuberosa Fcl. is found on wild and culti- 
 vated anemones. 
 
 Several other species of the genus, among 
 them S. alni Maul, S. betulae Wor., S. aucupa- 
 riae Ludw, S. crategi Magn., are found on 
 Ericacese, Betulacese, Rosacese, Graminese, etc., but they are not 
 of sufficient economic importance to warrant further notice 
 here. 
 
 Fig. 99. — Cultures of .scle- 
 rotinia from tobacco on 
 potato agar, showing 
 sclerotia. After Clinton. 
 
 K 
 
 Fig. 100.— C. serug- 
 inosum. J, ascus; 
 K, ascospores; L, 
 conidia. After 
 Rehm and Bre- 
 feld. 
 
144 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Chlorosplenium Fries (p. 135) 
 
 Ascoma mostly aggregated, small, stalked, smooth without, 
 green; asci cylindric, 8-spored; spores elongate, 1-celled, guttulate, 
 hyaline; paraphyses linear. 
 
 The genus consists of some ten species only one of which is of 
 interest hero. 
 
 C. aeruginosum (Oed.) d Not. 
 
 The apothecia and mycelium are verdigris-green as is also the 
 
 Fig. 101. — D. wilkomii. A, natural size and single apothe- 
 cium enlarged; B, an ascus. After Lindau. 
 
 wood penetrated by it. The fungus appears to be mainly sapro- 
 phytic but may be partially parasitic. Fig. 100. 
 
 Dasyscypha Fries (p. 135) 
 
 This is a genus of some one hundred fifty species, mostly sapro- 
 phytic but sometimes parasitic on twigs. The apothecia are small, 
 short-stalked or sessile, waxy or membranous, bright colored in the 
 disk, with mostly simple hairs on the outside and margin. Asci 
 cylindrical or clavate, 8-spored; spores ellipsoid or fusiform, 
 hyaline, 1-celled, rarely 2-celled, sometimes guttulate; paraphyses 
 blunt, needle-like. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 145 
 
 D. willkommii Hart.''' causes a serious European larch disease 
 and affects also the pine and fir. 
 
 The stromata appear as yellowish-white pustules on the bark 
 soon after its death. Here hyaline conidia are produced on the 
 open surface or in cavities. Apothecia 2-5 mm. broad appear 
 later. The ascospores can infect wounds: the conidia seem to be 
 functionless. The myce- 
 lium spreads through the 
 sieve tubes, intercellular 
 spaces, and xylem to the 
 pith. 
 
 Apothecia short-stalked, 
 yellowish without, orange 
 within; asci 120 x 9 fx; 
 spores 18-25 x 5-6 n; 
 paraphyses longer than 
 the ascus. 
 
 D. resinaria Rehm ''^ is 
 a wound parasite much 
 like the above in its ef- 
 fects. It occurs chiefly on 
 spruce and larch but sometimes also on pine, both in Europe 
 and America. 
 
 Ascophores upon cankers on branches and trunk of the host, 
 very similar to those of the preceding species but with more evident 
 stipe and paler disk; spores very minute, subglobose, 3 x 2-2.5 ju; 
 conidia 2x1 ix. 
 
 D. calyciformis (d Wild.) Rehm occurs on several conifers; 
 D. subtilissima (Sacc.) on fir and larch; D. abietis Sacc. on Picea. 
 
 Fig. 102. — Lachnella. F, habit sketch ; G, ascus 
 and paraphyses. After Rehm. 
 
 Lachnella Fries (p. 135) 
 
 This is similar to the last genus but with the apothecia usually 
 sessile and the spores usually 2-celled at maturity, and in two 
 rows in the ascus. There are about forty species. 
 
 L. pini Brun.^® injures pine twigs. The apothecia are brown 
 outside; the disc reddish-yellow with a white margin. 
 
 Ascoma short-stipitate, 5 mm. in diameter, pale brown; disk light 
 
146 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 orange-red with a pale margin; asci 109 x 8-9.5 fx; spores 19-20 x 
 6.5-8.5 fx, hyaline. 
 
 Hymenoscypha Fries (p. 136) 
 
 This genus of over two hundred species is mainly saprophytic, 
 one species only in its conidial stage being parasitic. 
 
 Ascoma sessile or short-stipitate, usually 
 smooth; asci cylindric to globoid, 8-spored; 
 spores elliptic, blunt to pointed, hyaline; 
 paraphyses filamentose, apically enlarged, 
 hyaline. 
 
 H. tumulenta P. & D.^° in its conidial 
 stage as Endoconidium, affects rye grain 
 causing it to shrivel and assume poisonous 
 properties. The conidia are borne en- 
 dogenously in the terminal branches of the 
 hyphse and escape through an opening in 
 the end of the branch. 
 
 Fig. 103. — Hymenoscy- 
 pha. J, habit sketch; 
 K, ascus and paraphy- 
 ses. After Rehm. 
 
 MoUisiaceae (p. 134) 
 
 Ascocarp free from the first or sunken in 
 the substratum and later erumpent, at first 
 more or less globose, becoming flattened; asci 8-spored, opening 
 by a slit; spores hyaline, 1 to many-celled; paraphyses slender. 
 Above four hundred species. 
 
 Key to Genera of Mollisiaceae 
 
 Ascocarp fleshy, waxy, rarely membranous. I. Mollisieae. 
 Ascocarps not sunken in the substratum 
 Ascocarps on a visible, often radiate 
 mycelium 
 Spores elongate, often fusiform, 
 
 1-celled 1. Tapesia. 
 
 Spores filiform, many-celled 2. Trichobelonium. 
 
 Ascocarps not seated on a visible my- 
 celium 
 Spores 1-celled 
 
 Spores spherical 3. Mollisiella. 
 
 Spores elongate 4. MoUisia. 
 
THE FIINGI WHICH CAUSE PLANT DISEASE 147 
 
 Spores becoming 2-celled 5. Niptera. 
 
 Spores elongate filiform, -l-celled .... 6. Belonidium. 
 
 Spores filiform many-celled 7. Belonopsis. 
 
 Ascocarps at first smiken in the substra- 
 tum, later erumpcnt 
 Ascocarps bright colored, only slightly 
 erumpent 
 Spores ellispoid or elongate, rounded, 
 
 1-celled 8. Pseudopeziza, p. 147. 
 
 Spores becoming many-celled 9. Fabraea, p. 149. 
 
 Ascocarps dark colored, at length 
 strongly erumpent 
 Spores ellipsoid or fusiform, 1-celled 
 Ascocarps bristly externally and on 
 
 the margin 10. Pirottaea. 
 
 Ascocarps externally smooth, the 
 margin at most merely shred- 
 ded 11. Pyrenopeziza. 
 
 Spores many-celled by transverse 
 
 septa 12. Beloniella. 
 
 Ascocarps gelatinous gristly, horny when 
 
 dry 11. Callorieae. 
 
 Of this large number of genera only two are important patho- 
 gens, several of the others are parasitic on non-economic hosts 
 while others are saprophytic chiefly on decaying woody parts. 
 
 Pseudopeziza Fuckel 
 
 The genus comprises some ten species, all parasitic on leaves, 
 several of them upon economic plants causing serious disease. 
 The very small apothecium develops subepidermally breaking 
 through only at maturity, light colored; spores 1-celled, hyaline, 
 in two ranks in the ascus; paraphyses somewhat stout, hyaline. 
 Conidial forms are found in Gloeosporium, Colletotrichum and 
 Marssonia. 
 
 P. medicaginis (Lib.) Sacc.^^' ^" 
 
 The epiphyllous apothecia are in the older leaf spots, subepider- 
 mal at first but eventually breaking through. 
 
 Apothecia saucer-shaped, light colored, fleshy; asci clavate; 
 
148 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Fig. 104. — P. trifolii. Ascus and paraph- 
 yses; germiuating spores. After Ches- 
 ter. 
 
 spores hyaline, 10-14 ^u long; paraphyses numerous, filiform. A 
 Phyllosticta thought to be its conidial stage has been reported.^' 
 
 On dead spots in leaves of alfalfa and black medick. 
 
 P. trifolii (Bernh.) Fcl. 
 
 This is closely related to, perhaps identical with, the last species. 
 Sporonema (Sphseronsema) phacidioides Desm. is supposed to be 
 
 \lj/f^ ^^ its conidial form. This co- 
 
 ^'' ^ nidial stage has not however, 
 
 'm 9->, r-^, M /, ^^ been observed on alfalfa. 
 
 Ascocarps mostly epiphyl- 
 lous, on dead spots, averaging 
 0.5 mm. broad, yellowish or 
 brownish; spores elliptic 10- 
 14 X 5-6 ix. 
 
 Conidia in cup-shaped pyc- 
 nidia which are numerous, small, light brown; disk cinnamon- 
 colored; conidia ovoid-oblong, 5 /x, bi-guttulate. 
 
 P. tracheiphila Miiller-Thurgau ^^ is found upon the grape in 
 Europe. 
 
 P. salicis (Tul.) Pot. occurs on Salix. Conidia ( =Gloeosporium 
 salicis). 
 
 P. ribis, Kleb.^^-^7 
 
 Apothecia appear in the spring on dead leaves of the previous 
 season; saucer-shaped, fleshy, somewhat 
 stalked; asci clavate, spores hyaline, 
 ovoid; paraphyses simple or branched, 
 slightly clavate, rarely septate. 
 
 Conidial phase (=Glceosporium ribis) 
 on the leaves of the host forming an 
 abundant amphigenous infection; acer- 
 vuli stromatic; conidiospores commonly 
 19 X 7 ju, varying from 12-24 x 5-9 /jl, 
 escaping in gelatinous masses. 
 
 On red and white currants less com- 
 monly on black currants and gooseberries both in Europe and 
 America. 
 
 The ascigerous stage of this fungus was demonstrated by 
 Klebahn "''^ in 1906 to be genetically connected with what had been 
 
 Fig. 105.— p. ribis 
 cium in section, 
 bahn. 
 
 Apothe- 
 After Kle- 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 149 
 
 earlier known as Gloeosporium ribis (Lib.) Mont. & Desm. Old 
 leaves bearing the latter fungus were wintered out-doors in filter 
 paper and in the spring were found with this ascigerous stage. 
 The ascospores were isolated, grown in pure culture and typical 
 conidia were produced. The ascospores also infected the host 
 leaves successfully producing there the typical Gloeosporium. 
 The conidial stage is the only one ordinarily seen. The acervuli 
 are subepidermal elevating the epidermis to form a pustule which 
 eventually ruptures and allows the spores to escape as a gelatinous 
 whitish or flesh-colored mass. The spores are curved and usually 
 larger at one end than at the other. 
 
 Fabraea Saccardo (p. 147) 
 
 This is a genus of some ten species of small leaf parasites 
 which much resemble Pseudopeziza but differ from it in its 2 to 
 4-celled spores. 
 
 F. maculata (Lev.) Atk.^^-^o 
 
 The perfect stage is common on pear and quince leaves which 
 have wintered naturally. When such leaves are wet the white 
 8-spored asci may be seen 
 crowding through the surface 
 in small elliptical areas. The 
 apothecium is paraphysate; the 
 spores hyaline and 2-celled. 
 
 Conidial form ( = Entomo- 
 sporium maculatum) on leaves 
 and fruits; acervuli, black, 
 subepidermal, the epidermis 
 breaking away to expose the p,^_ loe.— F. maculata. i, acervuius of 
 spore mass; spores hyaline Aftir'soutSrth ^''''^'°"' ^' ^p"'"''^* 
 18-20 X 12 /x, 4-cells in a 
 
 cluster, the lateral cells smaller, depressed; stipe filiform 20 x 
 0.75 n; the other cells with long setse. 
 
 Atkinson ^^ proved the connection of the ascigerous with the 
 conidial form by cultivating the conidia from the ascospores. The 
 conidial form is very common and destructive on pear and quince 
 leaves and fruit. The mycelium which abounds in the diseased 
 spot is hyaline when young, dark when old. It collects to form a 
 
150 THE FUiNGI WHICH CAUSE PLANT DISEASE 
 
 thin subcuticular stroma. On this the spores are produced on 
 short erect conidiophores, Fig. 106; eventually the cuticle ruptures 
 and the spores are shed. The spores germinate by a tube which 
 arises from near the base of a bristle. 
 
 F. mespili (Sor.) Atk. on medlar with the conidial form Entomo- 
 sporium mespili (D. C.) Sacc. is perhaps identical with the above. 
 There are only minor and uncertain differences in the conidial 
 stage.^^ Sorauer by inoculation with conidiospores produced on 
 pear typical spots which bore mature pustules after an interval of 
 about a month. He referred the fungus to the genus, Stigmatea 
 Fries. See p. 243. 
 
 Cenangiaceae (p. 134) 
 
 Ascoma at first buried, later erumpent, on a stroma, dark, with a 
 rounded or elongate disk; asci 8-spored; spores long or filiform, 1 to 
 many-celled, often muriform, hyaline or dark; paraphyses branched 
 forming a complete epithecium. About two hundred fifty species. 
 
 Key to Subfamilies and Genera of Cenangiaceae 
 
 Ascocarps coriaceous, corneous or waxy 
 
 when fresh I. Dermateae. 
 
 Ascocarps without a stroma, at first im- 
 mersed. 
 Spores 1-celled 
 Ascocarps externally bright colored, 
 
 downy 1. Velutaria. 
 
 Ascocarps externally dark 
 
 Ascocarps smooth; spores hyaline. 2. Cenangium, p. 151. 
 Ascocarps downy; spores colored. . 3. Schweinitzia. 
 Spores 2 to 4-celled, elongate 
 Spores hyaline 
 
 Spores always 2-celled; ascocarp 
 
 smooth 4. Cenangella. 
 
 Spores 2 to 4-celled; ascocarps 
 
 downy externally 5. Crumenula. 
 
 Spores at length brown or black 
 
 Disk elongate with a thick rim. . . 6. Tryblidiella. 
 Disk rounded 
 
 Rim thin; spores 2-celled 7. Pseudotryblidium. 
 
 Rim involute; spores 4-celled. . 8. Rhytidopeziza. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 151 
 
 Spores many-celled, filiform 9. Gordonia. 
 
 Ascocarps springing from a more or less 
 developed stroma 
 Spores 8, not sprouting in the ascus. . . 10. Dermatea, p. 152. 
 Spores sprouting in the asci which be- 
 come filled with conidia 11. Tympanis. 
 
 Ascocarps gelatinous when fresh II. Bulgarieae. 
 
 Ascocarps sessile or stalked, with smooth, 
 saucer-shaped disc 
 
 Spores 1-celled, round 12. Pulparia. 
 
 Spores 1-celled, elongate 
 Ascocarps soft, gelatinous inside, ses- 
 sile, thin 13. Bulgariella. 
 
 Ascocarps soft, gelatinous, stalked, 
 
 thick 14. Bulgaria, p. 152. 
 
 Ascocarps watery gelatinous 15. Sarcosoma. 
 
 Spores 2-celled 
 Spores unequally 2-celled rounded 
 
 at the ends 16. Paryphedria. 
 
 Spores elongate, acute at the ends. . 17. Sorokina. 
 
 Spores filiform 18. Holwaya. 
 
 Spores muriform 19. Sarcomyces. 
 
 Ascocarps with convolute tremelliform 
 discs 
 
 Spores 1-celled, hyaline 20. Haematomyces. 
 
 Spores muriform, blackish 21. Haematomyxa. 
 
 With few exceptions these genera are so far as known sapro- 
 phytes though it is probable that further study will reveal some of 
 them as weak parasites or possibly as destructive ones. 
 
 Cenangium Fries (p. 150) 
 
 Parasitic or saprophytic chiefly in bark, the apothecium de- 
 veloping subepidermally and later breaking through to the surface ; 
 sessile, light colored without, dark within; asci cylindric-globoid, 
 8-spored; spores ellipsoid, 1 or rarely 2-celled, hyaline or brown, in 
 one row; paraphyses colored. About seventy species. 
 
 C. abietis (Pers.) Rehm.^^ has caused serious epidemics upon 
 pine in Europe and America. 
 
 Ascoma dark-brown, erumpent, clustered; spores ellipsoid, 
 10-12 X 5-7 IX. 
 
152 
 
 THE FUNGI WHICH CAUSE PLAxNT DISEASE 
 
 Fig. 107. — Ceuangium, habit sketch, asci and 
 paraphyses. After Tulasne. 
 
 Conidia ( = Brunchorstia 
 destuens Erikss.) in pyc- 
 nidia which are partially 
 embedded in the host, 
 the smaller simple, the 
 larger compound, 1-2 mm. 
 in diam. ; spores 30-40 x 
 3 ju, tapering-rounded at 
 each end, 2 to 5-septate. 
 
 A second conidial phase 
 ( = Dothichiza ferruginosa 
 
 Sacc.) has simple spores. 
 
 C. vitesia occurs in conidial form as Fuckelia on Ribes. 
 
 In many 
 
 Dermatea Fries (p. 151) 
 
 A genus of over sixty .species some of them parasitic 
 species conidia in pycnidia are known. 
 
 Ascocarps scattered or clustered, stromate, sessile or not, 
 black or brown; asci small, thick- 
 walled, 8 or 4-spored; spores el- 
 lipsoid or spindleform, 1-celled, 
 becoming 4 to 6-celled, brown, 
 2-ranked; paraphyses septate, api- 
 cally enlarged and colored. 
 
 D. carpinea (Pers.) Rchm. is 
 a wound parasite on the horn- 
 beam and beech; D. cinnamomea 
 (Pers.) Rehm. on oaks; D. acerina 
 Karst, on maple (Acer pseudo- 
 platanus) ; all in Europe. 
 
 D. prunastri (Pers.) Fr., with 
 its conidial form Sphseronema spurium Fr. is found on Bark of 
 various species of Prunus, in Europe and America. 
 
 Bulgaria Fries (p. 151) 
 The gelatinous apothecium is rather large and dark colored; 
 asci 4 to 8-spored; spores 1-celled, elongate, brown. 
 There is one species worthy of mention. 
 
 Fig. 108.- 
 
 A, h a 1) i t 
 
 Dermatea. 
 sketch; C, ascus and paraphyses. 
 After Tulasne and Rehm. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 153 
 
 B. polymorpha (Oed.) Wett."'-' ''^ is a common saprophyte on 
 bark. It is said to sometimes become parasitic. Ascocarps black, 
 stipitate; disk scarcely cupped, ranging up to 4 cm. in diameter 
 although usually smaller. 
 
 Caliciaceae (p. 134) 
 
 Stroma more or less thalloid, with or 
 without algal cells, often rudimentary and 
 inconspicuous; ascoma more or less globoid, 
 stipitate; the apex of the ascus dissolv- 
 ing before the spores are matured, thus 
 allowing the hyaline unripened spores to es- 
 cape and mature afterwards. 
 
 This small family (less than one hun- 
 dred twenty-five species) contains the only 
 lichens of phytopathological importance, un- 
 less the foliose lichens which sometimes ap- Fig. io9. — C. 
 pear on poorly kept fruit trees be consid- 2, a s c u s. 
 ered. ^^''^^• 
 
 /^ 
 
 1 
 
 pallida 
 Root. 
 After 
 
 Key to the Genera of Caliciaceae 
 
 Ascoma with a long stalk 
 
 Spores spherical, or subspherical 
 
 Spores colorless or only slightly colored. 1. Coniocybe, p. 153. 
 
 Spores brown or brownish 2. Chaenotheca. 
 
 Spores elongated, septate 
 
 Spores elongate elliptic or egg-shaped, 
 
 usually two-celled 3. Calicium. 
 
 Spores elliptic to spindle-form, 4 to 
 
 8-celled 4. Stenocybe, 
 
 Ascoma short stalked 
 
 Spores 2-celled 5. Acolium. 
 
 Spores globose, 1-celled 6. Sphinetrina. 
 
 Coniocybe pallida (Pers.) Fr. is generally distributed through- 
 out Europe and America, commonly on the bark of various forest 
 trees and upon the crown and roots of the grape. The parasitic 
 
154 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 nature of the fungus is in doubt. The entire height of the as- 
 cocarp is 2 mm.; head white, then grayish brown; asci cyUndric, 
 8-spored; spore tinged with brown, 4-5 ix in diameter. The species 
 as a pathogen is usually referred to as Rcesleria hypogsea Thiim 
 & Pass, and given a place in the Geoglossaceae; but Durand ^* fol- 
 lows Schroter in excluding the species from that family. Fig. 109. 
 
 Phacidiales (p. 124) 
 
 This order, comprising some six hundred species only a few of 
 which are pathogens, is characterized as follows: mycelium well 
 developed, much branched, multiseptate; ascocarps fleshy or 
 leathery, free or sunken in the substratum or in a stroma, 
 rounded or stellate, for a long time enclosed in a tough cover- 
 ing which at maturity becomes torn; paraphyses usually longer 
 than the asci, much branched, forming an epithecium. 
 
 Key to Families op Phacidiales 
 
 Ascocarps soft, fleshy, bright colored 1. Stictidaceae, p. 154. 
 
 Ascocarps leathery or carbonous, always 
 black 
 Ascocarps at first sunken, later strongly 
 
 erumpent, hypothecium thick 2. Tryblidiaceae, p. 155. 
 
 Ascocarps remaining sunken in the sub- 
 stratum, hypothecium thin, poorly 
 developed 3. Phacidiacese, p. 155. 
 
 Stictidaceae 
 
 The members of this family (about twenty genera and two 
 hundred fifty species) are usually considered saprophytes, al- 
 though one species of Stictis has recently been described as a 
 parasite. 
 
 Stictis Persoon 
 
 Perithecia sunken, pilose, at length erumpent; asci cylindric, 
 containing eight filiform, multiseptate spores; paraphyses filiform, 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 155 
 
 richly branched apically. Of the seventy 
 or more species of the genus only one, 
 S. panizzei d Not., originally described 
 from fallen oUve leaves in Italy, has been 
 charged with producing disease.^^ It has 
 within the last few years become very de- 
 structive in Italy. 
 
 The Tryblidiaceae, with six genera and 
 some seventy species, are likewise chiefly 
 saprophytes with the possible exception of 
 the two generj^ Heterosphseria and Sclero- 
 derris. The former occurs on umbellifere 
 while the latter may contain the perfect 
 stage of certain currant and gooseberry 
 fungi (Mastomyces and Fuckelia) of Europe 
 as well as a European parasite of the wil- 
 low. 
 
 T-»t. -J" / -I r- A\ FiG- 110. — Stictis. D, 
 
 Phacidiaceae (p. 154) habit sketch, ^.ascus 
 
 and paraphyses. Af- 
 
 Apothecia sunken, more or less erumpent, er e m 
 disk-like or elongate, single or grouped, leathery or carbonous, 
 black, firm, opening by lobes or rifts. 
 
 Key to Genera of Phacidiaceae 
 
 Apothecia not inseparably united to the sub- 
 stratum I. Pseudophacidieae. 
 
 Spores elongate, hyaline, 1-celled 1. Pseudophacidium. 
 
 Spores elongate, spindle-form or filiform, 
 multicellular. 
 Spores elongate to filiform, not muri- 
 form 
 Apothecia rounded, opening by a 
 rounded mouth 
 Spores elongate or spindle-form 
 
 paraphyses, none 2. Dothiora, p. 156. 
 
 Spores elongate-globoid, 2-celled; 
 
 paraphyses present 3. Rhagadolobium. 
 
156 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Spores needle-like ; paraphyses 
 
 present 4. Coccophacidium. 
 
 Apo.thecia elongate; opening by a 
 
 slit 5. CUthris, p. 157. 
 
 Spores elongate, muriform, with pa- 
 raphyses 6. Pseudographis. 
 
 Apothecia firmly united to the substratum. 11. Phacidieae. 
 Apothecia separate, no stroma 
 
 Spores ellipsoid or globoid, 1 to 4-celled 
 Spores 1-celled 
 
 Apothecia rounded 
 
 Paraphyses not forming an epi- 
 
 thecium 7. Phacidium, p. 157. 
 
 Paraphyses forming an epithe- 
 
 cium 8. Trochila, p. 157. 
 
 Apothecia irregular, elongate, 
 opening by an irregular 
 
 mouth 9. Cryptomyces, p. 158. 
 
 Spores 2 to 4-celled 
 Spores hyaline 
 
 Apothecia rounded, spores 2 to 
 
 4-celled 10. Sphaeropeziza. 
 
 Apothecia elongate, spores 
 
 2-celled 11. Schizothyrium. 
 
 Spores brown 12. Keithia. 
 
 Spores filiform or needle-like, 1 to 
 
 many-celled 13. Coccomyces. 
 
 Apothecia collected on a stroma, opening 
 elongate 
 Spores 1-celled, hyaline 
 
 Spores ovate 14. Pseudorhytisma. 
 
 Spores filiform or needle-like 15. Rhytisma, p. 158. 
 
 Spores 2-celled 
 
 Spores hyaline 16. Marchalia. 
 
 Spores brown 17. Cocconia. 
 
 Dothiora Fries (p. 155) 
 
 There are about ten wood-inhabiting species. Ascocarp at first 
 sunken in the substratum, later irregularly erumpent; disk black; 
 asci clavate, 8-spored; spores elongate or spindle-form, many- 
 
THE FUxNGI WHICH CAUSE PLANT DISEASE 
 
 157 
 
 celled or muriform, hyaline or slightly yellowish; paraphyses 
 wanting. 
 
 D. virgultorum Fr. grows on birch. 
 
 Clithris Fries (p. 156) 
 
 A small genus of about twenty species found 
 on wood and bark; mainly saprophytes. 
 
 Ascoma sunken, then erumpent, elongate, 
 with lip-like margins, dark colored; asci clavate, 
 8-spored, often blunt pointed; spores linear or 
 spindle-shaped, multicellular; paraphyses fili- 
 form, coiled apically, hyaline. 
 
 C. quercina (Pers.) Rehm. is found on oak 
 branches and is perhaps identical with C. aureus 
 Mass. on willows. C. juniperus is found on liv- 
 ing juniper. 
 
 Phacidium Fries (p. 156) 
 
 Over seventy species chiefly on leaves or ^ 
 
 herbaceous stems. Ascoma single, flattened, Fig. in.— Clithris. 
 
 ... Asciis with spores 
 
 soon becommg lenticular, breaking open by and paraphyses. 
 an irregular rift; asci clavate, 8-spored; spores ^^ '^ ™' 
 
 ovate or spindle-shaped, hyaline, 1-celled; paraphyses thread-like, 
 hyaline. Conidial form probably in part =Phyllachora. 
 P. infestans Karst. is a parasite on pine leaves. 
 
 Trochila Fries (p. 156) 
 
 Perithecia sunken and closed, later erumpent, black, leathery; 
 asci clavate 8-spored; spores long, hyaline, 1-celled; paraphyses 
 filamentose forming an epithehum. Fig. 112. 
 
 T. popularum Desm. is thought by Potebnia -^^ and Ed- 
 gerton -^^ to be the ascigerous form of Marssonia castagnei 
 D. &M. 
 
 T. craterium is the ascigerous form of Gloeosporium para- 
 doxum. See p. 541. 
 
158 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Cryptomyces Greville (p. 156) 
 
 A genus of some ten species living on wood or leaves, forming 
 large black blotches. 
 
 Ascoma sunken in the substratum, flattened, erumpent, irregu- 
 lar in outline, coal black; asci clavate, 8-spored; spores elongate, 
 1-celled, paraphyses filiform. 
 
 C. maximus (Fr.) Rehm is a parasite on willow and dogwood 
 twigs in Europe and America, forming large carbonous areas 
 under the bark. 
 
 Rhytisma Fries (p. 156) 
 
 To Rhytisma belong about twenty-five species which cause very 
 conspicuous, though but slightly injurious, black leaf -spots. The 
 spots which are white within, are due to sclerotial 
 cushions formed in the host tissue. Thickening 
 of the leaf occurs in the infected part. One- 
 celled conidia (Melasmia form) are abundantly 
 produced in pycnidia early in the season, followed 
 by sclerotium formation. Much later, usually well 
 into winter or the following spring, the apothecia 
 miai appear. Besides the asco-spore-producing forms 
 
 Fig. 112. — Tro- several species of which the asco-spores are un- 
 and %araphy- known have been referred here, 
 ses. After Ascoma on a sclerotial stromatic layer, which 
 is black above, white within; ascocarps elongate, 
 opening by a lip-like slit; asci clavate, often blunt pointed, 
 8-spored; spores filiform or needlelike, hyaline, mostly 1-celled, 
 lying parallel and lengthwise of the ascus; paraphyses filiform, 
 hyaline, often arched above. 
 R. acerinum (Pers.) Fr. 
 
 The spot is at first yellow and thickened and in this stage bears 
 numerous conidia upon short conidiophores. The apothecia 
 ripen in spring and rupture by numerous irregular fissures which 
 follow the ridges of the wrinkled surface. Klebahn secured infec- 
 tion by ascospores resulting in three weeks in yellow spots and in 
 eight weeks in conidiospores. The conidia are supposed to aid in 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 159 
 
 spreading the fungus during the summer though they have not 
 yet actually been observed to germinate or to cause infection. 
 
 Apothecia radiately arranged on the stroma which is about 
 0.5-1.5 cm. across; asci 
 120-130 X 9-10 ju; spores 
 large, 65-80 x 1.5-3 fj.; 
 paraphyses numerous, in- 
 curved or hooked. 
 
 Conidia ( = Melasmia 
 acerina Lev.) preceding _ 
 
 the asci, producing numerous - ii.^'<^p¥^.{l'X'<l{'j(sf/^'^^^^ 
 
 small, hyaline, 1-celled ^.^r^'"'" 
 spores in an extended hy- ^w^i ^ ; n ' 
 
 menial layer. '" ^'~^ ^^^^^^^m^ 
 
 On various species of Fig. 113.— R. acerinum. F, conidial layer; 
 maple, apparently consist- ^. ascus and paraphyses. After Tulasne. 
 
 ing of races since in different localities the host differs without a 
 crossing over of the fungus. 
 
 R. punctatum (Pers.) Fr. also occurs on maple, especially Acer 
 pseudoplantanus. It may be distinguished from the preceding by 
 its small, speck-like stromata. 
 
 R. salicinum (Pers.) Fr. is found on willow in Europe and 
 America. It is quite similar in external appearance to R. acerina 
 except for the smaller average size of the spots. 
 
 R. symmetricum Miill. is another willow inhabiting species. 
 The apothecia are amphigenous and are said to mature in autumn 
 on the still live leaves. 
 
 Other species are common especially on various Ericaceffi and 
 Coniferse in Europe and America. 
 
 Hysteriales (p. 124) 
 
 Small species with elongated, black, covered apothecia which 
 open by a long narrow slit exposing the hymenium; asci 8-spored; 
 spores usually long and slender. Some few are leaf parasites but 
 most are wood saprophytes. Pycnidia are found in some species. 
 The order serves as a bridge between the Discomycetes and the 
 Pyrenomycetes. About four hundred species. 
 
160 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Key to Families of Hysteriales 
 
 Ascocarps immersed; walls of the ascocarps 
 connate with the membranous cover- 
 ing 1. Hypodennataceae, p. 160. 
 
 Ascocarps at first immersed, erumpent, 
 
 walls free 
 WaUs membranous or coriaceous, black. 2. Dichaenaceae, p. 162. 
 Walls thick, almost corky, gray or 
 
 black 3. Ostropaceae. 
 
 Ascocarps from the first free 
 Walls carbonous, black; shield-shaped, 
 round, oval or more commonly 
 
 linear 4. Hysteriaceae, p. 163. 
 
 Walls membranous or horny, brown, 
 
 ascocarps vertical, clavate 5. Acrospermaceae. 
 
 The third and fifth families contain no pathogens. 
 
 Hypodermataceae 
 
 Ascocarp flattened, rounded or elongate, rarely branched, 
 united to the substratum; opening by a slit; asci 4 to 8-spored; 
 paraphyses apically branched, the branches forming an epi- 
 thecium, or hooked or crimped. About fifty species, chiefly 
 saprophytes. 
 
 Key to Genera of Hypodennataceae 
 
 Spores elongate, rather broad 
 
 Spores 1-celled or by cross walls 2 to 
 many-celled 
 Spores 1-celled 
 Asci 8-spored, spores spindlc-form 
 
 Spores hyaline 1. Henriquesia. 
 
 Spores brown 2. Farlowiella. 
 
 Asci 4-spored, spores hyaline 3. Hypodermella, p. 161. 
 
 Spores 2-celled, hyaline 
 
 Apothecium black 4. Hypoderma, p. 161. 
 
 Apothecium red 5. Angelinia. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 161 
 
 Spores 4 to many-celled, spindle-form 
 
 Spores 4-celled, mostly hyaline 6. Gloniella. 
 
 Spores 4 to many-celled, brown 7. Rhytidhysterium. 
 
 Spores muriform, hyaline 8. Hysteropsis, p. 161. 
 
 Spores fihform, 1-celled 9. Lophodermium, p. 161. 
 
 Of these genera only four are important here. 
 
 Hypodermella Tubeuf (p. 160) 
 
 This differs from the next genus in its pyriform unicellular 
 spores; asci 4-spored. Two species, both European and economic. 
 H. larius Tub. affects larch needles in Europe. ^^ 
 H. sulcigena Link is on pine needles. 
 
 Hypoderma De Candolle (p. 160) 
 
 Apothecia oblong, opening through a thin black cover by a 
 long fissure; asci 8-spored; spores cylindrical or fusiform, 2-celled 
 at maturity; paraphyses hooked at the end. 
 
 H. desmazieri Duby,-^^ on pine needles in America and Eu- 
 rope. 
 
 Amphigenous; asci broadly clavate, sessile; spores hyaline, 
 linear-elliptic, obtuse and 2-rowed. 
 
 H. laricis, H. strobicola, H. pinicola, produce premature leaf 
 fall in various conifers. 
 
 Hysteropsis Rehm 
 
 Asci clavate, 8-spored; spores hyaline, muriform; paraphyses 
 branched, forming an epithecium. 
 H. brasiliensis occurs on cacao trees. 
 
 Lophodermium Chevall 
 
 Spores long, thread-like, continuous; conidiospores in pycnidia. 
 
 L. pinastri (Schr.) Chev. occurs in Europe ^'' and America on 
 Pinus sylvestris especially on young plants causing the leaves to 
 fall. The first year pycnidia only are formed, the asci not ap- 
 pearing until the second year.^^^ 
 
162 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Ascocarps scattered on the leaf, shining black, up to 1 mm. 
 long; asci clavate, 8-spored; spores nearly as long as the ascus, 
 90-120 X 1.5 iJL. Conidia cylindric, hyaline, 
 continuous, 6-8 x 1 /jl. 
 L. brachysporum Rost. 
 Perithecia epiphyllous; asci cylindric, short- 
 stalked, apex rounded, 120 x 20-25 ju, 8- 
 spored; paraphyses bacillar, apex curved; 
 spores oblong, 1-rowed, hyaline, 28-30 x 
 9-10 /i. 
 
 It is common on pine leaves. ^^^ 
 Several other species are parasitic upon 
 various conifers, among them: L. macrospo- 
 rium (Hart.) Rehm, on spruce leaves, in 
 Europe and America; L. nervisequum (D. C.) 
 Rehm, on fir leaves, a very destructive 
 European species; the pycnidial stage is 
 'h, habh skSf"; Septoria pini Fuckel; L. juniperinum (Fr.) 
 d Not, on juniper leaves and twigs in 
 Europe and America; L. gilvum Rost., on 
 pines; L. abietis Rost., on spruce leaves; L. laricinum Duby, on 
 larch. The last four species are European. 
 
 ascus and paraphy- 
 ses. After Rehm. 
 
 Dichaenaceae (p. 160) 
 This family contains the single genus Dichsena. 
 
 w(kl 
 
 Dichaena Fries 
 
 Apothecia grouped in rounded spots; at 
 first sunken, then erumpent, rounded or elon- 
 gate, dark brown; asci irregularly pyriform, 4 
 to 8-spored; spores ellipsoidal, at first 1-celled, ^j- --^^vi^^^^^^^i. 
 at maturity multicellular; paraphyses filiform, pio. 115.— Hysterium 
 Some seven species are found upon various rnamjsporum. Af- 
 trees. 
 
 D. quercina Fr. causes rough black patches on bark of young 
 oaks in Europe and America; D. faginea Fr., a similar effect on 
 beech. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 163 
 
 Hysteriaceae (p. 160) 
 
 Ascocarps free, seated upon the substratum, 
 elongate or linear, straight, curved or even 
 branched, disk-form, boat-shaped or band-like, 
 black; asci usually 8-spored; paraphyses fila- 
 mentous, often forming an epithecium. 
 
 About fourteen genera and some two 
 hundred fifty species, many but poorly 
 known. Several genera contain plant patho- 
 gens, but they are not often of economic im- 
 portance. 
 
 Fig. 116. — D. quer- 
 cina. Ascus and 
 paraphyses. After 
 Rehm. 
 
 2. Aulographum. 
 
 Glonium. 
 Hariotia. 
 
 Key to Genera of Hysteriaceae 
 
 Ascoma linear, flattened, broadly sessile 
 Spores ellipsoid or spindle-shaped, many- 
 celled 
 
 Spores 1-celled, 16 in each ascus 1. Cyclostomella. 
 
 Spores 2-cellcd, sometimes 4-celled, 
 ellipsoid or elongate 
 Spores hyaline 
 
 Asci 8-spored, spores 2 to 4-celled 
 Paraphyses scarcely branched. . 
 Paraphyses forming an epithe- 
 
 cimii 3. 
 
 Asci many-spored, spores 2-celled. 4. 
 Spores colored, 2-celled; leaf infect- 
 ing fungi 
 Paraphyses present 
 Ascoma seated on a cottony 
 
 stroma 5. Lembosia. 
 
 Ascoma radial, on a circular 
 stroma 
 Spores 2-celled, 8 in each 
 
 ascus 6. Parmularia. 
 
 Paraphyses absent, stroma irreg- 
 ularly circular 7. Hysterostomella. 
 
 Spores 4 to 8-celled, elongate or spindle- 
 form 
 Spores hyaline, spindle-form, 4- 
 
 celled. 8. Hysteroglonium. 
 
164 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Spores brown, elongate, 4 to 
 
 8-celled 9. Hysterium. 
 
 Spores elongate, muriform 10. Hysterographium, p. 164. 
 
 Ascoma boat or band-shaped, not sessile 
 Spores spindle-formed, brown, many- 
 celled 
 Spores 4 to 8-celled; asci 8-spored. 11. Mytilidium. 
 Spores many-celled ; asci 4-spored . 12. Ostreion. 
 Spores filamentose, hyaline or yellow 13. Lophium. 
 Ascoma stellate 14. Actidium. 
 
 Hysterographium Corda 
 
 Asci clavate, 8-spored; spores muriform, dark colored when 
 mature; paraphyses branched forming an epithecium. About 
 seventy species. 
 
 H. fraxini (Pers.) de Not. occurs on Oleacese, particularly on 
 
 Fig. 1 17. — H. 
 fraxini. Ascus 
 and paraphyses. 
 After Rehm. 
 
 Fig. 118. — Gymnoaseus, sexual organs. 
 After Dale. 
 
 the ash, perhaps only as a saprophyte. It is found both in Europe 
 and America. 
 
 Aspergillales (p. 124) 
 
 The Aspergillales are clearly distinguished from the other 
 Ascomycetes by the possession of a closed ascocarp in which the 
 asci are not collected in a hymenium but are irregularly scattered. 
 The forms with the least developed peridium are evidently related 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 165 
 
 to the Endomy cetaceae ; the forms with a more highly developed 
 peridium, to the Pyrenomycetes, particularly to the Perisporiales. 
 Conidial forms are usually present, indeed in many cases they 
 preponderate almost to the entire exclusion of the ascigerous form 
 which may be seen only under very exceptional conditions. 
 
 Sexual reproduction has been demonstrated in several families. 
 In the Gymnoascacese (Dale ^^ and Eidam ^^) there are usually two 
 twisted branches (Fig. 118) which conjugate. These branches 
 are multinucleate at the time of fusion. The ascogonium de- 
 velops from this fertilization much as is described on pages 116- 
 117. In the Aspergillacese similar sexual organs are formed but 
 parthenogenesis or a much reduced form of fertilization is often 
 met. In all, the species number two hundred fifty or more. 
 
 Key to Families of Aspergillales 
 
 Peridium made up of loose floccose hyphse . 1 . Gymnoascacese. 
 Peridium compact, closed 
 
 Ascocarps mostly small, not subterranean 
 Ascocarps mostly sessile without 
 
 stroma; peridia remaining closed. . 2. Aspergillaceae, p. 166. 
 Ascocarps mostly stalked ; peridia open- 
 ing at maturity by lobes, or ir- 
 regularly 3. Onygenaceae. 
 
 Ascocarps sessile, the spores issue in 
 columnar masses from the goblet- 
 shaped peridia 4. Trichocomaceae. 
 
 Ascocarps sessile on a small stroma. . . 5. Myriangiaceae, p. 170. 
 Ascocarps mostly enlarged, tuberous, sub- 
 terranean. 
 Peridium clearlj' distinct from the 
 walls of the ascocarp ; spore masses 
 
 powdery at maturity 6. Elaphomycetaceae. 
 
 Peridium not clearly limited, continu- 
 ous with the walls of the ascocarp; 
 spore masses never powdery 7. Terfeziaceae. 
 
 Of these the second and fifth families only contain pathogens. 
 The Gymnoascacese of five genera and some fifteen species are 
 found on manure, and other organic matter. The third and fourth 
 
166 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 families are monogeneric; the third on hoofs, horn, etc.; the 
 sixth is subterranean and the Terfeziacese more or less subter- 
 ranean. 
 
 Aspergillaceae (p. 165) 
 
 The ascocarp, in many forms but rarely seen, is a small spherical 
 or tuber-shaped body, usually indehiscent, rarely opening by a 
 pore. The spherical or pyriform asci bear from 2 to 8 spores which 
 may be from 1 to many-celled. The ascocarp is in some genera 
 provided with appendages which strongly resemble these of 
 the Erysiphaceae (Microascus). Conidia are produced in great 
 abundance. 
 
 In Aspergillus and Penicillium fertilization is said by some 
 observers to be accomplished by conjugation of a straight oogo- 
 nium with a spirally coiled antheridium, this act resulting in an 
 ascogenous hypha. Recent work of Dale ™ (see also Fraser and 
 Chambers '^^) denies such fusion in one species of Aspergillus 
 which she studied, though sexual organs were often present, 
 and predicates a reduced form of sexuality consisting of fusion 
 of the nuclei of the ascogonium with each other. 
 
 Key to Genera of Aspergillaceae 
 
 Spores 1 -celled 
 
 Perithecium flask-shaped, beaked or papil- 
 late 1. Microascus. 
 
 Perithecium not beaked 
 
 Perithecium with hair-like appendages; 
 peridium compact, mostly dark 
 colored 
 Appendages straight hairs or forming 
 
 a hairy felt 2. Cephalotheca. 
 
 Appendages apically coiled hairs. ... 3. Magnusia. 
 Perithecium unappendaged ; peridium 
 membranous or fleshy 
 Conidia borne directly on the myce- 
 lium 
 Chlamj'^dospores borne in chains. . 4. Thielavia, p. 167. 
 Chlamydospores borne singly 5. Rostrella, p. 168. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 167 
 
 Conidia borne on distinct conidio- 
 phores 
 Conidia borne singly; conidio- 
 phores branching at right 
 
 angles 6. Aphanoascus. 
 
 Conidia borne in chains 
 
 Conidiophorcs simj)le, aggre- 
 gated into bundles 7. Emericella. 
 
 Conidiophorcs enlarged apically 
 bearing numerous sterig- 
 mata 
 
 Sterigmata simple 8. Aspergillus, p. 168. 
 
 Sterigmata branched 9. Sterigmatocystis. 
 
 Conidiophores, sympodially 
 
 branched 10. Eurotiopsis. 
 
 Conidiophores bushy branched 
 Conidiophores single, peri- 
 
 thccia sessile 11. Penicillium, p. 169. 
 
 Conidiophorcs in bundles, api- 
 cal cells swollen, peri- 
 
 thecia stalked 12. Penicilliopsis. 
 
 Spores 2-celled; peridium at maturity stel- 
 late 13. Testudina. 
 
 Of the thirteen genera and some one hundred to two hundred 
 species only four of the genera are of interest here. The others 
 occur on rotting leaves, manure, etc. 
 
 Thielavia Zopf ^-'^^ (p. 166) 
 
 T. basicoia (B. and Br.) Zopf. 
 
 This, the one species of the genus, is on the boundary between 
 the Aspergillales and the Perisporiales and is classed by some with 
 the one, by some with the other order. 
 
 The ascocarps, which are the form less commonly seen, are 
 round, brown, completely closed and have no appendages. The 
 asexual spores are of two kinds. First: hyaline conidia produced 
 endogenously within "pistol-formed" conidiophores from the 
 ends of which they are expelled. Second: short cylindrical conidia 
 or chlamydospores with a thick brown wall; borne in series of 
 
168 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 three to six on the ends of hyahne branches, Fig. 119. These 
 conidia fall apart as they age. 
 
 The hyaline conidia preponderate in early disease, giving the 
 surface of the root a mildewed appearance; the dark conidia pre- 
 ponderate later, covering the 
 root with a black coating. 
 Finally, after the host is dead, 
 the ascocarps appear. 
 
 The delicate hyaline myce- 
 lium wanders through the 
 affected root disorganizing its 
 tissue. The superficial myce- 
 lium is lightly tinted. 
 
 Perithecia 80-100 /i; asci 
 ovate, 8-spored; spores len- 
 ticular, vacuolate, 1-celled, 
 chocolate-colored, 8-12 x 
 4-5 Ai; chlamydospores in 
 chains, at maturity separa- 
 ting, short-cylindric, about 
 5-8 X 12 /i; the entire group 
 25-65 /i long; conidia hyaline 
 about 10-20 X 4-5 ^l. 
 
 In Europe and Eastern 
 North America on Aralia quinquefolia, Begonia rubra, Begonia 
 sp., Catalpa speciosa, Cyclamen sp., Gossypium herbaceum, 
 Linaria canadensis, Lupinus angustifolius, L. albus, L. luteus, 
 L. thermis, Nasturtium armoracea, Nemophila auriculata, Nico- 
 tiana tabacum, N. rustica, Onobrychis cristagalli, Oxalis stricta, 
 Phaseolus vulgaris, P. multiflorus, Pisum sativum, Senecio elegans, 
 Trifolium repens, Trigonella coerulea, Vigna sinensis and Viola 
 odorata. 
 
 Rostrella cofifeae Zimm. is described as the cause of canker of 
 coffee in Java."^ 
 
 Aspergillus Micheli (p. 167) 
 
 The ascocarps are small, spherical, indehiscent, smooth bodies 
 which at maturity are entirely filled with 8-spored asci; spores 
 
 Fig. 119. — Thiclavia basicola, showing two 
 conidial forms and ascus and ascospores. 
 After Van Hook and Zopf. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 169 
 
 1-celled. The conidiophores, which serve better to characterize 
 the genus, are swollen at the end, and bear numerous sterigmata 
 (Fig. 120) on which the spores are borne basipetally in chains. 
 Sclerotia are sometimes formed. 
 
 The members of the genus are all saprophytes but some of them 
 
 Fig. 120. — Asper- 
 gillus, c o n i d i o- 
 phore. After 
 King. 
 
 Fig. 121. — Penicillium, 
 showing a conidio- 
 phore; a, producing 
 chains of conidia, c; 
 s, three spores more 
 highly magnified. 
 After Longyear. 
 
 cause injury to fruit in the tropics; for example, A. ficuum, Reich, 
 on figs; A. phoenicis Pat. & Del. on dates. 
 
 Penicillium Link "^ (p. 167) 
 
 The ascocarp is much as in the last genus, with the asci 4 to 
 8-spored. It may develop directly from the mycelium or with the 
 intervention of a sclerotial stage. The characteristic conidiophore 
 serves to distinguish the genus by its mode of branching. Fig. 121. 
 Instead of being apically swollen as in the preceding genus it 
 branches repeatedly, the branches bearing terminal sterigmata 
 and giving the conidiophore the appearance of a brush; hence the 
 name. For species see page 573. 
 
170 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Myriangiaceae (p. 165) 
 
 Perithecia numerous upon or in a stroma; asci in a pseudo- 
 parenchymatous substance within the perithecium; spores muri- 
 form. 
 
 Key to Genera of Myriangiaceae 
 
 Stroma valsoid, perithecia superficial ... . 1. Myriangium. 
 Stroma effused, perithecia immersed. ... 2. Myriangiella, p. 170. 
 
 Myrangiella orbicularis Zimm. parasitizes coffee in Java.^°° 
 
 Pyrenomycetes 
 
 52 
 
 The four following orders are usually grouped together as the 
 Pyrenomycetes ; separated from the preceding forms by their closed 
 ascocarp with the asci arranged in a hymenium. They constitute 
 a vast assemblage of more than ten thousand species, the large 
 majority saprophytic and unimportant except in the general 
 economy as scavengers. 
 
 Perisporiales (p. 124) 
 
 The present order is characterized by its almost universal 
 parasitic habit, the evident mycelium and the globoid perithecia 
 without ostioles, or in one family flattened, ostiolate perithecia. 
 The mycelium is superficial upon the host and frequently quite 
 conspicuous. 
 
 Key to Families of Perisporiales 
 
 Perithecia mostly spherical, imperforate 
 Mycelium white; perithecia with append- 
 ages 1. Erysiphaceae, p. 171. 
 
 External mycelium dark colored or want- 
 ing, perithecia without true append- 
 ages, but sometimes surrounded by 
 
 appendage-like hyphae 2. Perisporiaceae, p. 189. 
 
 Perithecia flattened, shield-shaped, ostio- 
 late 3. Microthyriaceae, p. 195. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 171 
 
 Erysiphaceae (p. 170) 
 
 46. 52. 77. 78 
 
 Fig. 122. — I, E. graniinis, showing branching 
 haustoria. 33, Phyllactinia, intercellular 
 hyphffl. After Smith. 
 
 This family on account of its abundance everywhere, its sim- 
 plicity of structure, and its possession of typical ascigerous and 
 conidial stages forms a favorite type for introductory study of the 
 Ascomycetes. Its members 
 are easy of recognition, form- 
 ing a coating of white conidia, 
 conidiophores and mycelium 
 upon the surface of its hosts 
 and giving them an appear- 
 ance much as though they had 
 been lightly dusted with flour. 
 Later in the season the white 
 patches are more or less 
 liberally sprinkled with the 
 black perithecia leading to 
 the common name powdery 
 mildew. An important list 
 of the economic forms and their hosts has been published by 
 Halsted." 
 
 The mycelium except in Phyllactinia is entirely superficial. It 
 is usually quite hyaline and is branched, septate and its cells 
 uninucleate. It fastens to the host and penetrates its epidermal 
 cells by uninucleate haustoria which by their various lobings aid 
 in specific characterization. Figs. 122, 123. 
 
 Haustoria may be grouped in three general classes; (1) those 
 arising directly from the lower surface of the mycelium; (2) those 
 arising at the side of the mycelium as small semicircular processes ; 
 (3) arising from more or less deeply-lobed lateral swellings of the 
 mycelium. The relation of the haustoria to the host cells has 
 been extensively studied by Smith.*^^ 
 
 The conidia arise in basipetal succession on simple scattered 
 conidiophores (Fig. 129); are hyaline, oval or barrel-shaped, 
 smooth, 1-celled. Neger has shown that they vary greatly in size 
 with nutrition conditions .^° 
 
 Conidia germinate readily at once in dry air, better in humid 
 air, producing from one to three germ tubes. Haustoria are 
 
172 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 c 
 
 ^Ii9 
 
 formed at once and the mycelium develops to a more or less 
 circular colony, producing new conidia in a few days. Artificial 
 inoculations on susceptible plants, using conidia, usually result 
 within two to five days in typical mildew spots. 
 
 Neger,^° who studied the germination of conidia extensively has 
 shown that light hastens the growth of the germ tubes, which in 
 many cases are negatively phototropic. Con- 
 tact stimulus leads to the growth of appres- 
 soria. 
 
 The perithecia are subspherical, often some- 
 
 ^ what flattened, white to yellow when young, 
 
 Fig. 123. — Erysiphe, , , , , , , • i , , 
 
 showing lobed haus- dark to blacK and reticulated when mature; 
 
 toria. After Salmon. ^^^ without OStiole but are provided with 
 
 appendages of various types. Figs. 130, 133-136, which give main 
 characters to mark the genera. The appendages serve by hygro- 
 scopic movements to aid in the distribution of the fungus.^^ The 
 ascospores become free after dissolution of the perithecium by 
 weathering. The asci are either solitary or quite numerous within 
 the perithecium and bear two to eight hyaline spores each. 
 
 The conidia are short-lived summer spores. The perithecia 
 mature more slowly and constitute the hibernating condition. 
 In some instances the ascus-form is unknown; 
 the fungus is then classified solely by its 
 conidial stage and falls under the form genus 
 Oidium (see p. 569.) 
 
 In Sphserotheca ^^ an antheridial and an 
 oogonidial branch, each uninucleate, are de- 
 veloped, and cut off by septa. The oogo- 
 nium enlarges; the antheridium lengthens, Fig. 124.— Ascogomum- 
 its nucleus divides, and a septum is run in \ube with five nuclei. 
 
 ' ^ ^ After Harper. 
 
 separating the stalk cell from the antheri- 
 dium. The sperm nucleus enters the oogonium and fuses 
 with the oogonial nucleus. Simultaneous with fertilization oc- 
 curs, from the stalk cell of the oogonium, the development of 
 a sterile system of enveloping threads which surround and pro- 
 tect the fertilized oogonium and eventually mature into the 
 sporoearp. The fertilized oogonium divides several times trans- 
 versely producing a series of cells, one of which is binucleate. 
 
THE FUNGI WHICH CAUSP: PLANT DISEASE 173 
 
 This binucleate cell after fusion of its nuclei develops into the 
 one ascus characteristic of the genus. The ascus nucleus by 
 division gives rise to the spore nuclei and the spores are cut out of 
 the periplasm by reflexion of the astral rays. 
 
 In Erysiphe ^^ the oogonium and antheridium arise in a very 
 similar way, the oogonium being somewhat curved. Fertilization 
 is also similar consisting of the union of two gametic nuclei. After 
 fertilization the oospore nucleus divides and the oogonium de- 
 velops into a short bent tube, which contains from five to eight 
 nuclei. Septa now appear cut- 
 ting off cells, some uninucleate, 
 some with two or more nuclei. 
 The ascogenous hyphse develop 
 a knot and soon divide into 
 two or three cells each and 
 give rise to the asci which are 
 in the beginning binucleate. 
 
 T _,^, ,, , • • 04 ,1 Fig. 125. — Phyllactmia, male and female 
 
 In Fhyllactmia "** the OOgO- branches; uninucleate oogonium and 
 nium, antheridium and fertili- '^^theridium. After Harper. 
 
 zations are as in Erysiphe, though the oogonium may be quite 
 curved so as to make almost a complete turn around the anther- 
 idium. Fig. 125. 
 
 After fertilization the antheridium degenerates and enveloping 
 protective hyphse arise both from the oogonium and the antheridium 
 stalk cells. The oogonium becomes three to five nucleate and 
 develops to a row of cells of which the penultinate cell has more 
 than one nucleus. The ascigerous hyphse arise from this binu- 
 cleate cell, perhaps also from other cells of the series, become 
 septate and form the asci either terminally, laterally or inter- 
 calary. The young ascus is binucleate, fusion follows and the 
 spores develop as in the preceding genera. 
 
 The family contains, according to Salmon, forty-nine species 
 and eleven varieties, according to Saccardo more than one hun- 
 dred species. These are parasitic on some one thousand five 
 hundred hosts, some of them upon economic plants and of 
 serious harmfulness. 
 
 The matter of delimiting species and even genera is often diffi- 
 cult, owing to intergrading forms. This question is complicated 
 
174 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 still further by biologic specialization such that forms which are in- 
 distinguishable under the microscope show in inoculation tests dif- 
 ferent abilities regarding host infection. Thus Neger,^° Salmon,^^' ^^ 
 Reed,^'' and others have shown that spores borne on a particular 
 host are capable of infecting only that host or in other cases only 
 nearly related species of the same host genus. Forms which can 
 pass from one genus to another are less common. Forms morpho- 
 logically distinct are regarded as separate species. Differentiations 
 within such species, regarding the species of host plant which they 
 parasitize, give rise to "biologic species" or "biologic varieties," 
 
 Reed ^'' writes of these biologic forms thus: 
 
 "So far as investigated, Erysiphe cichoracearum, is the only 
 one with doubtful exceptions, . . . shown to be capable of in- 
 fecting plants belonging to more than one genus." 
 
 "There are other cases where the mildew is limited closely to 
 plants of a single genus," and "Several cases are recorded where 
 the mildew from one species will not infect other species of the same 
 genus. Most of these claims, however, rest on insufficient data." 
 
 Some morphological species show a very wide range of hosts; 
 one species, Phyllactinia corylea is known on forty-eight genera 
 in twenty-seven families, others are limited to single genera or 
 to single species of host plant. Two, three, and even five species 
 are recorded for some species of host. 
 
 Geographically the Erysiphacese are widely distributed, prac- 
 tically of world distribution, but they are more abundant in the 
 temperate zones than elsewhere. 
 
 A pycnidium-bearing parasite, Cicinnobolus, p. 494, is quite 
 frequently found on the mycelium and conidiophores of the Ery- 
 siphacese. 
 
 Owing to the extreme variability of the perithecial characters 
 and the almost promiscuity of host selection this family presents 
 a most difficult problem to the taxonomist who must either segre- 
 gate or "lump " species. No middle ground seems open at present. 
 
 Key to Subfamilies and Genera op Erysiphaceae 
 Mycelium wholly external to the tissues of the 
 host plant, usually sending haustoria 
 into the epidermal cells only, perithecial 
 appendages various, more or less flaccid I. Erysipheae. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 175 
 
 Perithecial appendages indeterminate, 
 similar to the mycelium, simple or ir- 
 regularly branched 
 Pcrithecia containing a single ascus. . . 1. Sphaerotheca, p. 175. 
 
 Perithecia containing several asci 2. Erysiphe, p. 177. 
 
 Perithecial appendages determinate 
 Appendages hooked or coiled al the 
 
 apex 3. Uncinula, p. 180. 
 
 Appendages dichotomous at the apex 
 
 Perithecia containing a single ascus. 4. Podosphaera, p. 182. 
 Perithecia containing several asci ... 5. Microsphaera, p. 185. 
 Mycelium with special intercellular haus- 
 toria-bearing branches which enter the 
 host by the stomata; perithecial ap- 
 pendages rigid, with a bulbous base. . . II. Phyllactinieae. 
 A single genus 6. Phyllactinia, p. 187, 
 
 Sphaerotheca, Leveille 
 
 Perithecia subglobose; appendages floccose, brown or hyaline, 
 spreading horizontally and often interwoven with the mycelium, 
 simple or vaguely branched, frequently obsolete; ascus single, 
 8-spored. Five species, accorcUng to Salmon; Engler and 
 Prantl give fourteen. 
 
 S. humuli (D. C.) Burr.^s-s^ 
 
 Amphigenous; mycelium usually evanescent; perithecia usually 
 somewhat gregarious, but varying from scattered to cespitose, 
 58-120 n in diameter; cells small, averaging 15 n; appendages 
 few or numerous, usually long, often exceeding nine times the 
 diameter of the perithecium, more or less straight, septate, dark 
 brown throughout: variations are, short, flexuose, pearly-brown, 
 white or even obsolete. Ascus broadly-elliptic to subglobose, 
 rarely abruptly stalked, 45-90 x 50-72 /a; spores 20-25 x 12-18 n, 
 rarely larger, averaging 22 x 15 n. 
 
 Conidia ( = Oidium fragariae) ovate, white, membrane smooth. 
 
 Salmon^'' has shown that subjecting the conidia of this variety 
 to low temperature, 0° two hours, increases their germinating power. 
 Sowing ascospores from the hop, on hop, Potentilla and Spirea he 
 secured infection only on the hop.^^ Conidia from hop infected 
 hop but not Spirea. 
 
176 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 The species is cosmopolitan and among its numerous hosts are 
 the economic genera Dipsacus, Fragaria, Humulus, Phlox, Pyrus, 
 Rosa, Ribes, Rubus, Scabiosa, Spirea and Viola. 
 
 It is a common rose mildew of America and England and is also 
 especially destructive on the strawberry. 
 S. humili var. fuliginea. (Schl.) Sal. 
 
 Perithecia usually smaller than in the last, sometimes only 50 /x 
 in diameter, wall usually harder and more brittle, cells larger, ir- 
 regularly shaped, averaging 25 fi; 
 appendages usually short, pale 
 brown; spores 20-25 x 12-15 /x- 
 
 Throughout Europe, Asia and 
 North America. 
 
 It is recorded on Arnica, 
 Calendula, Coreopsis, Fragaria, 
 Gaillardia, Impatiens, Phlox, 
 Scabiosa, Taraxacum, Verbena, 
 Viola, and several other non- 
 economic genera. 
 
 S. pannosa (Wallr.) Lev.^-"^^ 
 Mycelium persistent, forming 
 dense satiny patches on the 
 stem, calyx, petiole, and rarely 
 on leaves, at first shiny white, then becoming gray, buff or 
 rarely brown; perithecia more or less (usually completely) im- 
 mersed in the persistent mycelium, globose to pyriform, 85-120 n 
 in diameter, usually about 100 fj,; cells obscure, about 10 fi wide; 
 appendages few, often obsolete, very short, tortuous, pale brown, 
 septate; ascus broadly-oblong to globose, 88-115 n, averaging 
 100 X 60-75 fi; spores 20-27 x 12-15 m- 
 
 Conidia ( = Oidium leucoconium) ovoid, 20-30 x 13-16 n, 
 hyaline; conidiophores short. 
 
 Hosts: peach and rose; cosmopolitan. 
 
 The conidia are very common on the rose, but the perithecia 
 are rare. What often passes for this species on roses in America 
 is in reality S. humili." 
 
 S. mors-uvae (Schw.) B. & C.^^"^^ 
 
 The mycelium at first white, is exceptional among the Erysipheae 
 
 Fig. 126. — S. mors-uvae, a perithecium 
 discharging its single ascus which 
 contains eight spores. After Long- 
 year. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 177 
 
 in that it later becomes quite brown. It is found in closely felted 
 patches on stems and fruit. Perithecia begin to form in June. 
 
 Amphigenous; mycelium persistent, at maturity forming dense 
 pannose patches of brownish hyphae; perithecia gregarious, more 
 or less immersed in the persistent mycelium, subglobose, 76-110 
 /i in diameter; cells large, at first well defined, then becoming 
 obscure, 10-25 n wide; appendages usually few or even obsolete, 
 pale-brown, short, rarely longer, up to five times the diameter of 
 the perithecium, tortuous; ascus elliptic-oblong to subglobose, 
 70-92, rarely 100 x 50-62 m; spores 20-25 x 12-15 /x. 
 
 On wild and cultivated species of Ribes in America; recently 
 introduced into Europe where it is very destructive. 
 
 S. lanestris Hark, occurs on various species of oaks in the United 
 States. 
 
 Erysiphe Hedwig (p. 175) 
 
 Perithecia globose, or slightly depressed, rarely concave; ap- 
 pendages floccose, simple or irregularly branched, sometimes 
 obsolete, usually more or less similar to the mycelium and inter- 
 woven with it; asci several, 2 to 8-spored. 
 
 Salmon recognizes eight species; Engler and Prantl,"' twenty. 
 
 E. polygoni D. C.^^ 
 
 Amphigenous; mycelium very variable, persistent, thin, effused 
 and arachnoid, rarely thick, or more often evanescent; perithecia 
 gregarious or scattered, usually rather small, 
 averaging 90 /x, but ranging from 65 to 180 ix; 
 cells usually distinct, 10-15 n wide; append- 
 ages very variable in number and length, 
 few or many, distinct or more or less inter- 
 woven with the mycelium, brown or colorless; ^ -.^^ ^ 
 
 •^ . ,, . Fig. 127.— E. polygoni, 
 
 asci 2-8 or rarely as many as 22, variable m the asci. After Sal- 
 shape and size, usually small and ovate, with 
 or without a short stalk, 46-72 x 30-45 fx; spores 3-8 rarely 2, 
 19-25 X 9-14 M- 
 
 Conidiophores ( = Oidium balsamii) medium; conidia ovate, 
 hyaline. 
 
 One of the commonest species, especially destructive to the pea 
 and turnip. It was studied by Salmon on one hundred ninety host 
 
178 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 species belonging to eighty-nine genera; one hundred forty-six 
 more hosts, some doubtful, are reported. Among the economic 
 host genera are Adonis, Alyssum, Anemone, Aquilegia, Brassica, 
 Calendula, Catalpa, Clematis, Cucumis (?), Cucurbita (?), Dahlia, 
 Daucus, Delphinium, Diervilla, Dipsacus, Fagopyrum, Lupinus, 
 Lycopersicum, Medicago, Pseonia, Phaseolus, Pisum, Tragopogon, 
 Trifolium, Verbena, Vicia, Scabiosa, Symphytum, Valeriana. 
 
 This is the most variable species of this genus varying widely 
 in its every character. It includes several species which have by 
 
 some been set aside as distinct, e. g., 
 E. martii, E. umbelliferarum and 
 E. liriodendri. 
 
 Salmon ^^ found that the conidia 
 of this form grown on Trifolium 
 pratense were unable to infect other 
 species of Trifolium. 
 
 E. cichoracearum D. C.^^ 
 Amphigenous; mycelium usually 
 evanescent, rarely persistent, white 
 or sometimes pink; perithecia gre- 
 garious or scattered, 80-140 or 
 rarely 180 p.; cells variable, often 
 very distinct, 10-20 ju; appendages 
 variable in number and size, some 
 Fig. 128.— E. cichoracearum, asci shade of brown; asci usually nu- 
 
 and spores. After Salmon. , -, ^ -, ^ i 
 
 merous, about 10-15, but varymg 
 from 4 to 36, variable in size and shape, narrowly ovate or 
 subcylindric to broadly-ovate, more or less stalked, 58-90 x 
 30-35 m; spores 2, rarely 3, 20-28 x 12-20 At. 
 
 Conidiophores ( = Oidium ambrosise Thum), short; conidia 
 minute, elliptic, white, 4-5 x 7-5.3 ix. The species is quite vari- 
 able sometimes closely approaching E. polygoni. 
 
 Cosmopolitan. The hosts are very numerous, among them 
 being: Borago, Calendula, Centaurea, Cichorium, Clematis, 
 Cucurbita, Dahlia, Helianthus, Humulus, Mentha, Nicotiana, 
 Phlox, Tragopogon, Valeriana, Verbena, Symphytum. It is of 
 especial import on composites and cucurbits. 
 
 Reed ^^ has made very extensive culture studies of this species 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 179 
 
 and concludes that the same form of ''Erysiphe cichoracearum 
 D. C, occurs on at least eleven species of the cucurbits, belonging 
 to seven genera, infection occurring in these cases in fifty per cent 
 or more of the trials. Six other species were also infected, but in 
 a smaller percentage of cases. ... It is also plain that the biologic 
 form of Erysiphe cichoracearum, occurring on so 
 many cucurbits is not entirely confined to the 
 species of this one family. Out of fifty-four 
 leaves of Plantago rugelii, a species belonging to 
 the Plantaginacese, which were inoculated, ten 
 became infected. . . . Furthermore out of ten 
 leaves of squash seedlings, inoculated with conidia 
 from plantain, six became infected . . . and the 
 sunflower, Helianthus annuus, was infected in 
 thirty-five per cent of the trials in which conidia 
 from the squash were sown on leaves of seed- 
 lings. . . . The cucurbit mildew could not be 
 transferred to asters and goldenrods nor was the 
 mildew occurring on these in nature able to in- 
 fect the squash. Neither the aster mildew nor 
 the cucurbit mildew proved able to infect a 
 goldenrod, Solidago csesia. Nor was the mildew 
 on this host able to infect asters or squashes." 
 
 E. taurica Lev. is found in Europe, North 
 Africa and Asia on Capparis, Cicer, Clematis 
 and various other hosts. 
 
 E. graminis D. C. Fig. 129.— e. gra- 
 
 . minis, conidial 
 
 Usually epiphyllous, rarely amphigenous; myce- stage. After Sal- 
 lium more or less persistent, forming scattered ™°"' 
 patches, at first white, then brown or gray; perithecia large, 
 135-280 fi, usually about 200 n, scattered or gregarious, cells ob- 
 scure; appendages rudimentary, few or numerous, very short, 
 pale brown; asci numerous, 9-30, cylindric to ovate-oblong, more 
 or less long-pedicellate, 70-108 x 25-40 fx; spores 8, rarely 4, 
 20-23 X 10-13 /x, seldom produced on the living host plant. 
 
 Conidial form ( = Oidium monilioides) with a grayish cast; coni- 
 diophores medium tall ; conidia ovoid, white or sordid, 25-30 x 8-10 ju. 
 
 It is found on a large number of species of the Gramineae in- 
 
180 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 eluding species of Avena, Festuca, Hordeum, Phleum, Poa, Sac- 
 charum, Secale, and Triticum. 
 
 The asci are peculiar in that they usually contain undifferenti- 
 ated granular protoplasm, not spores, though in some cases the 
 spores, normally 8, are present. Wolff ^^'^ found that after a few- 
 days in water the undifferentiated ascoplasm developed spores 
 which proceeded to normal germination. 
 
 This species on grasses shows no morphological differences, yet 
 inoculation tests have revealed in it numerous biologic varieties. 
 Reed^^ summarizes the results of his own work together with 
 that of Marchal ^"^ and Salmon ^"^ as follows: 
 
 "So far as tested, all species of Avena are susceptible to the 
 oat mildew. All species of Triticum are likewise susceptible to 
 the wheat mildew. We find, however, that certain varieties of 
 Triticum dicoccum are practically immune to the wheat mildew. 
 Other varieties of this same species are entirely susceptible. Some 
 species of Hordeum are immune to the barley mildew, and the 
 same seems to be true of certain species of Secale with reference 
 to the rye mildew. 
 
 To these general statements there are two possible exceptions. 
 Marchal states that the oat mildew will infect Arrhenatherum 
 elatius. Salmon, however, obtained a negative result with the 
 oat mildew on this grass. The evidence is not conclusive either 
 way. The other exception is that, according to Salmon, conidia 
 from wheat can infect Hordeum silvaticum. 
 
 ' It would seem then that under normal conditions there are 
 well-defined forms of Erysiphe graminis occurring respectively 
 on the species of each of the four cereals." 
 
 It is thought that some hosts may act as bridging species and 
 enable the parasite to pass from one host to another to which it 
 could not pass directly. 
 
 Uncinula Leveille (p. 175) 
 
 Perithecia globose to globose-depressed; appendages simple or 
 rarely once or twice dichotomously forked, uncinate at the apex, 
 usually colorless, rarely dark brown at base or throughout; asci 
 several, 2 to 8-spored. 
 
 There are eighteen or twenty species. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 181 
 
 U. necator (Schw.) Burr.io^' ^o^' ^o^ 
 
 Amphigenous; mycelium subpersistent; perithecia usually epi- 
 phyllous, occasionally hypophyllous or on the inflorescence, 
 more or less scattered, 70-128 n; cells distinct, rather irregular 
 shape, 10-20 /x; appendages very variable in number and 
 
 m 
 
 length, 7-32, rarely up to 40, 1 to 4-times the diameter of the 
 perithecium, septate, thin walled, light or dark amber-brown bas- 
 ally, rarely branched, asci 4-6 rarely up to 9, broadly-ovate or 
 ovate-oblong to subglobose, with or with- 
 out a short stalk, 50-60 x 30-40 n; spores 
 4-7, 18-25 X 10-12 fi. 
 
 Conidial form ( = Oidium tuckeri), coni- 
 diophores short; conidia elliptic, oblong, 
 or obtusely rounded, 2 to 3-catenulate, 
 hyaline, 25-30 x 15-17 /x. 
 
 Hosts Vitis, Ampelopsis and Actinidia. 
 One of the worst pests- of the family. 
 
 The mycelium is thin walled and spar- 
 ingly septate. The haustoria arise from 
 lobed lateral swellings of the hyphae, 
 penetrate the epidermis with a filamen- 
 tous projection and swell within the host 
 cell to a bladder-like body. The para- ^-^ — ttv 
 
 sitized cells and later the neighboring pi^ 130— u. necator. 11 
 ones turn brown and die. Sa\t?Tnf a.^ef ' iT 
 
 The conidia germinate readily in moist Group of asci removed 
 
 ,. /. ,, r from perithecium emit- 
 
 air or m water, sendmg forth trom one ting s, ascospores. After 
 to several germ tubes. ^' 
 
 The perithecia are found well developed as early as June or 
 July in the United States and are rather evenly scattered over 
 the affected surfaces. Bioletti ^'^^ says that a period of warm moist 
 weather which favors luxuriant mycelial growth, followed by sud- 
 den lowering of temperature to about 50° F., favors their most 
 rapid formation. They are at first hyaline, later brown. After 
 their form and walls become definite, usually during winter, the 
 appendages develop as outgrowths from the outer walls. During 
 winter the appendages break off. Galloway ^°'* failed to secure 
 germination of ascospores earlier than February or March, but 
 
182 
 
 THE FUXGI WHICH CAUSE PLANT DISEASE 
 
 perithecia which had been exposed to the weather until spring 
 and were then placed in a hanging drop culture afforded spores, 
 some of which grew though many of them burst as they emerged 
 from the perithecium. Ascospores are known to have remained 
 viable for at least eighteen months. ^°^ No successful infections 
 were made from ascospores. 
 
 Though perithecia are frequently found in America they were 
 not found in Europe until 1892 ^*'' and are now found there but 
 rarely. It appears that in their absence the fungus hibernates in 
 
 .1 B 
 
 Fig. 131. — U. necator. Photomicrographs of perithecia on surface of leaf. 
 
 A, Magnified 8 times. B, Magnified 35 times. After Bioletti. 
 
 specially resistant cells of the mycelium which develop within 
 
 • 330 
 
 knotty swellings near the haustona. 
 
 U. salicis (D. C.) Wint. on willow and poplar in Europe, Asia, 
 and America, U. aceris (D. C.) Sacc. and U. circinata C. &. P. 
 on maple are common species. U. flexuosa Pk. occurs on tEscuIus. 
 and elm, U. clandestina (Biv.) Schr. on elm, U. prunastri (D. C.) 
 Sacc. on species of Prunus, especially P. spinosa in Europe. U. 
 mori Miy. is on Morus in Japan. ^°^ Several other species of small 
 importance affect numerous hosts. 
 
 Podosphaera Kunze (p. 175) 
 
 Perithecia globose or globose-depressed; ascus solitary, sub- 
 globose, 8-spored; appendages equatorial or apical, dark-brown 
 or colorless, dichotomously branched at the apex, branches simple 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 183 
 
 and straight or swollen and knob-shaped; appendages rarely of 
 two kinds, one set apical, brown, rigid, unbranched or rarely 
 1 to 2-times dichotomous at the apex, the other set basal, short, 
 flexuous, frequently obsolete. 
 
 Salmon recognizes four species; Engler and Prantl seven. 
 
 P. oxyacanthae (D. C.) De Bary i«^' ^^^ 
 
 Amphigenous; mycelium variable, persistent in thin patches 
 or evanescent; perithecia scattered or more or less gregarious, 
 subglobose, 64-90 /x; cells 10-18 /jl; appendages spreading more 
 
 
 V 
 
 
 /r?'; 
 
 
 ■•■*'V 
 
 ^i^ 
 
 ^ ...C!>. 
 
 r/ 
 
 . 1 
 
 .^ 
 
 l'*'*^.-- 
 
 a 
 
 /^ 
 
 
 c 
 
 Fici. loL'. — P. oxjarantlia'. ", piTithcciuni showing tlie apix'inlagcs with 
 tips; 6, the one large ascus containing eight spores; c, the summer 
 spore-form; d, a spore germinating in water. After Longyear. 
 
 or less, equatorial, variable in number and length, from 4-30 in 
 number and from 3^-6 or even 10-times the diameter of the 
 perithecium, usually unequal in length, dark brown for more than 
 half their length from the base, apex 2 to 4-times dichotomously 
 branched, branches usually short and equal, ultimate branches 
 rounded, swollen, and more or less knob-shaped, Fig. 133; ascus 
 broadly obovate, or subglobose, 58-90 x 45-75 )u; spores 8, rarely 
 6, 18-30 X 10-17 M- 
 
 Conidia ( = Oidium cratsegi). 
 
 Salmon finds the species very variable but cannot set aside as 
 separate species P. tridactyla and P. myrtillina as is done by some 
 authors. On some hosts perithecia are rare. It is thought that 
 the mycelium remains alive over winter. 
 
 Hosts: Amelanchier, Crataegus, Diospyros, Prunus, Pyrus, 
 
184 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 t h a e, appendage 
 tips. After Sal- 
 mon. 
 
 Spirea and Vaccinium. Especially damaging to cherry and apple. 
 Throughout the northern hemisphere. 
 
 P. tridactyla (Wal.) De Bary is considered by Salmon ^^° as a 
 variety of the last species. Hosts: Plum and 
 other species of Prunus and of Spirea. 
 
 Similar to the preceding in habit and general 
 character but differing in more critical charac- 
 ters. Perithecia 70-105 ix; cells 10-15 m; ap- 
 FiG. 133.— P. oxycan- pendages 2-8 usually 4, 1 to 8-times the 
 diameter of the perithecium, apical in origin, 
 more or less erect, apically 3-5 or 6-times 
 dichotomously branched, primary branches usually more or less 
 elongate, sometimes slightly recurved; asci globose or subglobose, 
 60-78 X 60-70 m; spores 8, 20-30 x 13-15 m- 
 
 Chiefly European but found also in Asia and America. 
 P. leucotricha (E. & E.) Salm. 
 
 Mycelium amphigenous, persistent, thin, effused; perithecia 
 densely gregarious, rarely more or less scattered, 75-96 /x, sub- 
 globose, cells 10-16 m; appendages of two kinds, one set apical 
 the other basal; apical appendages 3-11 in number, more or less 
 widely spreading, or erect-fasciculate, 4 to 7-times the diameter 
 of the perithecium, apex undivided and blunt or rarely once or 
 twice dichotomously branched, brown basally; basal appendages 
 nearly obsolete or well developed, short, tor- 
 tuous, pale brown, simple or irregularly branched; 
 ascus oblong to subglobose, 55-70 x 44-50 n, 
 spores 22-26 x 12-14 fx, crowded in the ascus. 
 
 Conidia ( = Oidium farinosum): elhpsoid, trun- 
 cate, hyaline, 28-30 x 12 ^u. 
 
 Primarily American but occurring in Europe 
 and Japan. A most serious pest of the apple. 
 This and P. oxyacanthae, the apple mildews of 
 America, have been variously treated by writers ^^cotrtch^ 
 so that the literature presents an almost inex- 
 tricable tangle as has been pointed out by Pam- 
 mel ^^^ and by Stewart, ^^^ Podosphsera oxyacanthae being fre- 
 quently reported instead of P. leucotricha. Sphserotheca mali 
 and Podosphsera oxyacanthae have also been much confused, due 
 
 leu- 
 ap- 
 pend a g e tips. 
 After Salmon. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 185 
 
 to similarity of habit and the frequent abnormal development 
 of the appendages, so that the published references are not always 
 reliable. 
 
 Microsphaera Levielle (p. 175) 
 
 Perithecia globose to subglobose; asci several, 2 to 8-spored; 
 appendages not interwoven with the mycelium, branched in a 
 definite manner at the apex, usually dichotomously and often 
 very ornately, rarely undivided or merely once dichotomous. 
 
 According to Salmon there are thirteen species; Engler and 
 Prantl recognize thirty. 
 
 M. grossulariae (Wal.) Lev. 
 
 Epiphyllous or amphigenous; mycelium evanescent or sub- 
 persistent; perithecia scattered or densely aggregated, globose- 
 depressed, 65-130 n; cells 14-20 n; 
 appendages 5-22, colorless, 1-1 M 
 times the diameter of the perithe- 
 cium, 4 to 5-times closely dichoto- 
 mously branched, branches of first 
 and second order very short, all fiq. 135.— m. grossuiari^B, append- 
 segments deeply divided, tips not age tips. After Salmon, 
 
 recurved; asci 4-10, broadly ovate or oblong, usually with a very 
 short stalk, 46-62 x 28-38 fx; spores 4-6, rarely 3, 20-28 x 
 12-16 fx. 
 
 On five species of Ribes and two of Sambucus. This is the 
 common European gooseberry-mildew, which is not common in 
 America except on the elder. 
 
 M. berberidis (D. C.) Lev. occurs on the barberry in Europe 
 and Asia. 
 
 M. alni (Wal.) Salm. 
 
 Amphigenous; mycelium evanescent or persistent; perithecia 
 scattered to gregarious, globose-depressed, very variable in size, 
 usually small, 66-110 /x, or even up to 135 ix; cells 10-15 n 
 wide; appendages variable in number (4-26) and length, ^/s to 
 2}/^ times the diameter of the perithecium, more or less rigid, 
 colorless throughout or amber-brown at base, apex variously 
 
186 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 (but not always) more or less closely 3 to 6-times dichotomously 
 branched, tips of ultimate branches regularly and distinctly re- 
 curved; asci 3-8, ovats to ovate-globose, 42-70 x 32-50 m, usually 
 
 but not always short stalked; 4 to 
 ^^^0^^ 8-spored; spores 18-23 x 10-12 /z. 
 "^ This species is the most variable of 
 
 the Erysiphese showing large latitude in 
 number of spores in the ascus, in length, 
 color and branching of appendages, in 
 Fig. 136.— m. alni, appendage size of perithecia. It occurs upon very 
 
 tips. After Salmon. i ^ mi 
 
 numerous hosts. Ihe economic ones on 
 which it is most common are: Syringa, Lonicera, Alnus, Betula, 
 Quercus, Carya, Castanea, Juglans, Platanus. 
 
 It is confined to the northern hemisphere. 
 
 Salmon recognizes in addition to the typical form six varieties. 
 Those of economic importance are: 
 
 (a) extensa (C. & P.) Salm., a robust form on various American 
 species of oaks; 
 
 (b) calocladophora (Atk.) Salm., also a robust form on American 
 oaks but having pseudo-trichotomously branched appendages 
 and large spores; 
 
 (c) vaccinii (Schw.) Salm., in America on Catalpa and various 
 genera of Ericaceae is a small-spored, long-appendaged form. It 
 includes M elevata on Catalpa; 
 
 (d) lonicerae (D. C.) Salm., on species of Lonicera in Europe. 
 M. diffusa C. & P. 
 
 Amphigenous; mycelium persistent, thin and effused, or sub- 
 persistent and forming vague patches, or quite evanescent; peri- 
 thecia scattered or gregarious, globose-depressed, very variable in 
 size, 55-126 n in diameter, averaging 90-100 n, cells 10-20 fx 
 wide; appendages very variable in number and length, 4-30, or 
 rarely crowded and as many as 50, IJ^ to 7-times the diameter of 
 the perithecium, smooth, aseptate or 1 to 3-septate in the lower half, 
 colorless or pale brown towards the base, flaccid when long, thin- 
 walled above, becoming thick-walled towards the base, apex 3 to 5- 
 times dichotomously or subdichotomously divided, branching dif- 
 fuse and irregular, branches of the higher orders sub-nodulose, 
 often apparently lateral, tips of ultimate branches not recurved; 
 
THE FUxXGI WHICH CAUSE PLANT DISEASE 187 
 
 asci 4-9, 48-60 x 28-30 At, ovate-oblong with a very short stalk; 
 spores 3-6, usually 4, 18-22 x 9-11. 
 
 Hosts: Desmodium, Glycyrrhiza, Lespecleza, Phaseolus, Sym- 
 phoricarpos. 
 
 M. betae Vanha ^^^ has recently been described as a species in- 
 jurious to the beet. It is said to resemble E. polygoni but that 
 cross inoculation between the beet and clover could not be made. 
 
 M. ferruginea Erik, is found on cultivated Verbenas ^^^ in 
 Sweden. 
 
 M. euphorbiae (Pk.) B. & C. occurs on various hosts in America 
 and Asia, including Astragalus, Colutea, Cuphea and Euphorbia. 
 Its only economic importance is as the cause of a disease of the 
 roselle and cowpea ^^^ on which it is very common. 
 
 Amphigenous; mycelium usually subgeniculate; perithecia gre- 
 garious in floccose patches or scattered, 85-145 n, rarely 180 n, 
 cells 10-15 jjl; appendages 7-28, usually narrow, more or less 
 flexuose and nodose, 2.5 to 8 times the diameter of the perithecium, 
 colorless above, 3 to 4-times dichotomously branched, branching 
 irregular and lax; asci 4-13, rarely up to 26, ovate or ovate-oblong, 
 short-stalked, 48-66 x 26-35 fj.; spores usually 4, rarely 3, 5 or 6, 
 16-21 X 10-12 fjL. 
 
 Phyllactinia Leveille (p. 175) 
 
 Perithecia large, globose-depressed to lenticular; asci many, 2 
 or 3-spored; appendages equatorial, rigid, acicular, with a bul- 
 bous base; apex of perithecium with a mass of densely crowded 
 branched outgrowths. 
 
 Typical epidermal haustoria are not produced but the mycelium 
 sends special branches through the stomata into the intercellular 
 spaces of the leaf.^^^ These branches attain some length and con- 
 stitute a limited internal mycelium, a character that is considered 
 by some as of sufficient importance to set the genus apart in a 
 separate family. The internal mycelium gives off haustoria which 
 penetrate cells of the mesophyll. The appendages exhibit strik- 
 ing hygroscopic movements and aid in dissemination. 
 
 Only one species is recognized by Salmon. 
 
 P. corylea (Pers.) Karst. 
 
 Hypophyllous or rarely amphigenous; mycelium evanescent 
 
188 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 or more or less persistent; perithecia usually scattered, rarely 
 gregarious, 140-270 n, rarely up to 350 n; cells rather obscure, 
 15-20 fx; the apical outgrowth becomes mucilaginous attaching 
 the perithecium firmly to places where it may fall; appendages 
 
 Fig. 137. — Phyllactinia corylea. 1. Natural size, on 
 chestnut leaf. 2. Perithecium enlarged. 3. Two asci. 
 4. Three spores. 5. Conidia-bearing hyphae. 6. Co- 
 nidium germinating. After Anderson. 
 
 5-18, equatorial, 1 to 3-times the diameter of the perithecium; 
 asci 5-45, subcylindric to ovate-oblong, 60-105 x 25-40 /x, more 
 or less stalked, 2, rarely 3-spored; spores 30-42 x 16-25 fi. 
 
 Conidia (=Ovulariopsis) acrogenous, solitary, hyaline, sub- 
 clavate. 
 
 On Magnolia, Liriodendron, Berberis, Xanthoxylum, Ilex, Celas- 
 trus, Acer, Desmodium, Crataegus, Heuchera, Ribes, Hamamelis, 
 Fraxinus, Asclepias, Catalpa, Cornus, Ulmus, Betula, Alnus, Cory- 
 lus, Ostrya, Carpinus, Quercus, Castanea, Fagus and Typha. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 189 
 
 Perisporiaceae (p. 170) 
 
 Aerial mycelium covering the substratum with a dark growth, 
 rarely absent, usually astromate. Perithecia on the mycelial threads 
 or on a stroma, black, more or less globose, without opening or 
 appendages, although in some genera (Meliola, etc.) mycelial out- 
 growths from the base of the perithecium simulate appendages. 
 Asci elongate, numerous; spores various; paraphyses none. 
 
 Chiefly parasites, although several genera are saprophytes. 
 About three hundred species. 
 
 Aside from ascospores, in some species conidia of one or several 
 forms are known. These may be borne in pycnidia or uncovered 
 on hyphae. Apiosporium is especially rich in the number of its 
 conidial forms. 
 
 Key to Genera of Perisporiaceae 
 Spores 1-celled 
 Spores not curved 
 
 Spores hyaline 1. Anixia. 
 
 Spores brownish 2. Orbicula. 
 
 Spores curved, green 3. Pseudomeliola. 
 
 Spores 2-celled 
 Spores, at least when immature, ap- 
 
 pendaged 4. Zopfiella. 
 
 Spores not appcndaged 
 
 Perithecia borne on the aerial mycelium 
 Spores not enlarging after maturity 
 Spores smooth 
 Aerial mycelium prominent. ... 5. Dimerosporium,p. 191. 
 Aerial mycelium none, or poorly 
 developed 
 Asci cylindric-clavate ; para- 
 sites 6. Parodiella. 
 
 Asci saccate, large; sapro- 
 phytes 7. Zopfia. 
 
 Spores finely echinulate 8. Marchaliella. 
 
 Spores enlarging after maturity ... 9. Richonia. 
 Perithecia borne on a hairy stroma. ... 10. Lasiobotrys, p. 191. 
 Spores 3 or more celled 
 
 Aerial mycelium none or poorly developed 
 
190 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Spores with cross walls only 
 Spores elongate to cylindric 
 
 Spores 4-celled, saprophytes 11. Perisporium. 
 
 Spores 4 to 8-celled; parasites. ... 12. Schenckiella. 
 
 Spores needle-formed 13. Hyaloderma. 
 
 Spores muriform 
 
 Spores brown 14. Cleistotheca. 
 
 Spores hyaline 15. Saccardia. 
 
 Aerial mycelium prominent 
 Spores with cross walls only 
 Spores hyaline 
 
 Saprophytic 16. Scorias. 
 
 Parasitic 17. Zukalia, p. 191. 
 
 Spores brown 
 
 Perithecia without apparent ap- 
 pendages 
 Perithecia rounded, opening 
 
 irregularly 18. Antennaria, p. 192. 
 
 Perithecia elongate, clavate, 
 
 opening by regular slits. . 19. Apiosporium, p. 191. 
 Perithecia appearing to have 
 appendages 
 
 Stromatic 20. Limacinia, p. 193. 
 
 Not stromatic 21. Meliola, p. 193. 
 
 (Some species of Meliola have muri- 
 form spores) 
 Spores muriform 
 Spores with an appendage at each 
 
 end 22. Ceratocarpia. 
 
 Spores not appendaged 
 
 Subicle crustose 23. Capnodium, p. 192. 
 
 Subicle radiate 24. Pleomeliola, p. 193. 
 
 The genera of interest as pathogens induce disease rather by- 
 covering, shading and smothering leaves with dense sooty-black 
 coatings than by parasitizing their hosts. They are not strictly 
 speaking parasites but live saprophytically upon the surfaces of 
 leaves, fruit and twigs often subsisting upon insects or insect 
 exudations, the so called "honey dew." 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 191 
 
 Dimerosporium Fuckel (p. 189) 
 
 Perithecia depressed-globose, membrano-carbonous; asci clavate 
 to ovate, 8-spored; spores 2-celled, hyaline or brownish; mycelium 
 abundant, dark, forming a film and often bearing conidia on 
 conidiophores. 
 
 D. mangiferum Sacc. does some harm to the mango. 
 
 D. pulchrum, Sacc. grows upon the leaves of several woody 
 plants, such as privet, Lonicera, Carpinus and 
 Cornus. Conidia=Sarcinella heterospora. 
 
 D. collinsii (Schw.) Thiim., forms witches ^ "^ ^^S 
 brooms on the service berry. 
 
 Lasiobotrys Kunze (p, 189) 
 
 Fig. 138. — Dimerospo- 
 
 Perithecia superficial, globose, minute, JonidTife^ascu^: 
 black, aggregated in botryose fashion, stro- ^^^^^ Winter. 
 mate; asci cylindric, 8-spored; spores oblong, 2-celled, hyaline. 
 
 The one species L. lonicerae Kze. forms dark coatings on honey- 
 suckle leaves in Europe, North Africa and Siberia but does little 
 or no harm. 
 
 Zukalia Saccardo (p. 190) 
 
 This genus is like Meliola except in its hyaline spores and in 
 its perithecium. 
 
 Z. stuhlmanniana is on seedling cocoanuts and other palms. 
 
 Apiosporium Kunze (p. 190) 
 
 Perithecia superficial, minute, globose to pyriform, membra- 
 nous or carbonous; asci ovate to clavate, 8-spored; spores 
 globose to oblong, hyaline; paraphyses none. Conidia=Torula, 
 Fumago, Chaetophoma, etc. 
 
 Several forms are known to constitute sooty coatings on leaves 
 of woody plants, subsisting on insect secretions. The specific 
 limitations in the genus have not been satisfactorily worked out 
 owing to the comparative rarity of the ascigerous stages. 
 
 A. salicinum. (Pers.) Kze. is common on leaves of many species 
 of woody plants. 
 
 Perithecia brownish, gregarious, globoid-oblong, composed of 
 
192 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 minute cells as in the Erysiphacese; spores ovate, guttulate, hyaline, 
 10 X 8 m; conidia of various kinds, formed from the bases of the 
 perithecia, (a) multicellular macroconidia, (b) unicellular micro- 
 conidia, (c) gemmae. 
 
 A. brasiliense Noack is reported on grape ^^^ in Brazil. 
 
 Various species also occur on numerous woody and herbaceous 
 plants which are infected with aphids or upon which their "honey 
 dew" falls. 
 
 Antennaria Link differs but little from Apiosporium. 
 
 A. pithyophila Nees. occurs on leaves of fir; A. elaeophila Mont. 
 
 Fig. 139. — ^Apiosporium salicinum. After Anderson. 
 
 on the Olive; A. setosa Zimm. on coffee; A. footi B. & D. com- 
 monly on green house plants; A. piniphilum Fcl. on fir. 
 
 Capnodium Mont. (p. 190) 
 
 This is easily distinguished from genera of similar habit by its 
 muriform spores. 
 
 C. quercinum Pers. occurs on oak; C. taxi S. & R. on Taxus; 
 C. foedum Sacc. on Oleander; C. coffeae Del. on coffee; C. tiliae 
 
THE FUNGI WHICH CAU8E PLANT DISEASE 
 
 193 
 
 Fcl. on Tilia; C. citri B. & P. on leaves of citrus fruits in Europe 
 and America. 
 
 C. stellatum Bern, and C. guajavae Bern, cause sooty mold 
 on various trees in the tropics; '^'^'^ C. corticolum McAlp. on citrous 
 trees in New South Wales ^^^ and Australia; C. javanicum Zimm., 
 on coffee. ^^^ C. meridionale Arnaud is on Oleander, oak, and 
 olive, in Europe; ^^" C. olea Arnaud ^^^ on olive in France. 
 
 Limacinia tangensis P. Henn. is on the mango and cocoanut in 
 Africa. 
 
 Pleomeliola hyphaenes P. Henn. is on leaves of Hyphaene in 
 Africa. 
 
 Meliola Fries (p. 190) 
 
 Perithecia globose, surroimded by dichotomously branched 
 hyphae which resemble the appendages of the Erysiphacese; asci 
 short, broad, 2 to 8-spored; 
 spores oblong, 2 to 5-septate, 
 rarely muriform; paraphyses 
 none. 
 
 This is a genus of over one 
 hundred thirty species, whose 
 mycelium grows superficially 
 upon leaves and twigs. 
 
 M. camelliae (Catt.) Sacc. oc- 
 curs on Camellia. 
 
 Mycelium, copious, black, 
 bearing various sporing bodies; 
 perithecia black, spherical, 80- 
 150 n., containing several 8- 
 spored asci; spores 16-18 x 45 fi, 
 olivaceous, 4-celled. Stylo- 
 spores ovoid, 5 ix, hyaline, borne 
 in flask-shaped pycnidia which 
 may be as much as 1 or 2 mm. 
 high; pycnidia globose resem- 
 bling the perithecia but smaller, 
 containing spherical spores of about the same size as the stylo- 
 spores. Chlamydospores are also formed by the breaking up of 
 
 Fig. 140. — M. camelliae. 3, pypnidium 
 and spores. 4, other form of pyc- 
 nidium. 5, perithecium, ascus and as- 
 cospores. After Webber. 
 
194 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 the mycelium. Fumago camellise Catt. is a conidial form of this 
 species. 
 
 M. penzigi Sacc.^^^'^^^ is found on Citrus forming a sooty black 
 mold. It subsists on "honey dew," following principally certain 
 insects as Aleyrodes, Ceraplastes, Dactylopius, and Aphis. The 
 species is quite similar to the preceding. 
 
 The hyphse are from olive-green to dark brown and when old 
 are connected into a compact membrane. The fungus is entirely 
 superficial, possessing, however, small knob-like projections for 
 attachment and large discs (hyphopodia). Reproduction is by 
 conidia, pycnidia, stylospores and perithecia. 
 
 Webber says: 
 
 "Several forms of conidia are produced, some being but slight 
 modifications of the common cells of the mycelium, while others 
 are compound spores. Pycnidia are small, spherical black repro- 
 ductive bodies, about 40 /x in diameter, and are usually present 
 in considerable numbers in the mycelium. They may be readily 
 seen with a strong magnifying hand lens, but cannot be definitely 
 distinguished from perithecia or the young stages of the stylospores. 
 Stylospores are borne in conceptacles, which in their simplest form 
 resemble flasks with long drawn-out necks. Frequently, however, 
 they are much branched, and as they project from 1 to 2 mm. be- 
 yond the mycelium they form quite a conspicuous part of the 
 fungus. They are easily recognized with the unaided eye, and can 
 be seen with considerable distinctness with a hand lens. Perithecia 
 are black, spherical reproductive bodies closely resembling pycnidia, 
 from which they can not be distinguished with a hand lens. How- 
 ever, they are larger, being eighty micro millimeters in diameter. 
 Each perithecium contains several asci and each of these bears 
 eight ascospores. Some of the investigators who have studied 
 this disease have failed to find perithecia, and only twice has the 
 writer found them in his examination of material from Florida. 
 
 "The various reproductive bodies other than perithecia, partic- 
 ularly the conidia and stylospores, are developed in great abun- 
 dance." 
 
 M. niessleanea Wint. is common on Rhododendron. 
 
 Several entomogenous fungi i i^*i '^ have been found which by prey- 
 ing upon those insects which secrete honey dew, lessen the injury 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 195 
 
 from all sooty molds. Among these are the genera Aschersonia^^^ 
 and Sphaerostilbe. 
 
 Microthyriaceae (p. 170) 
 
 Mycelium superficial, dark; perithecia superficial, separate, 
 shield-shaped, unappendaged, black, membranous to carbonous, 
 formed of radiating chains of cells; asci 4 to 8-spored, short; pa- 
 raphyses usually present, 
 
 A family of over twenty genera and more than three hundred 
 species, chiefly poorly understood. 
 
 Only two species have been noted as serious economic patho- 
 gens; Scolecopeltis aeruginea Zimm, and Microthyrium coffae 
 both on coffee in Africa. 
 
 The genera of the Ascomycetes which remain to be treated, 
 and which are separated from those preceding by the possession 
 of an ostiole, are by some known under the name Pyrenomycetes. 
 Cf. p. 170. There are three orders, the Hypocreales, Dothidiales 
 and Sphseriales. 
 
 Hypocreales (p. 124) 
 
 The chief character separating this order from other Pyrenomy- 
 cetes is the brighter color — yellow, purple, scarlet, red, etc. — and 
 the more tender texture of its perithecia, — soft, fleshy, cottony, 
 patellate or effused. 
 
 The perithecium also differs from that of the preceding orders in 
 the possession of a distinct opening, ostiole, for the exit of spores. 
 
 Perithecia globose to cylindric or flask-shaped, free on the sub- 
 stratum (rarely subepidermal) or united by a common matrix, 
 which varies from a cottony subiculum to a distinct fleshy stroma, 
 wall membranous or at least not truly carbonous; asci cylindric, 
 clavate or subovoid, mostly 4 to 8-spored but often becoming 
 16-spored by the separation of each original spore into two globose 
 or subglobose cells; spores simple or compound, hyaline or colored, 
 globose to filiform. 
 
 Conidia are usually produced freely, each genus usually possess- 
 ing at least one form of free-borne conidia, while in some genera 
 several diflferent kinds of conidia are found. Pycnidia are rare. 
 Often the ascigerous stage is nearly suppressed and rare while 
 one or more of the conidial forms predominates. 
 
196 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Such form genera as Verticillium, Tubercularia, Sphacelia, 
 Sphaerostilbe and Isaria are connected with the Hypocreales. 
 
 The order includes some sixty genera, and over eight hundred 
 species. Of these only a half dozen genera contain important plant 
 parasites, another half dozen genera, parasites of less importance. 
 The rest are saprophytes, insect parasites, etc., of no economic 
 significance. 
 
 Opinion differs as to the characters which should be made the 
 basis for subdivision of this family, whether to throw main stress 
 upon the structure of the perithecium or upon the character of 
 the spores. 
 
 Following Lindau the order contains a single family, Hypo- 
 creaceae,^^^"^^^ which may be divided into six subfamilies. Accord- 
 ing to a more recent treatment of the American members of the 
 group by Seaver ' two families and four tribes are recognized. 
 Lindau's tribes Hyponectrieae, Hypomycetese, and Melanosporeae 
 are united with a part of Nectriese under the last name while the 
 remaining genera, referred by Lindau to this tribe, constitute the 
 tribe Creonectrese, These tribes constitute the family Nectriaceae. 
 The remaining tribes, Hypocreese and Clavicipitese with about the 
 same limits constitute the family Hypocreacese. 
 
 Key to Tribes of Hypocreaceae 
 
 Perithecia at first sunken in the substratum, 
 
 later erumpent 1. Hyponectrieae. 
 
 Perithecia not sunken in the substratum; 
 stroma present or absent 
 Stroma cottony, never fleshy; perithecia 
 immersed in the stroma, or borne on 
 
 its surface 2. Hypomyceteae. 
 
 Stroma fleshy or wanting 
 
 Spores dark colored; perithecia free on 
 the substratum (in some species 
 of Melanospora with a cottony . 
 
 stroma) scattered 3. Melanosporeae. 
 
 Spores hyaline, yellow or red 
 
 Perithecia without a stroma, or on a 
 
 fleshy stroma 4. Nectrieae, p. 197. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 197 
 
 Perithecia sunken in a fleshy stroma 
 
 Spores not filiform ; perithecia half 
 or entirely sunken in the 
 stroma, and distinct from it. . 5. Hypocreeae, {). 198. 
 
 Spores filiform; perithecia com- 
 pletely embedded in the 
 stroma and not clearly dis- 
 tinct from it 6. Clavicipiteae, p. 199. 
 
 The first tribe contains no parasitic genera while the second and 
 third contain but one each. Of the Hypomycetese, the genus 
 Hypomyces (p. 200) is set off from the others by its 2-celled hyaline 
 fusiform spores, and its cottony stroma. Of the Melanosporeae 
 the genus Melanospora (p. 200) is distinguished by the long beaks 
 of its flask-shaped perithecia, which are brown rather than black, 
 and its brown 2-celled spores. 
 
 Keys to the Genera of Nectrieae, Hypocreeae and Clavicipiteae 
 
 Tribe IV. Nectrieae (p. 196) 
 
 Conidiophores not of the Stilbum tj^pe 
 Spores elongate, 1-celled; perithecia free 
 on the substratum; stroma none 
 Spores not appendaged 
 Perithecia yellow or red 
 Asci cylindric; ostiole concolorous 
 
 with the perithccium 1. Nectriella. 
 
 Asci clavate-cylindric; ostiole 
 
 darker than the perithecium.. 2. Thelocarpon. 
 
 Perithecia violet or blue 3. Lisiella. 
 
 Spores appendiculate 4. Eleutheromyces. 
 
 Spores elongate, 2 to many-celled 
 Spores with cross walls only 
 Spores 2-celled 
 Asci 8-spored; often with 1-celled, 
 conidia formed in the ascus 
 Perithecium yellow or red 
 
 Spores hyaline 5. Nectria, p. 201. 
 
 Spores brown 6. Neocosmospora, p. 205. 
 
 Perithecium blue or violet 7. Lisea. 
 
198 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Asci many-spored 
 
 Perithecium fleshy, ostiole ele- 
 vated 8. Metanectria. 
 
 Perithecium hard, ostiole sunken 9. Cyanocephalium. 
 Spores 2 to many-celled 
 Spores not appendiculate 
 
 Perithecium bright colored, not 
 
 blue 10. Calonectria, p. 205. 
 
 Perithecium blue or violet 11. Gibberella, p. 206. 
 
 Spores appendiculate, 4-celled 
 Perithecia clavate, ostiole wart- 
 like 12. Paranectria. 
 
 Perithecia flask-shaped, ostiole 
 
 elongate 13. Lecythium. 
 
 Spores muriform 
 
 Perithecium bright colored, not 
 
 blue 14. Pleonectria, p. 207. 
 
 Perithecia dark colored or blue. . . 15. Pleogibberella. 
 Spores filiform 
 
 Perithecia fleshy, bright colored 16. Ophionectria, p. 207. 
 
 Perithecia horny, brown 17. Barya. 
 
 Conidiophores of the Stilbum type, stroma 
 wanting 
 
 Spores 2-celled 18. Sphaerostilbe, p. 207. 
 
 Spores 4-celled 19. Stilbonectria. 
 
 Spores muriform 20. Megalonectria. 
 
 Tribe V. Hypocreeae (p. 197) 
 
 Stroma sunken in the substratum or grown 
 to it, usually free later 
 
 Spores 1-celled 21. Polystigma, p. 207. 
 
 Spores 2-celled 22. Valsonectria, p. 208. 
 
 Spores several-celled by cross walls 23. Cesatiella. 
 
 Spores muriform 
 
 Spores hyaline 24. Thyronectria. 
 
 Spores olive-brown 25. Mattirolia. 
 
 Stroma from the first separable from the 
 substratum 
 
 Spores 1-celled 26. Selinia. 
 
 Spores 2-celled 
 
 Cells of the spores separating in the ascus 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 199 
 
 Stroma patellate or effuse 27. Hypocrea, p. 209. 
 
 Stroma erect, simple or branched. . . 28. Podocrea. 
 Cells of the spores not separating in the 
 ascus 
 
 Stroma patellate or effuse 29. Hypocreopsis. 
 
 Stroma erect, branched 30. Corallomyces. 
 
 Spores 3 to many-celled 
 Stroma bright or dark colored, not 
 
 conidia-bearing 31. Broomella. 
 
 Stroma dark, green or black, with 
 conidia 
 
 Conidia of two kinds 32. Loculistroma, p. 215. 
 
 Secondary conidia absent 33. Aciculosporium, p. 211. 
 
 Spores muriform 34. Uleomyces. 
 
 Tribe VI. Clavicipiteae (p. 197) 
 Stroma effused 
 
 Stroma forming a sheath about the host. 35. Epichloe, p. 210. 
 Stroma flat, tuberculate, or disk-shaped 
 Stroma not conidia-bearing 
 
 Stroma thick, usually light colored. . 36. Hypocrella. 
 
 Stroma thin, black 37. Dothiochloe, p. 210. 
 
 Stroma with the inner portion conidia- 
 bearing 38. Echinodothis, p. 211. 
 
 Stroma erect 
 
 Stroma small, saccate, membranous 39. Oomyces. 
 
 Stroma large, erect, with distinct sterile 
 
 and fertile portions, the latter often 
 
 knob-like 
 
 Stroma formed in the bodies of insects 
 
 and spiders, or in subterranean 
 
 fungi 40. Cordyceps. 
 
 Stroma formed in the inflorescence of 
 
 Glumacea^, etc., spores continuous 
 
 Stroma not growing from a sclero- 
 
 tium 41. Balansia, p. 209. 
 
 Stroma growing from a sclerotium 
 after a period of rest 
 
 Asci preceded by conidia 42. Claviceps, p. 211. 
 
 Asci preceded by smut-like chla- | 43. Ustilaginoidea, p. 213. 
 mydospores I 44. Ustilaginoidella,p.ll4. 
 
200 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Hypomyces Fries (p. 197) 
 
 Stroma an effused cottony subiculum, often of considerable 
 extent; perithecia numerous, usually thickly scattered and im- 
 mersed in the subiculum, rarely superficial; asci cylindric, 8-spored; 
 
 spores fusoid or fusiform, 
 usually apiculate, rarely 
 blunt, 2-celled, hyaline; 
 conidial phase variable. 
 
 This genus of some forty 
 species contains but few 
 saprophytes, the majority 
 being parasitic, chiefly on 
 the larger fungi. The genus 
 is of economic interest only 
 as affecting mushrooms, 
 though one species, H. 
 hyacinthi has been found 
 causing secondary infec- 
 tion in onions, following 
 a bacterial trouble, and 
 another; H. solani Reinke 
 follows a similar disease 
 on potatoes. Chlamydospores and conidiospores develop, be- 
 longing to various form genera as Verticillium, Mycogone, Fuligo, 
 Diplocladium, Dictylium, Sepedonium, Blastotrichum. 
 
 Allied to this genus are probably Mycogone rosea and M. per- 
 niciosa) which are destructive enemies of mushroom culture. 
 
 C 
 
 Fig. 141. — Hypomyces ochraceus. B, peri 
 thecia; C, asoi and spores; D, spores; E, co 
 nidia; F, chlamydospores. After Tulasne. 
 
 Melanospora Corda (p. 197) 
 
 Perithecia superficial, without a stroma, globose-pyriform or 
 flask-shaped, with a long neck which is usually clothed at the 
 tip with a fringe of hairs, perithecia often hairy; asci broadly 
 clavate, 4 to 8-spored; spores 1-celled, brown to brownish-black. 
 
 The genus contains some forty species, mostly common 
 saprophytes. 
 
 M. damnosa (Sacc.) Lin. is serious on wheat and rye.^-^' ^^^ 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 201 
 
 M. stysanophora Mat. is said to be an ascigerous stage of 
 Dematophora glomerata, cf. p. 230, so injurious to the grape. 
 
 Nectria Fries (p. 197) 
 
 Stroma absent or tubercular, fleshy, bright colored; perithecia 
 single, or gregarious, on or in the stroma or among cottony hyphse, 
 globose or ovate, walls fleshy, yellow, red or brown, smooth or 
 hairy; ostiole papillate or not; asci cylindric or clavate, 8-spored; 
 spores elongate blunt or pointed, 
 hyaline, rarely red, 2-celled, form- 
 ing conidia in the ascus; paraphyses 
 usually none. 
 
 As conidial stages occur the form 
 genera Cephalosporium, Tubercu- 
 laria, Fusarium, Spicaria, Fusidium 
 and Chsetostroma. Much doubt 
 exists as to specific limitations, and 
 as to the life histories of the species. 
 Some two hundred fifty species have 
 been described. Several are cred- 
 ited with causing serious diseases, 
 most of them occurring as wound parasites and unable to effect 
 entrance into sound tissue. Other species are pure saprophytes 
 and harmless. 
 
 The genus Nectria is divided into seven sub-genera, which are 
 frequently given generic rank, as follows : 
 
 Fi 
 
 142. — Melanospora. K, peri- 
 thecium ; L, asci ; M, spores. After 
 Lindau. 
 
 Key to Subgenera of Nectria 
 
 Spores smooth 
 Perithecia smooth 
 
 Stroma fleshy 1. Eunectria, p. 202. 
 
 Stroma a cottony subiculum 2. Hyphonectria. 
 
 Stroma usually absent; perithecia 
 
 scattered 3. Dialonectria, p. 205. 
 
 Perithecia hairy 4. Lasionectria. 
 
 Perithecia scaly 5. Lepidonectria. 
 
 Spores tuberculate 6. Cosmonectria. 
 
 Spores appearing striated, golden brown ... 7. Phaeonectria. 
 
202 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 The majority of economic species belong to the first subgenus. 
 
 Eunectria (p. 201) 
 
 N. cinnabarina (Tode) Fr. 
 
 Stroma erumpent, tubercular, at first pinkish or yellowish-red, 
 darker with age, 1-2 mm. high and broad; perithecia almost glo- 
 bose, the ostiole rather prominent, becoming slightly collapsed, at 
 first bright cinnabar-red, darker with age, granular, 375-400 n 
 in diameter; asci clavate, 50-90 x 7-12 m; spores mostly 2-seriate, 
 
 elliptic elongate, ends obtuse, 
 slightly curved, 12-20 x 4-6 n; 
 paraphyses delicate. 
 
 Tubercularia vulgaris borne on 
 the stroma is the conidial stage. 
 Conidiophores aggregated into tu- 
 bercular masses each 50-100 ju long; 
 conidia on short lateral branches, 
 elliptic, hyaline, 4-6 x 2 /x. 
 
 The closely septate delicate 
 hyphse grow rapidly through the 
 wood or bark, penetrating nearly 
 every cell and turning the wood 
 After black and collecting to form stro- 
 mata on or in the bark. These 
 stromata in fall or spring break through the epidermis and produce 
 warty, gray to pink, excrescences, which at first bear profuse 
 conidia both terminally and laterally on short stalks and later 
 dark-red ascigerous structures; though the latter are much less 
 common and are often absent. The fungus is said to be unable to 
 affect living cambium and cortex. 
 
 It is found saprophytically on many decayed woody plants that 
 have been frost killed, and parasitically on pear, Tilia, ^sculus, 
 China berry, Betula, Ribes, Acer, Carya, Morus, Prunus, Quercus, 
 Ulmus, etc. Mayer ^-^ germinated spores on a cut branch; the 
 mycelium spread to and killed the main stem; tubercles appeared 
 and during the following year perithecia developed on these 
 tubercles. In America the species has attracted attention on the 
 currant ^-^' ^^^ in which host the mycelium invades chiefly the 
 
 Fig. 143. — N. cinnabarina, perithe- 
 cia in stroma, ascospores issuing in 
 cirri ; germinating spores 
 Hartig. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 203 
 
 cambium. On this host, however, it is now said to be non- 
 parasitic.^'^ 
 
 Durand,^^^ culturing the conidial form on sterile currant stems, 
 observed the formation of tubercles with abundant conidia after 
 about fourteen days. On agar conidia were produced directly from 
 single hyphae without any stroma. Perithecia were found in the 
 field on the tubercles with the conidia in February. 
 
 N. ditissima Tul. 
 
 Stroma light colored; perithecia cespitose, densely and irregu- 
 larly clustered, or rarely scattered, ovate, ostiole prominent, bright 
 red, smooth or roughened; asci cylindric to clavate, 80-90 x 8-10 m; 
 spores fusoid, 12-16 x 4-5 fx. 
 
 The unicellular microconidia are followed by falcate, multi- 
 cellular, macroconidia (Fusidium candidum), which are borne on 
 pale stromatic cushions. 
 
 Common on dicotyledonous trees, especially beech, oak, hazel, 
 ash, alder, maple, lime, apple and dogwood, where it is usually a 
 wound parasite, particularly common after hail. It is especially 
 well known from Europe and has more recently attracted atten- 
 tion in America. 
 
 The mycelium does not usually advance more then one centi- 
 meter in each year. It is believed that it can travel within the 
 wood and break through the cambium and cortex at points some 
 distance from the place of original infection, thus producing new 
 spots. Very minute conidia produced in the bark aid in tissue de- 
 composition. White conidial (Fusidium) stromata appear near 
 the periphery of affected spots and here, too, in groups or scattered, 
 appear the deep red perithecia. 
 
 N. cucurbitula Sacc. 
 
 Perithecial clusters erumpent, often irregular in form, 1-2 mm. 
 in diameter; perithecia densely clustered, bright red, ovate, with 
 a prominent ostiole, rarely collapsing; asci cylindric to clavate 
 75-100 X 6-8 fj.; spores at first crowded and partially 2-seriate, 
 finally becoming 1-seriate, lying obliquely in the ascus, broad, 
 fusoid, rarely subelliptic, 14-16 x 5-7 ju. 
 
 Its hosts are spruce, fir, pine and other conifers in Europe and 
 North America. 
 
 The fungus is usually a wound parasite, often following hail. 
 
. 204 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Germ tubes from ascospores or conidia enter the cortex and 
 develop a rich mycehum in the sieve tubes and soft host. This 
 advances most rapidly during the dormant period of the bast. 
 
 White or yellow stromata the size of a pin- 
 head appear and bear numerous conidia. Later 
 come the red perithecia whose ascospores ripen 
 in winter or spring. 
 N. ribis (Tode) Rab. 
 Fig. 144.— n. ipo- Cespitose, stroma compact; perithecia sub- 
 
 of p e'r i t h e c i a. globose, smooth ; ostiole papillate ; asci subclavate, 
 
 After Halsted. gQ-lOO X 15; spores elongate or fusoid, hyaline, 
 1-septate, 18-20 x 5-6 mm. On currant. 
 
 N. ipomoeae Hals. 
 
 Perithecia clustered, ovate, roughened, red; asci cyhndric- 
 clavate; spores elliptic; conidial phase (Fusarium) appearing as a 
 white mold-like covering of the host; conidia several-celled, falcate. 
 
 Halsted ^-^ inoculated sterilized egg-plant stems with the Nectria 
 spores and the Fusarium form developed, followed by the asci- 
 gerous stage. Ascospores in hanging drop were also seen to give 
 rise to the Fusarial stage. The Nectrias found upon egg-plant 
 and sweet potato, morphologically alike, were proved by cross 
 inoculations to be identical. 
 
 N. rousselliana Tul. and N. pandani Tul. are parasitic on Buxus 
 and Pandanus respectively, the former with the conidial stage. 
 Volutella buxi. 
 
 N. solani Ren. & Bert, is said by Massee to be the ascigerous 
 form of Fusarium solani. 
 
 Perithecia crowded on a stroma, minute, conic-globose, smooth, 
 blood-red; asci clavate; spores hyaline, 8-9 x ^. 
 
 5 fx; paraphyses slender, tips strongly clavate. W^f \Ji 
 
 Conidia ( = Fusarium solani) hyaline, 3 to // L i 
 5-septate, fusiform, 15-40 x 5-8 /x, but very u"^ |] I // 
 variable, borne on erect, simple or branched Fig. 145. — N. ipo- 
 conidiophores. ^Zkllt. A^to 
 
 N. coffeicola Zimm. is on cacao and vanilla; Halsted. 
 N. bainii Mas. N. amerunensis A. & Str. and N. diversispora 
 Petch. are reported parasitic on cacao ^^^ pods. The three latter 
 names are probably synonyms of the first. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 205 
 
 N. vandae Wah. and N. goroshankiniana (Wah.) grow on cul- 
 tivated \'anda: N. theobromae Mass., probably identical with 
 N. striatospora Zimm., is found on cacao trunks as is also N. jun- 
 geri Henn. 
 
 N. bulbicola. Henn. is on orchids and N. gigantispora Zimm. on 
 Ficus. 
 
 Dialonectria (p. 201) 
 
 N. graminicola B. & B., the conidial stage of which is Fusarium 
 nivale is destructive to winter wheat and rye 
 in Europe.^^^ 
 
 Less known are N. bogoriensis Bern and 
 N. vanillas Zimm. on vanilla; N. luteopilosa 
 Zimm. and N. fruticola Zimm. on coffee; ^^^ 
 N. theobromicola Mass. on Theobroma. 
 
 Neocosmospora E. F. Smith was reported by 
 Smith ^^^ as the ascigerous form of Fusarium -pia. 146.— N. ipo- 
 vasinfectum and consequently as the cause of moese, an aseus. 
 
 ^ "^ o,c, a, germination 
 
 many serious wilt diseases. Recent work by of ascospores. Af- 
 Higgins ^^^' ^^^ and by Butler ^^^ has shown 
 that in all probability there is no genetic connection between 
 these forms and that the fungus under discussion is merely a 
 harmless saprophyte. 
 
 Calonectiia (p. 198) 
 
 Perithecia free, often closely gregarious, true stroma wanting 
 but perithecia often surrounded by a radiate, white mycelium 
 which may simulate a stroma; perithecia globose to ovate, red 
 or yellow; asci elongate, 8-spored; spores elongate, more than 
 2-celled. About sixty species. 
 
 C. p3rrochroa (Desm.) Sacc, has been reported parasitic on 
 Platanus. ^ Its conidial stage is Fusarium platani. 
 
 C. flavida Mass. is in the West Indies on cacao causing 
 canker. 
 
 C. cremea Zimm. with Spicaria colorans, Corymbomyces albus, 
 
206 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Clanostachys theobromse ^^^ probably as its conidial stages, is on 
 fruits and stems of cacao. 
 
 C. bahiensis Hem. reported in South America on cacao stems 
 is really an Anthostomella; C. gigaspora Mass. is found on 
 sugar-cane. 
 
 Gibberella Saccardo (p. 198) 
 
 Stromata tuberculate, more or less effused; perithecia cespitose 
 or occasionally scattered on or surrounding the stroma; asci clavate, 
 8-spored; spores fusoid, 4 to many-celled, hyaline; conidial phase 
 a Fusarium. 
 
 Of the thirteen species but few are parasitic. 
 G. saubinetii (Durieu & Mont.) Sacc. ^^^' ^^^ 
 Perithecia gregarious, leathery membranous, verrucose, ovate, 
 
 subpedicellate, bluish, papillate, 
 200-300 X 170-220 m; asci oblong 
 clavate, acuminate, 60-76 x 10- 
 12 ju; spores one or obhquely 
 two-ranked, fusiform, curved or 
 straight, acute, 4-celled, 18-24 x 
 4-5 fi; mycelium effused, crus- 
 
 FiG. 147.— G. saubinetii; 2, Fusarium tose, white to rose colored. Co- 
 spores, 5, the asci. After Selby. / t-i 
 
 nidia ( = Fusanum) solitary, or 
 clustered, fusiform, curved, acute or apiculate, 5-septate, hyaline, 
 24-40 X 5 /x. 
 
 Many species of Fusarium, e. g., F. culmorum, F. avenaceum, 
 F. hordei, F. heterosporum, have been referred to this ascigerous 
 stage. Spherical stylospores are also reported. ^""^ 
 
 The mycelium and the conidial stages often coat the grains and 
 heads of cereals with red or pink. Perithecia are rare as shining 
 dark dots on the grains in the late season. The Fusarium stage 
 also is said to cause a clover and alfalfa disease and the fungus by 
 inoculation and culture is shown to be identical on wheat, clover, 
 barley, rye, spfelt, emmer, and oat. It is carried from season to 
 season on infected seed and causes large loss of young plants. 
 Doubt as to the relationship of the Fusarial forms mentioned with 
 the ascigerous stages has been raised by the work of Appel and 
 Wollenweber. See also Fusarium (p. 646). 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 207 
 
 G. cerealis Pass., the cause of a serious wheat disease in Italy '^^ 
 may be identical with the last species. 
 
 G. moricola Ces. & d. Not. grows on Morus. 
 
 Pleonectria Saccardo (p. 198) 
 
 Perithecia cespitose or separate, globose, pale, papillate; asci 
 8-spored; spores many-septate, muriform, hyaline. 
 
 P. berolinensis Sacc, which occurs on various species of 
 wild and cultivated currants both in Europe and America has 
 been reported by Durand ^^® as associated with a currant trouble 
 in New York. 
 
 P. coffeicola Zimm. attacks coffee. 
 
 Ophionectria Saccardo (p. 198) 
 
 Stroma globose, tubercular, depressed or none; perithecia su- 
 perficial, clustered or scattered; asci cylindric to clavate, 2 to 
 8-spored; spores 4 to many-celled, fusoid to subfiliform, hyaline 
 or subhyaline. 
 
 About fourteen species. O. coccicola E. & V. attacks scale in- 
 sects and is said also to cause gummosis of oranges.^^* O. foliicola 
 Zimm. is found on coffee. 
 
 Sphaerostilbe Tulasne (p. 198) 
 
 Stroma a slender stalk with a globose or conical head; perithecia 
 bright colored, membranous, globose, subglobose or ovate; asci 
 cylindric or subcylindric, 8-spored; spores 2-celled, elliptic or 
 subelliptic, hyaline. Conidial phase Stilbum, Atractium or Micro- 
 cera. 
 
 Some twenty species. S. repens B. & Br. in India causes a 
 root disease of Hevea^^^ and arrowroot. 
 
 22 
 
 S. flavida Mass. causes disease of coffee in tropical America. 
 
 Polystigma De Candolle (p. 198) 
 
 Stroma jQeshy, effused, red or reddish-brown, growing on leaves; 
 perithecia sunken, only the ostiole being above the surface, thin, 
 leathery, hyaline; asci elongate, clavate, 8-spored; spores ellipsoid, 
 1-celled, hyaline. Three species. 
 
208 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 P. ruba (Pers.) D. C. causes reddish spots on the leaves of 
 
 #Prunus. Stroma at first bearing pycnidia 
 A (Libertella rubra) with fiUform hooked, con- 
 I 1 1 tinuous conidia. Perithecia produced on old 
 ^ " leaves, bearing ellipsoid to elongate asci; 
 spores 10-13 x 6 ^i, smooth. 
 
 The invaded leaf tissue is colored by the 
 mycelium which bears a reddish oil. Nu- 
 merous perithecia are immersed in the 
 diseased area and, opening to the surface, 
 extrude spores which seem incapable of in- 
 fecting. During winter the stroma darkens, 
 ^ ^,„ „ , turns hard and produces the perithecia and 
 
 Fig. 148. — P. rubrum. ^ . , • , ,., 
 
 D, asci; E, conidia. ascosporcs. Ascogomum and trichogjoie-like 
 
 organs have been described. ^^* 
 P. ochraceum (Wahl.) Sacc. occurs on Prunus padus. 
 
 Valsonectria Spegazzini (p. 198) 
 
 Stroma thin, cushion-shaped, under the bark of the host; peri- 
 thecia similar to those of Valsa, sunken in the stroma, the beak 
 erumpent, red; asci cylindric, 8- 
 spored; spores 2-ceIled, hyaline or 
 light brown. 
 
 A genus of but three species which 
 differ from Valsa chiefly in their ]^ 
 red color. ' ^ 
 
 V. parasitica (Murr.) Rehm.^^^' ^^^' 
 
 Pustules numerous, erumpent, at — ~ q -■;., 
 
 first yellow, changing to brown at fig. 149— Shoeing a pycmdium of 
 
 maturity; perithecia usually ten to Valsonectm and the manner in 
 •^ ' ^ "^ which the j^porcs issue irom it. 
 
 twenty in number, closely clustered. After MurriU. 
 flask-shaped, deeply embedded in the stroma in the inner bark, 
 scarcely visible to the unaided eye; necks long, slender, curved, 
 with thick black walls and rather prominent ostiola; asci oblong- 
 clavate, 45-50 x 9 m, 8-spored; spores usually biseriate, hyaline, 
 oblong, rounded a,t the ends, often slightly constricted, unisep- 
 tate, 9-10 X 4-5 /x- Summer spores very minute, 1 x 2-3 n, pale- 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 209 
 
 yellowish, cylindrical, slightly curved, discharged in twisted threads 
 as in Cytospora. 
 
 This fungus, originally described as Diaporthe parasitica, is a 
 serious parasite on the chestnut. The mycelium grows through 
 the inner bark in all directions from the initial wound at which in- 
 fection occurred, eventually girdling the part. The wood is also 
 affected. The perithecia appear in abundance upon or in cracks 
 of the bark, extruding their spores in greenish to yellow threads. 
 
 Hypocrea Fries (p. 199) 
 
 Stroma subglobose to patellate, fleshy or subfleshy; perithecia 
 entirely immersed, subglobose to ovate, the necks slightly pro- 
 truding; asci cylindric, originally 8-spored, spores breaking each 
 into two so that the asci at maturity contain sixteen hyahne 
 spores. About one hundred ten species. 
 
 H. ceretriformis Berk, occurs on the bamboo in Tonkin; 
 
 H. sacchari on sugar cane. 
 
 Balansia Spegazzini (p. 199)^^^ 
 
 Sclerotium composite, formed of the affected parts of the host 
 embedded in a well developed mass of fungous tissue; stroma 
 arising from the sclerotium, stipi- 
 tate and capitate or sessile, pul- 
 vinate, obovate, discoid, or sepa- 
 rated from the sclerotium as 
 soon as the latter is mature, sur- 
 face slightly papillate from the 
 projecting ostiola of the im- 
 mersed scattered perithecia; asci 
 8-spored; paraphyses none. Co- 
 nidia, when known, an Ephelis 
 and preceding the stroma. 
 
 B. hypoxylon (Pk.) Atk. oc- 
 curs on various grasses, chiefly 
 in the southern United States. 
 B. claviceps Speg. infests Setaria 
 and Pennisetum in tropical lands. 
 The remaining species, chiefly of warm regions, are mostly grass 
 inhabiting. 
 
 Fig. 150. — B. hypoxylon, section of 
 pseudosclerotium and one stroma 
 showing perithecia, stem, leaf ele- 
 ments and an ascus. After Atkinson. 
 
210 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Dothichloe Atkinson (p. 199) ^^^ 
 
 Stroma thin, hard when dry, black, especially the outer portion, 
 lighter within, effuse, pulvinate, disciform or armilla-form, partly 
 or entirely surrounding the host; perithecia crowded, confluent 
 with the stroma, but the thin walls of distinctive structure, im- 
 mersed, the apex projecting; asci cylindric, 8-spored; spores fili- 
 form, septate at maturity, and eventually 
 separating at the septa into short seg- 
 ments. 
 
 Like the preceding genus, both species 
 D. atramentosa (B. & C.) Atk. 'and D. 
 aristidae Atk. are grass inhabitors of 
 warm regions of the United States. The 
 former is the commoner species with a 
 wider range of hosts. 
 
 Epichloe (Fries) Tul. (p. 199) 
 
 Stroma effused, subfleshy, at first pale, 
 becoming bright orange, sheathing the 
 host; perithecia immersed or with the 
 ostiola protruding; asci cylindric, 8- 
 spored; spores filiform, many-celled. Of 
 some nine species only one is important. 
 E. t3rphina (Pers.) Tul. Stroma ef- 
 fused, at first pale, becoming bright 
 orange, forming sheaths 2-5 cm. long 
 Fig. 151.— Epichloe. ^, habit around stems of various grasses, often 
 L'tf^rrb^'afcusT A^iTo? destroying the inflorescence; perithecia 
 spore. After Winter, Bre- thickly scattered, partially or entirely im- 
 
 feld and Lindau. i • i n, ^ 
 
 mersed in the stroma, soft, membranous, 
 concolorous with the stroma, the ostiole rather prominent; asci 
 very long; spores almost as long as the ascus, closely fasciculate, 
 multiseptate, about 2 /i in diameter; conidia elliptic, hyaline, 
 4-5 X 3 M, preceding the perithecia on the stroma. 
 
 Many grasses are affected, often to serious extent. The mycelium 
 shows first as a yellowish cobwebby growth surrounding the leaf 
 sheath and soon develops a conidial stroma. Later the stroma 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 211 
 
 turns to orange-color and the perithecia appear, forming a 
 layer. 
 
 Echinodothis Atkinson (p. 199) ^^^ 
 
 Stromata subfleshy or corky, light-colored, pulvinate to sub- 
 globose or irregular in form, often constricted at the base, some- 
 times entirely surrounding the host, consisting of several layers of 
 different consistency; perithecia superficial, scattered, subcylindric, 
 sessile, giving an echinulate appearance to the stroma; asci cylin- 
 dric, 8-spored; spores linear, septate, at length separating at the 
 septa into short segments. 
 
 Two species, parasitic on grasses in the warmer parts of the 
 western hemisphere. 
 
 E. tuberiformis (Berk. & Rav.) Atk.^^s 
 
 Stromata subglobose, 1 cm. or more in diameter, entire, lobed, 
 or divided, seated upon the reed or upon the leaf-sheath and fas- 
 tened by a whitish mycelium consisting of radiating threads which 
 are sometimes tinged yellowish-brown ; substance leathery or corky, 
 consisting of three layers, an inner layer white to pinkish, an inter- 
 mediate layer light ochraceous and an outer layer cinnamon; 
 stroma externally dark brownish becoming black; conidiophores 
 needle-shaped; conidia ovoid to fusoid, 3-4 x 7-10 n; perithecia 
 entirely superficial in small clusters or evenly distributed over 
 the exposed surface of the stroma, subconic in form, giving the 
 whole stroma a spiny appearance, clothed except the apex with a 
 dense covering of minute threads which are at first whitish, be- 
 coming cinnamon colored, the naked apex becoming black, about 
 0.3 X 1 mm. ; asci cylindric, with a swelUng at the apex, very large, 
 475-750 x 14-20 /x; spores nearly as long as the ascus, hyaline or 
 slightly yellowish, many-septate, the joints 15 x 4-5 n. 
 
 On Arundinaria in the Southern States. 
 
 Asciculosporium take Miy.^^^ forms witches' brooms on bamboo 
 in Japan. It is closely related to Dusiella and Epichloe. 
 
 Claviceps Tulasne (p. 199) 
 
 Sclerotium formed within the hypertrophied tissues of the 
 ovary of the host, succeeding the conidial stage which is a 
 Sphacelia; stroma erect, with a long sterile base and a fertile. 
 
212 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 usually knot-like head; perithecia closely scattered, sunken in 
 the stroma with only the ostiole protruding, flask-shaped, the 
 walls scarcely distinguishable from the stroma; asci cylindric, 
 
 
 ^-0 
 
 
 
 
 
 Fig. 152. — C. purpurea. D, Sphacelia stage; E', germinated sclerotia; G, sec- 
 tion of stroma; H, section of a perithecium; J, ascus with spores. After 
 Tulasne. 
 
 8-spored; spores hyaline, continuous. Some twelve or fifteen 
 species are recorded all affecting the ovaries of the Graminese. 
 
 C. purpurea (Fr.) Tul.^^^ 
 
 Sclerotium elongate, more or less curved, and resembling a much 
 enlarged grain, after a period of rest producing few or many, 
 clustered or scattered stromata which are 0.5-1.5 cm. high; spore 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 213 
 
 60-70 fji. long. Conidia ( = Sphacelia segetum) produced on the 
 grain before the sclerotium is formed, conidiophores short, cyUn- 
 dric, arranged in a compact palisade, bearing small, oval, hyaline, 
 1-celled conidia. Hosts, rye, wheat, oats and numerous other 
 grasses. 
 
 Infection of the ovary at blooming time is followed by complete 
 possession and consumption of the ovarial tissue by the mycelium, 
 and by considerable development of stroma beyond the ovary. 
 On the external much-folded part of this stroma, particularly at 
 its distal end, are borne layers of conidiophores and numerous 
 conidia and a sweet fluid is exuded. The conidia, carried by in- 
 sects, spread summer infection. Later the stroma, losing a large 
 part of the distal region, rounds off to a definite sclerotium, smooth, 
 firm, blue to black in color, and several times larger than the 
 normal grain of the host plant. 
 
 After a period of rest, usually lasting till the following season, 
 the sclerotium gives rise to several stalked, capitate, perithecial 
 stromata. The perithecia are arranged around peripherally, the 
 ostioles protruding and giving the head a rough appearance. The 
 sclerotium constitutes the ergot of pharmacy and contains a 
 powerful alkaloid capable of causing animal disease if eaten. 
 
 This species appears to be differentiated into a number of 
 biologic races. ^^^ 
 
 C. microcephala (Wal.) Tul. infects numerous grasses both in 
 Europe and America, being especially destructive to blue grass. 
 
 Two species C. paspali S. & H. and C. rolfsii S. & H. have been 
 reported on Paspalum.^^^ 
 
 Ustilaginoidea Brefeld (p. 199) 
 
 150 
 
 Sclerotium formed in the grain of the host, resembling super- 
 ficially a smut sorus, in the center composed of closely interwoven 
 hyphse, externally the hyphse are parallel, radiating towards the 
 periphery and bearing echinulate, globose, greenish conidia; stroma 
 with a long sterile stem and a fertile head; perithecia immersed 
 in the stroma as in Claviceps; asci and spores also as in Claviceps. 
 
 Two species are known, one on Setaria which produces an 
 ascigerous stage, the other on rice, the ascigerous stage of which 
 
214 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 is not known but which is placed in this genus on account of the 
 similarity of its conidial stage with that of the other species. 
 
 U. virens (Cke.) Tak. Ascigerous stage unknown, sclerotia spher- 
 ical, about 5 mm. in diameter; conidia spherical, at first smooth- 
 walled, hyaline, at maturity 
 echinulate and olive green, 
 4-6 IX. 
 
 The short thick walled 
 hyphae of the interior of the 
 sclerotium are closely in- 
 !:> 1 ro T7 ■ "^ • X 1 • terwoven to a false tissue, 
 
 i^iG. 153. — U. virens; a, spores germinated in . ' 
 
 water; h, germinated in bouillon. After toward the periphery they 
 
 become parallel and are di- 
 rected radially. Here a yellow layer is produced and spores are 
 formed laterally on the hyphae. When mature the spores are in 
 mass dark olive-green and form an outer green layer on the 
 sclerotium. The spores germinate in water, producing a vegeta- 
 tive mycelium which bears secondary spores and somewhat re- 
 sembles the mycelium of the Ustilaginales.^^^ Successful inocula- 
 tions have not been made. 
 
 Ustilaginoidella Essed (p. 199) 
 
 This is a genus erected by Essed ^"^ to receive the species 
 U. musaeperda, which he regards as the cause of the "Panama 
 disease" of bananas, at least as it occurs in Suriname. 
 
 Sclerotia similar to those of Ustilaginoidea are found; chlamyd- 
 ospores and conidia obtain, among the latter are some of marked 
 Fusarium type; others are in pycnidia. 
 
 U. cedipigera Essed is also described by Essed ^^^ as the cause 
 of another less important banana disease in Suriname and Colum- 
 bia; a disease accompanied by hypertrophy of the base of the 
 stem and leading to the common name "bigie footce." This 
 fungus differs from the last in its 1 to 2 to 3-celled conidia. 
 
 U. graminicola Essed causes a rice disease. ^"^ This species 
 differs but slightly from the two preceding. Chlamydospores 
 smaller, conidia 1 to 5-celled. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 215 
 
 Loculistroma Patterson & Charles ^^- (p. 199) 
 
 Stromata upright, sessile, at the nodes of the host, fleshy, soft, 
 green or black, containing conidial chambers in which are pro- 
 duced hyaline filiform conidia and on the outer surface of which 
 are borne Cladosporium-like conidia; perithecia scattered, partly 
 immersed, ostiolate; asci clavate, cylindric, 8-spored; spores fusi- 
 form, 3 to many-septate, olivaceous, biseptate; paraphyses none. 
 There is only one species known. 
 
 L. bambusa. P. & C.^^^ 
 
 Stromata 1 cm. long by 2 mm. in diameter; perithecia almost 
 spherical, 125 x 100 n; asci 45-50 x 9-10 /x; spores 22 x 4. 5-5 n; 
 primary conidia 14-16 x 0.75-1 n; borne in chambers on basidia, 
 8 X 0.5 n; secondary conidia external, 1 to 3-celled, borne on 
 external olivaceous hyphae. 
 
 It causes a witches' broom of bamboo (Phyllostachys sp.), in 
 China. Infection probably occurs in the terminal node. The 
 fully developed sclerotia-like structures, resembling those of 
 Claviceps, are dark green to black when mature, and consist of 
 a central hyaline sclerotial tissue in which are many round 
 conidial chambers. Perithecia develop from the peripheral 
 layer. 
 
 Dothidiales (p. 124) 
 
 There is only one family the Dothidiaceae. 
 
 Mycelium developed in the substratum, septate, at length form- 
 ing a thick, dense, very dark stroma in which the perithecia are 
 sunken and with which their walls are completely fused, rarely 
 partly free; asci borne from the base of the perithecium; paraphyses 
 present or none. 
 
 The Dothidiaceae contain some four hundred species and more 
 than twenty-four genera. They differ from the last order in their 
 firm black sclerotium-like stromata which are usually pale to white 
 within. The perithecia are usually grouped together in great num- 
 bers in the external layer of the stroma, sunken in its undiffer- 
 entiated body. Conidia of various forms are present. 
 
216 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Key to Genera of Dothidiaceae 
 
 Stromata at first sunken later more or less 
 free 
 Perithecia standing free on the stroma ; 
 
 spores at maturity, 4-celled, dark 1. Montagnella., 
 Perithecia almost completely embedded 
 in the stroma 
 Stromata variable, more or less irreg- 
 ular in outline but never elongate 
 Spores 1-celled 
 Spores hyaline 
 Asci typically borne at the 
 base of the perithecium 
 Asci 8-spored 
 Spores ellipsoid 
 
 Perithecia few 2. Mazzantia. 
 
 Perithecia numerous. . 3. Bagnisiella. 
 
 Spores filiform 4. Ophiodothis. 
 
 Asci many-spored 5. Myriogenospora. 
 
 Asci borne laterally at the 
 equator of the perithe- 
 cium, spores ellipsoid. . . 6. Diachora, p. 217. 
 
 Spores brown 7. Auerswaldia. 
 
 Spores 2-celled 
 Spores hyaline 
 
 Spores ovate 8. Plowrightia, p. 217. 
 
 Spores needle-like 9. Rosenscheldia. 
 
 Spores colored 
 
 Cells of the spore similar. ... 10. Rousscella. 
 Cells of the spore dissimilar. . 11. Dothidea, p. 220. 
 Spores several-celled 
 
 Spores with cross walls only 
 
 Spores hyaline, 4-celled 12. Darwiniella. 
 
 Spores colored, multicellular 13. Homostegia. 
 Spores muriform 
 
 Spores hyaline 14. Curreyella. 
 
 Spores colored 15. Curreya. 
 
 Stromata elongate, linear or lanceo- 
 late 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 217 
 
 Spores hyaline 
 
 Spores 1-celled 16. Scirrhiella. 
 
 Spores 2-celled 17. Scirrhia. 
 
 Spores 4 to 8-celled, fusiform. .. 18. Monographus. 
 Spores colored, multicellular, fusi- 
 form 19. Rhopographus. 
 
 Stromata sunken, permanently united to 
 the epidermis and substratum 
 
 Spores 1-celled 20. Phyllachora, p. 220. 
 
 Spores 2-celled 
 
 Spores of similar cells 21. Dothidella, p. 221, 
 
 Spores of dissimilar cells 22. Munkiella. 
 
 Stromata from the first superficial 
 
 Stromata encrusted, widely spreading ... 23. Hyalodothis. 
 Stromata cushion-shaped, limited 24. Schweinitziella. 
 
 Of these genera only five are of interest as plant pathogens. 
 The majority contain only saprophytes. 
 
 Diachora Miiller (p. 216) 
 
 The genus is easily recognized by its peculiarity of bearing asci 
 only as an equatorial band instead of 
 on the floor of the perithecia, a char- 
 acter unique among the Pyrenomy- 
 cetes. 
 
 D. onobrychidis (D. C.) Miill. is 
 reported as causing black spots on 
 leaves of sainfoin and Lathyrus in 
 Europe. 
 
 
 Plowrightia Saccardo (p. 216) 
 Stromata formed within the tissues pio. 154.-d' onobrychidis. E, co- 
 
 of the host plant, erumpent, tuber- nidial stage ;f',ascocarp and asci. 
 , 111 After Muller. 
 
 cular or cushion-shaped, depressed or 
 
 elevated, smooth, later frequently wrinkled, white within; asci 
 cyhndric, 8-spored; spores ovate, 2-celled, hyaline or light green; 
 conidial forms Cladosporium, Dematium, etc. 
 
218 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Some twenty species are known. They are distinguished from 
 Dothidia by the hyaline spores. 
 
 
 ' -si 
 
 T!?^T« 
 
 Ik. l.")") — V nioil)<)sa h, maKiiihcd section of a knot showing the 
 poiithcda, c, conidiophon ^ .uid conidia; d, section of a peri- 
 thecium showing numeioub abci, one of which is shown more highly 
 magnified at e; /, several of the two-celled ascospores germinating 
 in water. After Longyear. 
 
 P. morbosa (Schw.) Sacc^^^^-^"' -^^ 
 
 Stromata elongate, cushion-shaped, rarely tubercular, up to 2 or 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 219 
 
 3 dm. long; perithecia scattered, often entirely suppressed; asci 
 about 120 n long; spores variously arranged in the ascus, 16-20 x 
 8-10 IX, ovate, the cells usually unequal; paraphyses filiform. 
 
 Conidia ( = Cladosporium sp.) pro- 
 duced upon greenish areas on the young 
 stromata; conidiophores erect, flexuose, 
 septate, simple, 40-60 x 4-5 /x; conidia 
 borne singly at the apex of the conidio- 
 phore, obovate, unicellular, light brown, 
 about 6-8 X 2-5 /z. 
 
 Hosts: Cultivated sour cherry and 
 plum, wild red and yellow plum, 
 Chickasaw plum, choke cherry, wild 
 red cherry and wild black cherry, fig. 156.— p. morbosa; host 
 
 Fnimrl nnlv in Amprinn showing o p port u ni ty for 
 
 i^OUna Omy m America. lodgement for spores in a 
 
 The mycelium invades the cambium crotch. After Lodeman. 
 of twigs and from it grows outward into the bark region causing 
 the bark elements to overgrow and the twig to swell slightly dur- 
 ing the first summer. With the renewed growth of the following 
 spring the swelling proceeds rapidly. During May to June the 
 mycelium ruptures the bark which is soon lost and a dense fun- 
 gous pseudoparenchyma is formed. From this the conidiophores 
 appear, forming a velvety growth of olivaceous color. At this 
 period the knot consists largely of a fungous stroma with an ad- 
 mixture of bark elements and even some wood cells. 
 
 Later in the season conidiophores cease to form and the knot 
 turns to a black hard stroma. Perithecia now become easily 
 visible in this black stroma and in January or later the asci mature. 
 Farlow has described " stylospores " (a form named Hendersonula 
 morbosa by Saccardo the connection of which to P. morbosa is 
 in some doubt) and spermogonia and pycnidia. Humphrey ^^^ 
 from ascospores, in artificial media, raised a pycnidial form which 
 seemed to be distinct from any of these. That the fungus is 
 the actual cause of the black knot was first demonstrated by 
 Farlow ^^^ in 1876, though the fungus was described as early as 
 1821 by Schweintiz.158 
 
 Lodeman ^^^ considered that infection is favored by cracks 
 existing at crotches of the tree. Fig. 156. 
 
220 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 P. ribesia (Pers.) Sacc. is found in Ribes twigs and 
 
 P. virgultorum (Fr.) Sacc. on birch. Both are European. 
 
 P. agaves occurs on the maguey. ^^^ 
 
 Dothidea Fries, distinguished from Plowrightia by its colored 
 spores, contains some twenty-five species which occur on twigs of 
 Sambucus, Rosa, Buxus, Betula, Juniperus, Quercus and many 
 other woody plants. 
 
 D. rosae Fries, is common as the supposed cause of a rose tumor. 
 
 D. noxia Ruhl. causes an oak twig disease in Germany. ^^^ 
 
 Phyllachora Nitschke (p. 217) 
 
 Stroma sunken, united to the parenchyma and epidermis of 
 the host leaf, rarely erumpent, encrusted, usually jet-black; peri- 
 thecia sunken in the stroma, rather numerous, 
 with more or less distinct ostioles; asci cyhndric, 
 8-spored; spores ellipsoid or ovate, 1 -celled, 
 hyaline or yellowish; paraphyses present. 
 
 More than two hundred species, largely 
 tropical, are known on a wide range of hosts. 
 All are leaf parasites. 
 
 P. graminis (Pers.) Fcl. Stromata variable in 
 size and form, causing conspicuous black spots 
 on leaves of the host; perithecia immersed, os- 
 tiolate; asci short-pedicillate, cylindric, 70-80 x 
 7-8 n; spores obliquely uniseriate, ovoid, hya- 
 line, 8-12 X 4-5 n; paraphyses filiform. No 
 conidia are known. 
 
 This fungus occurs on many grasses and 
 After sedges with slight injury to them. 
 
 P. pomigena (Schw.) Sacc. produces black 
 spots, scarcely ever above 5 mm. in diameter, on apples, especially 
 the Newton Pippin, in the eastern United States. Little is 
 known of the species. 
 
 P. trifolii (Pers.) Fcl. causes small black spots 1 mm. or less 
 in diameter on clover leaves; asci cylindric; spores uniseriate, oval, 
 hyaline, 8-10 x 5-6 fx. 
 
 Conidia ( = Polythrincium trifolii) precede the asci on the stro- 
 
 FiG. 157. — P. gram- 
 inis. B, stroma in 
 section ; C, an ascus 
 and spores 
 Winter. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 221 
 
 mata; conidiophores wavy or zigzag, erect, simple, black, conidia 
 obovate, 1-septate, constricted, pale olivaceous, 20-24 x 9-10 n. 
 
 The conidial form is very common on various species of clover 
 in Europe and America while the ascosporic stage is mentioned 
 only by Cooke '*'° and Clevenger.^^^ 
 
 P. cynodontis (Sacc.) Niess. on Cynodon, P. poae (Fcl.) Sacc. 
 on Poa and P. dapazioides (Desm.) Nke. on 
 Box and Rhododendron are European. 
 
 P. makrospora Zimm. occurs on Durio zibel- 
 linus; 
 
 P. sorghi V. Hoh. on Sorghum vulgare.^^" 
 
 Dothidella Spegazzini differs from Phyllachora 
 in having 2-celled hyaline spores, the cells un- 
 
 , . . ^, ^f., . » Fig. 15S. — D. betu- 
 
 equal m size. Ihere are over mty species of Una. Asci and 
 the genus. Epiphyllous, subrotund confluent, winter.^' ^^^^^ 
 convex, grayish-black, on white spots; ostiole 
 granular; asci cylindric, short-stipitate, 60-70 x 8 m; spores ob- 
 long, ovate oblong, hyaline, 10-15 x 5 m- D. ulmi Duv.^^'^ Co- 
 nidia =Septoria ulmi and Piggatia astroidea. On elm in Europe 
 and America. Other species are D. thoracella (Rostr.) Sacc. on 
 Sedum, in Europe, D. betulina (Fries) Sacc. on Betula in Europe 
 and Asia. 
 
 Sphaeriales (p. 124) 
 
 Mycelium chiefly confined to the substratum; perithecia vari- 
 able, usually globose, with a more or less elongated ostiole, hairy 
 or smooth, free on the substratum, more or less deeply sunken, or 
 borne on or sunken in a stroma; asci borne basally, variable in 
 size, opening by a pore; spores variable, globose, ovate to elongate 
 or filiform, hyaline or colored; paraphyses usually present; conidial 
 forms various. 
 
 The stromata may vary from a delicate hyphal weft to a firm 
 crustaceous structure. The pycnidia are mostly carbonous, black 
 and brittle. Conidia of many forms are present and often con- 
 stitute the only truly parasitic form of the fungus; the asci- 
 gerous form developing only after the death of the part of the 
 host involved. 
 
222 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 The order is very large, embracing according to Engler & Prantl 
 some eighteen families and over six thousand species. 
 
 Key to Families of Sphaeriales 
 
 Perithecia free, either without a stroma, 
 partly seated in a loose mass of myce- 
 lium, or sessile above an imperfect 
 stroma 
 Walls of the perithecia thin and mem- 
 branous; asci soon disappearing 
 Perithecia always superficial, with 
 copious tufts of hair at the mouth 
 Perithecia usually sunken, with only 
 
 short hairs about the mouth 
 
 Walls of the perithecia coriaceous or car- 
 bonous 
 Perithecia either entirely free, or with 
 the base slightly sunken in the 
 substratum or stromatic layer 
 Stroma wanting or only thread-like 
 or tomentose 
 Mouths of the perithecia mostly in 
 the form of short papillae. . . . 
 Mouths of the perithecia more or 
 less elongate, often hair-like. . 
 Stroma present 
 
 Stromata mostly well developed, 
 indefinite; perithecia in close 
 irregular masses, never flask- 
 like of funnel-like at the apex 
 Stromata small, sharp-bordered; 
 perithecia in rows or in regu- 
 lar rounded masses, flask- 
 shaped with funnel-shaped 
 
 mouths 
 
 Perithecia more or less deeply sunken 
 
 in the substratum at base, free 
 
 above 
 
 Mouths of the perithecia circular in 
 
 outline 
 
 1. Chaetomiaceae. 
 
 2. Sordariacese, p. 224. 
 
 3. Sphaeriaceae, p. 225. 
 
 4. Ceratostomataceae, 
 p. 232. 
 
 5. Cucurbitariaceae, p. 234. 
 
 6. Coryneliaceae. 
 
 7. Amphisphaeriaceae. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 223 
 
 Mouths of the perithecia laterally 
 
 compressed 8. Lophiostomataceae. 
 
 Perithecia without a stroma, and sunken in 
 the substratum, or with a stroma 
 Stromata none; perithecia rarely united 
 
 above by a black tissue (clypeus) , 
 
 Asci not thickened at the apex, mostly 
 projecting at maturity 
 Walls of the perithecium thin, cori- 
 aceous; mouth mostly short or 
 plane 
 Asci clinging together in fascicles, [p. 235. 
 
 without parapliyses 9. Mycosphaerellaceae, 
 
 Asci not fasciculate; with para- 
 
 physes 10. Pleosporaceae, p. 250. 
 
 Walls of the perithecia carbonous or 
 thick coriaceous; spores large, 
 
 mostly enveloped by gelatine. . 11. Massariaceae, p. 262. 
 Asci usually thickened apically, open- 
 ing by a pore; perithecia usually 
 beaked 
 
 Perithecia without a clypeus 12. Gnomoniaceae, p. 263. 
 
 Perithecia with a clypeus 13. Clypeosphaeriaceae, 
 
 Perithecia firmly imbedded in a stroma, p. 276. 
 
 the mouths only projecting, or becom- 
 ing free by the breaking away of the 
 outer stromatic layers 
 Stromata fused with the substratum 
 
 Conidia produced in pycnidia 14. Valsaceae, p. 277. 
 
 Conidia developed from a flattened 
 
 surface 15. Melanconidaceae, 
 
 ' Stromata formed almost wholly of hard- p. 279. 
 ened fungal Ityphse 
 Spores small, cylindric, 1-celled, 
 mostly curved, hyaline or yel- 
 lowish-brown 16. Diatrypaceae, p. 281. 
 
 Spores rather large, 1 to many-celled, 
 hyahne or brown, conidia mostly 
 
 in cavities jn the stroma 17. Melogrammataceae, 
 
 Spores 1-celled, rarely 2-celled, p. 282. 
 
 blackish-brown. Conidia devel- 
 
224 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 oped on the upper surface of 
 
 the young stroma 18. Xylariaceae, p. 284. 
 
 Families Nos. 1, 6, 7, 8, 17 are saprophytes on plants and 
 animals. 
 
 Sordariaceae (p. 222) 
 
 Perithecia superficial or deeply sunken in the substratum, often 
 erumpent at maturity, thin and membranous to coriaceous, slightly 
 transparent to black and opaque; stroma usually absent, if present 
 the perithecia immersed in it with projecting papilliform beaks; 
 asci usually very delicate, cylindric, 8-spored; spores usually 
 dark-colored; paraphyses abundant. 
 
 A small order, chiefly dung inhabiting. 
 
 Key to Genera of Sordariaceae 
 Spores continuous 
 Without a stroma 
 
 Neck of the perithecium hairy 1. Sordaria. 
 
 Neck of the perithecium with black 
 
 spines 2. Acanthorh3rnchus, p. 224. 
 
 With a stroma 3. Hypocopra. 
 
 Spores 2 or more celled 
 Spores 2-celled 
 
 Spores hyaline 4. Bovilla. 
 
 Spores dark-brown 5. Delitschia. 
 
 Spores 4 to many-celled 
 
 Stroma absent 6. Sporormia. 
 
 Stroma present 7. Sporormiella. 
 
 Spores muriform; stroma present 8. Pleophragmia. 
 
 Acanthorhynchus Shear ^^^ 
 
 Perithecia scattered, submembranous, buried, beaked, the beak 
 with non-septate spines; asci opening by an apical pore; paraphyses 
 present, septate; spores continuous, brownish-yellow. 
 
 There is a single species, A. vaccinii Sh.^^^ 
 
 Amphigenous: perithecia subglobose to flask-shaped, scarcely 
 erumpent, 120-200 jj. in diameter, neck stout, exserted, ^U-^U the 
 length of the perithecium; spines 50-70 x 8-9 m; asci subelliptic 
 to somewhat clavate, subsessile, 120-155 x 24-44 /x; spores oblong- 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 225 
 
 elliptic, surrounded by a mucilaginous layer, 24-32 x 12-18 n; 
 paraphyses exceeding the asci. 
 
 The mycelium produces rot of cranberries, also leaf spots, but 
 the fructification of the fungus is rarely found in nature except on 
 
 Fig. 159. — A single perithecium 
 of A. vaccinii taken from a 
 pure culture on corn meal. 
 After Shear. 
 
 Fig. 160. — Acan- 
 thorhynchus; a 
 germinating as- 
 cospore bearing 
 the peculiar 
 appressorium, 
 17, view from 
 above. After 
 Shear. 
 
 old fallen leaves. In culture, however, it produces abundant peri- 
 thecia. When on the leaf the perithecia are subepidermal and 
 are sparsely scattered over the lower surface. No conidial or 
 pycnidial form is known. Remarkable appressoria are produced 
 by the germ tubes from the spores, Fig. 160. 
 
 Sphaeriaceae (p. 222) 
 
 Perithecia single or clustered, free or with a false stroma in 
 which they are more or less sunken; walls leathery, horny or woody; 
 ostiole rarely elongate, usually papillate; spores frequently ap- 
 pendaged. 
 
 The family is distinguished by its free perithecia with papillate 
 ostioles. It contains about seven hundred species. 
 
 Key to Genera of Sphaeriacese 
 
 Perithecia hairy above, rarely smooth above 
 and hairy beneath 
 Spores 1 or 2-celled 
 
 Perithecia thin, cuticulate or leathery 
 Spores 1-celled; asci apically thick- 
 ened 1. Niesslia. 
 
226 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Spores 2-celled; asci not apically 
 
 thickened 2. Coleroa, p. 227. 
 
 Perithecia thick, leathery or carbon- 
 ous 
 Spores hyaline, sometimes becoming 
 brown, 1 or 2-celled 
 
 Spores ellipsoid 3. Trichosphaeria, p. 228. 
 
 Spores cylindric, bent 4. Leptospora. 
 
 Spores dark colored, 2-celled 5. Neopeckia. 
 
 Spores more than 2-ccllcd 
 
 Perithecia thin, leathery or cuticula- 
 
 rized 6. Acanthostigma, p. 229. 
 
 Perithecia thick, carbonous or woody 
 Spores 4-celled, the two middle cells 
 
 brown, the end cells hyahne. .. . 7. Chaetosphaeria. 
 Spores many-celled, concolorous, 
 hyaline or brown 
 
 Spores spindle-form 8. Herpotrichia, p. 229. 
 
 Spores elongate-cylindric 9. Lasiosphaeria. 
 
 Perithecia smooth 
 
 Perithecia tuberculate or irregularly 
 thickened 
 Spores ellipsoid, 2 to many-celled, 
 
 hyaline 10. Bertia. 
 
 Spores spindle-form, 4 to 11-celled, 
 
 hyaline 11. Stuartella. 
 
 Spores muriform, dark 12. Crotonocarpia. 
 
 Perithecia not tuberculate 
 Spores 1-celled, dark 
 Spores with hyaline appendages on 
 each end ; perithecia thick, leath- 
 ery 13. Bombardia. 
 
 Spores unappendaged, perithecia 
 
 carbonous 14. Rosellinia, p. 230. 
 
 Spores 2 to many-celled 
 
 Perithecia thin, leathery; spores 2- 
 
 celled 15. Lizonia. 
 
 Perithecia thick, leathery or car- 
 bonous, brittle 
 Spores ellipsoid 
 Spores 2-celled 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 227 
 
 Spores hyaline, sometimes be- 
 coming brown 16. Melanopsamma. 
 
 Spores hyaline to green 17. Thaxteria. 
 
 Spores dark-colored 18. Sorothelia. 
 
 Spores 3 to many-celled 
 
 Spores hyaline 19. Zignoella. 
 
 Spores dark-colored 20. Melanomma. 
 
 Spores elongate, spindle-form, hya- 
 line, many-celled 21. Bombardiastrum. 
 
 Coleroa Fries (p. 226) 
 Perithecia free, small, globose, flask-shaped; asci 8-spored; spores 
 
 V:' •:■:'--■■ ■ '-^^^^ 
 
 Fig. 161. — C. chsetomium. C, perithecia; D, asci. 
 After Lindau and Winter. 
 
 ovate, 2-celled, hyaline, green or golden-brown; paraphyses poorly 
 developed. 
 
 Conidia= Exosporium. 
 
 This genus, of some thirteen species all of which are parasitic, 
 is quite similar to Venturia. The chief economic species are C. 
 chaetomium (Kze.) Rab. (Conidia= Exosporium rubinus) on Rubus 
 in Europe and C. sacchari v. B. d H., on sugar cane in Java.^^^ 
 
228 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Trichosphaeria Fuckel (p. 226) 
 
 Perithecia usually free, globose, woody or carbonous, hairy, 
 ostiole flat or papillate; asci-cylindric,8-spored; spores 1 to 2-celled, 
 hyaline; paraphyses present. 
 
 There are some forty species, mainly saprophytes. 
 
 T. sacchari Mass.^^^' ^^^ 
 
 Perithecia broadly ovate, dark-brown, beset with brown hairs; 
 spores elongate-ellipsoid, 1-celled; the conidial forms are various 
 
 .%f4Ae^ A 
 
 ■p i 
 
 Fig. 162.^Trichosph:Bria. E, habit sketch; G, conidial 
 stage. After Lindau, Winter and Brefeld. 
 
 and their genetic connection is by no means certain. (1) (=Conio- 
 thyrium megalospora) Pycnidia 1-3, on a dark-colored, parenchy- 
 matous stroma; conidia elongate, straight or curved, brownish, 
 12 X 5 /x, (2) The macroconidia ( = Thielaviopsis ethaceticus) 
 see p. 596, are often found forming intensely black, velvety 
 layers lining cracks and cavities in diseased canes. (3) Micro- 
 conidia produced on the surface in Oidium-like chains. Their 
 connection with this fungus is disputed and uncertain.^^^ 
 It is a sugar cane parasite. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 229 
 
 Acanthostigma de Notaris (p. 226) 
 
 Perithecia free, globose or ovate, very small; walls leathery, 
 black, beset with stiff bristles, ostiole 
 short; asci usually cylindric, rarely 
 ovate, 8-spored; spores spindle-shaped, 
 multicellular by cross walls, hyaline; 
 paraphyses few or none. 
 
 There are some thirty species, 
 mostly saprophytes. 
 
 A. parasiticum (Hart.) Sacc.^^""^^^ 
 
 Perithecia globose, minute, with 
 rigid divergent hairs, 0.1-0.25 mm. 
 in diameter; asci 50 fj. long, early 
 disappearing; spores fusoid, straight 
 or curved, smoky, 15-20 /x, continuous 
 or 2 to 3-septate. 
 
 Common on leaves of Abies, Tsuga 
 and other conifers in Europe and 
 America. The hyaline mycelium 
 grows on the lower sides of branches 
 and onto the leaves killing them 
 and matting them to the branches. 
 The mycelial cushions later turn brownish and eventually very 
 small perithecia form on them. 
 
 Fig. 163.— Peiithecium of A. Tri- 
 chosphaeria parasiticum, show- 
 ing ostiole, bristles, asci, para- 
 physes and spores. After 
 Hartig. 
 
 Herpotrichia Fuckel (p. 226) 
 
 Perithecia superficial, globose or subglobose, texture firm, 
 coriaceous to subcarbonous, hairy or smooth, ostiole papillate 
 or not; asci oblong to clavate; spores fusiform, 2 or many-celled, 
 hyaline or brown; paraphyses none. 
 
 The species, numbering about twenty-five and growing on 
 woody plants, are mostly saprophytes. 
 
 H. nigra Hart.^^^ 
 
 Mycelium dark-brown, widely spreading, haustoria slender, 
 Hghter in color; perithecia globose, dark, 0.3 mm. in diameter; 
 asci elongate, 76-100 x 12 /x; spores constricted, 1-3 septate. 
 
230 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Common in Europe on branches of Larix, Abies, Juniperus, 
 spruce and pine, doing great damage. The dark-brown mycelium 
 grows over the plant, killing and matting the leaves. 
 
 Rosellinia Cesati & de Notaris (p. 226) 
 
 Perithecia superficial, but often with the bases more or less 
 sunken in the substratum, coriaceous or car- 
 bonous; brittle, spherical or ovate, bristly or 
 not; asci cylindric, 8-spored; spores elhptic, 
 oblong or fusiform, 1-celled, brown or black; 
 paraphyses fusiform. Conidia of the type of 
 Coremium, Sporotrichum, etc. 
 
 In most cases the active parasitic stage 
 occurs on roots and consists of a vigorous 
 white mycelium, which remains for a long time 
 Fig. 164. — Herpotri- sterile, developing large branching and inter- 
 
 chia. B, ascus; . , /t-T \ i • i i 
 
 c, spore. After lacmg rhizomorphs (Dematophora) which later 
 ^° ^^' become brown. These resemble somewhat, but 
 
 are distinguishable from, the rhizomorphs of Armillaria mellea; 
 again, they are Rhizoctonia-like. 
 
 There are over one hundred seventy species, mostly saprophytic. 
 
 R. necatrix (Hart.) Berl.i^"- ^^^ 
 
 A destructive fungus, long known as Dematophora necatrix, 
 possesses a white mycelium which invades the small roots, thence 
 passes to larger ones, extending in trees through the cambium 
 and wood to the trunk, occasionally rupturing the bark and pro- 
 ducing white floccose tufts. Sclerotia of one or more kinds are 
 produced in the bark and often give rise to conidia on tufted conidi- 
 ophores in a Coremium-like layer (Fig. 165). The mycelium, 
 when old, turns brown and produces large branching, interlacing 
 rhizomophic strands which spread to the soil, or wind about the 
 roots. 
 
 In some instances the connection of the ascigerous with the 
 sterile or conidial stages is well established; in others the asci 
 have been found but rarely and the evidence of genetic connection 
 is not complete. It is probable that some fungi reported as Dema- 
 tophora do not in reality belong to Rosellinia. 
 
 The fungus attacks nearly all kinds of plants. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 231 
 
 Perithecia were found by Viala ^^^ and by Prillieux ^^^ on old 
 wood, long dead from such attack. These belong to the genus 
 Rosellinia and are believed to present the ascigerous form of Dema- 
 tophora necatrix. Similar claims of relationship of this fungus to 
 several other genera have 
 been made and its actual 
 position cannot be consid- 
 ered as established with 
 certainty. 
 
 R. massinkii Sacc. 
 
 Perithecia sparse, globose 
 or depressed, carbonous, 
 165 ix) asci cylindric, 54 x 
 8 )u; spores dark-brown, el- 
 Uptic, 1-rowed, 10 x 5 /x. 
 
 It is reported by Halsted 
 on hyacinth bulbs. 
 
 R. bothrina B. & Br. is 
 the cause of a tea root 
 disease. 
 
 Pseudodematophora 
 closely allied to the above 
 forms is described by Beh- 
 rens ^"^^ on diseased grape 
 roots. 
 
 R. quercina Hart, is 
 parasitic on roots and stems 
 of young oaks, producing a 
 Rhizoctonia-like mycelium, at first white, later brown. Perithecia 
 are usually abundant. Black sclerotia the size of a pin head are 
 also present superficially. 
 
 R. radiciperda Mas. closely allied to R. necatrix, affects a large 
 number of hosts, among them apple, pear, peach, cabbage, and 
 potato. 
 
 An undetermined species of this genus is said to cause a cran- 
 berry disease.^^^ Shear, however, in his extensive studies of cran- 
 berry diseases, did not find it. 
 
 R. aquila (Fr.) d. Not. injures Morus. Its conidial form is 
 
 Fig. 165. — R. necatrix. 4< coremium and co- 
 nidia; 5, perithecia extruding spores; 6, asci 
 and paraphyses. After Hartig, Prillieux and 
 Viala. 
 
232 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Sporotrichum fuscum. R. ligniaria (Grev.) Nke. occurs on ash 
 trees. R. echinata Mas. is reported on "all kinds of Dicotyledon- 
 ous shrubs and herbs." 
 
 Melonomma Fcl. in the species M. henriquesianum Bros. & 
 Roum. is parasitic on cacao stems. 
 
 M. glumarum Miy. is on rice.^°^ 
 
 Ceratostomataceae (p. 222) 
 
 The fungi of this family are very similar to the Sphaeriacese, 
 but are distinguished by less pronouncedly carbonous perithe- 
 cia which may be merely membranous, and open by an elongate, 
 beak-like ostiole. It is a family of only about one hundred 
 twenty-five species, chiefly saprophytes. 
 
 Key to Genera of Ceratostomataceae 
 
 Spores 1-celled 
 
 Spores hyaline 1. Ceratostomella, p. 232. 
 
 Spores brown 2. Ceratostoma. 
 
 Spores 2-celled 
 
 Spores hyaline 3. Lentomita. 
 
 Spores dark-colored 
 
 Perithecia on a cottony stroma 4. Rhynchomeliola. 
 
 Perithecia not on a cottony stroma. . . 5. Rhynchostoma. 
 Spores many-celled 
 
 Spores with cross walls only 
 
 Spores elongate, 4 to many-celled, hya- 
 line or brown 6. Ceratosphaeria. 
 
 Spores filiform, many-celled, usually 
 hyaline 
 
 Perithecia erect, astromatic 7. Ophioceras. 
 
 Perithecia horizontal in stromatic 
 
 nodules 8. Cyanospora, p. 233. 
 
 Spores muriform 9. Rhamphoria. 
 
 Ceratostomella Saccardo 
 
 Perithecia superficial, firm; asci ovate, 8-spored, disappearing 
 early; spores elongate, blunt or pointed, 1-celled, hyaline. About 
 thirty species. An extensive study of the genus was made by 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 233 
 
 Hedgcock ^'^ who recognizes several species as discoloring lumber. 
 C. pilifera (Fr.) Wint. has been described in detail by von 
 Schrenk as the cause of a blue color in pine wood/^^ 
 
 Cyanospora Heald & Wolf (p. 232) 
 
 Perithecia solitary or in clusters of two or three on stromatic 
 nodules, immersed, horizontal; ostiole lateral, neck short; asci 
 
 Fig. 166. — C. pilifera peri- Fig. 167. — C. albicedrse. Sec- 
 thecium, asci and tion of a perithecium in 
 
 spores. 
 Schrenk. 
 
 After von 
 
 its stroma. 
 Wolf. 
 
 After Heald and 
 
 Fig. 168.— C. albicedrje. 
 Upper part of an ascus 
 showing thickened 
 apical wall and coiled 
 spores. After Heald 
 and Wolf. 
 
 slender, linear, surrounded by a gelatinous matrix, apically thick- 
 ened; spores filiform, multiseptate, hyaline. 
 
 A single species. 
 
 C. albicedrae Heald & Wolf. 
 
 Stroma on bark or wood of the host, varying from gray on the 
 bark to black on wood, lenticular, 1-2 mm. long, solitary or clus- 
 tered; perithecia 825-1200 x 260-400 n; asci 700-1100 x 8-10 /i; 
 spores 600-1000 x 3 /z; paraphyses numerous, continuous, 1 fx 
 in diameter. 
 
 The fungus is described in detail by Heald and Wolf ^^^ as caus- 
 
234 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 ing whitening of the mountain cedar (Sabina sabinoides) from 
 Texas to Central Mexico. The seat of infection is the younger 
 twigs and the young trees, especially where in shade. The disease 
 may kill the entire trees. 
 
 Cucurbitariaceae (p. 222) 
 
 Perithecia clustered, immersed at first, then erumpent, seated 
 on a stroma, leathery to carbonous; paraphyses present. The 
 species numbering about one hundred fifty are mostly saprophytes. 
 
 Key to Genera of Cucurbitariaceae 
 Spores 1-celled 
 Asci 8-spored 
 
 Spores large, green 1. Bizzozeria. 
 
 Spores small, hyaline 2. Nitschkia. 
 
 Asci many-spored. 3. Fracchiaea. 
 
 Spores 2 or more-celled 
 Spores 2-celled 
 
 Perithecia bristly, spore walls hyaline . . 4. Gibbera, p. 234. 
 
 Perithecia smooth, spore walls brown. . 5. Otthia. 
 
 Spores more than 2-celled 6. Gibberidea. 
 
 Spores muriform 7. Cucurbitaria, p. 234. 
 
 Gibbera Fries 
 
 179 
 
 Perithecia cespitose on a superficial, thick, Demataceous, conidia- 
 bearing, carbonous, fragile, bristly stroma; ostiole papillate; asci 
 cylindric, 8-spored; spores oblong, elliptic, hyaline, uniseriate. 
 
 The genus contains some half dozen species, one of which G. 
 vaccinii (Sow.) Fr. occurs on Vaccinium in Europe. The conidial 
 form is Helminthosporium vaccinii. Fig. 169. 
 
 Cucurbitaria Gray 
 
 Perithecia cespitose or more rarely gregarious on a crustaceous 
 stroma covered by Demataceous hyphse, spherical, glabrous, black, 
 coriaceous; asci cylindric, 8-spored; spores uniseriate, oblong or 
 elliptic, muriform, brownish, paraphyses present. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 235 
 
 Over seventy species, several of which are parasitic but none of 
 importance in America. 
 
 C. laburni Pers. is on branches of Cytisus; 
 
 C. sorbi Karst on Sorbus twigs; 
 
 C. pityophila (Kze.) d Not. on various conifer twigs; 
 
 C. berberidis (Pers.) Gray on Berberis; 
 
 C. elongata (Fr.) Grev. on Robinia; 
 
 C. piceae Brothwick, on Picea. 
 
 Mycosphaerellaceae (p. 223) 
 
 Perithecia mostly subepidermal, rarely subcuticular, finally 
 more or less erumpent or even superficial, membranous or leathery, 
 
 Fig. 169.— 
 Gibbera vac- 
 cinii. An 
 ascus. After 
 Winter. 
 
 Fig. 170. — Cucurbitaria berberidis. Q, 
 habit sketch ; H, ascus. After Lindau 
 and Winter. 
 
 fragile; asci fasciculate, 8-spored; spores variable, septate, rarely 
 muriform, hyahne to dark-brown; paraphyses none. 
 
 This family of over seven hundred species contains many sap- 
 rophytes and several very important parasites. 
 
 Key to Genera of Mycosphaerellaceae 
 
 Spores 1 to 2-celled 
 Spores hyaline or green 
 
 Spores 1-celled or not clearly 2-celled 
 
 Perithecia very small, on a basal 
 
 growth of thick branched hyphse 
 
 1. Ascospora, p. 236. 
 
236 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Perithecia without such a basal 
 growth 
 
 Spores typically 1-celled 2. Massalongiella. 
 
 Spores usually unequally 2-celled. 3. Guignardia, p. 237. 
 Spores 2-celled 
 
 Perithecia produced on living 
 
 plants 4. Stigmatea, p. 243. 
 
 Perithecia appearing after the death 
 
 of the host 5. Mycosphaerella, p. 243. 
 
 Spores dark-colored 
 
 Spores 1-celled 6. Miillerella. 
 
 Spores 2-celled 
 
 Lichen-inhabiting 7. Tichothecium. 
 
 Not Hchen-inhabiting 8. Phaeosphaerella. 
 
 Spores several-celled, hyaline 
 Spores elongate, with cross walls only 
 
 Spores 2 to 4-celled; on lichens 9. Pharcidia, p. 250. 
 
 Spores 4-celled; with a cottony subicu- 
 
 lum 10. Sydowia. 
 
 Spores many-celled 11. Sphaerulina, p. 250. 
 
 Spores muriform 12. Pleosphaerulina,p.250. 
 
 Ascospora Fries (p. 235) 
 
 Perithecia borne on a subiculum of thick, brown, much-branched 
 hyphse, globoid, black, carbonous; asci clavate, 
 clustered, 8-spored, small; spores 1-celled, hya- 
 line; paraphyses none. 
 
 ■^ ^^^l^!^^ About half a dozen species, one of which is 
 
 _, ,_, , said by Vuillemin ^^° to be the ascigerous form 
 
 Fig. 171. — Ascospora '' ... • 
 
 himantia. Asci. of Coryneum beyerinckii, a wound parasite 
 common on drupaceous trees causing gum- 
 mosis. Cultural evidence of this relationship is lacking, but his 
 hypothesis may be tentatively assumed. 
 
 A. beyerinckii Vuil. Perithecia black, depressed-globose, apapil- 
 late; ostiole indistinct or absent, 100-130 /x in diameter; spores 
 elliptic-fusoid, ends obtuse, continuous, hyaline, guttulate, 15 x 5- 
 7 n. 
 
 Conidia, 1. (=Phyllosticta beyerinckii) pycnidia globoid with 
 hyaline spores. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 237 
 
 Conidia, 2. (=Coryneum beyerinckii) conidiophores short, 
 crowded, from a minute subepidermal stroma; conidia single, 
 elliptic-oblong, 1 to 5-septate, brown, about 36 x 15 ix. On 
 drupaceous hosts. 
 
 In spots on the bark the mycelium is often sterile, but when 
 it becomes old distinct pustules usually show in a well developed 
 subepidermal stromatic tissue and from these pustules, as they 
 rupture the epidermis, the conidiophores are produced. Conidia 
 usually abound on the surface of twigs which have borne affected 
 leaves. They germinate readily and produce either a sooty super- 
 
 FiQ. 172. — Section through a Coryneum pustule on peach. 
 After Smith. 
 
 ficial mold or if on new bark enter the host tissue and induce 
 spotting. 
 
 The conidial stage (Coryneum) of the fungus was grown in arti- 
 ficial culture by Smith ^^^ but no ascigerous stage corresponding 
 with that of Vuillemin was found. 
 
 A. geographicum (D. C.) Desm. is common on leaves of pome 
 fruits and A. padi Grev. defoliates cherries in Europe. 
 
 Guignardia Viala & Ravaz (p. 236) 
 
 Perithecia sunken, globoid or flattened, black, leathery; ostiole 
 flattened or papillate; asci clavate, 8-spored; spores ellipsoid or 
 fusiform, hyaline, somewhat arched, 1 or 2-celled; paraphyses 
 none. 
 
238 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Over one hundred thirty species are known. Some are impor- 
 tant parasites. 
 
 Conidial forms are found in Phoma and Phyllosticta. 
 
 G. bidwellii (E.) V. & R."' '''"^^^ 
 
 Perithecia minute, globose, subepidermal, erumpent, perforate; 
 asci clavate-cylindric, obtuse, 60-70 x 10-13 /x; spores elliptic to 
 oblong, continuous, 12-17 x 43^-5 fi. 
 
 Conidia ( = Phoma uvicola, Phyllosticta labruscse, Naemospora 
 ampelicida) borne in pycnidia 180 x 180 fx, subepidermal, elliptic, 
 
 oscospore 
 
 qerminof/oiT 
 
 Fig. 173. — Diagrammatic section of a perithecium con- 
 taining ascospores. Germination of a spore at the 
 right. After Reddick. 
 
 thick- walled; conidiophores short, simple; conidia ovate to elliptic, 
 8-10 X 7-8 ^t. Filiform microconidia ("spermatia") are borne in 
 flask-shaped pycnidia 0.1-0.2 x 0.45-0.46 /z. 
 
 The fungus has been placed successively in the genera Sphaeria, 
 Physalospora, Laestadia and Guignardia. 
 
 An extensive synonomy is given by E. Rose who concludes 
 that the name should be G. ampelicida. 
 
 It is found on all green parts of Vitis and Ampelopsis, the as- 
 cigerous stage common only on the mummified fruits. 
 
 Perithecia were first found in 1880 by Dr. Bidwell in New Jersey. 
 They are abundant on berries, which have wintered out doors. 
 
 Reddick admirably describes the development of the spots as 
 follows: 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 239 
 
 On the leaves the first evidence of the spot is the slight blanching 
 of a single one of the smaller areola of the leaf. Soon the blanch- 
 ing extends to adjacent areolae, and if an areola is entered it is 
 usually entirely involved. The small veinlets form the margin 
 of the spot so that the outline is finely crenulate. By the time 
 the spot is .3 to .4 mm. in diameter it has a cinereous appearance. 
 The margin, while sharply defined, is not changed in color. By 
 the time the spot is 1 mm. in diameter, the margin appears as a 
 black line, while the remainder of the spot is grayish-brown. A 
 
 Germinated 
 053i=, Spores 
 
 Fig. 174. Diagrammatic section througii a pycnidium, show- 
 ing how the spores are produced and how they germinate. 
 After Reddick. 
 
 little later the margin is a brownish band and the brown gradually 
 extends inward until the whole spot is covered. As soon as the 
 brown band attains some width the blackish line on the margin 
 is to be seen again. A second wave of deeper brown may pass 
 across the spot but sometimes it does not get entirely across and 
 thus leaves a marginal band of a deeper brown than the central 
 disc. Spots vary in size from 1 m.m. up to 8 mm. in diameter, but 
 in general are 3 to 5 mm. or larger. Occasionally the whole leaf is 
 destroyed but this is by the coalescence of many spots. When 
 the spot has attained full size pycnidia protrude from under the 
 cuticle and either dot the entire surface of the spot with minute 
 specks or are more often confined to a more or less concentric ring. 
 The different shades of color are apparent on the under side of 
 
240 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 the leaf on such varieties as have leaves which are smooth beneath. 
 The pyncidia, however, have never been seen on the under side 
 of the leaf in our varieties. 
 
 On stems, tendrils, peduncles, petioles and leaf veins the 
 spot in its first appearance is a small darkened depression which 
 soon becomes very black. On a cane the lesion rarely extends 
 more than a quarter of the way round, while on a tendril or leaf 
 petiole it may extend from half to all of the way round. On shoots, 
 
 the lesions never extend so 
 deep as to cut off the sap 
 supply, but on petioles this 
 occasionally happens, rarely 
 so on peduncles, and quite 
 commonly so on pedicels and 
 tendrils. The first indication 
 of Black Rot on the berry 
 is the appearance at some 
 point of a small circular 
 blanched spot, scarcely 1 mm. 
 in diameter. The blanching 
 is so sHght as to be detected 
 only by careful observation. It rapidly becomes more apparent 
 and has a whitish appearance, the contrast becomes more ap- 
 parent by the appearance of a brownish line at the mar- 
 gin. The whitish center increases in size and the brownish or 
 reddish-brown ring increases in diameter as well as in width 
 and is quite evident when the spot is 2 mm. in diameter. When 
 the spot is 3 mm. in diameter the ring is one-half mm. in width 
 and enough darker to give a bird's eye effect (a light circular 
 disc with an encircling darker band). The spot rapidly increases 
 in size so that in twelve hours more it may be 6 to 8 mm. in diam- 
 eter, and the encircling band nearly 2 mm. in width. After five 
 hours more, the spot is 8 or 9 mm. in diameter and there begins 
 to appear an outer darker band and an inner lighter brown one 
 which have in some cases a much lighter line between them. The 
 aureole is thus composed of two or three bands or rings. Eighteen 
 hours later, the spot is 1 cm. or more in diameter, is distinctly 
 flattened, and numerous minute brown specks appear on the 
 
 Fig. 175. — Section of a pustule showing 
 « microconidia. After Longyear. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 241 
 
 white center of the spot. In five hours more they are so numerous 
 as to give a blackish appearance. 
 
 In New York, Redchck found that the asci begin to ripen in May 
 and continue to mature throughout the summer being still abundant 
 in October. The asci swell in water often to twice the length 
 given above; spores are forcibly ejected from the 
 asci at maturity, being thrown to a height of 
 2 to 4 cm. There is at one end of the asco- 
 spore a hyaline vesicle which probably aids in 
 fixing it to the host.^^^ They germinate but 
 slowly, requiring from thirty-six to forty-eight 
 hours to show germ tubes. Reddick deter- 
 mined the incubation period on fruit as from 
 eight to twenty-one days and found that only 
 tender leaves still growing are susceptible. 
 The berry is susceptible even after the calyx 
 has fallen. The pycnidial spores are said by 
 some to show a hyaline appendage ^^^ though 
 others by careful study fail to find it.^'-*^ 
 These spores often live over winter. ^^"^ The 
 microconidia which develop in pycnidia similar 
 to those of the macroconidia do not occur so 
 abundantly early in the season as they do 
 later and seem to be mainly limited to the 
 fruits. Sporeless pycnidia, pycnosclerotia, also 
 occur and may eventually develop into perithecia. Conidia on 
 hyphse of questionable relationship to the fungus are sometimes 
 seen. 
 
 Reddick ^^" secured pure cultures in the following ways. 
 
 1. In poured plate dilution of asci; some twenty days were 
 required. 
 
 2. By inverting a plate of sterile agar over a bunch of mature 
 mummies floating on water. The ejected ascospores thus clung 
 to the agar and gave pure cultures in ten days. 
 
 3. By aseptic transfer of the mycelium. 
 
 4. By aseptic transfer of pycnospores. 
 
 Artificial infections have been reported in Europe from both 
 conidia and ascospores: Reddick, who made many thousand in- 
 
 FiG. 176.— G. bid- 
 wellii; 26, nearly ma- 
 ture ascus with 
 spores; 27, mature 
 ascospores; 28, ger- 
 minating ascospores, 
 29, same with ap- 
 pressoria. After 
 Reddick. 
 
242 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 oculations under all conceivable conditions, failed utterly of posi- 
 tive results. 
 
 From the Caucasus Prillieux and Delacroix ^^^ have described a 
 Guignardia causing a black rot of grapes which is regarded as 
 distinct from the usual American form, differing both in the peri- 
 thecial and conidial stages. This is called G. baccae (Cav.) Jacz. 
 Its conidial form Phoma reniformis eventually covers the whole 
 berry with pustules. Two kinds of pycnidia 
 are described. 
 
 G. vaccinii Sh.^^^- '^^ 
 
 Perithecia on young fruit or flowers, sub- 
 epidermal, globose, walls thick, carbonous; 
 asci clavate, 60-80 n long; spores elliptic 
 or subrhomboidal, hyaline, becoming tinted. 
 /^^^ ^~~^^ Conidia (=Phyllosticta) borne in pycnidia 
 
 Fig. 177.— A vertical sec- similar to the perithecia but thinner-walled, 
 orSuiUrdL^vaccin™ 100-120 ^', conidia hyaline, obovoid, 10.5- 
 
 showing asci. After 13 5 ^ 5.5 „ Qn Vacciuium. 
 Shear. ^ 
 
 In the decaying berries all sporing forms 
 of the fungus are rare though in the softened tissues fungous 
 hyphae abound. Transferred to culture media these hyphse grow 
 readily and produce spores abundantly. 
 
 The conidial form is common in artificial culture; the peri- 
 thetical form comparatively rare. Pycnidia on leaves are sub- 
 epidermal, usually hypophyllous, and are quite abundant. The 
 spores at maturity issue in coils from the ostiole. 
 
 The fungus was studied extensively in artificial culture by Shear, 
 wet sterilized cornmeal proving a most suitable medium. Pycni- 
 dia appeared in four to eight days after inoculation and spores were 
 mature at twelve to eighteen days. Both pycnidia and perithecia 
 were obtained in pure cultures. The rarity of cultures able to pro- 
 duce perithecia is explained by Shear on the assumption "that 
 there is some inherent potentiality in the mycelium of the fungus 
 in certain strains, races, or generations which causes it to produce 
 the ascogenous stage whenever conditions for its growth are favora- 
 ble, i. e., on favorable culture media without special reference to 
 their exact composition or environment or on the leaves of its nat- 
 ural host." Conclusive infection experiments have not been made. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 243 
 
 G. theae Bern. ^^^ grows on tea leaves. 
 
 G. (Laestadia) buxi Desm. The perithecia develop on box 
 leaves. It is probably saprophytic although sometimes considered 
 a parasite. 
 
 Stigmatea Fries (p. 236) 
 
 Perithecia subepidermal, or subcuticular, thin, black; asci 
 oblong, subsessile, 8-spored; spores ovoid-ellipsoid, 2-celled, yel- 
 lowish or hyaline; paraphyses present. The 
 ascigerous stage of two species of Entomo- 
 sporium are said by Lindau to belong to 
 this genus. Atkinson, however, places them in 
 the genus Fabrea, see p. 149. 
 
 S. juniperi (Desm.) Wint., on living leaves 
 of Juniperus in Europe and America and on „ i -§_§(.• 
 Sequoia in California. Asci and spores. 
 
 After W inter 
 
 Perithecia scattered, lenticular or subhemi- 
 spheric, rough, 200-300 fi in diameter, asci rounded and obtuse 
 above, abruptly tapering below into a short stipe, 60-70 x 20 /x; 
 spores ovate-lanceolate, unequally 2-celled, yellowish-hyaline, 16- 
 25 X 6-8 fi. 
 
 S. alni occurs on alder leaves in Europe. 
 
 Mycosphaerella Johans. (p. 236) 
 
 Perithecia subepidermal, suberumpent, globose-lenticular, thin, 
 membranous, ostiole depressed or short papillate; asci cylindric 
 to clavate, 8-spored; spores hyaline or greenish, ellipsoid, 2-celled; 
 paraphyses none. 
 
 This large genus of over five hundred species formerly known as 
 Sphserella contains several serious plant pathogens. It is often 
 found in its conidial" forms as: Ramularia, Ascochyta, Septoria, 
 Phleospora, Cercospora, Ovularia, Cylindrosporium, Phyllosticta, 
 Graphiothecium, Phoma, Diplodia or Septogloeum. In many cases 
 the relationship of the ascigerous and conidial forms is as yet but 
 imperfectly known. The perithecia are usually found late in the 
 season, often only on leaves that have borne the conidial stage in 
 the summer and have then wintered. 
 
 V. 
 
244 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 M. fragariae (Tul.) Lin.^" 
 
 Perithecia on leaves, are produced late in the season, globose, 
 subepidermal, membranous, black, thin-walled; asci few, clavate, 
 
 Fig. 179. — Mycosphaerella fragarise. b, conidiophores burst- 
 ing through the epidermis; c, arising from apex of a 
 pyenidium; d, summer spores, one germinating; e, section 
 of a spermogonium; /, section of perithecium; g, ascus 
 containing eight two-celled spores. After Longyear. 
 
 8-spored, 40 fx long; spores hyaline, 2-celled, with acute tips, 
 15 X 3-4 /x. 
 
 Conidia ( = Ramularia tulasnei) abundant in early summer on 
 reddish spots, stromatic, conidiophores simple; conidia elliptic 
 20-40 X 3-5 n, 2 to 3-celled. On Fragaria. 
 
 The life history was first studied in 1863 by the Tulasne brothers 
 under the name Stigmatea. The generic name was changed to 
 Sphaerella in 1882 and later to Mycosphaerella. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 245 
 
 The slender mycelium pervades the diseased areas disorganizing 
 the host cells and resulting in reddish coloring of the sap. Ob- 
 servations of Dudley ^^^ indicate that the mycelium or portions of 
 it can remain alive over winter in the host tissue ready to produce 
 abundant conidia in the spring. 
 
 The most abundant conidial stage is the Ramularia-form 
 (Fig. 179) which abounds all summer. Sowings of these conidia, 
 under conditions of humid atmosphere, result in characteristic 
 spots in from ten to eighteen days. Toward winter sclerotial 
 bodies are formed from the mycelium. These in culture dishes 
 have been seen to produce the typical summer conidia. Some of 
 these sclerotia-like bodies have been reported as "spermogonia," 
 bearing numerous "spermatia" 1 x 3 ;u. Perithecia abound in au- 
 tumn. These are larger than the spermogonia and are usually 
 embedded in the leaf tissue, though they sometimes appear super- 
 ficially. Conidiophores are often borne directly on the perithecium 
 wall. Ascospores germinate within the ascus. From the mycelium 
 resulting from ascospores Dudley ^^^ observed the formation of 
 typical summer conidia. 
 
 M. grossulariae (Fr.) ^^^ 
 
 Perithecia hypophyllous, gregarious, spherical, with minute 
 ostiole, black; asci short-pedunculate, clavate, 55-66 x 8-12 fi; 
 spores fusoid, filiform, curved or straight, uniseptate, hyaline, 
 26-35 X 3-4 At. 
 
 It has been reported on the gooseberry associated with Cer- 
 cospora angulata and Septoria ribis. 
 
 M.rubina (Pk.) Jacz.^oo 
 
 Perithecia minute, gregarious, submembranous, obscurely papil- 
 late, subglobose or depressed, erumpent, black; asci cylindric, 
 subsessile, 70-80 x 10-12 ^t; spores oblong, obtuse, uniseptate, 
 generally constricted in the middle, 15 x 6-7 fx, upper cell broadest. 
 
 Conidia ( = Phoma) are associated with the perithecia and are 
 supposed to be genetically connected with them as is also a second 
 spore form ( =Coniothyrium). 
 
 The species is held responsible for bluish-black spots on rasp- 
 berry canes. 
 
 M. cerasella Aderh.^''^ is reported as the perithecia! stage of 
 Cercospora cerasella common on cherry. 
 
246 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Fig. 180. — M. sentina, yeptoria stage. 
 Portion of a section through a pear leaf 
 spot, showing e, e, epidermis; p, pali- 
 sade cells sp, spongy parenchyma; a, 
 S. piricola pycnidium, giving out 
 spores, b. After Longyear. 
 
 M. sentina (Fr.) Schr. 
 
 Perithecia, 80-110 n; on dead spots of leaves, the long ostiole 
 erumpent; asci clavate, 60-75 x 11-13 /jl, colorless; spores fusiform, 
 
 curved or straight, 26-33 x 
 4)u. 
 
 Conidia (=Septoria piricola) 
 borne in pycnidia which are 
 similar in size and form to the 
 perithecia; conidia filiform, 
 curved, 3-celled, 40-60 x 3 ju- 
 On pear and apple. 
 
 The conidial form was men- 
 tioned in America as early as 
 1897 by Atkinson ^04 and was 
 the subject of a comprehensive 
 bulletin by Duggar in 1898.203 
 The ascigerous stage was demon- 
 strated by Klebahn in 1908.202 
 The pycnidia, mainly hypophyllous, are sunk deeply into the 
 leaf tissue and are surrounded by a delicate pseudoparenchyma. 
 The conidia are distinctly tinted, green or smoky. 
 
 The perithecia are numerous, and crowded on grayish spots, 
 hypophyllous, on old wintered leaves. They are without stroma. 
 Klebahn by inoculations (June, 1904) with ascospores secured 
 spots in fifteen days and pycnidia in twenty- 
 nine days, bearing the characteristic conidia. 
 From ascospores he also made pure cultures 
 which soon developed pycnidia with conidia. 
 Pure cultures made from conidia in the hands 
 of both Klebahn and Duggar have failed to 
 give typical perithecia. 
 M. citrullina (C. 0. Sm.) Gros. 
 Perithecia roughish, dark-brown or black, 
 depressed-globose to inverted top-shaped, 
 usually with a papillate ostiole, densely 
 scattered, erumpent, 100-165 n; asci cylindric to clavate, 45-58 x 
 7-10 ft; spores hyaline, oblong-fusoid, constricted at the sep- 
 tum. 
 
 Fig. 181.— M. sentina. 
 Conidial layer, co- 
 nidiophores and co- 
 nidia. After Kle- 
 bahn. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 247 
 
 Conidia ( = Diplodina citrullina) Pycnidia similar to the peri- 
 thecia, spores 2-celled, hyaline, straight or curved, more or less 
 cylindric, 10-18 x 3-5 fx. 
 
 The fungus was isolated in pure culture by Grossenbacher ^°^ 
 from muskmelons by direct transfer of diseased tissue to potato 
 agar. Inoculations from these cultures proved the fungus capable 
 of entering healthy uninjured tissue, the • 
 
 disease showing about six days after in- 
 oculation. The brownish pycnidia origi- 
 nate from an extensive subepidermal, 
 partially cortical, much-branched, brown- 
 ish mycelium but soon break through and 
 
 , , r • 1 iTTi • Fig. 182. — M. sentina. .4, 
 
 appear almost superhcial. When mois- perithecium and asci. Af- 
 tened, spores issue in coils. Darker peri- *'^'' Kiebahn. 
 thecia, nearly superficial, are found on old diseased spots. Both 
 ascospores and conidia are capable of causing infection. Inocu- 
 lations on pumpkin and watermelon gave positive results; these 
 on cucumber, West Indian gherkin, squash, pumpkin, and gourd 
 were negative. The same fungus has been reported as cause of 
 canker of tomatoes.'"^ 
 
 M. tabifica (P. & D.) Johns.^o^'^io 
 
 Perithecia rounded, brown; asci oblong-clavate, 8-spored; spores 
 hyaline, upper cell larger, 21 x 7.5 /jl. 
 
 Pycnidia (=Phoma) subglobose; conidia elliptic, hyaline, 5-7 x 
 3.5 fjL, escaping as a gelatinous cirrus. 
 
 This conidial form, common on beets causing leaf spot through- 
 out the summer, is said by Prillieux and Delacroix to be connected 
 with M. tabifica the perithecial form, which is found upon the 
 dead petioles at the end of the season. Convincing evidence ^°^ of 
 this connection seems wanting. The conidial stage ^"^ is variously 
 known as Phoma betae, Phoma sphserosperma, Phyllosticta 
 tabifica. The Phoma-form from stems and rotten roots and the 
 Phyllosticta-forms from leaves were both studied by Hedgcock ^^^ 
 in pure cultures on many media and many inoculations were made, 
 all leading to the conclusion that the Phoma and the Phyllosticta 
 are identical. 
 
 M. tulasnei Jacz.-^^ 
 
 Perithecia subglobose, minute; asci cylindric fusoid; spores 
 
248 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 oblong, rather pointed, upper cell in the ascus somewhat larger 
 than the others, 28 x 6.5 n. 
 
 Conidia of two kinds, (1) (=Cladosporium herbarum) tufts 
 dense, forming a velvety blackish-olive, effused patch, conidio- 
 phores erect, septate, rarely branched, often nodose or keeled; 
 conidia often in chains of 2 or 3, subcylindric pale-olive, 1 to 
 3-septate, 10-15x4-7 fx. (2) ( = Hormodendrum cladosporioidies 
 Sacc.) Hyphse erect, simple, bearing apically or laterally a tuft 
 
 Fig. 183. — M. citrullina, A. pycnidium (Diplodia) in sec- 
 tion, B, perithecium ; C, ascus and spores. After Grossen- 
 bacher. 
 
 of small, elliptic, continuous, brown conidia in simple or branched 
 chains. 
 
 It is the cause of serious disease in Europe, being especially 
 injurious to cereals after a rainy season preceded by a drought 
 and is found also parasitic on pea, apple, raspberry, cycad, agave 
 and as a saprophyte almost anywhere. 
 
 M. stratiformans Cobb, affects sugar cane. The perithecial 
 stage alone is known. ^^^ Further study is desirable. 
 
 M. gossypina (Cke.) Er.^^^"-^^ 
 
 Perithecia ovate, blackish, partly immersed, 60-70 x 65-91 mJ 
 asci subcylindric, 8-10 x 40-45 n; spores elliptic to fusoid, con- 
 stricted at the septum, 3-4 x 15-18 /x. 
 
 Conidia (=Cercospora gossypina); hyphae flexuose, brown, 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 249 
 
 120-150 n high; conidia attenuate above, 5 to 7-.septate, hyahne, 
 70-100 X 3 M- On cotton. 
 
 The intercellular mycelium is irregular, branched, septate, and 
 produces tuberculate stromata from which the brownish hyphae 
 arise. The perithecia, much less common, are partly immersed 
 in old leaves. 
 
 M. morifolia (Fcl.) Ljn. in its conidial stages, Cylindrosporium 
 mori and Septogloeum mori, affects Morus. 
 
 M. maculiformis (Pers.) Schr. grows on many trees. Especially 
 common are its conidial stages Cylindrosporium castinicolum and 
 Phyllosticta maculiformis. 
 
 M. rosigena E. & E. -^8-219 
 
 Amphigenous on reddish-brown, purple-bordered spots which 
 are about 3-4 mm. in diameter; perithecia thickly scattered over 
 the spots, minute, 60-75 n, partly erumpent, black; asci sub- 
 clavate to oblong, 25-30 x 8-10 ix; spores biseriate, clavate- 
 oblong, hyaline, 1-septate, 10-12 x 2 ju, ends subacute. 
 
 It causes leaf spots of rose in America. 
 
 M. brassicaecola (= Phyllosticta brassicaecola) grows on cabbage. 
 
 M, punctiformis Pers. produces leaf spot on oak, lime, hazel; 
 
 M. fagi Auser. on beech; 
 
 M. pinifolia Due. on pine leaves; ^°^ 
 
 M. abietis (Rost.) Lin. a leaf disease of balsam.^^" 
 
 M. taxi Cke. grows on yew; 
 
 M. hedericola t)esm. on Hedera leaves; 
 
 M. gibelliana Pass, on Citrus leaves; 
 
 M. vitis Fcl. on grape leaves; 
 
 M. elasticae Kr. ^-^ on Ficus elastica. 
 
 M. cydoniae Vogl. ^"^ on quince is probably identical with 
 M. sentina on pear and apple. 
 
 M. ulmi Kleb. occurs on elm with its conidial forms, a Phleo- 
 spora and Phyllosticta bellunensis. 
 
 M. comedens Pass, is on the same host. 
 
 M. larcina Hart, and its conidial form Leptostroma larcinum 
 affect larch, causing defoliation. 
 
 M. loefgreni N. on oranges and M. coffeae N. on coffee are 
 tropical forms. 
 
 M. populi Schr. (=Septoria populi) is on Populus.^"* 
 
250 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 M. pinodes Berk & Blox. 
 
 Perithecia numerous, 100-140 /x; asci oblong-cylindric, 58-62 x 
 12 ju; spores 2-rowed, 14-16 x 5. 
 
 Pycnidia (=Septoria pisi), with large ostiole; spores 35-45 x 3- 
 3.5 fx, 1 to 3-septate. On pea stem and leaves.^°^' ^^^ 
 
 M. primulae is on primrose; 
 
 M. tamarindi on tamarinds in Africa. 
 
 M. cinxia Sacc. is on lilies, causing leaf blight; 
 
 M. fusca Pass, on the gladiolus; 
 
 M. coffeicola on coffee in Mexico. 
 
 M. shiraina Miy. and M. hondai Miy. are on rice. 
 
 M. convexula (Sch.) Rand. 
 
 Perithecia hypophyllous, gregarious or scattered, finally erum- 
 pent, 100-200 /x in diameter, papillate at maturity; no paraphyses; 
 asci fasciculate, 54-100 x 9-11 n, 8-spored; spores allantoid, 
 1-septate, hyaline, 13-27 x 3.5-5.5 /x. 
 
 Forming a leaf spot on pecans.^^^ 
 
 An undetermined species of Mycosphaerella has been reported 
 on the grape by Rathay.^^^ 
 
 Many other species are known on ferns, cereals, lilies, and va- 
 rious trees and herbs. 
 
 In the genus Pharcidia. P. orzas Miy. is on rice.^°^ 
 
 In Sphaerulina the species Sphaerulina taxi Mass. is injurious on 
 yew leaves. 
 
 Pleosphaerulina Passer (p. 236) 
 
 Perithecia subepidermal, erumpent, small, globoid or lenticular, 
 black; asci 8-spored, clavate; spores muriform, hyaline; paraphyses 
 none. 
 
 P. briosiana Pol. causes a leaf disease of alfalfa in Italy. 
 
 Pleosporaceae (p. 223) 
 
 Perithecia sunken, at length erumpent, or from the first more 
 or less free, membranous or coriaceous, usually papillate; asci 
 clavate-cylindric, double-walled; spores variable, but usually 
 colored, oblong, fusoid or elliptic; paraphyses present. 
 
 An order of some nineteen hundred species most of which are 
 saprophytes, although several are parasites, some of considerable 
 importance. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 251 
 
 Key to Genera of Pleosporaceae 
 
 Spores 1-celled 
 
 Spores with blackish appendages, elon- 
 gate, hyaline 1. Urospora. 
 
 Spores unappendaged 
 
 Spores elongate, hj^aline or light yel- 
 low 2. Physalospora, p. 252. 
 
 Spores elongate, fusoid, hyaline; tips 
 
 bent 3. Therrya. 
 
 Spores 2-celled 
 
 Spores with the 2 cells very unequal in 
 size 
 Upper cell the smaller; parasitic on 
 
 Riccia 4. Arcangelia. 
 
 Basal cell the smaller; saprophytes. ... 5. Apiospora. 
 Spores with both cells about equal 
 
 Perithecia hairy; spores hyaline or 
 
 brown 6. Venturia, p. 253. 
 
 Perithecia smooth 
 
 Spores hyaline 7. Didymella, p. 255. 
 
 Spores brown 
 
 Perithecia not stromatic 8. Didymosphaeria, p. 256. 
 
 Perithecia borne on a stroma 9. Gibbellina, p. 256. 
 
 Spores more than 2-celled 
 
 Spores elongate, with cross walls only 
 Spores appendaged 
 
 Spores clavate, 4 to 6-celled, brown, 
 the basal cell hyaline long- 
 
 appendaged 10. Rabentischia. 
 
 Spores filiform, many-celled, with 
 
 filiform appendages 11. Dilophia, p. 257. 
 
 Spores not appendaged 
 Spores fusoid or elongate, blunt, never 
 filiform or separating into cells 
 Spores elongate, 3 to many-celled, 
 hyaline or brown 
 Spores with a thick, dark-brown 
 epispore and a thin hj^a- 
 line endosporc, 4-celled, el- 
 lipsoid 12. Chitonospora. 
 
252 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Spores not as above, elongate 
 3 to many-celled hyaline or 
 brown 
 
 Perithecia hairy 13. Pocosphaeria. 
 
 Perithecia smooth 
 
 Spores hyaline 11. Metasphaeria, p. 257. 
 
 Spores yellow or dark- 
 brown 15. Leptosphaeria, p. 257. 
 
 Spores fusoid, 7 to many-celled, 
 the central cell enlarged and 
 
 brown, the rest hyaline IG. Heptameria. 
 
 Spores fusoid, up to 30-celled hya- 
 line or brown 17. Saccardoella. 
 
 Spores filiform, often separating into 
 cells 
 
 Perithecia hairy 18. Ophiochaeta. 
 
 Perithecia smooth 19. Ophiobolus, p. 259. 
 
 Spores muriform 
 Asci 8-spored 
 
 Spores appendaged 20. Delacourea. 
 
 Spores not appendaged 
 
 Perithecia hairy.. 21. Pyrenophora, p. 262. 
 
 Perithecia smooth 22. Pleospora, p. 259. 
 
 Asci 16-spored 23. Capronia. 
 
 Physalospora Niessl. (p. 251) 
 
 Perithecia subglobose, covered, membranous, or coriaceous, 
 
 black, with the ostiole erum- 
 pent; asci clavate-cylindric ; 
 spores ovoid or oblong, con- 
 tinuous, hyaline or subhya- 
 line; paraphyses present. 
 
 This genus contains over 
 one hundred thirty species, a 
 few of which are parasitic on 
 twigs and leaves. Some spe- 
 cies possess a Gloeosporium 
 as the conidial form. 
 gregaria and its conidial stages Tetradia saficicola and 
 
 Fig. 184. — Physalospora. Perithecia and 
 ascus. After Winter. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 253 
 
 Macrodendrophoma salicicola cause black cankers on oziers in 
 Ireland.22^ 
 
 P. abietina P. & D.-^ is found on Picea; P. cattleyae Maub, & 
 Las. in its conidial form, Gloeosporium macropus--^ parasitizes 
 Cattleya. P. laburni Bon. is on Cytisus. 
 
 P. woronini M. & F. is described as causing a disease of grapes 
 in the Caucasus. ^^'' 
 
 P. vanillae Zimm. is on vanilla; 
 
 P. fallaciosa Sacc. on banana leaves. 
 
 Venturia Cesati & de Notaris (p. 251) 
 
 Perithecia superficial or erumpent, bristly, ostiolate, membra- 
 nous, dark colored; asci sessile or short stipitate, ovate or saccate; 
 spores oblong to ovoid elliptic, hyaline or yellowish; paraphyses 
 usually none. 
 
 The conidial stages in some cases belong to the form genus 
 Fusicladium and constitute the parasitic portion of the life history 
 of the fungus, the ascigerous form usually being limited to old or 
 wintered parts of the host. 
 
 There are over fifty species, several of which cause diseases. 
 
 T7- «;^;^« A 1 \ 230, 312, 313, 350 
 
 V. pinna Aderh. ' 
 
 Perithecia gregarious, smooth or bristly, globoid, 120-160 /x; 
 asci cylindric; spores unequally 2-celled, yellowish-green, 14-20 x 
 5-8 M- 
 
 Conidia ( = Fusicladium pirinum) effused, velvety, blackish-ohve, 
 conidiophores short, wavy or knotted, thick- walled; conidia ovate 
 fusoid, olive, becoming 1-septate with age, 28-30 x 7-9 fji. 
 
 It is found on the pear wintering in perithecial form on leaves, 
 and in conidial form, or as mycelium on twigs. 
 
 V. inaequalis (Cke.) Aderh. (=V. pomi [Fries] Winter). 
 
 Perithecia globose, short-necked, 20-160 /x, smooth or bristly 
 above; asci cylindric, 40-70 fjL long; spores yellowish-green, un- 
 equally 2-celled, upper cell shorter and broader, 11-15 x 4-8 /i. 
 
 Conidia ( = Fusicladium dendriticum) effused, velvety, forming 
 dendritic patches of compact masses of erect closely septate 
 brown mycelium; conidiophores closely septate, brown, 50-60 x 
 4-6 /x, wavy or nodulose; conidia sohtary, terminal, obclavate. 
 
254 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Fig. 185.— V. insequalis. A, portion of a section through a scab spot on apple; b, spread- 
 ing under and hfting the cuticle, a; c, partly disorganized cells of the apple; e, healthy 
 cells of the apple. B, two conidiophores with summer spores /. C, spores ger- 
 mmating. D, portion of a section showing a perithecium and asci. E, two asci, each 
 containing 8 two-celled spores, three of which are shown at F. After Longyear. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 255 
 
 yellowish-olive, continuous when young but at length septate, 
 30 X 7-9 M- 
 
 Its hosts are apple and other pomaceous fruits except the pear. 
 Conidia of special form have been known under the name Napi- 
 cladium soraueri. 
 
 The two last conidial forms have been long regarded as identical 
 and are found in literature as Fusicladium dendriticum. The 
 olive-green mycelium in both cases grows subepidermally in the 
 leaf and fruit killing the epidermis and forming subepidermal 
 stromata from which conidiophores are produced. Stromatal 
 development is also said to be often subcuticular, resulting in a 
 separation of the cuticle from the epidermis. 
 
 The conidia are produced apically on short stalks and as each 
 conidium is cut off the conidiophore grows forward, leaving scars 
 equal in number to the conidia produced. Pycnidia have been 
 reported on the mycelium in twigs in winter. ^^^ 
 
 Perithecia first form on the lower leaf surface in October and 
 mature in April. They are most abundant when protected by 
 sod or piles of leaves, and appear as small black pustules often 
 on grayish spots. Their comiection with the conidial stage was 
 first shown by Aderhold ^^^ and confirmed by Clinton. ^^^ 
 
 The fungus from apple was cultured on apple-leaf-agar by Clinton. 
 Pure colonies developed in 4 to 5 days and infection was secured 
 on leaves. Cultures from ascospores gave rise to typical conidia. 
 
 V. crategi Aderh. occurs on Crataegus. 
 
 V. cerasi Aderh. ( = Fusicladium cerasi) is found on cherries. 
 Aderholt -^^ demonstrated the connection between the ascigerous 
 and conidial forms. 
 
 V. ditricha (Fr.) Karst. (= Fusicladium betulae) is found on 
 birches; V. tremulae Aderh. (= Fusicladium tremulse) on aspen; 
 V. fraxini Aderh. ( = Fusicladium fraxini) on ash; 
 
 V. inaequalis var. cinerascens Lin. (= Fusicladium orbiculatum) 
 on Sorbus. 
 
 Didymella Saccardo (p. 251) 
 
 Perithecia covered, membranous, globose-depressed, minutely 
 papillate; black; asci cylindric or clavate* spores ellipsoid or 
 ovate, 2-celled, hyaline; paraphyses none. 
 
256 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Of the some one hundred twenty species D. citri N. is of in- 
 terest since it forms cankers on orange trees in Brazil. 
 
 Didymosphaeria Fuckel (p: 251) 
 
 Peritheeia immersed, later erumpent; asci cylindric to clavate, 
 8-spored; spores elliptical to ovate, 2-celled, brown. 
 
 This genus differs from Didymella chiefly in the dark-colored 
 spores. It contains some one hundred twenty species and has 
 occasional parasitic representatives on leaves and twigs. 
 
 Fig. 186.— Didymella. A, 
 ascus; B, hymenium of 
 a pycnidium. After 
 Brefeld. 
 
 Fig. 187. — Didymo- 
 sphseria. C, an as- 
 cus; D, c o n i d i o- 
 phore and conidia. 
 After Brefeld. 
 
 Fig. 188. — Dilo- 
 p h i a graminis. 
 J, ascus; K, 
 spore. After 
 Winter. 
 
 D. sphaeroides (Pers.) Fr. is. on Populus leaves in Europe. 
 
 D. catalpae.^^^ 
 
 Peritheeia very small, scattered, embedded in the tissue of the 
 leaf, pyriform to nearly spherical, varying in width from 48-104 fj. 
 and in depth from 64-140 /x; ostiole broadly conical, erumpent; 
 asci 8-spored, cylindrical, usually somewhat curved; paraphyses 
 few or wanting; spores oblong-elliptical, hyaline or yellowish, 
 uniseptate, constricted in the middle, 9.6-13 x 3-4 /j,. On Catalpa. 
 
 D. populina Vuill., causes death of poplars in Europe.^^"* 
 
 D. epidermidis Fr. is found on Berberis, Sambucus and Salix. 
 
 Gibbellina Passerina (p. 251) 
 
 Stromata black, sunken in the substratum, formed of thin, closely 
 interwoven hyphse; peritheeia sunken in the stromatn, globose; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 257 
 
 asci elongate-globoid; spores elongate, 2-celled, brown; paraphyses 
 present. Genus of one species. 
 
 G. cerealis Pers. causes a serious grain disease in Europe, es- 
 pecially of wheat in Italy. -"^'^ 
 
 Dilophia Saccardo (p. 251) 
 
 Perithecia sunken, not erumpent, delicate, dark-colored, ostiole 
 papillate; asci long-cylindric; spores elongate- fusiform to filiform, 
 multicellular, each end appendaged, the appendages hyaline, the 
 spores hyaline or yellow. Fig. 188. 
 
 There are three species, one of which D. graminis (Fcl.) Sacc. 
 parasitizes rye and wheat in Europe. The conidial form Dilo- 
 phospora graminis Desm. is especially common, 
 
 Metasphaeria Saccardo (p. 252) 
 
 Perithecia clavate, sunken in a stroma, at first covered ; leathery, 
 dark, with ostiole; asci cylindric to clavate, 8-spored; spores ellipsoid, 
 elongate, blunt or appendaged, 3 to many-celled; paraphyses filiform. 
 
 M. albescens Thum. is on rice in Japan. 
 
 Leptosphaeria Cesati & de Notaris (p. 252) 
 
 Perithecia at first subepidermal, at last more or less erumpent, 
 subglobose, coriaceo-membranous, globose, ostiole usually papil- 
 late; asci subcylindric; spores ovoid, oblong or fusoid, two or more 
 septate, olivaceous, yellowish or brown. 
 
 There are about five hundred species, many of which in the 
 conidial forms embrace Cercospora, Phoma, Hendersonia, Sporides- 
 mium, Septoria, Coniothyrium or Cladosporium. 
 
 L. coniothyrium (Fcl.) Sacc.^^'*' ^^^ 
 
 Perithecia gregarious, subepidermal, depressed, globose, black; 
 ostiole papillate, erumpent; asci cylindric, stipitate, 8-spored, 
 66-96 X 4-6 n; spores 1-rowed, oblong, 3-septate, constricted, 
 fuscous, 10-15 X 3.5-4 /x. 
 
 Pycnidia (= Coniothyrium fuckelii), similar to perithecia; spores 
 ovate, continuous, .fuscous. 
 
 It occurs on black and red raspberries and numerous other hosts. 
 
 Stewart ^^^ verified the assumed identity of the conidial form 
 with this ascigerous fungus by pure culture studies. 
 
258 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 L tritici (Gar.) Pass ^^^ (=Pleospora tritici). On wheat.^^^ 
 Perithecia innate, globose, black, papillate; asci clavate, short- 
 
 stipitate, 8-spored; paraphyses filiform, 48-50 x 15-16 n; spores 
 
 2-seriate, round, fusoid, 3-septate, constricted, pale, 18-19 x 4.2- 
 
 5.5. 
 L. herpotrichoides d. Not.^^^ parasitizes rye causing the stalks 
 
 to break at the nodes; 
 
 Fig. 189. — Cross-section of raspberry bark showing 
 two perithecia of L. coniothyrium at the top, A, and 
 two pycnidia of Coniothyrium fuckelii, at the bot- 
 tom, B. 4. An ascus of L. coniothyrium. 5. Spores 
 of L. coniothyrium. After Stewart. 
 
 L. sacchari V. B. d H. occurs on sugar-cane. 
 
 L. napi (Fcl.) Sacc. (=Sporidesmium exitiosum) is found on 
 rape; L. phlogis Bos. (=Septoria phlogis) on Phlox; 
 
 L. circinans (Fcl.) Sacc. kills alfalfa roots, potato, clover, beets 
 and other hosts; -^^ 
 
 L. vitigena Schul. occurs on grape tendrils; 
 
 L. stictoides Sacc. on Liriodendron; L. rhododendri on Rho- 
 dodendron ; 
 
 L. iwamotoi Miy. on rice; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 259 
 
 L. taxicola R. K. on Taxus canadensis; 
 L. vagabunda Sacc. spots linden branches, 
 is perhaps Phoma tilise.-^^ 
 
 Its conidial form 
 
 Ophiobolus Riess (p. 252) 
 
 Perithecia scattered, subglobose, submembranous, covered or 
 suberumpent, ostiole papillate or elongate; asci cylindric; spores 
 fusiform, hyaline or yellowish. 
 
 Fig. 190. — Ophio- 
 bolus. B, asfus; 
 C, spore. After 
 Lindau and Win- 
 ter. 
 
 Fig. 191. — Pieospora from 
 passion-fruit. The spores 
 are just beginning to ger- 
 minate, the end cells start- 
 ing first. After Cobb. 
 
 A genus of some one hundred twenty-five species. 
 O. graminis Sacc. and O. herpotrichus Sacc. occur on grasses 
 and are quite injurious in Europe. ^^'^ 
 O. oryzeae Miy. is found on rice.^"'' 
 
 Pieospora Rabenhorst (p. 252) 
 
 Perithecia covered at first, later more or less erumpent, usually 
 membranous, black, globose; asci oblong to clavate; spores elon- 
 gate or ovate, muriform; paraphyses present. 
 
260 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Conidia occur as Macrosporium, Alternaria, Cladosporium, 
 Sporidesmium, Phoma, Helminthosporium. 
 
 There are over two hundred twenty-five species, mostly sap- 
 rophytic. Many conidial forms whose connection to this genus 
 have not yet been definitely proved probably belong to it and are 
 in many instances parasites. 
 
 P. tropeoli Hals, is reported as the cause of disease of the cul- 
 tivated Nasturtium. ^'^'^ 
 
 Perithecia pyriform, 140-160 /x; asci oval, one-sided, spores 
 hyaline or very light-olivaceous, 25-35 x 6-8 fx. 
 
 The Alternaria-form was grown from the ascospores by Halsted 
 and from the Alternaria spores, grown in pure culture, perithecia 
 were obtained in about twelve days. 
 
 P. albicans Fcl. occurs on chicory as Phoma albicans; 
 
 P. hyacinthi Sor. on hyacinths with its conidia as Cladosporium 
 fasciculare; P. hesperidearum Cotton, in its conidial form, Spori- 
 desmium pyriforme, causes a black mold on oranges. 
 
 P. herbarum (Pers.) Rab. (conidia= Macrosporium commune) 
 is a common saprophyte which sometimes becomes parasitic. 
 
 P. pisi (Sow.) Fcl.^^^ is found on the garden pea; 
 
 Perithecia and spores as in P. herbarum but spores more narrow. 
 
 P. ulmi. Fr. causes an elm leaf spot. P. infectoria Fcl. a com- 
 mon saprophyte, parasitizes tobacco. 
 
 P. oryzae Miy. is on rice; 
 
 P. negundinis Oud. is injurious to nursery stock of Negundo; 
 
 P. putrefaciens (Fcl.) Fr. (conidia = Sporidesmium) is on carrots. 
 
 Pleosporae on grains.'-^^' ^^^ 
 
 Several species of Pleospora with their attendant conidial forms 
 of Helminthosporium and Alternaria are known on various grains 
 and grasses. Cross inoculation experiments have shown here 
 biologic specialization similar to that encountered among the 
 Erysiphese, in that conidia or ascospores from one host usually 
 give negative results on host species other than that on which they 
 grew. Thus Diedicke ^^^ says the Pleospora of Bromus cannot 
 be grown on Triticum repens nor on cultivated barley or oats. 
 Helminthosporium was formerly thought to be the conidial stage 
 of all of these grain Pleosporas, but recent work of Diedicke shows 
 that one form which he regards as P. trichostoma (Fr.) Wint. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 261 
 
 22 
 
 possesses an Alternaria conidial form. Following Diedicke, the 
 forms given below would be recognized. 
 
 P. bromi Died. 
 
 Perithecia brown, hairy; asci 189-288 x 34-59 n, saccate, thin- 
 walled; spores 2-seriate, golden-brown, 4-xelled, 48-83 x 19-33 fx. 
 
 Conidia ( = Helminthosporium bromi) on brownish spots, 108- 
 150 X 13-20 M, 5 to 7-celled, dark colored. On Bromus. 
 
 P. gramineum Died. 
 
 Conidia (=Helminthosporium gramineum); conidiophores short, 
 subflexuose, light-brown; conidia solitary, elongate-cylindric, 4 to 
 7-celled, 15-19 n wide and of variable length. 
 
 The mycelium invades the tissue causing long brown spots. 
 These later become covered with an abundance of conidiophores 
 which emerge through the stomata. Potter also reports in- 
 vasion and complete occupation of ovaries by the mycelium 
 Sclerotia-like bodies are 
 formed on leaves and 
 stems. They were first 
 seen in artificial cul- 
 tures of the fungus by 
 Ravn ^^^ and have been 
 since found in nature 
 (Noack2«). 
 
 The conidiospores 
 have been shown to be 
 long-lived, and spring 
 infection begins largely 
 from conidia carried 
 over winter on seed. 
 Extensive study was made of the conidial form by Ravn who 
 found the mycelium to be of two kinds, one aerial and hyaline, 
 the other strict and dark. It grew well on acid or neutral media. 
 
 Careful infection experiments (Ravn) proved the pathogenicity 
 of H. graminum for barley but showed it incapable of infecting 
 oats, rye or wheat. 
 
 Ravn regards the disease produced by H. gramineum as often 
 general, not local, in that the mycelium may invade the growing 
 points, resulting in infection of all the leaves. 
 
 Fig. 192.^— p. trichostoma. 1, group of asci, 2, a 
 singlo spore at the apex of an ascus. After 
 Diedicke. 
 
262 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 P. tritici-repentis Died, is found on Triticum repens (=Agropy- 
 ron repens.) Conidia=Helminthosporium tritici repentis. 
 
 P. trichostoma (Fr.) Wint. ( = Pyrenophora trichostoma (Fr.) 
 Sacc.242 
 
 Perithecia gregarious, innate, conical, black, ostiole surrounded 
 by black hairs, which are simple, septate, 6-8 fx in circumference; 
 asci clavate 300 x 40 /x; spores broadly oblong, obtuse, unequally 
 4 to 6-septate, muriform, brownish, 52 x 20 m; paraphyses branched. 
 
 On rye with the conidial form =Alternaria trichostoma Died. 
 
 In the present state of our knowledge little is to be gained by 
 recognition of these purely "biologic species," and all the forms 
 may be grouped under the name P. trichostoma, recognizing the 
 fact that it shows biologic differentiation. 
 
 Two hypothetical forms P. teres Died, and P. avense Died, 
 pertain to Helminthosporiums of corresponding names. 
 
 Massariaceae (p. 223) 
 
 Stroma none; perithecia separate, sunken, not erumpent, open- 
 ing by a small pore, leathery or carbonous, compact; spores usually 
 surrounded b}^ a jelly-like substance; paraphyses present. 
 
 This family of ten genera and about one hundred twenty-five 
 species contains only one parasite of interest. 
 
 Key to Genera of Massariaceae 
 
 Spores 1-celled 
 
 Spores not surrounded by a jelly-like sub- 
 stance 1. Enchnoa. 
 
 Spores surrounded by a jelly-like sub- 
 stance 2. Pseudomassaria. 
 
 Spores several-celled 
 Spores not muriform 
 Spores hyaline or yellow 
 
 Spores ellipsoid to spindle-shaped, 
 
 several-celled, hyaline 3. Massarina. 
 
 Spores spindle-formed, curved, 3 to 4- 
 
 celled, yellow 4. Ophiomassaria. 
 
 Spores 2 to 4-celled, elongate, hya- 
 line 5. Charrinia, p. 263. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 263 
 
 Spores brown 
 Spores 2-celled 
 
 Perithecia scattered irregularly. . . G. Phorcys. 
 
 Perithecia in circular clusters 7. Massariovalsa. 
 
 Spores more than 2-celled 
 
 Spores ellipsoid to si)indle-shaped, 
 
 many-celled 8. Massaria, p. 263. 
 
 Spores cylindric, bent, S-celled. . . 9. Cladosphaeria. 
 Spores muriform 10. Pleomassaria. 
 
 Massaria theicola Peteh invades the ducts of the tea plant. The 
 genus Charrinia is said by Viala & Ravaz -^'^ to contain the ascige- 
 rous form of Coniothyrium diplodiella (Speg.) Sacc. 
 
 Gnomoniaceae (p. 223) 
 
 Perithecia sunken, Avith an elongate, cylindric, beak-like ostiole, 
 rarely with a papillate one; leathery or membranous, rarely borne 
 on a stroma; asci mostly thickened apically and opening by a pore; 
 spores hyaline ; paraphyses usually absent. 
 
 A family of about one hundred fifty species; four genera con- 
 tain important pathogens. 
 
 Key to Genera of Gnomoniaceae 
 
 Spores 1-celled 
 
 Mouth of the perithecium short 
 
 Asci cylindric, 8-spored 1. Phomatospora. 
 
 Asci clavate, 2-spored 2. Geminispora. 
 
 Mouth of the perithecium elongate, beak- 
 like 
 Mouth of the perithecium straight 
 
 Asci many-sporcd 3. Ditopella, p. 264. 
 
 Asci 8-spored 
 
 Spores ellipsoid or fusoid 
 
 A clypeus present 4. Mamiania. 
 
 Stroma present 5. Glomerella, p. 264. 
 
 Stroma absent 6. Gnomoniella, p. 273. 
 
 Spores elongate fusoid, or filiform 7. Cryptoderis. 
 Mouth of the perithecium recurved ... 8. Camptosphaeria. 
 
 --^ 
 
264 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Spores 2 or more-celled 
 Asci 8-spored 
 
 Spores elongate, 2 to 4-celled 9. Gnomonia, p. 274. 
 
 Spores fusiform, curved, 2-celled 10. Hendersonia. 
 
 Asci many-spored; spores elongate, 
 2-celled 
 
 Perithecia beaked 11. Rehmiella. 
 
 Perithecia not beaked 12. Rehmiellopsis, p. 276. 
 
 Ditopella de Notaris (p. 263) 
 
 Perithecia corticolous, covered, globose or somewhat depressed, 
 ostiole suberumpent; asci subclavate, polysporous; spores oblong 
 or fusoid, continuous, subhyaline; paraphyses none. 
 
 D. ditopa (Fr.) Schr. causes death of oak twigs in Europe; 
 
 D. fusarispora d. Not., occurs on alder in Europe. 
 
 Glomerella Spaulding & von Schrenk -«-• ^'~ (p. 263) 
 
 Perithecia cespitose, membranous, dark brown, rostrate, of a 
 lighter color at the apex in early stages, flask-shaped, hairy, on 
 or immersed in a stroma; asci sessile, clavate; spores 8, hyaline, 
 oblong, 1-celled, slightly curved, elliptic; paraphyses usually none. 
 Conidia=in part Colletotrichum and Gloeosporium. 
 
 This genus was first described by Stoneman, from perithecia 
 obtained from cultures of the conidia,"'^^ as Gnomoniopsis. On ac- 
 count of preoccupation it was renamed Glomerella by Spaulding and 
 von Schrenk -"^^ in 1903. Studies by Shear have shown that there 
 is much variation in pure line cultures both from ascospores and 
 from conidiospores.-^^ This leads to great uncertainty as to spe- 
 cific limitations as will become apparent in the paragraphs below. 
 The conidial forms are very common and are usually parasitic. 
 The ascigerous stages are comparatively rare. Sometimes they 
 are found in nature; again only in artificial culture. Some forms 
 known to be ascigerous may in one culture yield abundant peri- 
 thecia while other cultures of the same fungus may persistently 
 refuse to bear asci at all. 
 
 G. rufomaculans (Berk.) S. & S.^^O'-^^ 
 
 Perithecia on decaying fruits, subspherical, more or less grouped; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 265 
 
 asci subclavate, fugaceous, 55-70 fx; ascospores allantoic!, 12- 
 22 X 3-5 fi] conidial stage (=Gloeosporium rufomaculans) with 
 small sori, developing in more or less concentric circles, usually 
 soon rupturing and pushing out spores in small pinkish masses; 
 spores hyaline to greenish, 
 chiefly oblong, unicellular 10- 
 28 X 3.5-7 fx. 
 
 The conidial stage of this 
 fungus was first described by 
 .Rev. M. J. Berkeley in 1854 
 as a Septoria. It was later 
 transferred to the form genus 
 Glceosporium under which 
 
 name the literature pertaining Fig- 193.— ?. perithecium of G. rufomacu- 
 lans showing asci in situ; 6, asci show- 
 to it is largely to be found. ing detail. After Spaulding and von 
 
 See Southworth.2^0 The as- ^'^'^''^■ 
 
 cigerous stage was found by Clinton -""^ in 1902 and the fungus 
 described as a Gnomoniopsis. In 1903, it was given the present 
 name. A bibliography of some one hundred eighty titles is 
 given by Spaulding and von Schrenk.^^^ 
 
 The conidia germinating on apples send germ tubes through 
 the skin, usually through wounds, occasionally through a sound 
 surface. -'^^ The myceHum grows subepidermally, branching 
 rapidly, intercellularly and intracellularly, 
 absorbing the sugar and other nutrients 
 present, and resulting in brown discolora- 
 tion of cells and dissolution of their connec- 
 tion with neighboring cells. The mycelium 
 is first hyaline but later, especially in the 
 stromata, it ma}^ be quite dark. Acervuli 
 soon appear, often in concentric rings, lift- 
 
 FiG. 194. — G. cactorum. 
 Appressoria produced 
 by germinating spores. 
 
 After Spaulding and ing the epidermis with their palisades of 
 conidiophores. The latter, at first hyaline, 
 later olivaceous, bear the numerous conidia, which are pinkish, 
 rarely cream-colored, in mass. In germination the conidia be- 
 come uniseptate and often on the tips of the young mycelium 
 develop the dark thick-walled irregularly shaped spore-like struc- 
 tures, so common on the sporelings of the Melanconiales. These 
 
266 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 structures are regarded by Hasselbring -^- as organs of attachment 
 to aid in infection, though they doubtless serve other purposes as 
 well. 
 
 Perithecia of this species were first obtained by Clinton ^^^ who 
 grew them in abundance on artificial media from sowings of coni- 
 diospores taken from pure cultures. The typical Gloeosporium 
 stage was also grown from ascospores. 
 
 Perithecia were also found in pure cultures on apple agar by 
 Spaulding and von Schrenk. They appeared in black knotted 
 masses of mycelium which were often 4-5 mm. in diameter, the 
 perithecia varying from one to many in each such stroma. The 
 asci were evanescent, disappearing soon after the spores matured. 
 
 That this fungus is the cause of a limb canker was suggested by 
 Simpson's discovery of the canker in July, 1902 and was definitely 
 
 proved by Spaulding 
 and von Schrenck,-''^ 
 and by Burrill and 
 Blair ^^^ in the same 
 year. 
 
 In canker forma- 
 tion the mycelium 
 grows in the live 
 bark, killing it and 
 the cambium. The 
 cankers are thought 
 to be comparatively 
 short lived, perhaps 
 surviving only the 
 third year. Reciprocal inoculations between fruit and twigs 
 have proved the fungus in the two cases to be identical. Conidia 
 and ascospores develop on both fruit and twigs. 
 
 The fungus has been repeatedly grown in pure culture on numer- 
 ous media by many investigators and many inoculations with 
 conidia into both fruit and twigs have proved the causal relation 
 of the fungus to the apple rot and twig canker. Inoculations from 
 ascosporic material have given the same results. 
 
 That the spores may be insect-borne was shown by Clinton; -''^ 
 that they may also travel on the wind was shown by Burrill.-''^ 
 
 Fig. 195. — G. rufomaculans, 
 Note septa and appressoria. 
 von Schrenk. 
 
 germinating conidia. 
 After Spaulding and 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 267 
 
 The mycelium hibernates in hmb cankers and in mummified 
 fruit.-^^ 
 
 It is impossible morphologically to distinguish the conidial 
 stages of many species of Gloeosporium and Colletotrichum grow- 
 ing on a great variety of hosts, and much inoculation work has 
 been done to ascertain the relationships existing between these 
 many forms. Thus the author ^*^ in Dr. Halsted's laboratory 
 made inoculations as indicated in Fig. 367. Southworth cross 
 inoculated a Gloeosporium from 
 grape to apple and from apple 
 to grape; Stoneman from 
 quince to apple. -^'' Even such 
 cultures give little evidence of 
 difference between these forms 
 and it usually is impossible to 
 distinguish between the conidial 
 forms on either morphological 
 or biological grounds. 
 
 Some group under Glomeralla 
 rufomaculans as its conidial 
 forms, what were formerly 
 known as Gloeosporium fructi- 
 genum, G. rufomaculans, G. 
 versicolor and G. Iseticolor. 
 
 Further studies of the ascig- 
 erous stages have led to con- 
 solidation rather than to seg- 
 regation of species. Thus an 
 • ascigerous stage, a Glomer- 
 ella, was obtained in pure 
 culture from the following conidial forms by Shear and 
 Wood: 258 
 
 G. rufomaculans from grape, G. fructigenum from apple, G. 
 sps. from cranberry, G. elasticse from Ficus (see p. 544) a Gloeo- 
 sporium from Gleditschia, one from Ginkgo, Colletotrichum 
 gossypii from cotton (see p. 271) and C. lindemuthianum. (See 
 p. 547) from bean. These authors after careful study of these 
 perithecia and cultures conclude that: "in the present state of 
 
 Fig. 196. — Plate culture of G. rufomacu- 
 lans showing perithecia-bearing 
 masses. After Spaulding and von 
 Schrenk. 
 
268 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 our knowledge, it may be best to regard the various forms we 
 have studied as varieties of one species." 
 
 Among the hosts of G. rufomaculans may probably be num- 
 bered at least apple, grape, pear, quince, peach, tomato, egg- 
 plant, pepper, sweet pea ~^^ and cherry.-''^ 
 G. rufomaculans var. cyclaminis P. & C.^^^ 
 Perithecia densely gregarious, indefinite, light-colored, around 
 
 spots, brown, membranous, 
 subglobose or distinctly ros- 
 trate, ostiolate; asci clavate- 
 cylindric, apex pointed, 50- 
 65 X 8-9 /a; spores oblong 
 to elliptic, 16-18 x 4-4.5 fx. 
 C o n i d i a ( = Collet otri- 
 chum) ; acervuli amphi- 
 genous, brownish, large; 
 conidia oblong to linear, 
 obovate, straight, or shghtly 
 curved, ends round, 12-15 x 
 4-5 fi; conidiophores long, 
 slender; setae free, short, 
 rigid. 
 
 This variety is reported 
 on greenhouse Cyclamens, 
 causing leaf spotting. Ma- 
 ture perithecia were found 
 on the leaves. Cultures 
 from the ascospores gave a 
 Colletotrichum as the co- 
 nidial form and a similar Colletotrichum collected from the leaves 
 in pure culture gave the Glomerella. 
 G. cingulata (Atk.) S. & S. 
 
 Perithecia cespitose, stromate, dark-brown, flask-shaped, mem- 
 branous, 250-320 X 150 /jl, shortly rostrate, more or less hairy; 
 asci clavate, 64-16 ^i; spores hyaline, elliptic, slightly curved, 
 20-28 X 5-7 fji. 
 
 Conidia ( = Gloeosporium cingulatum); acervuli 100-150 n, 
 rupturing the epidermis, in age black; conidiophores numerous. 
 
 Fig. 197. — (j. rufomaculans. Pustules on 
 apple, enlarged. After Spaulding and von 
 Schrenk. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 269 
 
 crowded, simple, hyaline; conidia oblong to elliptic, straight or 
 curved, basally pointed, 10-20 x 5-7 jjl. 
 
 This was first described in conidial form as a Glceosporium by 
 Atkinson -^° on privet as cause of cankers. The fungus was isolated 
 and grown in pure culture. Later perithecia were obtained in 
 the pure cultures.-''^ 
 
 G. piperata (E. & E.) S. & S. 
 
 Perithecia cespitose, thinly membranous, dark-brown, pyriform, 
 hairy; asci clavate; spores slightly curved, elliptic, 12-18 x 4-6 ix. 
 
 Fig. 198. — Diagrammatic section through acervulus of G. rufomaculans. 
 a, parenchyma, h, cuticle, c, subhymenial fungous layer, d, conidiophores, 
 e, spores, 6, conidiophores and conidia in detail. After Clinton. 
 
 Conidia (= Glceosporium piperatum) on circular or oval spots; 
 acervuli pustular, concentrically arranged, conidia 12-23 x 5-6 ix.-^^ 
 
 The ascigerous stage was grown from pure cultures of the conidia 
 taken from pepper by Miss Stoneman ^^^ the perithecia appearing 
 about a month after inoculation. Typical conidia were also se- 
 cured from ascospore sowings. 
 
 G. cincta. (B. & C.) S. & S.--^ 
 
 Perithecia 180-280 p., flask-shaped, membranous, cespitose; 
 asci clavate, truncate or obtuse, 65-70 ii; spores elliptic, curved, 
 5-20 x 3 11.-^^ 
 
 Acervuli erumpent; conidia (=Colletotrichum cinctum) 12-15 x 
 
 >-«SH^ 
 
270 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 3-4 IX, elliptic, guttulate; setiE present, but almost obscured by 
 the spore mass. 
 
 The ascigerous stage was demonstrated by Stoneman ^^'^ from 
 pure culture studies. The conidial stage was described by Hal- 
 sted -^^ as the cause of a blighting of orchid leaves (Sobralia) in 
 New Jersey. 
 
 Various hosts are orchids, Sarracenia, rubber plant, Dracaena "^ 
 and Anthurium.^^^ 
 
 Fig. 199. — G. rufomaculans, acerv'ulus showing conidia, 
 conidiophores and setae. After Hasselbring. 
 
 G. rubicola (Ston.) S. & S. 
 
 Perithecia quite similar to those of G. piperata and G. cinta 
 but lacking the apical tuft of hair and rather larger in size. 
 
 Conidia ( = Colletotrichum rubicolum) forming large, dark- 
 brown patches on the upper surface of the leaf; sori small, dark, 
 suberumpent; conidia oblong, elliptic, 12.5 x 6 /z. 
 
 The conidial form on red raspberry was shown by Stoneman ^^' 
 by pure culture studies to possess this ascigerous stage. 
 
 G. psidii (Del.) Shel.^*'''-26^ 
 
 Perithecia 200-300 ix, spherical, rarely distinctly beaked; asci 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 271 
 
 cylindric to broadly elavate, blunt, 45-55 x 9-10 /x; spores 
 curved, continuous, granular, 13-15 x 5-6 n. 
 
 Conidia (=Gloeosporium psidii), acervuli subepidermal on defi- 
 nite spots, 90-120 ju; conidiophores hyaline, cylindric, 15-18 x 
 4-5 fi; conidia elliptic, oval, hyaline, 10-13 x 4-6 n. 
 
 Artificial culture studies by Sheldon ^^^' ^^"^ demonstrated the 
 ascigerous stage. Extensive study was made of the growth on 
 
 Fig. 200. — G. piperata, 99, perithecium external and in sec- 
 tion. 100, asci in detail. After Stoneman. 
 
 apple-agar, apples, plums, etc. Two distinct forms of conidia 
 were observed, one on loose hyphse, the other in acervuli. The 
 species should probably be regarded as a variety of G. rufo- 
 maculans. 
 
 It occurs on the guave. 
 
 G. gossypii (South.) Edg. 
 
 Perithecia distinct or crowded, very abundant, covered, dark 
 brown to black, subglobose to pyriform, 80-120 x 100-160 n, 
 beak up to 60 ^ long; asci numerous, elavate, 55-70 x 10-14 /x; 
 
272 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 spores elliptic, hyaline, rarely curved, 12-20 x 5-8 /x; paraphyses 
 long and slender, very abundant. 
 
 Conidia ( = Colletotrichum gossypii), acervuli erumpent, coni- 
 diophores colorless, longer than the spores, 12-28 x 5 n; conidia 
 irregularly oblong, hyaline or flesh-colored 
 in mass; setae single or tufted, dark at base, 
 colorless above, straight, rarely branched. 
 The conidial stage of this fungus was de- 
 scribed by Southworth ^^^' ^^^ and independ- 
 ently by Atkinson -^"' ^^^' ^^ on cotton. 
 
 The ascigerous stage was first seen by 
 Shear & Wood -^^ in artificial culture and by 
 them regarded as probably a variety of G. 
 rufomaculans. Since these studies Edger- 
 ton -^^ from examination of perithecia de- 
 veloped naturally in the open, has proposed 
 it as a separate species. 
 
 The mycelium is richly branched and sep- 
 tate, usually hyaline but sometimes slightly 
 Fig 201.— G. gossypii. ^moky. It grows between and in the host 
 Section of young "boll, cells which are often filled with it, causing 
 
 showing the fungus r i i in 11 
 
 penetrating the hull collapse, loss 01 chlorophyll, and brownmg. 
 young "^seed/ "^ Spores Studies by Atkinson and by Barre ^^^ show 
 are being produced ^hat in case of diseased bolls the mycelium 
 
 upon the outer por- ^ "^ 
 
 tion of the hull and may extend through the pericarp, sporing on 
 
 upon the surface of ., . ,, , i ,1 , ,1 i 
 
 the young seed coat, its inner Wall; extend thence to the seeds; 
 
 After Barre. penetrate and grow in them, Fig. 201, and in 
 
 the cells of the lint. Barre has shown that even the endosperm 
 and cotyledons may be invaded, Fig. 201, and spores produced 
 upon them while within the seed coats. Such seeds and lint may 
 appear outwardly as though perfectly normal. 
 
 The conidia are formed in acervuli, subtended by stromata. 
 Setae, from few to many increasing with age of the acervulus, 
 are present and conidia are occasionally found on them. In ger- 
 mination conidia usually develop one, sometimes two septa and 
 produce dark chlamydospores. Acervuli are common on bolls, 
 less so and smaller on leaves and stems. 
 
 The perithecia as found in the field by Edgerton in Louisiana 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 273 
 
 were usually entirely embedded, with the beaks only protruding 
 and were often numerous and crowded. Cultural evidence that 
 Edgerton's specimens were actually genetically connected with 
 the cotton anthracnose are wanting. 
 
 The fungus has been repeatedly studied in pure culture and 
 numerous inoculations have thoroughly proved its pathogenicity, 
 the disease usually showing within 
 a few days after inoculation, though 
 sometimes incubation is delayed 
 much longer. 
 
 Infection of stems is often at a 
 wound such as a leaf scar; or on 
 leaves at some point of weakness. 
 Cotyledons and young plants are 
 especially susceptible. On bolls 
 infection is common at the line 
 of dehiscence of the carpels. Ac- 
 cording to Barre, tRere is evidence 
 that the fungus may destroy the contents of the boll before 
 it shows upon the outside. Barre showed that 44% of flowers 
 that received spores within ten hours after opening produced dis- 
 eased bolls; but inoculations by spraying produced no results on 
 bolls after they were three-fourths grown. 
 
 Seed from a field that bore 35% infected bolls gave on germina- 
 tion, 12% of infected seedlings, the disease appearing upon cotyle- 
 dons or hypocotyls even before they unfolded. Atkinson ^"° found 
 that conidia five months old were alive, but that at seven months 
 they failed to germinate. Barre also found the conidia and the 
 mycelium of the fungus to be comparatively short lived. 
 
 G. atrocarpi Del. on Atrocarpus leaves has been described as 
 a perfect stage of Gloeosporium atrocarpi Del. 
 
 A fungus on Cattleya ^''^' -^- described by Maublanc & Lasnier 
 as a Physalospora should perhaps be considered as a Glomerella. 
 
 Fig. 202. — G. gossypii, D, and E, fun- 
 gus gro-.v-ing in cotton lint fibers. 
 After Barre. 
 
 Gnomoniella Saccardo (p. 263) 
 
 Perithecia sunken and usually remaining so, with a long cylin- 
 dric, erumpent ostiole, leathery, black; asci ellipsoid or fusoid. 
 
274 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 apically thickened and opening by a pore; 
 spore elliptic, 1-celled, hyaline; paraphyses 
 none. 
 
 This genus of some twenty-five species 
 contains G. tubiformis (Tode) Sacc. which 
 Fig. 203.— g. tubifor- jg g^^j^^ ^q j^g ^j^g ascigerous stage of Lepto- 
 
 mis, pentnecia. After ° , ° ^ 
 
 thyrium alneum Sacc. growing on Alder. 
 G. fimbriata and G. coryli are found on 
 
 Winter 
 
 Two other species, 
 
 hornbeam and hazel respectively. 
 
 Gnomonia Cesati & de Notaris (p. 264) 
 
 Perithecia covered, or erumpent, submembranous, glabrous, 
 ostiole more or less elongate; asci ellipsoid or fusoid, apically thick- 
 ened, opening by a pore; spores elongate, hyaline, 2 to 4-celled; 
 paraphyses none. 
 
 There are some sixty species. Fusicoccum, Myxosporium, Sporo- 
 nema, Gloeosporium, Marssonia, Asteroma, Leptothyrium occur in 
 some species as the conidial form. The ascigerous form usually 
 follows as a saprophyte after the parasitic conidial stage. 
 
 G. veneta (Sacc. & Speg.) Kleb.^^^. 222. 323. 335 
 
 Perithecia immersed, subglobose or slightly flattened, 150- 
 200 n, short, rostrate; asci long-clavate, 48-60 x 12-15 n, gen- 
 erally bent at right angles at the base, apically very thick, opening 
 by a pore; spores 14-19 x 4-5, straight 
 or slightly curved, unequally 2-celled, 
 the upper cell longer. 
 
 Conidia variable in habitat, and 
 habit. (1) ( = Gloeosporium nervise- 
 quum) acervuli subcuticular 100- 
 300 ix; conidiophores short, conidia 
 oozing out in a creamy-white mass, 
 hyaline, elhpsoid, 10-14 x 4-6 ix, 
 pointed at one end and rounded at the 
 other. (2) ( =G. platani) acervuU sub- 
 epidermal, conidiophores long; conidia 
 as above. (3) ( =Discula platani = Myxosporium valsoideum) form- 
 ing minute, subepidermal, erumpent pustules on twigs; conidia 
 elliptic to oblong, hyaline, 8-14 x 4-6 ju; (4) ( =Sporonema platani 
 
 ■G. veneta, perithe- 
 After Edgerton. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 275 
 
 = Fuscicoccum veroncnse). Pycnidia formed on old leaves on 
 the ground, crumpent, subcuticular, brown, 200-300 jn; conidia 
 numerous, oblong, ovoid to fusoid, 7-11 x 3-4 /j,. 
 
 The conidial form on sycamore and oak, first described in 1848, 
 is common on leaves and young branches, the mycelium checking 
 the sap-flow and causing death of surround- 
 ing tissue. A stroma is formed on the outer 
 layers of the mesophyll and from this arise 
 the short conidiophores to constitute the 
 acervulus. 
 
 Infection experiments by Tavel ~'^^ gave 
 negative results. Other infection experiments 
 have also been unsatisfactory. 
 
 The ascigerous form was first found by 
 Klebahn274 on old leaves on which it ma- -^'anf sp^r?s.'^ a£ Ed- 
 tured about Christmas time. While the co- gertou. 
 nidia are uniform in shape four modes of development are found, 
 as stated above. 
 
 Pure cultures from all the spore forms were compared by Edger- 
 ton ^-- confirming Klcbahn's conclusion as to their identity. Cul- 
 tures by Stoneman ^^^ showed the forms on sycamore and oak to 
 be the same. 
 
 G. leptostyla (Fr.) Ces. & d. Not. 
 
 Perithecia conic, short-beaked; asci subclavate, 45-65 x 10-12 
 jj,; spores fusoid, curved, 18-22 x 4 /i, hyaline. Conidial phase 
 (=Marssonia juglandis). Acervuli gregarious, hypophyllous, 
 rounded; conidia obovoid, 8-10 x 4-5 n, 1-septate, pointed 
 above, truncate below, greenish. 
 
 The connection between the conidial and ascigerous forms was 
 demonstrated by Klebahn -^" by pure cultures and by ascosporic 
 infection. The conidial form is common on walnut leaves; espe- 
 cially severe on the butter-nut (Juglans cinerea) often defoliating 
 this host in mid-summer. 
 
 G. quercus-ilicis Berl. occurs on oak leaves in Italy. 
 
 G. erythrostoma Auer. is the cause of a disease of cherry leaves 
 in Europe; ^''^' ^^^ 
 
 G. padicola Kleb. is the ascigerous stage of Asteroma padi 
 which is widely distributed in Europe on Prunus. 
 
276 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 G. oryzae Miy. occurs on rice.-"^ 
 
 G. rubi Rehm may occasionally cause disease of blackberry 
 canes. "^^ 
 
 Rehmiellopsis Bubak & Kabat (p. 264) 
 
 Similar to Rehmiella except that the perithecia are not beaked 
 and the pycnidia do not have a definite opening. 
 
 R. bohemica Bub. & Kab.; (conidia=Phoma bohemica)^^^ oc- 
 curs as a parasite on fir needles. 
 
 Clypeosphaeriaceae (p. 223) 
 
 Perithecia immersed, astromatic or with a pseudostroma built 
 of hyphse which, with the adjacent substratum, forms a thin cly- 
 peus that is usually evident only above; ostiole short to long- 
 beaked, erumpent, walls mostly carbonous to membranous; 
 paraphyses usually present. 
 
 A small family chiefly saprophytes. 
 
 Key to Genera of Clypeosphaeriaceae 
 
 Spores 1 -celled 
 Perithecia soft-membranous, spores hya- 
 line or brown 1. Trabutia. 
 
 Perithecia leathery; spores brown 2. Anthostomella, p. 276. 
 
 Spores more than one-celled 
 Spores with cross walls only 
 
 Spores cylindric, ellipsoid or fusiform 
 
 Spores hyaline, 1 to 3-septate 3. Hypospila. 
 
 Spores brown 
 
 Spores elongate 4. Clypeosphaeria. 
 
 Spores fusiform, more than 4- 
 
 septate, sometimes muriform . 5. Phaeopeltosphaeria. 
 
 Spores filiform, hyaline to yellow 6. Linospora. 
 
 Spores muriform 
 
 Spores ovate, brown 7. Peltosphaeria. 
 
 Spores short, fusiform, hyaline 8. Isothea. 
 
 Anthostomella Saccardo 
 
 Mycelium fusing with the upper surface of the substratum to 
 form a thin, black, rounded pseudostroma; perithecia sunken, sub- 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 277 
 
 globose, with a short, conical ostiole, walls 
 black, carbonous to leathery; asci cylindric, 
 8-spored; spores elliptic, continuous, brown, 
 unappendaged ; paraphyses usually present. 
 
 Over one hundred species, chiefly sapro- 
 phytes. 
 
 A. sullas Montem, occurs as the cause of a 
 leaf spot on sulla.-^^ Fig. 206.— a. des- 
 
 A. bohiensis (Hmp.) Speg. is on cacao; ^eiumT'^, t^us'w', 
 
 A. destruens Sh. on cranberry; spores; n, germi- 
 
 ■^ ' Dating spore. After 
 
 A. coffeae Desm, on coffee. ^^^' ~^^ 
 
 Shear. 
 
 Valsaceae (p. 223) 
 
 Stroma effused, subglobose, conic, or pulvinate, often indefinite; 
 perithecia sunken in the stroma, scattered or clustered, black, 
 leathery; asci cylindric or clavate; paraphyses usually present. 
 
 Over one thousand species, chiefly saprophytic. Conidia are 
 present on hypha; or in pycnidia. 
 
 Key to Genera of Valsaceae 
 Spores 1-celled 
 
 Spores cylindric or ellipsoid, with a brown 
 
 membrane 1. Anthostoma. 
 
 Spores ellipsoid, curved or not, with a 
 
 hyaline membrane. . . .• 2. Valsa, p. 278. 
 
 Spores more than I-celled 
 Spores with cross walls only 
 Spores hyaline 
 
 Spores unappendaged 
 
 Spores ellipsoid or fusoid 2 to 4- 
 
 celled 3. Diaporthe, p. 278. 
 
 Spores elongate, fusoid, constricted 
 
 in the middle 4. Vialaea. 
 
 Spores appendagcd, 1 appendage at 
 each end and 2 or 3 in the mid- 
 dle 5. Caudospora. 
 
 Spores brown 
 
 Spores 2-celled, ellipsoid 6. Rhynchostoma. 
 
 Spores many-celled, fusoid 7. Kalmusia. 
 
278 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Spores muriform 
 Stroma effused 
 
 Spores hyaline 8. Thyridella. 
 
 Spores colored 9. Thyridium. 
 
 Stroma none or pulvinate 10. Fenestella. 
 
 Valsa Fries (p. 277) 
 
 Perithecia on a more or less definite stroma, immersed, the 
 ostiole enimpent, black, firm; asci globose to cylijidrie, often 
 
 long-pedunculate ; spores 
 
 ^^^ -r-^^f^^^^^^, ^e'^^^qh 1-celled, rarely 2-celled, 
 
 lr\^? ^*4l)l r^&te M^'3 cylindric, rounded, hya- 
 
 r * « t. ,y*rfW \/a^3*^ \'j Wrap'- V r i- i,j. u 
 
 k *^»**v .IP|^^ mjf \^)J^^l ^io^ ^1^6 or light-brown; pa- 
 
 mf 1^*^, J iVs^JC^"' €"? li^ r- '/ c^ raphyses none. 
 
 ^l*S"s .lUI^C^^J B V. leucostoma (Pers.) 
 
 ^^"^r^^I!!!r^"^"^=^ 22, 229, 280 
 
 Fig. 207.— Valsa. A, habit sketch; B, perithecia; Stroma strongly COn- 
 C.asci. After Tulasne. ^^^^ 2-3 mm., whitish 
 
 and granular within, outer layer coriaceous; perithecia immersed; 
 asci fusoid-clavate, subsessile, 35-45 x 7-8 m; spores biseriate, 
 allantoid, hyaline, slightly curved, 9-12 x 2-2.5 /x. 
 
 Conidia ( = Cytospora rubescens); stromate, erumpent, reddish; 
 conidia allantoid, 4 fx. On pome and stone fruits throughout 
 Europe, Australia and America causing the disease known as 
 " dieback." The fungus was studied by Rolfs "^^' ^^^ who worked 
 out its life cycle. 
 
 V. oxystoma Rehm. occurs on Alnus in Europe; 
 
 V. (Eutypa) caulivora Rehm. affects Hevea. 
 
 V. ambiens Fr. is on the apple in Europe. 
 
 V. (Eutypella) prunastri (Pers.) Fr. is the cause of serious dis- 
 eases of apples, plums, etc., in England. 
 
 V. (Eutypa) erumpens Mas. is reported as a wound parasite 
 in the tropics on Ficus, and cacao. 
 
 Diaporthe Nitschke (p. 277) 
 
 Stroma very variable, usually definite; perithecia membranous 
 subcoriaceous, generally pale-cinereous within, with a cylindric 
 or filiform beak; asci fusoid; spores fusoid to subelliptic, 2-celled, 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 279 
 
 hyaline, appendaged or not; pa- 
 raphyses none. Conidia=Phoma, 
 Cytospora, etc. 
 
 D. taleola (Fr.) Sacc. 
 
 Stroma cortical, definite, de- 
 pressed, pulvinate, 2-4 mm., cov- 
 ered; perithecia few, 4-10, buried, 
 their ostioles converging, erumpent 
 in a small light-colored disk; asci 
 cylindric, 120-140 x 10-12 ix, spores 
 elliptic, uniseptate, constricted, with 
 setaceous appendages, 15-22 x 
 8-9 II. 
 
 It causes canker on oak, killing 
 the cortex over large areas. A 
 year later the cushion-like stromata 
 appear. The mycelium penetrates 
 both wood and bark, probably enter- 
 ing through wounds. 
 
 D. albocarnis E. & E. on Cornus is destructive. 
 
 D. ambigua and D. sarmentella are on pear and hop, D. stru- 
 mella on a wide range of hosts, in conidial form as Phoma. 
 
 Fig. 208. — Diaporthe. 
 in section; C, asci. 
 lasne. 
 
 o 
 
 B, stroma, 
 After Tu- 
 
 Melanconidaceae (p. 223) 
 
 A small family of less than two hundred species contains only 
 four parasitic genera. 
 
 Stroma pulvinate, sunken; perithecia sunken in the stroma, 
 the mouth erumpent; asci cylindric or clavate; paraphyses present. 
 
 Key to the Genera of Melanconidaceae 
 
 Spores 1-celled, hyaline 
 
 Spores ellipsoid or short-fusiform 1. Cryptosporella, p. 280. 
 
 Spores elongate-cylindric, curved 2. Cryptospora. 
 
 Spores 2-celled 
 Spores hyaline 
 
 Conidiainpycnidia; 1-celIed, hyaline. . 3. Valsaria. 
 Conidia not in pycnidia, dark brown. . 4. Melanconis, p. 281. 
 Spores brown 5. Melanconiella. 
 
 'N. 
 
280 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Spores more than 2-celled 
 Spores hyaline 
 
 Spores elongate, multicellular 6. Calospora, p. 280. 
 
 Spores fusiform, multicellular 7. Holstiella. 
 
 Spores brown 
 
 Spores elongate, multicellular; asci 
 
 8 or 4-spored 8. Pseudovalsa, p. 281. 
 
 Spores long-cylindric, very large, asci 
 
 1-spored 9. Titania. 
 
 Calospora Saccardo 
 
 One species, C. vanillae Mas., reported as causing a Vanilla 
 trouble,'^^^ is perhaps identical with Gloeosporium vanillae C. & M. 
 
 ^>^vi,w^j^'^ 
 
 Cryptosporella Tulasne (p. 279) 
 
 Stroma valsoid, pustuHform, covered; perithecia embedded, 
 subcircinate, with converging necks united in an erumpent disk; 
 
 asci cylindric to globoid; spores 
 elongate, cylindric, hyaline, 1-celled. 
 C. anomala (Pk.) Sacc.-^«' -^' 
 Pustules prominent, 2-5 mm., 
 erumpent; penetrating the wood 
 and generally having a thin black 
 crust beneath them, disk convex or 
 slightly depressed, cinereous to black ; 
 perithecia crowded, deeply em- 
 bedded in the stroma, often elon- 
 gate, ostioles scattered, black; asci 
 short, broad, fugaceous; spores hya- 
 line, elliptic, simple, 7-8 /x. 
 
 Common on hazel and filbert in 
 America, causing the destruction of the tops while the roots re- 
 main alive. 
 
 C. viticola Sh.^^^ 
 
 Pycnidia (=Fusicoccum) with labyrinthiform chambers, ostiolate 
 but frequently rupturing. Spores hyaline, continuous, of two forms 
 in the same cavity. 1. Subfusoid, 7.5 x 2-5 ju- 2. Long, slender, 
 curved, 18-30 x 1-1.5 /i. Perithecia buried in irregular pulvinate 
 
 Fig. 209. — C. anomala. 31, stroma 
 and perithecia; 32, an ascus; 33, 
 spores. After Humphrey. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 281 
 
 stromata, beak exserted; asci 60-72 x 7-8 ^l^, paraphyses slender, 
 septate, wavy; ascospores subelliptic, hyaline, continuous, 11-15 x 
 4-6 /x. Fig. 210. 
 
 The conidial stage was described by Reddick as the cause of 
 necrosis of grape vines ^^^ though he has since stated that the 
 amount of damage due to this disease is not so great as at first 
 thought. 
 
 The ascigerous form in pure culture in the hands of Shear ^-'^ 
 gave rise to the typical conidial form, identical with that grown 
 from pure cultures of the pycnospores. 
 
 Melanconis Tulasne (p. 279) 
 
 Stroma valsoid, seated in the substratum, partially erumpent; 
 perithecia clavate, immersed, with long cylindric beak; asci cylin- 
 dric, long-clavate, 8-spored; spores ellipsoid to elongate, hyaline. 
 
 About twenty species; chiefly saprophytes. 
 
 M. modonia Tul. in its conidial form (=Fusicoccum pernicio- 
 sum) causes a serious disease of the chestnut in Europe,^^^' ^^^ 
 
 Pseudovalsa longipes (Tul.) Sacc. is parasitic on oak. 
 
 Diatrypaceae (p. 223) 
 
 Stroma effused or pulvinate, built of thick hyphse, under the 
 peridium, at length erumpent, bearing both asci and conidia or 
 present only with the conidia; perithecia sunken in the stroma or 
 superficial, ostiolate; asci usually thickened apically; 4 to 8 or 
 many-spored; spores usually continuous, small, cylindric, curved. 
 
 About one hundred seventy-five species. 
 
 One parasitic genus occurs on cherry and plum. 
 
 Key to Tribes and Genera of Diatrypaceae 
 
 Stroma absent from ascosporic stage I. Calosphaerieae. 
 
 Asci 8 (rarely 4)-spored 
 
 Spores l-celled 1. Calosphaeria, p. 282. 
 
 Spores 2-celled 2. Cacosphaeria. 
 
 Asci many-spored 3. Coronophora. 
 
 Stroma present in the ascosporic stage II. Diatrypeae. 
 
282 
 
 THE P^UNGI WHICH CAUSE PLANT DISEASE 
 
 Calosphaeria. Tulasne (p. 281) 
 
 Perithecia astromate, free or on the inner bark, scattered or 
 clustered, ostiole more or less elongate; asci clavate, fasciculate; 
 spores small, cylindric, curved, hyaline, continuous; paraphyses 
 longer than the asci, stout lanceolate, evanescent. 
 
 About thirty-five species chiefly saprophytes. 
 
 C. princeps Tul. 
 
 Perithecia on the inner bark in orbicular or elliptic groups, gen- 
 erally densely crowded, globose, smooth and shining, necks long, 
 
 Fig. 210.— Crypto- 
 sporella viticola. 
 Asci and pa- 
 raphyses. After 
 Shear. 
 
 1.0' 
 
 Fig. 211. — Calosphajria princeps. A, group of 
 perithecia; B, conidial stroma. After Tu- 
 lasne. 
 
 decumbent, flexuose, cylindric, erumpent; asci 12-26 x 4 /z, 
 spores 5-6 x 1-5 ^i. 
 
 On plum, cherry, peach and even pomaceous trees. 
 
 Melogrammataceae (p. 223) 
 
 Stroma usually pulvinate, rarely effused, hemispheric, sub- 
 peridial then erumpent and more or less superficial; perithecia 
 sunken in the stroma; conidia occur in acervuli on the surface of 
 the young stromata, or in pycnidia. 
 
 A small family of about one hundred twenty-five species, only 
 one genus of which contains important pathogens. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 283 
 
 Key to Genera of Melogrammataceae 
 
 Spores l-celled 
 
 Spores roundish ellipsoid, asci long fusi- 
 form 1. Gibelia. 
 
 Spores ellipsoid or ovate, asci clavate. ... 2. Botryosphaeria, p. 283. 
 Spores 2 or more-celled 
 
 Spores with cross walls only 
 Spores 2-celled 
 Spores hyaline 
 
 Paraphyses present 3. Endothia. 
 
 Paraphyses absent 4. Myrmaeciella. 
 
 Spores brown 5. Myrmaecium. 
 
 Spores more than 2-celled, ellipsoid to 
 filiform 
 
 Spores hyaline many-celled 6. Sillia. 
 
 Spores hyaline 3-celled 7. Melanops, p. 284. 
 
 Spores brown 8. Melogramma, p. 284. 
 
 Spores muriform 9. Berlesiella. 
 
 Botryosphaeria Cesati & de Notaris 
 
 Stroma pulvinate, black; perithecia at first sunken in the stroma, 
 remaining so or becoming 
 more or less prominent, 
 usually small, globose, os- 
 tiole inconspicuous, papilli- 
 form; asci clavate; spores 
 elliptic to oval, hyaline, 
 continuous; paraphyses 
 present. 
 
 B. ribis G. &. Dug.-^s 
 
 Stromata black, more or 
 less pulvinate, outer sur- 
 face botryose, 1-4 mm. in 
 diameter, usually 2-3 mm., 
 and surrounded by the 
 fissured periderm, regularly scattered or in more or less definite, 
 longitudinal rows or elongated stromata. Perithecia somewhat 
 
 Fig. 212. — Botryosphferia. B, stroma 
 
 tion; C, part of perithecium and pycnidium 
 in section. After Tulasne. 
 
 sec- 
 
284 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 top-shaped, with papillate ostioles and usually projecting, some- 
 times practically superficial. Few to many in a stroma and usually 
 interspersed among pycnidia; 175-250 n in width. Asci clavate, 
 80-120 X 17-20 fx, and with numerous filiform paraphyses. 
 Spores fusoid, continuous, hyaline, 16-23 x 5-7 /x. 
 
 Pycnidia of the compound stylospbric form, Dothiorella, are borne 
 m the same or similar stromata; spores fusoid, continuous, hyaline, 
 18-31 X 4.5-8 ix. Pycnidia of the simple stylosporic form, Macro- 
 phoma, are embedded in the outer bark under the much-raised 
 primary cortex of young shoots, depressed globular, 175-250 mm. 
 wide; spores fusoid, hyaline, continuous, 16-25 x 4.5-7.5 ju. 
 
 The cause of a blight of canes of currants. 
 
 The fungus was first noted in sterile form by Fairchild."^^ Its 
 history was first fully worked out by Grossenbacher & Duggar.-^^ 
 Extensive inoculation experiments and pure culture studies de- 
 finitely established its pathogenicity. 
 
 B. dothidae Ces. & d. Not. causes epidemics of disease among 
 cultivated roses. 
 
 B. gregaria Sacc. is injurious on willows in Europe.^^^ 
 
 Melanops Fuckel (p. 283) 
 
 Stroma lens-shaped, black; perithecia sunken; asci elongate, 
 8-spored; spores elongate, 3-celled, hyaline; paraphyses elongate, 
 brown. 
 
 According to Shear, ^^^ the conidial stage of some members of 
 this genus is a Sphseropsis which is indistinguishable from S. vitic- 
 ola and S. malorum. 
 
 Melogramma henriquetii Br. & Cav. is parasitic on cork oak. 
 
 Xylariaceae (p. 224) 
 
 Stroma variable, usually free but often more or less sunken in 
 the matrix, either upright and often branched or horizontal, ef- 
 fused, crustaceous, pulvinate, globose or hemispheric, black or 
 becoming black, usually woody or carbonous; perithecia periph- 
 eral, immersed, leathery or carbonous, black; asci cylindric or 
 cylindric-clavate, 8-spored; spores continuous, brown or black, 
 fusiform or ellipsoid, paraphyses present or absent. 
 
 A family of over five hundred species. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 285 
 
 Key to Genera of Xylariaceae 
 
 Stroma encrusted, shield-form, globose or 
 
 hemispheric, without a sterile base. ... I. Hypoxyleae. 
 Conidial laj'er beneath the surface of the 
 
 stroma, erumpent 1. Nummularia, p. 285. 
 
 Conidial layer free from the first 
 Stroma encrusted 
 
 Spores 1-celled 2. Bolinia. 
 
 Spores 2-celled 3. Camarops. 
 
 Stroma discoid to hemispheric, en- 
 crusted together 
 Young stroma fleshy, covered by 
 
 conidia, at length carbonous. . . 4. Ustulina, p. 286. 
 Stroma carbonous or woody from the 
 first 
 Stroma without concentric layers. 5. Hypoxylon. 
 Stroma with concentric layers ... . 6. Daldinia. 
 Stroma erect, simple or branched, clavate or 
 
 cylindric, with a sterile base II. Xylarieae. 
 
 Most of these genera are saprophytic on wood or bark. 
 
 Nummularia Tulasne 
 
 Stroma orbicular, cupulate or discoid, becoming black, mar- 
 ginate; perithecia monostichous, peripheral, immersed; asci cy- 
 lindric; spores subelliptic, continuous, dark. 
 
 The genus contains forty species. Only one is recorded as 
 injurious. 
 
 N. discreta (Schw.) Tul. 
 
 Stroma erumpent, orbicular, 2-4 mm., cupulate, with a thick 
 raised margin; ovate, cylindric, nearly 1 mm. long, abruptly con- 
 tracted above into a short neck; asci 110-120 x 10-12 /x] spores 
 subglobose, nearly hyaline, then opaque, 10-12 /x; paraphyses 
 filiform. 
 
 This fungus is usually a saprophyte but has been reported by 
 Hasselbring as a serious parasite on the apple in Illinois. -^^ 
 
 The mycelium grows more rapidly in the wood than in the bark, 
 
286 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 attacking first the parenchyma cells and medullary rays. The 
 young stromata appear under the bark bearing when young small 
 unicellular conidia. The stromata later turn hard and black and 
 
 D 
 
 Figs. 213-214. — N. discreta, B, stroma and perithecia, C, a 
 perithecium, D. asci and spores. After Hasselbring. 
 
 in the upper layers bear numerous flask-shaped perithecia with 
 long necks, Figs. 213-214. 
 
 Ustulina Tulasne (p. 285) 
 
 Stroma superficial, subeffuse, rather thick, determinate, at first 
 clothed with a pulverulent cinereous conidial hymenium, finally 
 rigid, carbonous, black, bare and generally more or less hollow; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 287 
 
 perithecia immersed, large, papillate-ostiolate; asci pedicellate, 
 8-spored; spores ovoid-fusiform; paraphyses present. 
 
 A genus of about ten species, chiefly saprophytes. 
 
 U. zonata Lev. is the cause of the commonest root disease of 
 tea and is common also on Hevea. 
 
BIBLIOGRAPHY OF ASCOMYCETES* 
 
 1 Harper, R. A., Ann. Bot. U: 321, 1900. 
 
 2 Clausen, P., Bot. Zeit. 63: 1905. 
 
 3 Harper, R. A., Carnegie Inst. Pub., Oct. 1905. 
 ' Roze, E., C. R. Acad. Sc. Paris, 125: 780. 
 
 5 Radais, M., Bot. Gaz. 28: 65, 1899. 
 
 " Peglion v., C. Bak. 7: 754, 1901. 
 
 ' Lewis, C. E., Me. B. 178: 1910. 
 
 8 Atkinson, G. F., N. Y. (Cornell) B. 73: 1894. 
 
 8 Sadebeck, Jalirb. Hamburg Wiss. Anst. 1: 1884, 8: 1890 and 10: 1891. 
 
 10 Giesenhagen, Flora, 81: 267, 1895. 
 
 11 Wilcox, E. M., Ala. B. 126: 1903. 
 
 12 Pierce, N. B., V. P. P. B. 20: 1900. 
 
 13 Knowles, E., Bot. Gaz. 12: 216. 
 1^ U. S. D. Agr. R. 1888. 
 
 1^ Stewart, F. C, N. Y. (Geneva) R. 1^: 532, 1895. 
 1" Sturgis, W. C. Ct. State Sta. R. 19: 183, 1895. 
 1- Durand, E. J., Ann. Myc. 6: 289, 1908. 
 
 IS Rostrup, E., Oversight over de i 1884, indolubene. Foresporgsler 
 angaaende Sydomme hos Kultur-planter. 
 
 19 Hartig, F. u Nat. Zeit. 591, 1892. 
 
 20 Humphrey, J. E., Bot. Gaz. 18: 85, 1893. 
 
 21 Smith, E. F., J. Myc. 5: 124, 1889. 
 
 22 Norton, J. B. S., Trans. Acad. Sc. St. L. 12: 91, 1902. 
 
 23 Whetzel, H. H., Lectures, m s. 
 
 2* Scott, W. M. & Ayres, T. W., B. P. L, B. 17 4. 
 25 Sorauer, P., Zeit. 9: 230, 1899. 
 
 2« Woronin, Mem. Acad. Imp. Sci. St. Petersburg 8: Phys. Math. CI. 
 1015, 1899. 
 
 27 Pollock, J. B., Mich. Acad. Sc. R. 11: 33, 1909. 
 
 28 Prillieux & Delacroix, B. S. M. d. Fr. 9: 196, 1893. 
 
 29 Istvanffi, G., Annal. d. Inst. Cent. Amp. Roy. Hongrois 3: 1905. 
 
 30 Ward, S. Marshall, Ann. Bot. 2: 319, 1888. 
 
 31 Salmon, E. S., R. Econ. Myc. 92, 1908, 1909. 
 
 * See footnote, p. 53. 
 288 
 
BIBLIOGRAPHY OF A8C0MYCETES 289 
 
 ="2 De Bary, Bot. Zeit. 1886. 
 
 '' Stevens, F. L., N. C. B. 217. 
 
 '" Stevens, F. L., & Hall, J. G., N. C. T. B. 8: 1911. 
 
 '5 Humphrey, J. E., Mass. R. 10: 212, 1892. 
 
 '« Clinton, G. P., Ct. R. 326, 1906. 
 
 " Smith, R. E., Bot. Gaz. 29: 369, 1900. 
 
 ^8 Stone, G. E. & Smith, R. E., Mass. B. 69: 1900. 
 
 '' Rankin, W. H., Sp. Crops N. S. No. 94: 352. 
 
 *" Westerdijk, J., Med. uh. Phytopath. Lab. W. C. Scholten, Amster- 
 dam, Maart, 1911. 
 
 " Oudemans, C. A. J. A. & Koning, C. J., Kon. Ak. Wetensch, Amster- 
 dam, 1903. 
 
 « Behrens, J., Zeit. 3: 88, 1893. 
 
 " Chester, F. D., Del. R. 3: 85, 1890. 
 
 *' Eriksson, J., Bot. Cent. 1: 296. 
 
 « Rehm, E., Ent. Kleearten, Pilze., 1872. 
 
 " Wakker, Bot. Cent. 29: 1887: 
 
 *'Hartig, R., Unt. forstbot. Inst. Munchen, 1: 1880. 
 
 *^ Anderson, A. P., Torr. Bull. 29: 23, 1902. 
 
 *^ Brunchorst, Nogle norske skovsygd. Bergens Mus. Aarsteretcn, 1892. 
 
 '° B. S. M. d. Fr. 8: 22, 1892. 
 
 " Combs, R., la. B. 36: 858, 1897. 
 
 " Chester, F. C, Del. R. 3: 81, 1890. 
 
 " Voges, E., Zeit. 21: 107, 1911. 
 
 5" MuUer-Thurgau, C. Bak. 10: 8, 1903. 
 
 " Dudley, W. R., N. Y. (Cornell) B. 15: 196, 1889. 
 
 " Stewart, F. C, N. Y. (Geneva) B. 199: 64, 1901. 
 
 " Klebahn, H., Zeit. 16: 65, 1906. 
 
 '^ Scribner, F. L., U. S. D. Ag. R. 357, 1888. 
 
 *' Atkinson, G. F., Sc. 30: 452, 1909. 
 
 •"Atkinson, G. F., Garden & Forest, 10: 73, 1897. 
 
 ^' Schwartz, Erkrank. Kiefern durch Cenangium ahidis; Jena, 1895. 
 
 "2 Ludwig, F., Cent. Bak. 2: 521, 1887 and 3: 633, 1888. 
 
 «3 Hennings, Zeit. 4: 266, 1894. 
 
 «4 Durand, E. J., Ann. Myc. 6: 463, 1908. 
 
 «5Brizi, U., Bull. Uffic. Minist. Agricol. Ind. e. Comm. 1903. 
 
 «« Tubeuf, Bot. Cent. 21: 1885; 61: 1895. 
 
 6' Tubeuf, Zeit. f. L. u. F. 408, 1910. 
 
 68 Eidam, Cohns Beitrage, 267, 1883. 
 
 6» Dale, E., Ann. Bot. 17: 571, 1903. 
 
 '0 Dale, E., Ann. Myc. 7: 215, 1909. 
 
290 THE P^UNGI WHICH CAUSE PLANT DISEASE 
 
 71 Fraser, H. C. & Chambers, C. H. S., Ann. Myc. 5: 423, 1907, 
 
 72Zopf, W., Zeit. i;72, 1891. 
 
 " Gilbert, W. W., B. P. I. B. 15S: 1909. 
 
 7* Clinton, G. P., Conn. State, R 15: 166, 1891. 
 
 "5 Bull. Inst. Bot. Buitenzorg 4; 19, 1890. 
 
 7« Holm, Th., B. P. I. B. 120. 
 
 " Halsted, B. D., N. J. R. 517, 526, 1903. 
 
 '8 Lawrence, W. H., Wash. B. 70. 
 
 79 Smith, Grant, Bot. Gaz. 29: 153, 1900. 
 
 80 Neger, F. W., Flora 90: 221, 1902. 
 
 81 Neger, F., Flora 88: 333, 1901. 
 
 82 Harper, R. A., Ber. d. deut. Bot. Gaz. 13: 475, 1895. 
 
 83 Harper, R. A., Jahr. f. wiss. Bot. 29: 656, 1896. 
 
 84 Harper, R. A., Carnegie Inst. Pub. 37: 1905. 
 
 85 Salmon, Ann. Myc. 2: 70, 1904. 
 
 8» Salmon, Bot. Cent. 1/+: 261, 1903. 
 
 87 Reed, Geo. M., Bui. Torrey Bot. Club. 3G: 353, 1909. 
 
 88 Arthur, J. C, N. Y. (Geneva) R. 5: 291, 1886. 
 
 89 Humphrey, J. E., Mass. State R. 10: 239, 1892. 
 
 90 Salmon, E., Zeit. 11: 76, 1901. 
 
 91 Salmon, E., Tr. Ag. Sc. 2: 327, 1907. 
 
 92 Bailey, L. H., N. Y. (Cornell) B. 74: 381, 1894. 
 
 93 Halsted, B. D., N. J. R. 13: 281, 1892. 
 
 94 Halsted, B. D., U. S. D. Ag. R. 376, 1887. 
 
 95 Mass. R. 10: 240, 1892. 
 
 99 Mass. R. 10: 252, (1892), 1893. 
 
 97 Halsted, B. D., N. J. R. U: 357, 1893. 
 
 98 Salmon, E., New Phytologist, 3: 109, 1904. 
 
 99 Reed, G. M., Univ. of Wis. B. 250, 1908. 
 
 100 Wolff, Beitr. zur Kennt d. Schm.— pilze. 1875. 
 
 101 Marchal, C. R. 135: 210, 1902. 
 
 102 Salmon, Beih. Bot. Cent. 1^: 261, 1903. 
 
 103 U. S. D. Ag. R. 105, 1886. 
 
 10" Galloway, B. T., Bot. Gaz. 20: 486, 1895. 
 
 105 Bioletti, Cal. B. 186: 1907. 
 
 106 Riv. d. vit. 655: 9. 
 
 107 Couderc, G., C. R. 116: 210, 1893. 
 
 108 Pammel, L. H., Iowa, B. 13: 921, 1891. 
 
 109 U. S. Dept. Agric. R. 352, 1888. 
 
 110 Salmon, E. S., Mon. Torr. CI. 9: 36, 1910. 
 
 111 Vanha, J., Zeit. U: 178, 1904. 
 
BIBLIOGRAPHY OF ASCOMYCETES 291 
 
 12 Eriksson, J., Bot. Cent. 26: 335, 1886. 
 
 " Fawcett, H. S., Fla. R. 40: 1909. 
 
 1^ Palla, Ber. d. deut. Bot. Ges. 17: 64, 1899. 
 
 15 Fallow, W. G., Bull. Buss. Inst., 40-1, 1876. 
 
 16 Swingle, W. T. & Webber, H. J., V. P. P. B. 8: 25, 896. 
 " Webber, H. J., V. P. P. B. 13: 1897. 
 '« Fawcett, H. S. & Rolfs P. H., Fla. B. 94. 
 19 Fawcett, H. S., Univ. of Fla. Spec. Studies 1: 1908. 
 2« Seaver, F. J., Mycologia 1: 41, 1909, 177. 
 21 Aderhold & Ruhland, Arb. a. d. Biol. Abt. f. Land. u. Forst am Kais. 
 
 Gesund. 4: 429, 1905. 
 
 '2 Idem, 2: 48, 1909-1910. 
 
 23 Berlese, A. N., Riv. d. Pat. Veg. 5: 88, 1897. 
 
 2" Boeuf, F., B. d. Dir. d. L'Ag. et d. Comm. Tunis, 27: 1903, also 1905. 
 
 » Paddock, W., N. Y. (Geneva) B. 163: 204, 1899. 
 
 ^» Durand, E. J., N. Y. (Cornell) B. 125: 1897. 
 
 " Grossenbacher, J. G., & Duggar, B. M., N. Y. (Geneva) T. B. 18: 
 1911. 
 
 28 Mayer, H., Unt. forst bot. Inst. Munchen 3: 1, 1883. 
 
 29 Halsted, B. D., N. J. R. 12: 281, 1891; and 359, 1894. 
 
 30 Massee, Kew Bui. Jan. and Feb., 1899. 
 
 31 Ihssen, G., C. Bak. 27: 48, May, 1910. 
 
 32 Smith, E. F., B. V. P. P. 17: 1899. 
 
 33 Higgins, B. B., Sc. 31: 916, 1910. 
 31 Higgins, B. B., N. C. R. 32: 100, 1910. 
 35 Butler, Mem. Dept. Agric. India, Bot. Ser. 2: 9, 1910. 
 3« Zimmermann, A., C. Bak. 8: 148. 
 
 37 Fetch, T., Circ. & Ag. Jour. Roy. Bot. Gard. Ceylon, Nov., 1910. 
 
 38 Selby, A. D. and Manns, T. F., Ohio B. 203. 
 
 39 Selby, A. D., Ohio B. 97: 40, 1898. 
 «Sorakin, N., Zeit. 1: 238, 1891. 
 
 11 Cavara, Zeit. 3: 16, 1893. 
 
 12 Noack, F., Zeit. 10: 327, 1900. 
 
 13 Fetch, T., Circ. & Ag. J. Roy. Bot. Gard. Ceylon, 8: 65, 1910. 
 11 Frank, Ber. deut. Bot. Ges. 1: 58, 1883. 
 
 5 Atkinson, G. F., J. Myc. 11: 248, 1905. 
 
 8 Miyake, Bot. Mag. Tokyo Ag. 1908. 
 
 7 Williams, T. A., S. D. B. 33: 38. 
 « Stager, R., Bot. Zeit. Ill, 1903. 
 
 19 Stevens, F. L., & Hall, J. G., Bot. Gaz. 50: 460, 1910. 
 5« Brefeld, 0., Untersuch. 12: 194. 
 
292 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 " Fulton, H. R., La. B. 105: 17, 1908. 
 " Patterson, F., and Charles, V. K., B. P. I. 171: 9, 1910. 
 " Lodeman, E. G., N. Y. (Cornell) B. 81: 1894. 
 5^ Farlow, W. G., Bui. Bussey Inst., 440, 1876. 
 " Beach, S. A., N. Y. (Geneva) B. 40: 25, 1894. 
 5« Humphrey, J. E., Mass. R. 8: 200, 1891. 
 " Garman, H., Ky. B. 80: 250, 1899. 
 *^ Schweinitz, Syn. Fung. Carol. Sap. 134. 
 59 Ruhland, W., C. Bak. 12: 250, 1904. 
 8« Cooke, M. C, Grevillea 13: 63. 
 " Clevenger, I. T., Jour. Myc. 11: 160, 1905. 
 
 «2 Hohnel, F. von, Sitz, K. Akad. Wis. Vienna Math. Nat. Kl. 118: 
 813. 
 
 " Shear, C. L., B. P. I. B. 110 and Torr. Bui. 84: 305. 
 
 " Wakker & Went. De Sietleen von het suikerriet op Java, 153: 1898. 
 
 «5 Massee, Ann. Bot. 7: 515, 1893. 
 
 66 Massee, Ann. Bot. 10: 583, 1896. 
 
 ^' Hartig, Hedw. 12: 1888; Allegm. Forst. u. Jagd,— Zeit. Jan. 1884. 
 
 "8 Tubeuf, Bot. Cent. 41: 1890. 
 
 89 Hartig, Hedw. 12: 1888. 
 
 ■0 Stewart, F. C. & Blodgett, F. H., N. Y. (Geneva) B. 167: 1899. 
 
 ^1 Pierce, N. B., V. P. P. B. 154: 1892. 
 
 ^2 Viala, Pourridie d. Vignes et d. Arbres fruitiers. 
 
 " Prillieux, C. R. 135: 275, 1902. 
 
 7^ Behrens, J., C. Bak. 3: 584, 1897. 
 
 " Whitson, E. P., Sandsten et al, Wis. R. 21: 237. 
 
 ^6 Schrenk, H. von, B. P. L B. 36: 1903. 
 
 " Hedgcock, R. Mo. Bot. Card. 17: 59, 1906. 
 
 ^« Heald, F. D. & Wolf, F. A., Mycologia 2: 205, 1910. 
 
 '9 Tubeuf, C. von, Zeit. 3: 142, 1893. 
 
 «o Vuillemin, Jour, de Bot. 1: 315, 1888; 2: 255, 1890. 
 
 ". Smith, R. E., Cal. B. 191: 1907. 
 
 «2 Viala & Ravaz, Prog. Agr. Et. Vit. 9: 490, 188. 
 
 «3 Viala & Ravaz, B. Soc. Myc. d. Fr. 8: 63, 1892. 
 
 «" Jaczewski, A. von, Zeit. 10: 257, 1900. 
 
 85 Scribner, F. L., U. S. Dept. Agric. R. 109, 1886. 
 
 «6 Rathay, E., Zeit. 306, 1891. 
 
 " Chester, F. D., Del. B. 6: 1889. 
 
 8« Shear, C. L., Miles, G. F., Hawkins, L. A., B. P. L B. 155: 1909. 
 
 89 Price, R. H., Texas B. 23: 1892. 
 
 9" Reddick, D., N. Y. (Cornell) B. 293: 1911. 
 
BIBLIOGRAPHY OF ASCOMYCETES 293 
 
 >" Prillieux, B., Soc. M. d. Fr. 4: 59, 1888. 
 ''^ Shear, C. L., B. P. I. B. 110: 15, 1907. 
 133 Prillieux & Delacroix, C. R. 130: 298, 1900. 
 "^ Shear, C. L., Bui. Torr. Bot. Club, 3^: 305, 1907. 
 "'^ Shear, C. L., Bui. B. P. I. B. 110. 
 "8 Bernard, Ch., Bui. Depot Agric. Ind. Neerland 6: 1907. 
 1" Seribner, U. S. Dept. Agr. R. 334, 1887. 
 "« Dudley, W. R., N. Y. (Cornell) B. U: 1889. 
 i^^Pammel, L. H., la. B. 13: 70, 1891. 
 
 2™ Stewart, F. C. & Eustace, H. J., N. Y. (Geneva) B. 226: 356, 
 1902. 
 
 201 Aderhold, Ber. d. deut. Bot. Ges. 18: 242, 1900. 
 
 202 Klebahn, H., Zeit. 18: 5, 1908. 
 
 203 Duggar, B. M., N. Y. (Cornell) B. U5: 1898. 
 20" Atkinson, G. F., Garden & Forest 10: 73, 1897. 
 
 205 Grossenbacher, J. G., N. Y. (Geneva), T. B. 9: 1909. 
 
 206 Jour. Bd. Agr. London, 17: 215. 
 
 20- Zeit. 3: 90; 4: 13, Frank, C. Bak. 5: 197, 1899. 
 
 208 Halsted, B. D., N. J. B. 107 and Bui. Myc. Fr. 7: 15, 1891. 
 
 209 Potebnia, A., Ann. Myc. 8: 58, 1910. 
 
 210 Hedgcock, G. G., J. Myc. 10: 2, 1904. 
 
 2" Jaczewski, Bull. Acad. Sc. Cracow 1892, 1893, 1894. 
 
 212 Cobb, N. A., Hawaii B. 5: 93, 1906, Sugar Planters E.xpt. Sta. 
 
 2'3 Atkinson, G. F., 0. E. S. B. 33: 308. 1896. 
 
 21" Atkinson, G. F., Bui. Torrey Bot. CI. 18: 1891. 
 
 2'5 Seribner, F. L., U. S. Dept. Agr. R. 355, 1887. 
 
 2'« Atkinson, G. F., Ala. B. 41: 1893. 
 
 21^ Atkinson, G. F., Bot. Gaz. 16: 61, 1891. 
 
 2>8 Stewart, F. C, B. 328: 389, 1910. 
 
 219 Halsted, B. D., N. J. R. 381, 1893. 
 
 220 Rostrup, Tid. f. Skw. 17: 37, 1905. 
 
 221 Notizblatt k. Botan. Gart. u. Mus. Berlin-Dahlem .!,: 297, 1907. 
 
 222 Voligno, Ann. R. Acad. Agric. Torino J,8: 417, 1905. 
 
 223 Rathay, E., Zeit. 4: 190, 1894. 
 
 22" Johnson, J., Proc. Ry. Dublin Soc. N. S. 10: 153. 
 
 226 Prillieux and Delacroix, Bull. Soc. M. d. Fr. 6: 113. 
 
 228 Maublanc and Lasnier, Bull. Soc. M. d. Fr. 20: 167, 1904. 
 
 22^ Rev. in E. S. R. 13: 259. 
 
 228 Sheldon, J. L., J. Myc. 13: 138. 
 
 223 Smith, E. F., J. Myc. 7: 36, 1891. 
 
 230 Lawrence, W. H., Wash. B. 64: 1904. 
 
294 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 2" Aderholcl, R., Landw. Jahr. 25: 875, 1896. 
 
 232 Clinton, G. P., 111. B. 67: 1901. 
 
 233 Aderholdt, R., C. Bak. 6: 593, 1900. 
 
 234 Vuilleman, C. R. 108: 632, 1889. 
 
 235 Cavara, Zeit. 3: 16, 1893. 
 
 236 Frank, B., Zeit. 5: 10, 1895. 
 
 237 Delacroix, G., Agr. Prat. Pays chauds, 7: 235, 1907. 
 2.38 Wagner, Zeit. 6: 101, 1895. 
 
 239 Oudemans, C. A., J. A. Proe. Soc. Sci. Konin. Akad. Wet. Amster- 
 dam 3: 141. 
 
 2« Halsted, B. D., N. J. R. 13: 290, 1892. 
 
 2" Pammel, L. H., la. B. 116: 1910. 
 
 2 '2 Diedicke, C. Bak. 9: 317, 1902, and 11: 52, 1904. 
 
 2« Ravn, F. K., Zeit. 11: 1, 1901, and Zeit. 11: 13, 1901. 
 
 244 Noack, Zeit. 15: 193, 1905. 
 
 245 Viala and Ravaz, Rev. d. Vit. 197, 1894. 
 
 246 Bubak, Nat. Zeit. f. For. u. Land. 8: 313. 
 
 247 Stoneman, B., Bot. Gaz. 26. 
 
 248 Spaulding and von Schrenk, B. P. I. B. U: 1903. 
 
 249 Shear, C. L., So. 32: 808. 1910. 
 
 260 Southworth, E. A., J. Myc. 6: 164, 1891. 
 
 251 Clinton, G. P., 111. B. 69: 1902. 
 
 252 Hasselbring, H., Bot. Gaz. 42: 135, 1906. 
 
 253 BurriU, T. J. and Blair, J. C, 111. B. 77: 1902. 
 
 254 BurriU, T. J., Sc. 16: 909, 1902, and 111. B. 118: 578, 1907. 
 
 255 Hasselbring, H., Trans. 111. Hort. Soc. 36: 350, 1902. 
 
 256 Sheldon, J. L., Sc. 22: 51, 1905. 
 
 257 Osterwalder, A., C. Bak. 11: 225, 1904. 
 
 258 Shear, C. L. and Wood, A. K., Bot. Gaz. J^3: 2,59, 1907. 
 
 259 Patterson, F. W. and Charles, V. K., B. P. I. B. 171: 1910. 
 
 260 Atkinson, G. F., N. Y. (Cornell) B. 49: 310, 1892. 
 
 261 Halsted, B. D., N. J. "R. 11: 1890. 
 
 262 Edgerton, C. W., Bot. Gaz. 45: 404, 1908. 
 
 263 Sheldon, J. L., Sc. 21: 143, 1905. 
 
 264 Sheldon, J. L., W. Va. B. 104: 1906. 
 
 265 Southworth, E. A., J. Myc. 6: 100, 1890. 
 
 266 Humphrey, J. E., Zeit. 1: 174, 1891. 
 
 267 Atkinson, G. F., J. Myc. 6: 172, 1890. 
 
 268 Edgerton, C. W., Mycol. 1: 115, 1909. 
 
 269 Barre, H. W., S. C. R. 22: 1909. 
 
 270 Atkinson, G. F., 0. E. S. B. 33: 1896. 
 
BIBLIOGRAPHY OF ASCOMYCETES 295 
 
 "1 Bui. Sc. Myc. do France 18: 285, 1902. 
 
 "2 Idem., m: 167, 1904. 
 
 2" Tavel, F., J. Myc. 5: 53, 1889. 
 
 "•• Klebahn, H., J. Wis. Bot. 41: 515, 1905. 
 
 2" Klebahn, C. Bak. 15: 336, 1905. 
 
 278 Frank, B., Zeit. 1: 17, 1891. 
 
 "' Miyake, Bot. Mag. Tokyo 23: 1909. 
 
 278 Edgerton, C. W., Bui. Tor. Bot. CI. 34: 593. 
 
 2" Rolfs, F. M., Sc. ^^; 87, 1907. 
 
 280 Rant, A., Zeit. 17: 177, 1907. 
 
 281 Montemartini, L., Riv. Path. Veg. 4: 165, 1910. 
 
 282 Delacroix, G., Bull. Soc. M. d. France, W: 142, 1904. 
 
 283 Massee, Kew Bull. June, 1892. 
 
 284 Humphrey, J. C, Mass. R. 10: 242, 1893. 
 
 285 Grossenbacher, J. G. and Duggar, B. M., N. Y. (Geneva) B. IS: 1911. 
 288 Fairchild, D. G., Bot. Gaz. 16: 262, 1891. 
 
 287 Hasselbring, H., 111. B. 70: 225, 1902. 
 
 288 Butler, E. J., Ann. Myc. 9: 36, 1911. 
 
 283 Eulefeld, Natw. Zeit. F. & Land. 8: 527, 1910. 
 2^0 Woronin, M. & Nawaschin, S., Zeit. 6: 129, 1896. 
 2" Muller-Thiirgau, C. Bak. 6: 653, 1900. 
 
 292 Ikeno, Flora, 92: 1, 1903. 
 
 293 Quaintance, A. L., Ga. B. SO: 1900. 
 
 294 Cordley, A. B., Ore. B. 57: 1899. 
 
 295 Galloway, B. T., D. Ag. R. 349, 1888. 
 
 296 Potebnia, A., Ann. Myc. 8: 79, 1910. 
 
 297 Edgerton, C. W., Mycologia 2: 169, 1910. 
 
 298 Clinton, G. P., Ct. R. 319, 1906. 
 
 299 Spaulding, P., B. P. I. Circ. 35. 
 
 300 Zimmerman, A., C. Bak. 8: 183, 1902. 
 
 301 Miyake, I., Bot. Mag. 21: 1, 1907. 
 
 302 Essed, Ann. Bot. 25: 343, 1911. 
 
 303 Essed, Ann. Bot. 25: 364, 1911. 
 30" Essed, Ann. Bot. 25: 367, 1911. 
 308 Miyake, I., Bot. Mag. 23: 1909. 
 
 308 Hegy, P., B. Soc. M. d. Fr. 27: 155, 1911. 
 
 307 Ducomet, V., Ann. Ec. Nat. Agr. Rennes 2: 1. 
 
 308 Potebnia, A. Ann. Myc. 8: 48, 1910. 
 
 309 Potebnia, A., Ann. Myc. 8: 70, 1910. 
 
 310 Halsted, B. D., N. J. R. 358, 1893. 
 
 311 Rand, F. V., Phyto. 1: 133, 1911. 
 
296 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 '12 Duggar, B. M., N. Y. (Cornell) B. U5: 1898. 
 
 "=> Scribner, F. L., U. S. D. Agr. R. 341, 1887. 
 
 31" Stewart, F. C, N. Y. (Geneva), B. 328: 387, 1910. 
 
 315 Clinton, G. P. Ct., R. 307, 1906. 
 
 316 Heald, F. D., Sc. 28: 624, 1906. 
 
 317 Richardson, A. E. V., Jour. Dept. Agr. So. Aust. U: 466. 
 
 318 U. S. Dept. Agr. R. 129, 1886. 
 
 319 Atkinson, G. F., Ala. B. W- 1893. 
 
 320 Atkinson, G. F., 0. E. S. B. 33: 293, 1896. 
 
 321 Southworth, E. A., Dept. Agr. R. 407, 1890. 
 3" Edgerton, C. W., Bot. Gaz. 45: 367, 1908. 
 
 323 Galloway, B. T., U. S. Dept. Agr. R. 387, 1888. 
 32" Shear, C. L., Phytop. 1: 116, 1911. 
 
 325 Reddick, D., N. Y. (Cornell) B. 263: 13, 1909, and Reddick, D., 
 Phytop. 1: 106, 1911. 
 
 326 Griffon, E. and Maublanc, A., C. R. Sc. (Paris) 151: 1149, 1910. 
 
 327 Sadebeck, Unt. u die Pilsegall, 1884. 
 
 328 Metcalf, H., B. P. I. B. 121: IV, 1908. 
 
 329 MetcaU^, H., & Collins, J. F., B. P. I. B. Ul: 5, 1909. 
 33''Appel, see C. Bak. 11: 143. 
 
 331 Stewart, F. C, N. Y. (Geneva) B. 328: 318, 1910. 
 
 332 Appel 0. & Wallenweber, H. W., Arb. d. Kais. Biol Anst. f. Land 
 Forst. 8: Heft, 1, 1910. 
 
 333 Bernard, C, Bui. Dept. Agr. Indes, Neerl. 55, 1907. 
 33" Rolfs, F. M., Mo. Fruit B. 17: 1910. 
 
 335 N. Y. (Cornell) B. 15: 1889. 
 
 336 Atkinson, G. F., Bui. Torrey Bot. Club 21: 224, and Bot. Gaz. 
 16: 282, 1891. 
 
 337 Noack, F., Zeit. 9: 18, 1899. 
 
 338 McAlpine, D., Dept. Agr. Melborne 1.32, 1899. 
 
 339 Zimmerman, A., C. Bak. 8: 148, 1898. 
 3« See Arnaud, G., Ann. Myc. 8: 471, 1910. 
 3" Ann. Myc. 8: 472, 1910. 
 
 3"2 Sheldon, J. L., Sc. 23: 851, 1906. 
 
 3''3 Pammel, L. H., Proc. la. Acad. Sc. 7: 177, 1899. 
 
 3"" Parker, J. B., Ohio Naturalist, 9: 509, 1909.. 
 
 3"5 Griffon & Maublanc, B. S. M. d. Fr. 26: 371, 1910. 
 
 3"6 Shear, C. L., Sc. 31: 748, 1910. 
 
 3"7 Murrill, W. A., Torreya, 6: 189, 1906. 
 
 3*8 Stone, G. E. & Smith, R. E., Mass. R. 57, 1901. 
 
 3"9 Larsen, L. D. H., Sug. PI. Assn. B, 10, 
 
BIBLIOGRAPHY OF ASCOMYCETES 297 
 
 350 Aderhold, R., Landw. Jahr. So: 875, 1896 and 29: 541, 1900. 
 
 351 Brooks, F. J., Ann. Bot. ^: 285, 1910. 
 
 352 Prillieux, E. and Delacroix, G., Bui. Soc. M. d. France, 9: 269, 
 1893. 
 
 353 Bull. Soc. My. d. Fr. 14: 24, 1898. 
 
 354 Brefeld, Unt. 9. 
 
BASIDIOMYCETES (p. 64)Ufi8:«:5o;63:66:5l:6o'"' 
 
 This class is distinguished from all others by its basidium, which 
 typically is a sporophore bearing on its distal end short stalks, 
 
 the sterigmata, usually four, 
 on which are borne spores, 
 basidiospores, one on the 
 tip of each sterigma. Fig. 
 215. In the great ma- 
 jority of genera the basidia 
 are typical and are clearly 
 recognizable as such. 
 
 In many of the lower 
 basidiomycetes the basidia 
 deviate somewhat from the 
 typical form. Thus in the 
 H e m i b a s i d i i, the smut 
 fungi, the basidia are not 
 typical in that they always 
 arise from chlamydospores, 
 not directly from the my- 
 ceHum, Figs. 217, 231, and 
 that they may produce more 
 than the normal number 
 from lateral, not terminal 
 
 Fig. 215. — The typical basidium with sterig- 
 mata and .spores in different stages of de- 
 velopment. After De Bary. 
 
 of four sporidia and these often 
 sterigmata. 
 
 The basidia in the large group of rust fungi are also atypical. 
 The mycelium of the Basidiomycetes is septate and branched, 
 and is always well developed. It is often found invading cells 
 several meters from the sporogenous structures and frequently 
 weaves together to form rhizomorphs. 
 
 Peculiar cell connections known as clamp connections, or knee 
 joints, Fig. 287, arc often found. The basidia in many genera are 
 
 298 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 299 
 
 borne on large complex sporophores composed of the mycelial 
 threads interwoven to form a false 
 parenchyma. The spores may 
 germinate by tubes or by bud- 
 ding. 
 
 Typical sexuality seems en- 
 tirely wanting, even rudimentary 
 or vestigial sexual organs, cer- 
 tainly recognizable, have not been 
 found. The group is supposed in 
 this regard, to represent the results 
 of extreme simplification; the sex- 
 ual organs to have long ago dis- 
 appeared and the simple nuclear fusions that now exist to serve 
 functionally as fertilization. 
 
 Fig. 
 
 216. — Ustilago spores showing 
 development. After De Bary. 
 
 Key to thk Subclasses of Basidiomycetes 
 
 Chlamydospores at maturity free in a 
 sorus, produced intercalary, from 
 the mycelium ; basidiospores borne 
 on a promycelium and simulating 
 
 conidia I. Hemibasidii, p. 299. 
 
 Chlamydospores absent or when present 
 borne on definite stalks 
 Basidia septate, arising from a rest- 
 ing spore or borne directly on 
 
 a hymenium 2. Protobasidii, p. 323. 
 
 Basidia nonseptate, borne on a hy- 
 menium 3. Eubasidii, p. 393. 
 
 Hemibasidii 
 The Hemibasidii contain one order. 
 
 Ustilaginales 
 
 45, 47, 124, 126-129, 131, 137 
 
 Parasitic fungi, smut producers, mycelium consisting of hyaline, 
 somewhat septate, branched, mostly intercellular filaments, 
 practically limited to the interior of the host; at maturity often 
 
300 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 disappearing partially or wholly through gelatinization; fertile my- 
 celium compacting into masses and giving rise to numerous chlam- 
 ydospores formed from its contents. Conidia rarely develop on 
 the exterior of the host. Sori prominent, usually forming dusty or 
 agglutinated spore-masses that break out in definite places on the 
 host or more rarely remain permanently embedded in the tissues. 
 Spores (chlamydospores) light to dark colored, single, in pairs, 
 or in spore-balls, the latter often composed in part of sterile cells. 
 The Ustilaginales are all parasites on higher flowering plants. 
 The vegetative mycelium is mostly inconspicuous and is often 
 
 tb'h 
 
 Fig. 217. — Ustilago. 2, promycelium with nucleus in mi- 
 tosis; 5, with 4 nuclei; 6, with conidia. After Harper. 
 
 distributed very widely in the host plant without giving external 
 evidence of its presence until time of spore formation. It sends 
 variously formed botryose or spherical haustoria into the host 
 cells. At time of maturity of the fungus, the mycelium develops 
 in great abundance at certain special places in the host, often in 
 the ovary, leading to the development of large mycelial structures 
 in the place of the host tissue. 
 
 The chlamydospores develop directly from the vegetative my- 
 celium; new and numerous transverse cell-walls are formed; the 
 resulting short cells swell, round off and become coated with a 
 gelatinous envelope. This later disappears and the spores develop 
 a new, thick, usually dark, double wall which is variously marked. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 301 
 
 The chlamydospores may be simple or compound, fertile or in 
 part sterile and are variously shaped and marked as described in 
 the genera below. 
 
 The chlamydospores may germinate at once or after a more or 
 less protracted rest interval. In germination in water or nutrient 
 solution (manure water, etc.) a short tube is protruded, the pro- 
 mycelium, this cUffering in character in the two families, Figs. 217, 
 231. From the promycelium of most species there develop conidia, 
 (often called sporidia) 1-12 or even more. The promycelium is 
 regarded as homologous with the basidium of the other basidio- 
 mycetes and the conidia as basidiospores. 
 
 The conidia in suitable nutrient solutions often undergo repeated 
 and indefinite budding closely simulating yeast cells in appearance. 
 Fusion of conidia is not uncommon. 
 Fig. 218. Conidia finding lodgment 7, -„^,, 
 
 in suitable plant parts under suitable ^^ / ^i 
 
 environmental conditions give rise to '^'' 
 
 infection. The points at which in- -t) ' ' '^ -O ; 
 
 fection can occur are very diverse 
 with different species and will be 
 considered under the separate species V VI,^ '- 
 
 below. 
 
 „, , ,. ,, 1 • 1 j^ Fig. 218. — Ustilago. 17, conidia 
 
 The vegetative cells are bmucleate fusino'; 19, promyceiial cells 
 in Tilletia, multinucleate in the Usti- ^^ h.sion tu^be.^apieai^^^^^^ dis- 
 
 laginacese.^'^^® The young chlamydo- 
 spores were shown by Dangeard ^'^^^ in the case of Doassansia, 
 Entyloma, Ustilago and Urocystis to be binucleate. These two 
 nuclei, according to Dangeard, later fuse rendering the mature 
 spore uninucleate. In germination the one nucleus passes into 
 the promyceUum, then divides mitotically Fig. 217, 2. A second 
 division gives four nuclei (Fig. 217, 5) the spore nuclei.'* 
 
 In the fusions of smut conidia Federly has found an accom- 
 panying nuclear fusion, in salsify smut, while Lutman finds similar 
 fusion in the conjugating promyceiial cells of oat smut.^ 
 
 Whether or not these nuclear fusions represent a sexual act is 
 a much controverted point. 
 
 There are according to Clinton about four hundred species in 
 America.^' -"* 
 
 ^y 
 
302 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Key to Families of Ustilaginales 
 
 Promycelium usually with sporidia lateral 
 
 at septa 1. Ustilaginaceae, p. 302. 
 
 Promycelium with clustered terminal 
 
 sporidia 2. Tilletiaceae, p. 314. 
 
 Ustilaginaceae 
 
 Sori usually forming exposed dusty or agglutinated spore- 
 masses. Germination of chlamydospores by means of septate 
 promycelia which give rise to terminal and lateral sporidia or else 
 to infection-threads. 
 
 Key to Genera of Ustilaginaceae 
 
 Spores single 
 
 Sori dusty at maturity 
 
 Without definite false membrane 1. Ustilago, p. 303. 
 
 With false membrane of definite fungous 
 
 cells 2. Sphacelotheca, p. 310. 
 
 Sori agglutinated at maturity 
 
 Firmly agglutinated into conspicuous 
 
 tubercular nodules 3. Melanopsichium. 
 
 Developed around a central columella 
 
 (rarely dusty) 4. Cintractia. 
 
 Spores chiefly in pairs 
 
 Sori agglutinated (on leaves) 5. Schizonella. 
 
 Sori dusty (inside peduncles) 6. Mykosyrinx. 
 
 Spores in balls of more than two 
 Sori dusty or granular 
 Spore-balls often evanescent; spores 
 
 olive-brown or black-brown 7. Sorosporium, p. 312. 
 
 Spore-balls rather permanent; spores 
 yellowish or reddish, with markings 
 
 only on free surface 8. Thecaphora, p. 313. 
 
 Spore-balls quite permanent; spores ad- 
 hering liy folds or thickenings of 
 outer coat 9. Tolyposporium, p. 313 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 303 
 
 Sori agglutinated 
 
 Spore-balls (variable) composed of 
 
 thick-walled spores 10. Tolyposporella. 
 
 Spore-balls with peripheral spores and 
 
 central sterile cells 11. Testicularia. 
 
 Of these genera numbers three to eleven inclusive occur on un- 
 important plants. Among them are: Polygonum, Rynchospora, 
 Psilocary, Cyperus, Carex, Luzula, Juncus, Fimbrystylis, Cissis; 
 various unimportant grasses, members of the Carcluacese, Faba- 
 eeae, Nyctaginaceae, Amarantaceae, Cyperacese, Dracenacese, and 
 Eriocaulacese. The most important genera are Ustilago and 
 Sphacelotheca. 
 
 Ustilago (Persoon) Roussel (p. 302) 
 
 Sori on various parts of the hosts, at maturity forming dusty 
 spore masses, usually dark colored ; spores single, produced irregu- 
 larly in the fertile mycelial threads which early entirely disappear 
 through gelatinization, small to medium in size; germination by 
 means of a septate promycelium producing only infection-threads 
 or with sporidia formed terminally and laterally near the septa; 
 sporixiia in water usually germinate into infection-threads but in 
 nutrient solutions multiply indefinitely, yeast- 4 
 
 fashion. 
 
 About two hundred species, seventy-two of 
 which are given by Clinton ^ as occurring in 
 America. Besides the species discussed below 
 many others occurring upon grasses or other 
 plants of minor value are omitted. 
 
 U. avenffi (Pers.) Jens.^^. iie. ii7, 124, 125 
 
 Sori in spikelets, rarely in leaves, forming a 
 dusty olive-brown spore-mass, about 6-12 mm. Fig. 219.— u. aye- 
 
 . nae, germinating 
 
 long by half as wide, usually rather completely in water. After 
 destroying floral parts, eventually becoming dissi- 
 pated; spores lighter colored on one side, subspherical to spherical 
 though often elongate, minutely echinulate, 5-9 ju in length, 
 widespread on oats. 
 
 The fungus was known by the name Ustilago as early as 1552 
 
304 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 and was called U. avense in 1591. The species of Ustilago 
 on oats, wheat and barley were considered identical until 
 Jensen ^ showed that they are not intercommunicable. Wolff ® 
 showed that seedlings can be infected through the first sheath 
 leaf. Brefeld ^ studying infection more closely found it to be 
 accomplished by germ tubes from sporidia and that plants are 
 free from infection after the growing leaves have pushed one 
 centimeter through the sheath leaf. The mycelium, after infec- 
 tion, grows through the plant until blooming time when it seeks 
 the ovaries and the enclosing glumes in which it forms a mycelial 
 mass, which soon changes into spores. In nutrient solutions the 
 conidia bud indefinitely, while on the host plant they produce 
 infecting hyphse. 
 
 Germination was first studied by Prevost.^ It occurs read- 
 ily in water, a well de- 
 veloped promycelium 
 resulting in about 
 twenty-four hours, 
 Fig. 219. The sporidia 
 are mostly narrowly 
 elliptical. Fusion of 
 sporidia is common. 
 The promycelia are 
 usually four-celled and 
 occasionally branch, 
 especially near the 
 base. " ["«• ^-« 
 
 U. crameri Korn.-'- 
 Sori in the spikelets, 
 infecting all of the 
 spike, ovate, about 
 2-4 mm. in length, 
 chiefly destroying in- 
 
 FiG. 220. — Growing point of the stem of barley. ' rl K 1 + • 
 
 Much enlarged, showing smut mycelium. After ^^^ ana Dasai parts, 
 
 ^®^'*^®* spores reddish-brown, 
 
 chiefly ovoid to subspherical though occasionally more elongate 
 and irregular, smooth, with usually pitted contents, chiefly 8-11 m 
 in length. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 305 
 
 The promycelium is much branched but no sporidia are pro- 
 duced. 
 
 The smut commonly affects the ovaries of Panicum and Setaria, 
 In America it has been collected on millet in several states. 
 
 U. crus-galli T. & E.i^^ 
 
 Sori often encircling stems at nodes or at the juncture of the 
 inflorescence, infecting both stem and leaves, prominent, often 
 nodular, one to several centimeters in length, protected by a tough 
 hispid membrane which upon rupture discloses an olive-brown 
 dusty spore-mass; spores ovoid to spherical, occasionally more 
 elongate, rather bluntly echinulate or even verruculose, chiefly 
 10-14 IX in length. 
 
 On Panicum crus-galli throughout the United States. 
 
 U. bulgarica Bub. is on Sorghum vulgare. European. 
 
 U. medians Bieden, on barley, is closely like U. hordei.^^^ 
 
 U. scorzonerae (A. & S.) Schr. on Scorzonera is very close to 
 U. tragopogonis-pratensis. 
 
 U. sacchari Rab.^^ 
 
 Spore-mass black, spores globose or angularly globose, 8-18 n 
 in diameter, olive-brown or rufous, epispore thick, smooth. 
 
 On sugar-cane throughout the tropics, especially in the old 
 world. 
 
 In Java this fungus has been reported as the cause of serious 
 damage. Barrett observed it in Trinidad, where the damage was 
 less extensive. 
 
 The leaves especially the young ones which have not yet sepa- 
 rated from each other are the parts affected. From the upper part 
 of the affected cane, as a rule, no secondary shoots arise, and those 
 which do arise from the lower part become infected in their turn. 
 The discolored whip-like structure at the end of an attacked cane 
 becomes dusty and black and contains the spores of the fungus. 
 
 U. hordei (Pers.) K. & S.^^- '''' '^^ 
 
 Sori in spikelets, forming an adhering purple-black spore-mass, 
 about 6-10 mm. in length, covered rather permanently by the trans- 
 parent basal parts of the glumes ; spores lighter colored on one side, 
 usually subspherical or spherical, smooth, 5-9 n, the most elongate 
 rarely 9-11 /i in length. Common on barley. 
 
 This was first recognized as distinct from the oat smut in 1591 
 
30.6 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 by Lobelius.^'' Persoon in 1801 first gave a definitely recognizable 
 description.^^ In 1888 the species was separated from the other 
 smut on barley. ^^ 
 
 The spores germinate freely in water by one, rarely two, tubes, 
 usually 4-celled, and produce abundant sporidia; these increase by 
 budding, produce germ tubes, or fuse with each other. 
 U. levis (K. & S.) Mag. 2^' ''' 
 
 Sori in spikelets, forming a black-brown adhering spore-mass, 
 
 sometimes small and entirely concealed by the 
 
 3 f^ glumes but usually evident and destroying inner 
 
 ^ // and basal parts; spores lighter colored on one side, 
 
 subspherical to spherical or rarely elongate, smooth, 
 
 5-9 fjL, the most elongate rarely 11 /i in length. 
 
 On oats throughout America and Europe, prob- 
 ably more common than records show as it is very 
 difficult to distinguish from U. avenae from which 
 it differs chiefly in its smooth granular spores. 
 U. macrospora Desm. 
 
 Sori in leaves and glumes, generally showing as 
 linear striae, but often more or less merged, at 
 first covered by the epidermis, but this later rup- 
 turing and disclosing black-brown dusty lines of 
 spores; spores medium to dark reddish-brown, 
 chiefly ovoid to spherical or occasionally some- 
 what irregular and elongate, coarsely verrucose, at 
 circumference usually showing the projections as 
 tinted blunt scale-like appendages, sometimes even semi-reticulate, 
 12-19 M in length. 
 On various species of Agropyron in Europe and America. 
 U. nuda (Jens.) K. & S.^^- ''' 
 
 Sori in spikelets, forming a dusty olive-brown spore-mass, about 
 6-10 mm. long by half as wide, temporarily protected by a thin 
 membrane which soon becomes dissipated leaving the naked rachis 
 behind; spores lighter colored on one side, minutely echinulate, 
 subspherical to spherical or occasionally elongate, 5-9 n in length. 
 In Europe and America. This smut on barley is distinguishable 
 from the covered smut, U. hordei, by its olive-green spore-mass 
 and by its early shedding of spores. As a rule, each spikelet, ex- 
 
 FiG. 221.— U. le- 
 vis, germina- 
 tion in modi- 
 fied C o h D ' s 
 solution. Af- 
 ter Clinton. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 307 
 
 cept the awn and rachis is entirely transformed into smut. In 
 water and in nutrient solutions the spores germinate by a single 
 promycelium, 1 to 3-septate, and often branched, but without 
 sporidia. That infection is floral in loose smut of both wheat and 
 barley was first shown by Maddox ^^ and the fact was corrob- 
 orated by Wakagawa,^^ Brefeld ^'^ and Hecke.^^' ^^ The my- 
 celium has been demonstrated in the embryo by Broili.^^^ 
 
 The spores falling between the glumes germinate, penetrate 
 the ovary wall, and into the growing point of the embryo. The 
 mycelium here lies dormant until the seed germinates, when it 
 grows, keeping pace with the growing point throughout the season 
 and finally invading the ovaries to produce its spores. 
 
 The infection of the pistil, the penetration of the integuments 
 and the nucellus and embryo sac was followed in microtome sec- 
 tions by Lang.^-^ The embryo was reached by the mycelium some 
 four weeks after infection of the pistil. In resting grains the my- 
 celium is abundant in the scutellum as well as in 
 all embryo parts except the roots. 
 
 Cross inoculation by Freeman and Johnson ^^ 
 from barley to wheat and the reverse gave 
 negative results. The optimum time for infec- 
 tion has been determined as the period of full 
 bloom. 
 
 U. perennans Rost.^-^' ^^^ 
 
 Sori in spikelets, more or less destroying the 
 
 , , J . , ,. ■ • Fig. 222.— U. tritici, 
 
 basal and mner parts, sometimes even runnmg germination in 
 down on pedicels, oblong, about 3-8 mm. in modified John's 
 
 ' . solution. After 
 
 length, with dusty, olive-brown spore masses; Keilcmian and 
 mycelium perennial in perennial parts of host; 
 spores chiefly subspherical or spherical, occasionally ovate to el- 
 lipsoidal, usually lighter colored on one side, more or less 
 minutely echinulate, especially on the lighter side, 5-8 ^t in 
 length. 
 
 On the tall oat grass throughout its range. 
 
 U. rabenhorstiana Kiihn occurs on several species of Panicum. 
 
 U. tritici (Pers.) Rost-^-"' '''' 124, 125. 128 
 
 Sori in spikelets, forming a dusty olive-brown spore-mass, about 
 8-12 mm. long by half as wide, usually entirely destroying floral 
 
308 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 parts and eventually becoming dissipated and leaving behind only 
 the naked rachis; spores lighter colored on one side, usually sub- 
 spherical to spherical, occasionally elongate, minutely echinulate 
 especially on the lighter side, 5-9 n in length. On wheat where- 
 ever cultivated. 
 
 The smut mass is covered at first by a very delicate membrane. 
 Infection is floral as described for U. nuda. 
 
 The spores germinate in water by a long 2 to 3, or even 6 to 
 7-septate, promycelium, often curved. In nutrient solutions the 
 
 FiG; 223. — U. zese, stages in spore development. After Knowles. 
 
 promycelium branches profusely but sporidia are few or are en- 
 tirely absent. 
 
 U. zeae (Beck.) Ung.^^' 2^' '''-'-'' '''' '''' ^^^ 
 
 Sori on any part of the corn plant usually prominent, forming 
 irregular swellings from a few millimeters to over a decimeter in 
 diameter, at first protected by a sort of false white membrane 
 composed of plant cells and semi-gelatinized fungous threads, 
 soon rupturing and disclosing a reddish-brown spore-mass; spores 
 ellipsoidal to spherical or rarely more irregular, prominently 
 though rather bluntly echinulate, 8-11 n the most elongate 15 /x 
 in length. 
 
 The germination of the spores, which occurs but poorly in water, 
 was first studied by Kiihn 2° in 1857. In 1874 Kiihn saw the pene- 
 tration of the germ tubes through the epidermis of the corn plant. 
 Brefeld showed that the spores germinate well in nutrient solu- 
 tions and that secondary spores are formed; also that corn can be 
 infected by the sporidia at any point on its surface above ground 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 309 
 
 when the tissues are soft and actively growing; and that infection 
 is local on the host.~^ 
 
 It is now known that the chlamydospores are capable of ger- 
 mination without hibernation and that they remain viable one, 
 two, perhaps more 
 years. It was shown 
 by Brefeld in 1895 
 that the chlamydo- 
 spores produce conidia 
 in the air freely. It 
 is these, air-borne, 
 arising from spores 
 on the ground, ma- 
 nure, etc., which are 
 chiefly responsible for 
 infection. They must 
 reach the plant on a 
 susceptible part and 
 under suitable con- 
 ditions of moisture. 
 The germ tubes from 
 the conidia penetrate 
 the epidermis, grow 
 through or between 
 the cells, Fig. 223, 
 with an irregular my- 
 celium which branches 
 profusely and calls forth great hypertrophy of the surrounding 
 host tissue. In sporing, the mycelium forms a great number of 
 short, slender, irregular branches which make up a close tangled 
 network in the diseased tissue. These slender branches swell, 
 gelatinize, and portions of them round off as spores. Fig. 223. 
 
 U. striaeformis (West.) Niess.-^' ^'"^ 
 
 Sori in leaves, sheaths and rarely in the inflorescence, from short 
 to linear, often extending, apparently by terminal fusion, for 
 several centimeters, also occasionally fusing laterally to cover most 
 of the leaf; at first covered by the epidermis but this is soon rup- 
 tured and dusty brown to black, linear masses of spores become 
 
 Fig. 224. — U. zese. 1, germination after three days in 
 water; 2, similar but in air showing air sporidia. 
 After Clinton. 
 
310 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 scattered and the leaves become shredded; spores usually ellip- 
 soidal to spherical, occasionally irregular, prominently echinulate, 
 chiefly 9-14 ^u in length. 
 
 It appears to be perennial. The spores germinate sparsely. 
 The promycelium is long, branched, septate, and produces no 
 conidia. 
 
 On numerous species of grass, including red top, timothy and 
 species of Poa and Festuca throughout Europe and America. 
 
 Species of less importance, not all found in America are: 
 
 U. schiriana Hem. which attacks bamboo; "^ 
 
 U. secalis Rab. is European on rye; possibly a Tilletia. 
 
 U. esculenta P. Hen. which causes swellings on Zizania which 
 are eaten in the orient; 
 
 U. vaillantii Tul. in the sexual organs of the Liliacese; 
 
 U. panici-miliacei (Pers.) Wint. on Panicum miliaceum; 
 
 U. tragopogi-pratensis (Pers.) Wint. on the flowers of Trago- 
 pogon; 
 
 U. cruenta Kiihn, widespread in Europe on sorghum; 
 
 U. violacea (Pers.) Fcl. on the anthers of various members of 
 the Caryophyllacese; 
 
 U. tulipae Wint. on tulips and related hosts; 
 
 U. vrieseana Vuill. on eucalyptus roots, a very doubtful species; 
 
 U. sphaerogena Burr, on Panicum crus-galli. 
 
 The fungus described as U. fischeri Pers. from Italy on corn 
 is a Sterigmatocystis as is also U. phoenicis Corda on date fruits 
 and U. ficuum Reich on figs. 
 
 Sphacelotheca De Bary (p. 302) 
 
 Sori usually in the inflorescence, often limited to the ovaries, 
 provided with a definite, more or less temporary, false membrane, 
 covering a dusty spore-mass; and a central columella, usually 
 formed chiefly of the host plant's tissues. The false membrane 
 is composed largely or entirely of sterile fungous cells which are 
 hyaline or slightly tinted, oblong to spherical, and usually more 
 or less firmly bound together; spores single, usually reddish-brown, 
 developed in a somewhat centripetal manner as in Cintractia, 
 small to medium in size; germination as in Ustilago. 
 
 Sixteen species are recorded by Clinton for America. Of these 
 
THE FUNGI WHICH CAUSE PLAxXT DISEASE 
 
 311 
 
 
 f^fi 
 
 only three are of economic importance. By Engler and Prantl, the 
 genus is not separated from Ustilago. 
 
 Sphacelotheca sorghi (Lk.) Ci.^^' ^^^ ^^s. ne. lu 
 
 Sori usually in the ovaries or stamens forming oblong to ovate 
 bodies 3-12 mm. in length (rarely fusing the very young spikelets 
 into irregular forms), protected for 
 some time by a false membrane 
 upon the rupture of which the 
 olive-brown spore-mass becomes 
 scattered, leaving naked the dis- 
 tinct columella of plant tissue. 
 The sterile cells of the membrane 
 break up to some extent into 
 groups, hyaline, oblong to sub- 
 spherical, chiefly 7-18 /x in length; 
 spores subspherical to spherical, 
 smooth, contents often granular, 
 5.5 — 8.5 fi in diameter. 
 
 On Johnson grass and sorghum 
 throughout the world. The young 
 pistil and usually the stamens as 
 well are displaced by the fungous 
 mycelium, the two being often 
 blended together. The spores ger- 
 minate readily in water, either 
 when fresh or a year old, showing 
 papillae in from three to ten hours. 
 The promycelium is 2 to 3-septate 
 and from the ends of one or more 
 of its cells narrow tubes appear. 
 
 These later fuse with the adjacent cell, forming the ''buckle 
 joints." Either infection tubes or sporidia may also arise from 
 the promycelium. Infection is possible only with young plants. 
 
 The mycelium in the host plant grows rapidly into long irregu- 
 lar, hyaline, thin-walled threads 2-4 mm. thick, which run through 
 and between the cells. It is most abundant in the parenchyma, 
 advancing especially through the pith region with the growth of 
 the host. The young ovaries and stamens are eventually reached 
 
 X)\ 
 
 
 Fig. 2125. — S. sorghi, cross-section 
 through base of young infected 
 body (ovary), a, false membrane 
 of epidermal cells and sterile my- 
 celium, b, mature spores, b ', im- 
 mature spores, c, columella. After 
 Clinton. 
 
312 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 and the mycelium there develops richly under the epidermis. The 
 
 outer cells remain sterile and constitute the membrane; the inner 
 
 gelatinize and develop into spores. 
 S. reiliana (Kuhn) Cl.^^' '''' '''• '''' '^^ 
 
 Sori very prominent forming irregular masses including more or 
 less of the entire panicle, usually 
 5-15 cm. in length; often at first pro- 
 tected by the leaf-sheath. A whitish 
 false membrane encloses the black- 
 brown spore-mass and the ray-like re- 
 mains of the peduncles or columellas. 
 In time it becomes ruptured and the 
 spores scattered. Sterile cells are also 
 
 Fig. 226.— s. reiliana. Ger- scattered in groups through the spore- 
 mination in water. After mass, chiefly subspherical, 7-15 u in 
 
 Hitchcock and Norton. ' -^ ^ ' ^ 
 
 diameter; spores somewhat opaque, 
 chiefly subspherical to spherical or occasionally ovoid or slightly 
 angled, minutely but abundantly vcrruculose, 9-14 /j. in length. 
 
 This is a cosmopolitan but comparatively rare form on corn, 
 affecting the ovaries. It occurs also on sorghum. In germination 
 a 3 to 4-celled, often branched, promycelium is formed and conidia 
 are produced. 
 
 S. diplospora (E. & E.) CI. is found on Panicum crus-galli and 
 related grasses in the lower Mississippi Valley. 
 
 Sorosporium Rudolphi (p. 302) 
 
 Sori in various parts of the host, forming dusty, dark colored 
 spore-masses; spore-balls of medium size com- 
 posed of numerous fertile cells, often rather 
 loosely united and frequently at maturity com- 
 pletely separating; spores usually olive or 
 reddish-brown, of medium size; germination 
 similar to that of Ustilago; sometimes with 
 elongate germ thread and no sporidia. 
 
 Several species are parasitic on the coarser 
 range grasses. S. consanguineum E. & E., 
 S. everhartii Ell. & Gall., and S. ellisii Winter, are probably the 
 most important. S. dianthi Rab. is found on Dianthus. 
 
 Fig. 227. — Sorospo- 
 rium. Spore mass. 
 After Dietel. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 313 
 
 Thecaphora Fingerhuth (p. 302) 
 
 Sori in various parts of the host, often as indefinite masses in 
 the floral parts or forming rather firm pustules on the stem, at ma- 
 turity with a dusty spore- 
 mass; spore-balls composed 
 of few to many fertile cells, 
 of small to large size; rather 
 permanently united; spores 
 usually yellowish or reddish, 
 
 smooth on contiguous sides Fig. 228.— Thecaphora, spore ball germina- 
 
 but usually marked on the *^°^- ^^^^'^ ^^^^*^^'^- 
 
 free surface; germination, so far as known, by means of a single 
 
 sporidium at the tip of the elongate septate promycelium. 
 
 A small genus of slight economic importance. 
 
 T. deformans Dur. & IM.i-*'' '-^ 
 
 Sori in the seeds, showing when the legumes are broken open 
 as reddish-brown, dusty spore-masses which destroy most of the 
 seeds; spore-balls reddish-brown, ovoid to spherical, rather firm, 
 composed of 3-25 (usually 7-12) spores, chiefly 27-60 /j. in length; 
 spores in optical section triangular to polygonal or when free 
 irregular oblong, free surface with papillae that sometimes vary to 
 spiny processes, 15-25 ^i, chiefly 15-20 fx in length. 
 
 On a large number of Leguminous hosts, including species of 
 Vicia, Lathyrus, Lupinus, Trifolium, etc., in widely scattered 
 regions of both the old and the new world. 
 
 Tolyposporium Woronin (p. 302) 
 
 Sori usually in the inflorescence, especially the ovary, forming 
 granular spore-masses at maturity; spore-balls dark-colored, of 
 numerous spores permanently united, germination about as in 
 Ustilago. 
 
 A genus of about ten species. 
 
 T. bullatum Schr.i^s- 154 
 
 Sori in ovaries, infecting occasional ones, ovate, about 3-5 mm. 
 in length, covered with a thin, greenish, smooth membrane, upon 
 rupture of which the black granular spore-mass becomes scattered ; 
 
314 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 spore-balls black, opaque, oblong 
 to spherical or polyhedral, usually 
 containing one hundred or more 
 firmly agglutinated spores, chiefly 
 50-180 M in length; spores from 
 nearly hyaline, to light reddish- 
 brown, outer coat more or less 
 folded in ridges, often spiny, ovoid 
 to subspherical or polyhedral, 
 chiefly 7-10 ijl or rarely 12 ^u in 
 
 Fig. 229. — Tolyposporium. Spore length. 
 
 ball germination. After Bref eld. ^ t-. • n- • 
 
 On Panicum crus-galli m the 
 United States east of the Rocky Mountains also in Europe. 
 T. filiferum and T. volkensii, occur on sorghum in Africa. 
 
 Tilletiaceae (p. 302) 
 
 Sori either forming dusty erumpent spore-masses or permanently 
 embedded in the tissues. Germination by means of a short promy- 
 celium which usually gives rise to a terminal cluster of elongate 
 sporidia, that, with or without fusing in pairs, produce similar 
 or dissimilar secondary sporidia or germinate directly into infection 
 threads. 
 
 The American Tilletiaceae embrace nine genera and about one 
 hundred twenty-five species. 
 
 Key to Genera of Tilletiaceae 
 Spores single 
 
 Sori dusty at maturity 
 
 Spores without a conspicuous hyaline 
 
 appendage 1. Tilletia, p. 315. 
 
 Spores with an elongate hyaline append- 
 age 2. Neovossia. 
 
 Sori permanently embedded in the tissues 
 
 Sori definite, small 3. Entyloma, p. 320. 
 
 Sori indefinite, large 4. Melanotaenium. 
 
 Spores in balls 
 
 Sori dusty; spore-balls with sterile cor- 
 tex 5. Urocystis, p. 318. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 315 
 
 Sori rather permanently embedded in 
 tissues 
 Spore-balls without sterile cortex 
 Spore-balls consisting entirely of 
 
 dark-colored spores 6. Tuburcinia. 
 
 Spore-balls consisting of light-colored 
 spores 
 Spore-balls with or without central 
 
 sterile cells 7. Burrillia. 
 
 Spore-balls with central network of 
 
 filaments 8. Tracya. 
 
 Spore-balls with sterile cortex 9. Doassansia, p. 322. 
 
 Neovossia occurs on Phragmites; Tuburcinia on Convallariacese, 
 Primula, Trientalis and Geranium in Russia; Burrillia on Limnan- 
 themum, Echinodorus and Sagittaria; Tracya on Spirodela. 
 
 Tilletia Tulasne ^'^ (p. 314) 
 
 Sori in various parts of the hosts, usually in the ovaries, forming 
 dusty spore-masses; spores single and usually formed singly in 
 the ends of the mycelial threads 
 which disappear more or less 
 completely through gelatiniza- 
 tion, germination usually by a 
 short promycelium which bears 
 a terminal cluster of elongate 
 sporidia that in nutrient solu- 
 tions, with or without fusing in 
 pairs, may give rise to a con- 
 siderable mycelium bearing sec- 
 ondary air-sporidia. 
 
 The genus closely resembles 
 Ustilago except in its larger Fig. 230. 
 spores and mode of germination 
 
 Tw^enty-two American species are listed by Clinton 
 are of economic importance. 
 
 T. pancicii Bub. & Ran. is reported on barley heads in Servia.^^ 
 
 T. glomerulata. Cocc. & Mor. is a doubtful species on alfalfa. 
 
 T. ftt'teiis, spores. Photo- 
 micrograph. After Clinton. 
 
 Only three 
 
316 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 T. foetens. (B. & C.) Trel.-^' '-'' ''-'• ''' 
 
 Sori in ovaries, ovate or oblong, 5-8 mm. in length, more or 
 less concealed by the glumes, all or only part of the ovaries of 
 a spike infected; spores light to dark-brown, oblong to chiefly sub- 
 spherical or spherical, occasionally somewhat angular, foetid, es- 
 pecially when young, smooth, chiefly 16-22 fj,, the most elongate 
 rarely 28 n in length. 
 
 On wheat wherever grown. 
 
 Kiihn "'^ found that infection occurs as in oats in the very 
 young plants. From the infection point 
 the mycelium approaches the growing 
 point and follows the development of 
 its host, sending its branches into each 
 spikelet and finally into the growing 
 ovules. Here it develops a close knot 
 and in the ends of the threads and in the 
 short branches the spores form. The 
 spores germinate by a rather long, con- 
 tinuous, thick promycelium on the tip of 
 which a crown of long slender conidia de- 
 velops. The sporidia soon become arched 
 and often fuse in pairs; they develop in- 
 fection threads. 
 
 T. tritici (Beij.) Wint.^^s 
 Sori in ovaries, ovate to oblong, 5-8 mm. 
 which have united. One in length, more or less concealed by the 
 
 has produced a secondary up i t 
 
 sporidium at X and this is glumes; sterile cells lew, hyalme, sub- 
 thread^ °"A.fter Freeman spherical, with medium-thin wall, smaller 
 and stedman. ^^^n the fertile cells which are chiefly 
 
 subspherical, light to dark-brown, with winged reticulations 
 about 1 iJL high by 2-4 /j, wide, and 16-22 n in diameter. 
 On wheat everywhere. 
 
 Experiments have shown this distinct from T. foetans which it 
 closely resembles except for its reticulate spores. 
 T. texanaLong: Cl.^^g 
 
 Sori in ovaries, ovoid or oblong, al^out 3-5 mm. in length, more 
 or less hidden by enveloping glumes, forming a somewhat agglu- 
 tinated light-reddish-brown spore-mass; sterile cells not very 
 
 Fig. 231.— T. fretens. A, 
 germinating spore produc- 
 ing sporidia; B, Sporidia 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 317 
 
 numerous, hyaline, witli very thick, often lameUate walls; fertile 
 cells very light colored, orange-yellow appearing as if immature, 
 chiefly subspherical or spherical, with prominent conical tubercles 
 which extend out 2 3 ^x to the hyaline envelope, chiefly 19-25 n 
 in diameter (including envelope.) 
 
 On Hordeum nodosum in Texas. 
 
 T. hordei Kcke is an Asiatic form on Hordeum. 
 
 T. secalis (Cda.) Kiihn. occurs on rye in Europe. ^^^ 
 
 T. horrida Tak.^^' i^i. i49 
 
 Sori in the ovaries more or less destroying them, completely 
 
 Fig. 232. — Tillctia tritici. A. Two spores germinated in 
 moist air, promycelium and conidia, several of which have 
 fused in pairs. Secondary conidia at C. B. Spores ger- 
 minated in water, promyceUa elongate, septate. The pro- 
 toplasm passes over into the younger cells. After Tubeuf. 
 
 concealed by enveloping glumes; spores usually present in different 
 stages of development, the mature spores almost opaque, chiefly 
 subspherical to spherical, with very coarse hyaline or slightly 
 tinted, somewhat curved, scales which show at the circumference 
 of the spore as a band about 2—4 ju wide and on its top as polyg- 
 onal areas 2-3 m across; hyahne membrane more or less evident 
 and often at one side in a short thread-like projection, 22-33 /x 
 in length. 
 
 Cross sections of stems bearing smutted heads reveal the my- 
 celium in the chlorophyll parenchyma between the fibrous tissue.^^ 
 
 On rice in America and Asia. 
 
318 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Urocystis Rabenhorst "^ (p. 314) 
 
 Sori usually in the leaves or stems, occasionally in other parts, 
 producing dark-colored, usually dusty, spore-masses; 
 spore-balls permanent, composed of an enveloping 
 cortex of tinted sterile cells and usually one to 
 Fic. 233.— Spore several interior fertile cells; fertile cells generally 
 
 ymiL" After dark-colored; germination often by a short promyce- 
 
 Thaxter. jj^^j-j^ which pro- 
 
 duces terminally-grouped spori- 
 dia; these give rise to similar 
 secondary sporidia or to infec- 
 tion-threads. 
 
 Besides the forms discussed 
 below, foreign species are listed 
 on Anemone, Liliacese, Gladiolus, 
 Primula, etc. 
 
 U. cepulffi Frost.27' ^^' ^=^0' ''' 
 
 Sori in leaves, forming isolated 
 pustules or affecting them for 
 the greater part of their length 
 and breadth, sometimes occur- 
 ring at their bases, in the bulbs. 
 Upon rupture of the covering 
 membrane a dusty black-brown 
 spore-mass appears; spore-balls 
 ovoid to spherical, 17-25 /jl in 
 length; sterile cells tinted, ovoid 
 to spherical, small, rather com- 
 pletely covering the spores, 
 usually 4-8 /j. in length; fertile 
 cells reddish-brown, ovoid to 
 spherical, usually 1, rarely 2 in 
 a ball, chiefly 12-16 fjt, in length. 
 On Allium. 
 
 The first American description of the fungus was by Farlow ^^ 
 in 1876. A second thorough paper was from Thaxter in 1889.^^ 
 
 The mycelium grows between the host cells. At maturity lateral 
 
 Fig. 234. — Spores of U. cepulce germi- 
 nating. X, sporidia; 23, germinating 
 conidium. After Tliaxter. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 319 
 
 =4)==::;^ 
 
 Fifi. 
 
 235. — Successive 
 stages in formation 
 of spore balls. Af- 
 ter Thaxter. 
 
 outgrowths appear from the hyphae at various points. One of 
 these assumes a somewhat spherical form and matures to the fertile 
 spore, while the other branch or branches grow around it, Fig. 235, 
 branching and dividing into joints which eventually round off to 
 form the sterile exterior cells. Spores are 
 known to live in soil for at least twelve years. ^^ 
 A period of rest is necessary before they can 
 germinate. In germination the central spore 
 produces a single short hypha, commonly 
 branched, on which the conidia are borne ter- 
 minally and laterally. Fig. 234. Experiments 
 by Thaxter indicate that infection is subter- 
 ranean. 
 
 U. occulta (Wal.) Rab.i^^' ''' 
 Sori in leaves, especially in the sheaths, 
 culms and inflorescence, forming linear striae 
 usually of great length and often merged into 
 a continuous stratum of dusty, reddish-black, spore-balls; spore- 
 balls oblong to subspherical, 16-32 /j, in length; sterile cells 
 often incompletely covering the spores, hyaline or yellowish, sub- 
 spherical to oblong, usually with distended and uniformly thick- 
 ened walls; fertile cells reddish-brown, oblong to subspherical, 
 often flattened, smooth, 1 to 4 in a ball, 11-18 /x in length. 
 
 On rye wherever cultivated, though not common in America. 
 The seat of spore formation is most often on the stems or sheaths, 
 though all aerial parts of the plant are susceptible. In the vege- 
 tative parts the fungus is commonly found in 
 the tissue between the vascular bundles. 
 U. violse (Sow.) F. de W.^-^' "^' ''"^ 
 Sori on stems, rootstocks, petioles and leaves 
 forming prominent irregular swellings often sev- 
 eral centimeters in length, rather permanently 
 covered by the host tissues but upon rupture 
 ' disclosing black-brown spore-masses; spore-balls 
 reddish-brown, rather irregular, oblong to subspherical, chiefly 
 28-55 n in length; sterile cells yellowish-tinted with age, 6-10 /j. 
 in length; fertile cells light reddish-brown, ovoid to spherical or 
 polyhedral, chiefly 4-8 in a ball, mostly 11-15 jj. in length. 
 
320 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 On violets. In America it has been reported in Canada, Min- 
 nesota and Utah. 
 
 U. anemones (Pers.) Wint.^"^ occurs on various species of Ranun- 
 culacese in both the old and new world. 
 
 U. agropyri (Preu.) Schr.^ 
 
 Sori in various parts, commonly in leaves, forming striae, which 
 may be distinct or cover the surface of the leaf; at first lead-colored 
 and protected by the epidermis but soon rupturing and scatter- 
 ing the reddish-brown spores; spore-balls oblong to subspherical, 
 16-32 iJL in length; sterile cells hyaline to yellowish, oblong to 
 subspherical, usually completely covering the fertile cells, outer 
 wall thin and by collapsing giving a ridged effect to the covering; 
 spores 1 or 2, rarely 3 or 4 in a ball, reddish-brown, oblong to sub- 
 spherical, often flattened, smooth, 11-18 fx in length. 
 
 On Agropyron and some other coarse grasses throughout the 
 United States and Europe. 
 
 U. colchici (Schl.) Rab.^^^ On various species of Liliacese but 
 not on hosts of -economic importance in America. 
 
 U. italica Speg. probably not a true smut, is injurious to 
 acorns, chestnuts and the seeds of the white fir.^^ 
 
 Species of less importance or non- American are: 
 
 ■U. gladioli (Req.) Sm. on Gladiolus; 
 
 U. ornithogali Korn. on Ornithogalum; 
 
 U. kemetiana Mag. in pansy ovaries; 
 
 U. primulicola Mag. on primrose flowers. 
 
 Entyloma De Bary ^^^' "s (p. 314) 
 
 Sori usually foliar, generally forming discolored but not distorted 
 areas, permanently embedded in the tissues; spores single, pro- 
 duced terminally or intercalary in the mycelium which does not 
 entirely disappear through gelatinization, free (sometimes irregu- 
 larly adhering through pressure), hyaline to yellowish or reddish- 
 yellow, rarely dark-colored, germination by a short promycelium 
 bearing a terminal group of sporidia which usually conjugate in 
 pairs and produce secondary sporidia or infection-threads; sporidia 
 often formed by germination of the spores in situ, the promycelium 
 protruding through the stomata. 
 
 Twenty American species are recorded. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 321 
 
 Foreign species are on Papaver, Ranunculus, Delphinium, Calen- 
 dula, Thalictrum and several other hosts. 
 
 E. betiphilum Bub. is described on beet seed capsules; ^^ 
 
 E. lephroideum for the same host in France; 
 
 E. calendulae (Oud.) de B. on Calendula. 
 
 E. crastophilum Sacc." 
 
 Sori in leaves, subcircular to linear, about 0.25-2 mm. in length, 
 usually distinct though occasionally merged, black, long covered 
 by the epidermis; spores dark-brown, tightly packed and adhering 
 
 Fig. 237. — E. ellisii, chlamydospores germinating within 
 the leaf tissue, sporidia superficial. After Halsted. 
 
 more or less, chiefly ovoid to spherical or angled through pressure, 
 rather thick-walled, 8-14 /x in length. 
 
 On Poa, Phleum, Agrostis and other grasses in Europe and 
 America. 
 
 E. irregulare Joh. occurs on species of Poa in Europe and 
 America; 
 
 E. polysporum (Pk.) Farl. on various hosts including the com- 
 mon sunflower. 
 
 E. ellisii Hals.^i 
 
 Sori in leaves, forming pale white spots, indefinitely limited, 
 subconfluent; spores hyaline or slightly yellowish, clustered in the 
 intercellular spaces beneath the stomata, spherical, thick-walled, 
 (2-5 n) chiefly 16-20 n but varying from 11 to 25 ju in diameter; 
 conidia hypophyllous, abundant, acicular, small, 10-14 fx by less 
 than 1 )U. 
 
 On spinach, New Jersey.^^' ^^^ 
 
 The chlamydospores germinate in situ beneath the stomata 
 and bear the sporidia on tufts of promycelia which emerge through 
 the stomata, presenting much the appearance of a Hyphomycete. 
 
322 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 E. australe Speg. 
 
 Sori foliar, forming spots, yellowish to eventually dark, usually 
 0.5-6 mm. in length; spores light to reddish-yellow, ovoid to 
 spherical or sUghtly angled, chiefly 10-16 jj. in length; conidia 
 linear, somewhat curved, usually 30-55 x 1-2 }x. 
 
 Common and destructive on many species of Physalis and on 
 Solanum, especially on some of the cultivated forms throughout 
 the Americas and in Africa. 
 
 E. fuscum Schr.^^^ 
 
 Sori in leaves, about 2-6 mm. or by confluence much larger, 
 spores light yellow to chestnut-brown, provided (especially when 
 young) with a conspicuously swollen gelatinous envelope, smooth, 
 chiefly 13-19 ix in length; the hypophyllous matted outgrowths 
 usually show few conidia which are fusiform, single-celled or sep- 
 tate, 10-22 X 3 At. 
 
 It occurs on Papaver in Europe and Eastern North America. 
 
 E. nymphaeae (Cunn.) Set.^^'' 
 
 Sori in leaves, forming variable and irregular areas, usually 
 most prominent on the under side, yellowish or with age reddish- 
 brown, scattered or confluent; spores hyaline, ovoid to subspherical, 
 usually apiculate and with the remains of the hypha as a basal 
 appendix, smooth or under an immersion lens minutely verrucu- 
 lose, 10-14 fx in length; conidia not observed but spores said to 
 germinate in situ. 
 
 On leaves of various water lilies in both the old and new world. 
 
 Doassansia Cornu.^*^' "^ (p. 315) 
 
 Sori in various parts of the host, usually 
 in the leaves, rather permanently embedded 
 in the tissues; spore-balls conspicuous, per- 
 manent, consisting of a distinct cortical 
 layer and a central mass of fertile cells en- 
 T?,^ oQc T-. • tirely filHng the interior, or with the inner- 
 
 jbiG. 238. — Doaswansia. -^ ° ' 
 
 Part section through most cells Supplanted by parenchymatous 
 
 a spore ball showing , i i i i i i i- 
 
 sterile and fertile cells, cells or hyphal threads; spores hyalme or 
 
 After Dietel. yellowish, with smooth, usually thin, walls; 
 
 germination often in situ, by means of a short promycelium which 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 323 
 
 gives rise to a terminal group of elongate sporidia, these often 
 bearing secondary and even tertiary groups. 
 
 The only species of this genus which occur on economic plants 
 are D. gossypii Lagerh.^- on cotton in Ecuador and D. niesslii 
 de Toni (Niess) Schr. on Butomus. 
 
 The following genera, which are usually referred doubtfully to 
 the Ustilaginales will be found under "Genera of Unknown Af- 
 finity" page 663. 
 
 Graphiola Poit, on various palms. Schinzia Nag. on Solanum. 
 Bornetina M. & V. on Vitis. 
 
 Protobasidii (p. 299) 
 
 The three orders which belong to this group are characterized 
 by septate basidia. 
 
 Key to Orders of Protobasidii 
 
 Basidia with cross walls 
 
 Basidia arising from chlamydospores, 
 
 Life cycle polymorphic. Parasites 1. Uredinales, p. 323. 
 
 Basidia not arising from chlamydospores 
 Not polymorphic. Gelatinous sapro- 
 phytes 2. Auriculariales, p. 392. 
 
 Basidia with lengthwise partitions, gelat- 
 inous saprophytes 3. Tremellales. 
 
 Uredinales"' *'' ^^' ^°' ^^' ^'"'' ^"°-^^^' ''^' ^^^-^^^ * 
 
 Small fungi, mostly microscopic, parasitic in the tissues of 
 ferns and seed plants. Mycelium much branched, septate, and 
 with haustoria. Spores borne in sori below the surface of the host, 
 or rarely single within the host. Sori naked, enclosed by peridia 
 or paraphyses, or embedded in a thin stroma. Spores of five mor- . 
 phological sorts, not all present in every genus; (1) basidiospores, 
 minute, thin-walled, without surface sculpturing, (2) pycniospores, 
 small, smooth, of unknown function, (3) seciospores, verrucosely 
 sculptured, borne in chains, (4) urediniospores, echinulately or 
 
 * Arthur's terminology involving the words pycnium, spcium, urediniiim, 
 telium and derivatives from these words, will be followed in the treatment of 
 this order. 
 
324 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 verrucosely sculptured, borne singly, or sometimes in chains, 
 (5) teliospores, smooth or variously sculptured but not echinulate, 
 borne singly or in chains. In every species the mycelium even- 
 tually gives rise to teliospores, which produce in germination 
 four basidia, either remaining within the spore-cell or borne in 
 the air on a short promycelium, each basidium supporting a single, 
 stalked or sessile basidiospore. 
 
 The order of some two thousand species, constituting the 
 "rust" fungi, many of them living on cultivated plants of high 
 value, is of great economic significance. Its members are strict, 
 obligate, parasites which in no stage of the life except in the 
 promycelial stage can develop other than on the living host. 
 The complexities of the life histories of the species, with their five 
 distinct spore forms, inhabiting at different seasonal periods two 
 
 or even three different host 
 plants, renders the order both 
 difficult and exceedingly in- 
 teresting. 
 
 The life history of the most 
 complete of these fungi may 
 be stated as follows: 
 
 I. ^cia (aecidia) and O. 
 pycnia (often called spermo- 
 gonia or pycnidia). The my- 
 celium arising from a basidio- 
 spore invades the host plant, 
 and vegetates until vigor suf- 
 ficient to spore formation is 
 attained, meantime often pro- 
 ducing local spotting, hyper- 
 trophy, or other injury to the 
 host. The mycelium then de- 
 velops a stroma which pro- 
 duces spore beds (sori) and ruptures the epidermis. These sori 
 are usually deeply sunken in the host and cup-shaped and take 
 the common name "cluster cups," Fig. 239, technically aecia or 
 aecidia. The sporophores arise from a hyphal plexus at the base 
 of the cup and the spores are borne catenulate in acropetal suc- 
 
 FiG. 239. — ^^cium and pycnium. 
 Tavel. 
 
 After 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 325 
 
 cession. The whole structure is usually red or yellow. The outer 
 layer of the cup usually consists of a palisade of sterile sporo- 
 phores bearing sterile cells and constitutes the peridium. The 
 aeciospores are usually nearly globular, or angular by compression, 
 reddish and rough and sometimes bear germ pores. They are ca- 
 pable of germination at once and on germination give rise to germ 
 tubes which may infect susceptible hosts, leading to a mycelium. 
 This in turn again produces sori which in some species may be 
 secia, in others telia, but in most species, uredinia. 
 
 Associated with the secia, occasionally with other spore forms, 
 but never borne alone, are minute pycnia with sporophores 
 arising from their walls and bases. These bear unicellular pycnio- 
 spores. Sterile hairs usually protrude from the ostioles. The 
 whole structure in gross appearance is much like the pycnidium 
 of Phoma or Phyllosticta but it is reddish or orange in color. 
 These pycnia were formerly often spoken of as " spermogonia " 
 and the spores as "spermatia," due to the thought that they stood 
 for degenerated male organs; a view supported by the fact that 
 the spores were not observed to germinate. Germination -'^ has 
 now been observed and there is no longer reason to regard them 
 as sexual organs. 
 
 II. Uredinia (uredo-sori). The seciospores may infect the 
 same species of plant that produced the aeciospores (autoe- 
 cious) or plants of an entirely different species (heteroecious). 
 The mycelium produced by the seciospore develops within the 
 host; usually remains local, and causes spotting. When it has 
 attained sufficient vigor and age, usually after about two weeks, 
 it produces a sub-epidermal hyphal plexus from which arises a bed 
 of sporophores which bear unicellular, hyaline to brown, nearly 
 globose, thin-walled, usually echinulate or rough spores, each with 
 from 2 to 10 germ-pores variously placed. These are the ure- 
 diniospores borne in uredinia (uredo-sori). They may germinate 
 at once producing a germ tube which develops to a mycelium. 
 
 These spores falling on susceptible tissues, by infection, usually 
 stomatal, continue the production of uredinia and spread the 
 disease. The urediniospores are usually short-lived and function 
 to spread summer infection. They continue to form throughout 
 the growing season. 
 
326 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 In a few species ^^^' ^^^ there are what are known as amphispores 
 or resting forms of urediniospores provided with thickened walls. 
 They have colorless contents and pedicels more persistent than 
 those of the usual urediniospore. 
 
 III. Telia (teleuto-sori). Toward the latter part of the grow- 
 ing seasons another kind of spore appears, often in the same 
 sorus with the urediniospore and from 
 the same mycelium. It is of various 
 forms in different genera, one or more- 
 celled, varies in shape, thickness of 
 wall, surface marking, color, etc., but 
 is uniform in the character of the 
 germination which is very different from 
 that of any of the other rust-spores. 
 
 In teliospore germination, typically 
 each cell of the teliospore sends forth 
 one germ tube. These tubes soon cease 
 growth and by septation become 4-celled. 
 Each cell then sends out a short branch 
 (sterigma) on which there develops one 
 round or oval, 1-celled, thin-walled spore, 
 the basidiospore, often in this group 
 called the sporidium. 
 
 Morphologically the promyceUum is a 
 basidium bearing its four sterigmata and 
 Fig. 240.— termination of four basidiosporcs. Relationship is thus 
 AfterSh!^ ^' '''^'''■^^'" shown on the one hand to the Ustilagi- 
 nales, on the other hand to the Auricula- 
 riales, an assumption that is borne out by cytological evidence. 
 Deviations from the typical mode of germination are found in sev- 
 eral genera mentioned below (e. g., Coleosporium). 
 
 Basidiospores germinate immediately by germ tubes which on 
 suitable hosts give rise again to a?cia and pycnia or in some 
 species to other spore forms completing the life cycle. 
 
 The most complex life cycle is thus seen to comprise pycnio- 
 spores, seciospores, urediniospores, teliospores and basidiospores. 
 For brevity the first four stages are commonly designated by 
 the following symbols: 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 327 
 
 0. Pycnia or pycnial stage 
 
 1. iEcia or secial stage 
 
 11. Uredinia or uredinia stage 
 
 III. Telia or telial stage 
 
 The spores in all cases, except those of the basidiospores and 
 
 Fig. 241. — Ainiihispores, urediniospores and teliospore.^ i>l I'ik i inia vexans. 
 After Holway. 
 
 pycniospores arise by direct conversion of a mycelial cell into 
 a spore, i. e., they are chlamydospores. 
 
 Mesospore is a term applied to occasional unicellular forms of 
 teliospores found in Puccinia and related genera which do not 
 usually have unicellular teliospores. 
 
 As has been said the pycniospores seem to be functionless 
 though by some it is thought that they do function but that man 
 has yet failed to find the conditions under which they readily 
 germinate and cause infection. The secial stage appearing first, 
 and thus commonly in the spring, is often called the " spring stage." 
 
328 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 It serves as an early stage to propagate and spread the fungus. 
 The uredinia often called the "summer stage" constitute the 
 phase usually of longest duration and of most injury. Its function 
 is preeminently to multiply and spread the fungus. 
 
 The telia, often called the "winter stage," usually, but not al- 
 ways, constitute the resting, hibernating stage. In many instances 
 the teliospores must rest over winter before they are capable of 
 germination. Classification is based primarily on the tehospores. 
 
 While all five of the spore forms discussed above are typical of 
 many species there are many other species which do not possess 
 all of these forms or indeed which may possess only one spore form. 
 
 Schroter for convenience groups the rusts, according to the 
 spore forms that they show, under the following type names 
 though it must be recognized that such grouping is purely arti- 
 ficial and does not necessarily bring together closely related species. 
 
 Eu-type 0, I, II, III present; 
 
 Brachy-type O, II, III present; I omitted. 
 
 Opsis-type 0, I, III present; II omitted. 
 
 Hemi-type II, III present; O, I omitted. 
 
 Micro-type only III present; germination only after 
 
 a resting period. 
 Lepto-type only III present; germination without a 
 
 resting period. 
 
 As examples of the above we have the following : 
 Eu-type, Puccinia asparagi, 0, 1, II, and III, all on Aspar- 
 
 agus. 
 Brachy-type, Puccinia suaveolens, 0, II, and III, all on thistle. 
 Opsis-tjTDC, Puccinia tragopogonis, O, I, and III, all on salsify. 
 Hemi-type, Uromyces caryophyl- 
 
 linus, II, and III, both on Di- 
 
 anthus. 
 Micro-type, Puccinia ribis. III, on Ribes. 
 
 Lepto-type, Puccinia malvacea- 
 
 rum. III, on hollyhock. 
 
 Hundreds of the hemi-types will doubtless be revealed by study 
 to be heteroecious eu-types. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 329 
 
 Hetercecism.^-'' All of the examples just given are autoecious, 
 i. e., all known spore forms are found on the same species of host 
 plant. In many other rusts, however, heteroecism prevails, i. e., 
 one stage of the fungus is found on one species of host and another 
 stage upon another host; rarely three host plants are involved in 
 the cycle. Aside from the rusts only one other fungus (Sclcrotinia 
 ledi) is known to show heteroecism. 
 
 Heteroecism has been experimentally proved in some one hun- 
 dred and fifty cases and may be assumed to exist in many hun- 
 dreds of cases not yet investigated. 
 
 Examples of heteroecism are as follows: 
 
 Stages O, I. 
 Eu-type, Puccinia graminis, Berberis 
 
 " rubigo-vera, Boraginaceae 
 " sorghi, Oxalis 
 
 Uromyces pisi, Euphorbia 
 
 Opsis-type, Gymnosporangium 
 
 macropus, Apple 
 
 It frequently 
 happens that part 
 of the life cycle is 
 passed upon a mo- 
 nocotyledonous 
 plant, the remain- 
 der upon a dicoty- 
 ledon. In such 
 event it is more 
 often the II and 
 III stages that are 
 on the monocoty- 
 ledon while the O, 
 I stages are on the 
 dicotyledon; exam- 
 ples of this are af- 
 forded in the nu- 
 m e r o u s rusts of 
 grasses, sedges and rushes. 
 
 Stages II, III. 
 
 Wheat 
 
 it 
 
 Corn 
 Pea 
 
 Red cedar (III) 
 
 Fig. 242. — Urediniospore of P. asparagi germinating on 
 surface of plant, and separate spores. After Smith. 
 
 In one group the pycnia and the 
 
330 
 
 • THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 secia are on pines (Peridermium), while the other stages are 
 on dicotyledons. In the Gymnosporangiums the pycnial and 
 secial stages are on Rosacese; the tehal on Juniperus and its kin. 
 While a few general rules can be worked out concerning host 
 relations there are many exceptions and to know one stage of 
 a hetercecious rust generally gives little or no clue to what its 
 complementary host may be. 
 
 The mycelium of the rusts is usually intercellular and local though 
 in a few instances it is extensive and even perennial in the host. It is 
 abundantly branched, closely septate, gives off haustoria and usually 
 bears numerous oil drops which lend a yellow or orange color. 
 
 Irritation by the mycelium often induces marked hypertrophy 
 or even witches' brooms or other deformation of the host. Hy- 
 pertrophy is most common with the secia but may result 
 
 from the telia as 
 well, as is conspicu- 
 ously shown in the 
 genus Gymnospor- 
 angium. In some 
 instances the whole 
 habit of the host 
 plant is altered by 
 the presence of the 
 mycelium so as to 
 render it almost un- 
 recognizable, e. g., 
 the secium of Uro- 
 
 FiG. 243. — Cross-section, showing infection from spore Tr^-,Tna^ t-.i"oi* /\-n 1?n 
 of P. asparagi. After Smith. myCCS piSl OH £iU- 
 
 phorbia. 
 
 The host cells are seldom killed by the mycelium, which ab- 
 stracts its food supply from the carbohydrates and other nutrients 
 of the cell sap without direct injury to the protoplasm, though 
 ultimately there is serious effect upon both growth of the host 
 and its seed production. 
 
 Cytology.179' 180. i89. 313-315 Dangeard ^^^ and Sappin-Trouffy ^^ 
 showed that the mycelial cells of the rusts are binucleate, a condi- 
 tion which begins just below the secium. The origin and signifi- 
 cance of this condition is of much interest. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 331 
 
 In all of the rusts so far investigated that have an aecium or 
 primary uredinium there is in the seeio-mycelium or the primary 
 uredinio-mycelium a fusion of uninucleated cells, gametes. This 
 cellular fusion is not, however, followed by a nuclear fusion until 
 after long delay ; but the two nuclei remain in the fusion cell and 
 when this cell divides both nuclei divide mitoticallj^ and simul- 
 taneously but still independently of each other (conjugate division). 
 This process continues through the aecial sporophores, or uredinial 
 sporophores, and in the production of the spores, with the result 
 
 i^<r:'^^,— C.TTt. 
 (■©5/. — Cm, J. 
 
 Fig. 244.— Showing 
 conjugate nuclei and 
 degenerating cells in 
 conidiospore chain 
 of ^Ecidium. After 
 Sappin-Troufify. 
 
 Fig. 245. — Gymnospo- 
 rangium, clavariae- 
 forme, mitosis of a 
 nucleus in the promy- 
 celium. After Black- 
 
 FiG. 240. — Conjugate 
 nuclear division in 
 Gymnosporangium 
 clavarii3eforme show- 
 ing four chromatin 
 masses. After 
 Blackman. 
 
 that the cells of all of these are binucleate. The conjugate divi- 
 sion continues further through the uredinia and until teliospore 
 formation occurs, the whole intervening series of cells being binu- 
 cleate. Prior to the formation of the promycelium and in the 
 teliospore the nuclei unite, reducing the cells again to an uninu- 
 cleate condition. 
 
 In rusts which have only teliospores the binucleate condition 
 begins somewhere in the mycelium from which the teliospores 
 arise. 
 
 It is generally held that the cellular fusion is a sexual act 
 with long delayed fusion of the sexual nuclei: and consequently 
 that the uninucleate phase is the gametophyte; that the be- 
 
332 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 ginning of the binucleate condition marks the origin of the sporo- 
 phyte. 
 
 Biologic specialization ^^^' 1^2.174. 309 ^luch as is found in the Erys- 
 iphales occurs also in the Uredinales. There are many species, each 
 of which is found on a large number of hosts. Upon its numerous 
 hosts the fungus may show no morphological variation, yet at- 
 
 FiG. 247. — Conjugate nu- 
 clear division in cells of 
 P u c c i n i a podophylli. 
 After Christman. 
 
 Fig. 248. — Diagram- 
 matic representation 
 of fusion of nuclei 
 in the teliospore. Af- 
 ter Delacroix and 
 Maublanc. 
 
 tempts to inoculate from one host to another may uniformly give 
 negative results. It further often occurs that one stage, e. g., 
 the aecia of a species may grow upon only one host while the 
 uredinia or telia may grow upon many different species of hosts; 
 and in such cases that seciospores which have arisen on host X, 
 from infection with spores from host A, are capable of infecting 
 host A and that host only; while seciospores which have arisen 
 on host X, by infection with spores from host B, are capable of 
 infecting host B and only this host; and so on for numerous forms. 
 Yet the uredinia and telia of these different races may be mor- 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 333 
 
 phologically inseparable as are also their secia when grown upon 
 their common host. 
 
 An excellent example of such biologic specialization is offered 
 in the common pine Periclermium. ^cia may be produced upon 
 the pine by sowing of Coleosporium teliospores from Senecio, 
 Campanula, Pulsatilla, etc., but the seciospores which develop 
 on the pine are capable of in- 
 fecting only those species of 
 hosts from which the telio- 
 spores were taken. 
 
 Similarly Eriksson ^^^ has de- 
 termined that though rusts 
 from many grains can infect 
 the barberry, the seciospores 
 there produced are not capable 
 of infecting plants of species 
 other than those from which 
 the fungus was derived, or at 
 most they can infect but a 
 very limited number of species. 
 
 A further complication arises 
 from the facts obtained through 
 experiments in various coun- 
 tries, which have shown that what is apparently the same species 
 may consist of a large number of strains or varieties which be- 
 have differently in different geographic areas. The stem rusts of 
 wheat and barley, for instance, are very similar, interchanging 
 hosts easily and being capable of transfer to various grasses in this 
 country, though in Sweden the stem rust of wheat goes with 
 difficulty to barley and rye, while the stem rusts of barley and 
 rye interchange hosts very easily. 
 
 Owing to the prominence of its author and its place in litera- 
 ture a word may be given to the usually discredited mycoplasm 
 theory i^*'!^^. 312 ^f Eriksson. This affirms the existence in the 
 cells of wheat grain of an intimate mixture of rust protoplasm and 
 host protoplasm. This mycoplasm may rest thus for months. 
 Finally the host-cell nucleus becomes digested and the fungous 
 plasm develops to a mycelium which proceeds to invade the sur- 
 
 FiG. 249. — Urediniospores in Rubus show- 
 ing nuclear conditions. After Black- 
 man. 
 
334 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 rounding tissues of the seedling as these develop on germination 
 of the seed. 
 
 Infection Experiments. Since the method of studying the 
 rusts by observing their life histories in the laboratory where 
 they are under complete control of the observer has assumed 
 such prominence of late years the technique deserves notice. 
 The first step is to find associated in the field the secia and 
 other stages of a rust in such way as to suggest relation- 
 ship between two forms hitherto unknown to be connected. 
 
 Material of the rust is then collected and healthy host plants 
 are also removed to the laboratory. If the teliospores are col- 
 lected in the fall they are kept out of doors in cheese cloth bags 
 till germination time in the spring. Whether collected in spring 
 or fall the viability of the spores must be tested by sowing in a 
 hanging drop of water. If germination is plentiful then the infec- 
 tion experiment is made. First the suspected alternate host is 
 sprayed with water to give the spores proper conditions for ger- 
 mination, then masses of spores are placed directly on the plant 
 by a scalpel and a bell jar is placed over the plant to assure a humid 
 atmosphere. In from five to eight days yellow spots should indi- 
 cate where the infection has taken place and in a short time 
 pycnia and secia or other sori follow. In all infection work it is 
 imperative to know that the plants used be not already infected 
 in the field from another source. 
 
 The secium is by some regarded as a structure whose function 
 is to restore vigor to the rust fungus.^°^ On the other hand, 
 Freeman and Johnson ^°^ found that in fifty-two generations 
 of the fungus, without the intervention of aecia or telia there 
 was no apparent diminution in the vitality of the uredinial 
 generation. 
 
 Form Genera. The telial stage is regarded as the highest 
 stage of the rust fungus and is the one on which classification is 
 often based. Thus an secium, uredinium, cseoma, etc., that is 
 known to possess a telial form is regarded as part of the species 
 indicated by its teliospore, e. g., ^cidium berberidis being part 
 of Puccinia graminis has no specific identity but is regarded as 
 a stage of P. graminis. 
 
 There are numerous uredinia, secia and other non-telial forms 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 335 
 
 of which the telial stage is not yet known. It beconres neces- 
 sary for the present, for convenience of reference, to have 
 names by which to designate these forms. For this purpose the 
 form-genera ^Ecidium Cseoma, Peridermium, Roesteha and Uredo 
 are recognized. We group these under the heading Uredinales 
 Imperfecti. 
 
 Darluca and Tubercuhna, two imperfect fungi, are often found 
 growing as parasites upon the rust fungi. 
 
 Key to Families of Uredinales 
 
 Teliospores in germination becoming 
 4-celled, compacted laterally 
 into waxy layers; walls of the 
 
 spores weakly gelatinous 1. Coleosporiacese, p. 335. 
 
 Teliospores germinating by a promy- 
 
 celium 
 
 Teliospores compacted laterally 
 
 into a crust or column (rarely 
 
 solitary within the tissues); 
 
 walls of the spores firm 2. Melampsoraceae, p. 340. 
 
 Teliospores free or fascicled; walls 
 of the spores firm or with an 
 outer hygroscopic layer cov- 
 ered by cuticle 3. Pucciniaceae, p. 353. 
 
 Teliospores unknown 4. Uredinales Imperfecti, p. 389. 
 
 Coleosporiaceae 
 
 Teliospores united in a one or two-layered waxy cushion, ses- 
 sile or borne on a broad sac-like stalk and then at the beginning 
 2-celled. Each original spore-cell divides to four super-imposed 
 cells from each of which a simple sterigma emerges. This bears a 
 large basichospore. 
 
 The most important character is the peculiar mode of basidio- 
 spore production, the 4-celled promycelium being formed within 
 the spore. 
 
 The family is of little economic importance except in its secial 
 stage on conifers. 
 
336 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Key to Genera of Coleosporiaceae. 
 
 Basidiospore spindle-shaped 1. Ochropsora, p. 336. 
 
 Basidiospore ellipsoid 
 
 Teliospores in a single layer 
 
 Teliospore layer stronglj^ arched, form- 
 ing minute knobs 2. Mikronegeria. 
 
 Teliospore in a flat crust 3. Coleosporium, p. 336. 
 
 Teliospores in a double layer, long- 
 stalked 4. Chrysopsora. 
 
 Teliospores in a columnar mass 5. Trichopsora. 
 
 Ochropsora Dietel 
 
 II. Urediniospores solitary. 
 
 III. Teliospores in a waxy crust, loosely united, originally 
 I-celled, later 4-celled, each cell bearing a single basidiospore on 
 a simple sterigma. 
 
 0. sorbi (Oud.) Diet. 
 
 1. iEciospores (=JEi. leucospermum) on anemone. 
 II and III. Urediniospores on Sorbus and Spirea. 
 
 Coleosporium Levielle 
 
 0. Pycnia flattish, linear, dehiscent by a slit, without ostiolar 
 filaments. 
 
 I (=Peridermium). JEcia erumpent, definite. Peri chum color- 
 less with verrucose walls. Spores globose to oblong, with colorless 
 walls, the outer part formed of densely packed, deciduous tubercles. 
 
 II. Uredinia erumpent, definite, without peridium. Spores 
 catenulate, globoid to oblong, pulverulent; wall colorless, closely 
 verrucose, pores obscure. 
 
 III. Telia indehiscent except through weathering, waxy, some- 
 what indefinite, usually roundish. Spores sessile, 1-celled (by 
 early division of the contents appearing 4-celled) ; wall smooth, 
 colorless, thickened and gelatinous at apex. 
 
 The genus is usually heteroecious. Arthur lists some twenty- 
 four species for America. 
 
 There are many biologic forms, morphologically indistinguish- 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 337 
 
 able yet not inter-inoculable. The aecial stage is found on 
 leaves of conifers, the telia on a large variety of hosts. 
 C. ipomoeaB (Schw.) Burr. 
 
 and I. Unknown. * 
 
 II. Uredinia hypophyllous, widely scattered or somewhat 
 clustered, 0.25-1 mm. across, early naked, orange-yellow fading to 
 white, ruptured epidermis usually inconspicuous; spores ellipsoid, 
 13-21 X 18-27 jjL, more or less angular and irregular; wall thin, 
 1-1.5 fi, closely and noticeably verrucose. 
 
 III. Telia hypophyllous, widely scattered, often confluent, pul- 
 vinate, 0.5 mm. or less across, deep reddish-orange fading to pale- 
 yellow; spores with wall swelling 20-40 n above; contents orange- 
 yellow fading to colorless, oblong, or slightly clavate, 19-23 x 
 60-80 ix, rounded or obtuse at both ends. 
 
 Common on various Ipomoeas and their kin among them morn- 
 ing glory and sweet potato. ^^^ 
 
 C. soiidaginis (Schw.) Thiim.*'' '''"'" 
 
 O. Pycnia amphigenous, scattered, numerous, originating be- 
 tween mesophyll and cortical layer, noticeable, 0.3-0.5 mm. wide 
 by 0.5-0.8 mm. long, dehiscent by a longitudinal slit, low-conoidal, 
 80-100 Ai high. 
 
 1 ( = Peridermium acicolum). JEcia. from a limited mycelium, 
 amphigenous, numerous, scattered on discolored spots occupying 
 part of a leaf, erumpent from longi- 
 tudinal slits, tongue-shaped, 0.5-1 mm. 
 long by 0.5-0.7 mm. high; peridium 
 rupturing irregularly, moderately firm, 
 white, cells overlapping, 35-45 /x long, 
 not much narrower, walls transversely 
 striate, inner coarsely verrucose, thick, 
 5-6 fjL, outer less rough and somewhat 
 thinner; spores ellipsoid, 20-25 x 
 28-40 fi; wall colorless, closely and 
 coarsely verrucose with deciduous tu- 
 bercles which are directed away from a smooth spot extending 
 up one side, thick, 2-3 /x on the smooth spot, increasing to 
 5-6 fj, on the opposite side, including the tubercles. 
 
 II. Uredinia hypophyllous, rarely also epiphyllous, irregularly 
 
 Fig. 250. — Stages O. and I. of 
 Coleosporium soiidaginis 
 
 (Peridermium) on P i n u s 
 rigida. After Clinton. 
 
338 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 scattered, or at first somewhat gregarious and crowded, 0.3-0.5 mm. 
 across, soon naked, yellow or orange-yellow, ruptured epidermis 
 inconspicuous; spores ellipsoid or globoid, 17-22 by 20-30 n; 
 wall rather thin, 1-2 fjL, closely and strongly verrucose; contents 
 orange-yellow when fresh, fading to colorless. 
 
 III. Telia hypophyllous, scattered irregularly or sometimes 
 crowded and confluent, slightly elevated, 0.3-0.5 mm. across, 
 reddish-orange; spores with wall swelling 30-40 /x thick above; 
 contents orange-yellow fading to colorless, terete, 15-23 x 55- 
 80 /JL, rounded or obtuse at both ends; basidiospores globoid or 
 elliptical, about 12 x 18 fx, orange-yellow. 
 I. ^cia on Pinus rigida. 
 
 II and III. Uredinia and telia on Aster, Solidago and culti- 
 vated aster (Callistephenis) ; widespread and common. The con- 
 nection between the stages was demonstrated by inoculations by 
 Clinton. i9«' ''' 
 
 C. senecionis (Schum.) Fries. 
 
 O. Pycnia amphigenous, scattered, numerous, originating be- 
 tween mesophyll and cortical layer, noticeable, 0.2-0.3 mm. wide, 
 0.5-1 mm. long, dehiscent by a longitudinal 
 slit, 70-100 fx high. 
 
 I (=Peridermium oblongisporium) . vEcia 
 from a limited mycelium, amphigenous, bul- 
 late, tongue-shaped, 1-2 mm. long, 0.7- 
 1 mm. high, whitish; peridium rupturing ir- 
 regularly, fragile, white, cells overlapping, outer 
 and inner walls of same thickness, 3-4 jj,, outer 
 smooth, inner moderately verrucose; spores 
 Fig. 251.— "coleospo- broadly ellipsoid, 17-24 by 28-36 (jl, wall 
 rium senecionis, colorless, thick, 3^ n, densely verrucose with 
 
 showing germina- _ ' ' . 
 
 tion of teiiospores. prominent elongate papillae. 
 
 ^ ^ * II. Uredinia hypophyllous, thickly scattered, 
 
 about 0.5 mm. across; early naked, bright orange-yellow fading 
 to pale-yellow, ruptured epidermis evident; spores elliptical- 
 globoid or obovate-globoid, 17-21 by 20-27 /x; wall thin, 1- 
 1.5 /x, evenly but not densely verrucose, with low papillae. 
 
 III. Telia hypo-phyllous, scattered, often confluent, small, 0.3 
 mm. across, brilliant orange-yellow fading to pale orange-yellow; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 339 
 
 spores with wall swelling 15-25 /x thick above; contents orange- 
 yellow fading to pale-yellow, clavate or clavate-oblong, 16-20 ])y 
 60-83 /i, rounded at both ends or narrowed below. 
 
 I. JEcia on Pinus sylvestris. 
 
 II and III. Uredinia and telia on Senecio. What may be this 
 same fungus is reported also on cultivated Cineraria.^^^ The 
 teliospores hibernate in their dark-red sori producing promycelia 
 in the spring. The sporidia bring about spring infection of the 
 pine leaves and young twigs, later resulting in pycnia and secia. 
 The connection of the forms was established by Wolff in 1872. 
 
 L. pmi LTali. 
 
 0. Pycnia unknown, probably wanting. 
 
 III. Telia amphigenous, on yellow spots, usually near the tips 
 of the leaves, long covered by the epidermis, 1-5 mm. long, or 
 when confluent up to 10 mm. or more, reddish-orange fading to 
 pale-yellow or dirty- white, ruptured epidermis inconspicuous; 
 teliospores with . walls swelling 30-50 (j. above, and soon dis- 
 appearing upon exposure; contents orange-yellow fading to nearly 
 colorless, clavate, slender, 13-20 by 60-100 ^i, acute or rounded 
 above, much narrowed below, sides wavy or irregular. 
 
 This is set apart by Arthur as the type of a distinct genus, 
 Gallowaya, based on the absence of spore forms other than the 
 teliospores. 
 
 It causes serious leaf loss on Pinus virginiana. 
 
 C. campanulae (Pers.) Lev.^°" 
 
 0. Pycnia amphigenous, scattered, numerous, originating be- 
 tween mesophyll and cortical layer, noticeable, large, 0.2-0.4 mm. 
 wide, 1-2 mm. long, dehiscent by a longitudinal slit, 90-110 fx 
 high. 
 
 I ( = Peridermium rostrupi). JEcia from a limited mycelium, 
 amphigenous, scattered, 1-3 on discolored spots, bullate, tongue- 
 shaped, large, 1-3 mm. long, 0.7-1.5 mm. high, yellow, fading to 
 white; peridium rupturing irregularly, fragile, white, cells overlap- 
 ping, outer and inner walls same thickness, about 4-6 n, outer 
 smooth, inner moderately verrucose; spores broadly ellipsoid or 
 globoid, 17-22 by 22-31 m; wall colorless, thin, 2-3.5 /x, densely 
 verrucose, with prominent, elongate papillae. 
 
 II. Uredinia hypophyllous, scattered, often confluent, 0.5-1 mm. 
 
340 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 across, soon naked, orange-red fading to white, ruptured epidermis 
 evident; spores ellipsoid, 18-23 by 20-30 n; wall thin, 1-1.5 /x, 
 densely verrucose, with prominent, elongate papillae. 
 
 III. Telia hypophyllous, scattered, often confluent, small, 0.2- 
 0.5 mm. across, slightly elevated, blood-red, fading to pale brownish- 
 yellow; spores with wall swelling 15-25 ^ thick above; contents 
 orange-red fading to nearly colorless, cylindrical or clavate-oblong, 
 17-24 by 55-85 n, rounded or obtuse at each end. 
 
 and I on Pinus rigicla. 
 
 II and III on Campanula and kin. 
 
 There are numerous other species of less importance. 
 
 Melampsoracese (p. 335) 
 
 Telia. forming a more or less definite crust or column; teliospores 
 compacted laterally into layers or rarely solitary in the tissues, 
 sessile; wall firm or rarely with a gelatinous layer. 
 
 The family is pf little importance. Its urediniqil and telial stages 
 do slight injury on poplars and willows. 
 
 Key to Genera of Melampsoraceae. 
 
 Telia indehiscent. 
 
 Sori all subcuticular; teliospores com- 
 pacted in dense layers to form a crust ; 
 secia when present without a perid- 
 ium; uredinia when present without 
 a peridium or with an imperfect 
 one of paraphyses 
 Teliospores in a single layer; uredinia 
 with spores and paraphyses inter- 
 mixed 1. Melampsora, p. 342. 
 
 Teliospores in more than one layer 
 Uredinia with peripheral paraphyses 
 
 only 2. Physopella, p. 345. 
 
 Uredinia without paraphyses 3. Bubakia. 
 
 Pycnia subcuticular, other sori subepi- 
 dermal, or the telia within the epider- 
 mal cells or between the mesophyll 
 cells; uredinia when present with a 
 peridium 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 341 
 
 Teliospores approximating in a single 
 layer witliin or beneath the epider- 
 mis; urediniospores globoid to 
 oblong 
 Walls of the teliospores colored 
 Urediniospores echinulate through- 
 out 4. Pucciniastrum, p. 346. 
 
 Urediniospores echinulate except at 
 
 the apex 5. Melampsoridium,p.347. 
 
 Walls of the tehospores colorless 
 
 Urediniospores ecliinulate 6. Melampsorella, p. 348. 
 
 Urediniospores verrucose 7. Hyalopsora. 
 
 Tehospores solitary within the meso- 
 
 phyll; urediniospores pointed .... 8. Uredinopsis. 
 Telia erumpent, sori all subepidermal 
 Tehospores compacted laterally; aecia 
 when present with flattened perid- 
 ium, rupturing apicaUy; uredinia 
 when present with a dehcate perid- 
 ium and catenulate spores 
 
 With all spore forms in life cycle 9. Melampsoropsis, p. 349. 
 
 With telia and pycnia only 
 
 Promycelium of the ordinary type. 10. Chrysomyxa, p. 350. 
 Promycelial cells changing directly 
 
 to basidiospores 11. Barclayella. 
 
 Teliospores often adhering and extruded 
 in long columns; aecia when present 
 with inflated peridium, dehiscence 
 circumscissile ; uredinia when present, 
 with peridium, spores home singly on 
 pedicels. 
 Teliospores 1 -celled 
 Telia naked 
 
 Telia forming columns 
 
 Teliospores firmly united side- 
 wise and endwise 12. Cronartium, p. 350. 
 
 Teliospores loosely united later- 
 ally, separating in disks .... 13. Alveolaria. 
 Telia not extruded 
 
 Wall brownish, thick 14. Baeodromus. 
 
 Wall colorless, thin 15. Cerotelium. 
 
342 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Wall slightly colored 16. Cionothrix. 
 
 Telia with a peridium 
 
 Telia half projecting above the 
 
 host surface 17. Dietelia. 
 
 Telia sunken in the tissue of the 
 
 host 18. Endophyllum, p. 353. 
 
 Teliospores 2-celled 
 
 Peridium present 19. Pucciniosita. 
 
 Peridium none 20. Didymopsora. 
 
 Melampsora Castaigne (p. 340) 
 
 0. Pycnia half spherical. 
 
 1. iEcia of caeoma-type, no peridium or paraphyses. 
 II. Urediniospores solitary, membrane colorless. 
 
 III. Teliospores 1-celled, rarely 
 more, in flat irregularly limited 
 crusts. Basidiospores spherical. 
 
 The question of biologic speciali- 
 zation is especially complicated in 
 this genus. The uredinial and telial 
 stages occur in abundance on wil- 
 lows and poplars, the secial stage on 
 a wide range of plants embracing 
 gymnosperms, monocotyledons and 
 dicotyledons. 
 
 M. lini D. C. 
 
 0. Pycnia amphigenous, numer- 
 ous, scattered, inconspicuous, sub- 
 epidermal, pale-yellow, flattened 
 globoid or lens-shaped, 100-175 ix 
 in diameter, 65-95 /x high; spores 
 ellipsoid, 2-3 by 3-4 ix. 
 
 1. ^Ecia chiefly hypophyllous, nu- 
 merous, scattered, rounded, 0.2-0.4 mm. across, bright orange- 
 yellow, conspicuous, formed between epidermis and mesophyll, 
 soon naked, ruptured epidermis evident; spores globoid, 19-27 x 
 21-28 IX.) wall colorless, thin, about 1 ix, finely and evenly verru- 
 cose, with distinct papillae, pores not evident. 
 
 Fig. 252. — Pucciiiiastrum goepper- 
 tianum, showing g e r m i n a t i ng 
 teliospores. After Hartig. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 343 
 
 II. Uredinia amphigenous and caulicolous, scattered or some- 
 what gregarious, often crowded, round or on stems elongate, 
 0.3-0.5 mm. across, soon naked, reddish-yellow fading to nearly 
 white, pulverulent, ruptured epidermis noticeable; spores broadly 
 elliptical or obovate, 13-18 x 15-25 n, wall colorless, rather thin, 
 2 yu, evenly and finely verrucose, with low papillae, pores equa- 
 torial, obscure; paraphyses intermixed with the spores, capitate, 
 large, 5-22 x 40-65 fi, smooth, wall thick. 
 
 III. Telia amphigenous and caulicolous, scattered, often con- 
 fluent, round or elongate, 0.2-0.5 mm. across, slightly elevated, 
 reddish-brown becoming blackish; spores subepidermal, appressed 
 into a single layer, prismatic, 1-celled, 10-20 x 42-50 fi; wall 
 brown, smooth, thin, about 1 n, not thickened above. 
 
 Autoecious on flax. Sometimes very injurious. -'^^ 
 M. medusae Thiim. 
 
 0. Pycnia chiefly epiphyllous, scattered or somewhat gregarious, 
 minute, punctiform, pale-yellow, inconspicuous, subcuticular, 
 hemispherical, 40-80 /j, in diameter, half as high. 
 
 1. vEcia chiefly hypophyllous, scattered or somewhat grega- 
 rious, small, 0.1-0.3 mm. broad, round or oblong, pale-yellow 
 fading to white, inconspicuous, formed between epidermis and 
 mesophyll, soon naked, pulverulent, ruptured epidermis notice- 
 able; aeciospores globoid, 17-22 by 17-24 fx; wall colorless, thick, 
 2.5-3 fjL, minutely verrucose, with minute crowded papillae, pores 
 indistinct. 
 
 II. Uredinia amphigenous, or only hypophyllous, scattered, 
 roundish, small, 0.2-0.4 mm. across, early naked, somewhat pul- 
 verulent, orange-yellow, fading to pale brownish-yellow, ruptured 
 epidermis usually inconspicuous; urediniospores ellipsoid or 
 obovate-ellipsoid, 15-18 by 22-30 fx, usually flattened laterally; 
 wall colorless, 2.5-3 fx or up to 10 fx on the flattened sides, sparsely 
 and evenly verrucose, with fine papillae, except on the flattened 
 sides which are smooth; paraphyses numerous, intermixed with 
 the spores, capitate, smooth, 40-65 /x long, head 14-25 /x broad, 
 wall thick, 3-6 fx, peripheral paraphyses thinner-walled and more 
 clavate. 
 
 III. Telia amphigenous or only hypophyllous, scattered or 
 somewhat confluent, irregularly roundish, small, 0.2-0.4 mm. 
 
344 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 across, slightly elevated, light reddish-brown, becoming deep 
 chocolate-brown, subepidermal; teliospores prismatic, 12-15 by 
 30-45 jj.; wall smooth, cinnamon-brown, uniformly thin, 1 /x. 
 
 and I on Larix, II and III on Populus. Common on all 
 species of Populus and often doing serious damage by its early 
 defoliation of the trees. 
 
 M. bigelowii Thiim. with and I on Larix and II and III on 
 Salix is quite similar to the preceding. It occurs on practically 
 all species of willow. 
 
 Other species not found in America are: 
 
 M. allii-fragilis Kleb.^^^ 
 
 1 on Allium vineale and A. sativum. 
 II and III on Salix. 
 
 M. allii-salicis albae Kleb.^^^ 
 
 I on Allium. 
 
 II and III on Willow. 
 M. allii-populina Kleb.^^^ 
 
 I on AlUum. 
 
 II and III on Populus. 
 M. klebahni Bub. 
 
 I on Corydalis. 
 
 II and III on Populus. 
 
 M. larici-pentandrae Kleb.^^^ 
 
 I on Larix. 
 
 II and III on Salix. 
 
 M. larici populina Kleb.'^^^ 
 
 I on Larix. 
 
 II and III on Populus. 
 M. pinitorqua Rost.^^^ 
 
 I ( = Cseoma pinitorquum) . The Cseoma-stage is quite de- 
 structive to pine seedlings. The teliospores grow on Populus 
 leaves. 
 
 M. repentis Plow. 
 
 I ( =Ci3eoma orchidis); on Orchis. II and Illon Salix. 
 
 M. ribesii-viminalis Kleb.^^^ 
 
 I on Ribes. II and III on Salix. 
 
 M. rostrupii Wagn.^^^ 
 
 I on Mercurialis. II and III on Populus. 
 
THE FUNGI WHICH CAUSE PLXnT DISEASE 345 
 
 M. saxifragarum (D. C.) Schr. 
 I and III on Saxifrages. 
 
 Physopella Arthur (p. 340) 
 
 Cycle of development imperfectly known; only uredinia and 
 telia recognized, both subepidermal. Uredinia erumpent, definite, 
 roundish, pulverulent, encircled by more or less clavate paraphyses 
 which are often united at their bases, or wholly, into a pseudo- 
 peridium opening by a central pore. Urediniospores borne singly 
 on pedicels, obovate-globoid or ellipsoid; wall pale-yellow, echinu- 
 late or rarely verrucose, pores obscure. Telia indehiscent, form- 
 ing lenticular masses, two or more cells thick at center. Telio- 
 spores 1-celled; walls smooth. 
 
 P. vitis (Thiim.) Arth.*' 
 
 II. Uredinia hypophyllous, scattered thickly over wide areas, 
 round, minute, 0.1 mm. or less across, soon naked, arising between 
 epidermis and mesophyll, surrounded by numerous incurved pa- 
 raphyses, pulverulent, pale-yellow, fading to dirty white, ruptured 
 epidermis inconspicuous; urediniospores broadly ellipsoid or obo- 
 vate, 13-17 by 18-27 m; wall nearly colorless, thin, 1 /i, minutely 
 and rather closely echinulate, pores obscure; paraphyses hyphoid, 
 curved and irregular, 6-10 /x thick, 30-60 fx long, wall uniformly 
 thin, 1 n, yellowish. 
 
 III. Telia hypophyllous, scattered thickly over large areas, 
 roundish, minute, 0.1-0.2 mm. across, indehiscent, 3 to 4-cells 
 thick; teliospores ovoid, 12-15 by 20-30 ix, wall smooth, nearly 
 colorless, thin, 1 /x or less. 
 
 On grape leaves in Southern United States and West Indies. 
 Also in South America and Japan. 
 
 P. fici (Cast.) Arth." 
 
 II. Uredinia hypophyllous, scattered thickly over large areas, 
 roundish, usually small, 0.1-0.3 mm. across, or rarely larger, bullate, 
 arising between epidermis and mesophyll, tardily dehiscent by cen- 
 tral rupture, encircled by delicate, evanescent paraphyses, pulveru- 
 lent, pale cinnamon-brown, ruptured epidermis overarching or 
 erect; spores obovate-globoid, 14-20 by 18-27 ju) wall pale-yellow, 
 thin, 1-1.5 M, sharply and rather sparsely echinulate, pores ob- 
 
346 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 scure; paraphyses hyphoid, very delicate, collapsing, 60-80 n 
 long, wall colorless, very thin, slightly thickened at apex, 1 fx. 
 
 III. TeUa, unknown. 
 
 II. On fig and osage orange. 
 
 Pucciniastrum Otth. (p. 341) 
 
 Heteroecious. The cycle of development includes pycnia, secia, 
 uredinia and telia, with distinct alternating phases. 
 
 0. Pycnia subcuticular, low-conoidal, without ostiolar filaments. 
 
 1. JEicia erumpent, cylindrical. Peridium delicate, verrucosa 
 on inner surface. Spores ellipsoid, verrucose except one side which 
 is thinner and smooth. 
 
 II. Uredinia barely protruding through the epidermis, dehis- 
 cent by a central pore. Peridium hemispherical, delicate, cells 
 longer at orifice. Spores borne singly on pedicels, obovate to 
 ellipsoid ; wall colorless, echinulate, pores indistinct. 
 
 III. Telia indehiscent, forming more or less evident layers in 
 the epidermal cells or immediately beneath the epidermis. Spores 
 oblong or prismatic, 2 to 4-celled by vertical partitions in two 
 planes; wall smooth, colored. 
 
 Arthur lists nine American species but none are very impor- 
 tant. 
 
 P. hydrangeae (B. & C.) Arth. 
 and I. Unknown. 
 
 II. Uredinia hypophyllous, scattered, round, small, 0.1-0.2 mm. 
 across, dark-yellow fading to pale-yellow, ruptured epidermis 
 inconspicuous, dehiscent by a central pore; peridium hemispher- 
 ical, delicate, cells small, cuboid, walls uniformly thin, 1-1.5 /x, 
 ostiolar cells slightly or not elongate, 10-16 n, barely pointed, 
 walls thin, smooth; spores broadly elliptical or obovate, 12-18 
 X 16-24 n; wall nearly colorless, thin, 1-1.5 fx, sparsely and 
 strongly echinulate. 
 
 III. Telia amphigenous, or chiefly epiphyllous, effused, or 
 confluent into small angular groups, 0.3-0.8 mm. across, not 
 raised, reddish-brown; spores forming a single layer within the 
 epidermal cells, or sometimes between the epidermis and mes- 
 ophyll, globoid, 22-28 x 24-28 n, wall dark cinnamon-brown, 
 uniformly thin, 1.5-2 fx. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 347 
 
 It is found in the uredinial and telial stages on Hydrangea on 
 which it may l)e quite serious. '"- 
 P. goeppertianum (J. Kuhn.) Kleb. 
 
 I. ( =.E. coknnnare) on Abies leaves. Ill on Vaccinium. 
 The secial stage is the destructive form. It has been found 
 
 Fig. 253. — Melampsoridium, section through germinating 
 teiium. After Tulasne. 
 
 but a few times in America, -°^' ^^° while the telial stage is common. 
 Fig. 252. 
 
 P. pustulatum (Pers.) Diet. (=P. abieti-chamaenerii, P. epi- 
 lobii.) 
 
 and I on Abies. II and III on Epilobium. 
 P. padi (Kze. & Schm.) Diet. 
 
 1 ( = ^. strobilinum) on fir. 
 II and III on Prunus padus. 
 
 P. myrtilli (Schm.) Arth. is found in the uredinial and telial 
 stages on various Vacciniums. 
 
 Melampsoridium Klebahn (p. 341) 
 
 0. Pycnia fiattened-conoidal, without ostiolar filaments. 
 
 1. ^cia erumpent, subcylindrical. Peridium regularly dehis- 
 cent, cells rhomboidal. Spores ellipsoid to globoid; wall colorless, 
 thin, verrucose except one side which is thinner and smooth. 
 
 II. Uredinia somewhat erumpent. Peridium firm, dehiscent 
 by central pore; peridial cells isodiametric, those of orifice pro- 
 
348 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 longed into sharp points. Spores borne singly on pedicels, ellipsoid; 
 wall colorless, echinulate, pores indistinct. 
 
 III. Telia indehiscent, forming evident layers immediately 
 beneath the epidermis. Spores oblong or prismatic, 1-celled; 
 wall smooth, slightly colored. 
 
 M. betulae (Schlim.) Arth. occurs, O and I on larch, II and III on 
 Betula. 
 
 Melampsorella Schroter (p. 341) 
 
 0. Pycnia hemispherical, without ostiolar filaments. 
 
 1. ^cia erumpent, definite, oblong, buUate. Peridium color- 
 less, with thin-walled cells. ^Eciospores elUpsoid; wall colorless, 
 thin, verrucose, without smooth spot. 
 
 II. Uredinia barely protruding through the epidermis, dehiscent 
 by a central pore. Peridium hemispherical, delicate, cells slightly 
 or not enlarged at orifice. Urediniospores borne singly on pedicels, 
 obovate to ellipsoid; wall slightly colored, echinulate, pores ob- 
 scure. 
 
 III. Telia effused, indehiscent. Teliospores globoid to ellipsoid, 
 1-celled; wall smooth, colorless, thin. 
 
 M. elatina (A. & S.) Arth.-^^ 
 
 0. Pycnia epiphyllous, few, scattered, punctiform, inconspicu- 
 ous, subcuticular, not extending much into walls of epidermis, 
 depressed-hemispherical, small, 100-130 m broad, 40-50 n high. 
 
 1. J^^cia from a perennial mycelium, dwarfing the young shoots, 
 and forming witches' brooms, hypophyllous, forming two ir- 
 regular lines, deep-seated, wholly dropping out of the substratum 
 at maturity, roundish or irregularly oblong, large, 0.5-1 mm. 
 across, bladdery, soon open by falling away of the upper part; 
 peridium colorless, dehiscence irregular, cells with thin inner and 
 outer walls; seciospores broadly ellipsoid, or nearly globoid, 14- 
 18 X 16-28 fj.; wall colorless, thin, 1-1.5 fx, closely and rather 
 finely verrucose. 
 
 II. Uredinia amphigenous, scattered or somewhat grouped, 
 small, round, 0.1-0.4 mm. across, orange-red when fresh, pale- 
 yellow when dry; peridium hemispherical, dehiscent by a small 
 central orifice, cells elongate at sides, polygonal above, inner and 
 outer walls same thickness; urediniospores ellipsoid or obovoid. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 349 
 
 12-18 X 16-30 m; walls pale-yellow, rather thin, 1-1.5 n; sparsely 
 echinulate with short conical points. 
 
 III. Telia hypophyllous, on whitish or pale reddish spots; 
 teliospores within the epidermal cells, 1-celled, short-cylindrical 
 or polygonal, 13-20 ju broad; wall colorless, smooth, thin. 
 
 I ( =Peridermium elatinum) on fir causing swelling, cankers and 
 witches' brooms. 
 
 II and III on various members of the pink family. 
 
 All stages possess perennating mycelium. The secial stage 
 is of most economic significance, producing witches' brooms of 
 various sizes. The secia are formed only on the deformed needles 
 of the witches' brooms. 
 
 Melampsoropsis (Schroter) Arthur (p. 341) 
 
 Cycle of development includes pycnia, secia, uredinia and telia, 
 with distinct alternating phases; heteroecious. Pycnia and other 
 sori subepidermal. 
 
 0. Pycnia deep-seated, somewhat erumpent, flask-shaped. 
 
 1. ^cia erumpent, flattened laterally. Peridium firm, outer 
 wall of cells greatly thickened and transversely striate, inner wall 
 smooth. iEciospores ellipsoid to globoid; wall colorless, coarsely 
 verrucose with deciduous tubercles. 
 
 II. Uredinia erumpent, pulverulent. Peridium very delicate, 
 evanescent, sometimes wanting. Urediniospores catenulate, 
 globoid to lanceolate; wall colorless, verrucose with somewhat 
 deciduous tubercles, pores ol)scure. 
 
 III. Telia erumpent, definite, roundish, waxy becoming vel- 
 vety. Teliospores catenulate, 1-celied, oblong or cuboid; wall 
 colorless, thin, smooth. 
 
 M. rhododendri (D. C.) Arth. 
 
 Uredinial and telial stages on Rhododendrons; pycnial and 
 aecial stages ( = ^Ecidium abietinum) on Picea excelsa. 
 
 The pycnia appear on fir leaves in spring and about a month 
 later the secia. The aeciospores germinate upon the Rhododen- 
 dron. The mycelium perennates in its evergreen leaves and 
 produces the uredinial and telial stages, the former of which 
 serves for dissemination. The basidiospores infect the young fir 
 leaves. 
 
350 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Chrysomyxa linger (p. 341) 
 
 III. Teliospores formed of a series of superimposed cells, of 
 
 which the lower are sterile, 
 forming flat or slightly ele- 
 vated, orange or reddish, 
 waxy, crusts. Germina- 
 tion of the teliospore by a 
 promycelium from each 
 cell, which produces mostly 
 four basidiospores. 
 C. abietis (Wal.) Ung. 
 
 Fig. 254 -Melampsoropsisrhododendri, section r^ y ^^j j^ f 
 
 through tehum. After De Bary. 
 
 yellow spots on spruce 
 leaves and the basidiospores seem able to infect the same host. 
 European. 
 
 Cronartium Fries (p. 341) 
 
 0. Pycnia deep-seated, broad and flat. 
 
 I ( = Peridermium). ^Ecia erumpent, inflated. Peridium mem- 
 branous, rupturing at the sides rather than above, 2-4 cells thick, 
 outer surface smooth, inner verrucose. Spores ellipsoid; wall 
 colorless, coarsely verrucose with deciduous tubercles, except a 
 smooth spot on one side. 
 
 II. Uredinia somewhat erumpent. Peridium moderately firm, 
 rupturing above, upper part evanescent; peridial cells isodiametric. 
 Spores borne singly on pedicels, globoid to ellipsoid ; wall nearly or 
 quite colorless, echinulate, pores obscure. 
 
 III. Telia erumpent, at first arising from the uredinia, the 
 catenulate spores adhering to form a much extended, cylindrical or 
 filiform column, horny when dry. Spores oblong to fusiform, 
 1 -celled; wall slightly colored, thin, smooth. 
 
 Five American species are recognized by Arthur. 
 All knowTi secial stages are Peridermiums on stems of conifers. 
 C. ribicola F. de Wal.^^^-^se. 297 
 
 O. Pycnia caulicolous, scattered, honey-yellow, forming minute, 
 bladdery swellings. Spores hyaline, ovoid to elliptical, 1.9-4.7 fj,. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 351 
 
 I (=Peridermium strobi). ^cia caulicolous, causing fusiform 
 swellings of the stem, rounded to elongate; peridium inflated, rup- 
 turing at sides, thick, membranous. Spores ellipsoid to ovoid, 
 18-20 X 22-23 ix, wall colorless, coarsely verrucose except on 
 elongate smooth spot, 2-2.5 ^ thick, on smooth spot 3-3.5 fx 
 thick. 
 
 II. Uredinia hypophyllous, thickly scattered in groups, round, 
 pustular, 0.1-0.3 mm., at first bright yellow; peridia delicate. 
 
 Fig. 255. — Cronartium. A, urediuium; B, telium. 
 After Tubeuf. 
 
 Spores ellipsoid to obovate, 14-22 x 19-3.5 //, wall colorless, 
 2-3 /i thick, sparsely and sharply echinulate. 
 
 III. Telial columns hypophyllous, cylindrical, 125-150 ix thick, 
 up to 2 mm. long, curved, bright orange-yellow, becoming brown- 
 ish; spores oblong or cylindrical, 8-12 x 30-60 n; wall nearly 
 colorless, smooth, rather thick, 2-3 /x. 
 
 Heteroccious 0, I, on white pine, Pinus cembra and several 
 other 5-leaved species; II and III on currant and gooseberry and 
 several other species of Ril^es. 
 
 The telial stage was first noted in Geneva, N. Y., in 1906.-^'' 
 The rust is now known in some nine states. It has been known in 
 Europe since 1854. Its effects are most serious in its secial stage, 
 though the telial stage is very abundant and conspicuous. The 
 generic connections of the forms was proved by Klebahn in 1888 
 by inoculations. 
 
 The mycelium is doubtfully perennial in Ribes and certainly is 
 so in the bark of the pine. 
 
352 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 C. comptoniae Arth. 
 
 I (=Peridermium pyriforme) on Pinus trunks. Ill on Comp- 
 tonia. 
 
 The Peridermium is perennial in the trunks of the pine where 
 it does considerable injury. Clinton sowed seciospores from pine 
 
 P'iG. 256.— Croiuirtium comptoiiiui (Peridermium) on 
 Pinus. After Clinton. 
 
 on Comptonia and in about twelve days the uredinia began 
 to appear. ^^^ 
 
 C. quercus (Brond.) Schr. 
 
 Heteroecions I ( = Peridermium cerebrum) on pine. Ill on 
 oak. 
 
 Successful inoculations were first reported by Shear, ^^^ later by 
 Arthur and Hedgcock.^^'' Globoid swellings 5-25 cm. across are 
 formed on pine trees. 
 
 C. asclepiadeum (Wil.) Fries. 
 
 Heteroecious I ( = Peridermium cornui) on Pinus silves- 
 tris. 
 
 II and III on Cynachum, Paeonia, Gentiana and several other 
 hosts. European. 
 
 The mycelium is perennial in pine twigs and gradually kills 
 them. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 353 
 
 Endophyllum Levielle (p. 342) 
 
 The cycle of development includes only pycnia and telia, both 
 subepidermal. 
 
 O. Pycnia deep-seated, somewhat crumpent, flask-shaped, with 
 ostiolar filaments. 
 
 III. Telia bullate, definite, round, pulverulent. Peridium evan- 
 escent, cells resembling spores but flattened. Spores catenulate or 
 seemingly compacted without order, 1-celled, globoid to ellip- 
 soid; wall colored, medium thick, verrucose. 
 
 E. sempervivi (Alb. & Schw.) D. By. 
 
 Pycnial and telial stages on species of Sempervivum. Myce- 
 lium perennial in the host. 
 
 Pucciniaceae (p. 335) 
 
 Teliospores stalked (stalk sometimes short or evanescent) 
 1-celled or with several cells in a row or several united to form a 
 parasol-like head on a compound stalk; separate or gelatinous- 
 embedded. Basidiospores formed from promycelia. ^Ecia with 
 or without peridia. Urediniospores solitary. 
 
 This is the largest and most important family of the order, in- 
 lesting numerous valuable agricultural plants and causing enor- 
 mous loss. The species are manifold and the complexities owing to 
 polymorphism, heteroecism and biologic specialization are very 
 great. 
 
 Key to Genera of Pucciniaceae 
 
 Teliospores united into a head on compound 
 pedicles, or several sessile or stalked on 
 a common simple pedicel; sori subcutic- 
 ular or subepidermal; uredinia when 
 present without peridium or encircling 
 paraphyses. 
 Teliospores united into a head on a com- 
 pound pedicel 1. Ravenelia. 
 
 Teliospores free, 1-4 on a simple pedicel, 
 all but one lateral 
 Teliospores flattened laterallj- 2. Dicheirinia. 
 
354 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Teliospores flattened above and be- 
 low 3. Pileolaria. 
 
 Teliospores not flattened, but uredinio- 
 
 spores flattened laterally 4. Hemileia, p. 355. 
 
 Teliospores free, 2-8 at apex of a common 
 stalk 
 
 With all spore forms 5. Tranzschelia, p. 356. 
 
 With pyenia and teha only 6. Poly thelis. 
 
 Teliospores not borne on a common pedicel, 
 or united into heads. 
 Teliospore wall with a more or less evi- 
 dent gelatinous layer. 
 Teliospores with evident gelatinous 
 layer, pores lateral 
 
 Teliospores 3-celled 7. Phragmopyxis. 
 
 Teliospores 2-celled 8. Uropyxis. 
 
 Teliospores with obscure gelatinous 
 layer, pores apical. 
 Teliospores with appendaged pedi- 
 cels 9. Prospodium. 
 
 Teliospores without appendaged 
 
 pedicels 10. Nephlyctis. 
 
 Teliospore wall without gelatinous layer 
 Pyenia subcuticular, other sori sub- 
 epidermal; secia when present with- 
 out peridium; uredinia when pres- 
 ent without peridium, but usually 
 with encircling paraphyses. 
 Teliospores mostly tuberculate, the 
 pores more than one and lateral 
 
 Tehospores 1-celled 11. Trachyspora. 
 
 Tehospores with 3 or more cells 
 clustered at the apex of the 
 pedicel 
 
 Teliospores 3-celled 12. Triphragmium, p. 358. 
 
 Tehospores more than 3-celled . 13. Sphaerophragmium. 
 Teliospores with more than three 
 
 cells lineally arranged 14. Phragmidium, p. 358. 
 
 Teliospores mostly smooth, the pores 
 one in a cell and apical. 
 Teliospores 1-celled 15. Spirechina. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 355 
 
 Teliospores 2-celled Ki. Gymnoconia, p. 359. 
 
 Teliospores 3 or more-celled. 
 
 Without uredinia 17. Xenodochus, p. 3G1. 
 
 Without secia IS. Kuehneola, p. 3G1. 
 
 Sori all subepidermal; secia when 
 present with a peridium ; ure- 
 dinia when present with no 
 peridium or rarely with en- 
 circling paraphyses. 
 Teliospores embedded in a more 
 
 or less gelatinous matrix . . 19. Gymnosporangium, p. 361. 
 Teliospores not embedded in a 
 
 gelatinous matrix. 
 
 Teliospores colorless 20. Eriosporangium. 
 
 Teliospores colored 
 
 Teliospores I-celled 21. Uromyces, p. 371. 
 
 Teliospores 2-celled 22. Puccinia, p. 375. 
 
 Hemileia Berkley & Brown (p. 354) 
 
 Cycle of development imperfectly known; only uredinia and 
 telia recognized, both subepidermal. 
 
 n. Uredinia formed beneath the stomata, erumpent, without 
 peridium or paraphyses, spores ])orne singly on short pedicels, 
 which arise from a protruding hymenium of agglutinated hyphse, 
 obovate, laterally flattened and dorsiventral ; wall pale-yellow, 
 smooth on ventral side, papillose on dorsal side, pores obscure or 
 absent. 
 
 III. Telia replacing the uredinia. Spores borne singly on pedi- 
 cels, 1-celled, napiform; wall nearly or 
 quite colorless, smooth. "^ 
 
 H. vastatrix Berk. & Br. 
 
 II. Hypophyllous, thickly scattered, rhr^lllKXir 
 or rarely somewhat circinate, very small, ciFf^^ c 
 
 about 0.1 mm. across, light-orange fading ^^^ 257.-Hemileia vast a- 
 to pale-yellow, pulverulent, projecting trix, a, uredinium; c, 
 
 , , 1 , , 1 1 / • telio.spore. After D i e t e 1 
 
 through stomata and rarely rupturmg and Ward. 
 
 the epidermis; spores bilateral, slightly 
 
 obovate, flattened on the ventral side, 20-28 by 30-40 m; wall 
 
 pale-yellow, 1-1.5 ix thick, rather thickly and very coarsely papil- 
 
356 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 lose on dorsal side with Ijliintly pointed tubercles 2-4/1 long, 
 1-1.5 jLt in diameter, ventral side smooth, pores ol)scure. 
 
 III. Hypophyllous, arising from uredinia, thickly scattered, 
 very small, about 0.1 mm. across, pale-yellow; spores napiform 
 or globoid, somewhat umbonate above; wall pale-j'ellow or seem- 
 ingly colorless, thin, 1 jx, slightly if any thicker above, smooth; 
 pedicel hyaline, one-half to once length of spore, slender. 
 
 It constitutes a serious coffee parasite in the orient and is re- 
 ported also from Porto Rico. 
 
 H. woodii K. & C. is a serious coffee parasite and occurs also on 
 Vanguieria edulis. 
 
 H. oncidii Griff & Maub. is on cultivated Oncidiums in France. 
 
 Tranzschelia Arthur (p. 354) 
 
 Cycle of development includes pycnia, secia, uredinia and telia, 
 with alternating phases; autoecious or hetercecious. Pycnia sub- 
 cuticular, other sori subepidermal. 
 
 0. 1. Pycnia depressed-conical or hemispherical; hymenium flat. 
 
 ^cia erumpent, cylindrical. Peridium dehiscent at apex, be- 
 coming recurved. iEciospores globoid; wall colored, finely ver- 
 rucose. 
 
 II. Uredinia erumpent, definite, without peridium. Uredinio- 
 spores borne singly on pedicels, with paraphyses intermixed, 
 obovoid, somewhat narrowed at both ends; wall colored, usually 
 paler below, echinulate; pores equatorial. 
 
 III. Telia erumpent, definite, pulverulent, without peridium. 
 Teliospores forming heads or balls by being attached b}^ short, 
 fragile pedicels to a common stalk, which is short and incon- 
 spicuous, 2-celled by transverse septum, cells rounded and easily 
 falling apart, wall colored, verrucose. 
 
 T. punctata (Pers.) Arth.^i' '~^^' 232. 233 
 
 I (=^'Ecidium punctatum). Peridia uniformly scattered over 
 the whole of the foliage, hypophyllous, flat, semi-immersed, 
 with torn yellowish edges. Spores subglobose, pale yellowish- 
 brown, 15-24 II in diameter. Pycnia scattered, blackish, puncti- 
 form. 
 
 II. Uredinia light-brown, small, round, crowded, pulverulent, 
 often confluent. Spores ovate or subpyriform, apex darker, 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 357 
 
 thickened, bluntly conical, closely echinulate, brown, 20-35 x 
 12-16 jJL, mixed with numerous capitate brownish paraphyses. 
 
 III. Telia pulverulent, dark-brown, almost black. Spores con- 
 sisting of two spherical cells, flattened at their point of union, 
 the lower cell often being smaller and paler. Epispore uniformly 
 
 Fig. 25S. — T. punctata, urediuiusporos. Alter Holway. 
 
 thick, chestnut-brown, thickly studded with short stout spines. 
 Spores 30-45 x 17-25 ^i. Pedicels short, colorless. 
 
 Heteroecious : and I on Hepatica and Anemone. 
 
 II and III on Prunus sps., peach, almond, plum, cherry, apri- 
 cot. 
 
 Widely distributed in North America, Europe and Asia and 
 apparently introduced into Australia about 1883. The secial stage 
 is perennial. Urediniospores have also been shown to remain viable 
 over winter. The peculiar character of the urediniospores has 
 sometimes led this fungus to be mistaken for a Uromyces. 
 
 In 1904, Tranzschel -^^ made cultures of the secial stage from 
 Anemone on various Prunaceous hosts. Arthur made similar 
 inoculation from Hepatica in 1906. 
 
358 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Triphragmium Link (p. 354) 
 
 Teliospores 3-celled, one basal, tv/o apical, each cell with one 
 or more germ tubes. 
 
 T. ulmariae Schm. occurs on Ulmaria in England and at one 
 station in America. 
 
 Phragmidium Link (p. 354) 
 
 O. Pycnia present. 
 
 L iEciospores in l^asipetal chains. The first two spore forms 
 
 Fig. 259. — Triphragmium ulmarias, germi- 
 nating teliospore. After Tulasne. 
 
 Fig. 260.— Phragmi- 
 dium bulbosum, 
 teliospore germi- 
 nating. After Tu- 
 lasne. 
 
 are in pulverulent sori, surrounded by clavate or capitate, hyaline 
 paraphyses. 
 
 11. Urediniospores single. 
 
 IIL Teliospores separate, pedicellate, consisting of from three 
 to ten superimposed cells, the uppermost of which has a single 
 apical germ pore, the others about four each, placed laterally. 
 
 The secial stage is a Cseoma but with a border of incurved pa- 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 359 
 
 raphyses. The unicellular urediniospores are similarly surrounded, 
 and bear numerous germ pores. The genus is limited to Rosaceous 
 hosts and its species are autoecious. 
 
 Eight American forms are recognized by Arthur ^^^ on roses as 
 follows: 
 
 P. montivagum Arth., P. disciflorum (Tode) James, P. ameri- 
 
 vo/ 
 
 Fig. 261. — Uredinio- and teliospores of; 1. P. americanum ; 2. P. rosse-setigerae ; 3. P. rosae 
 calif ornicse; 4. P. rosae-arkansanse ; 5. P. montivagum; 6. P. disciflorum. After Arthur. 
 
 canum Diet., P. rosae-setigerae Diet., P. rosae-californicae Diet., 
 P. rosae-arkansanae Diet., P. subcorticinum (Schr.) Went, and 
 P. rosae-acicularis Sire. 
 
 They are mostly on wild roses and of but little economic im- 
 portance. 
 
 P. violaceum (Schul.) Went, is often serious on Rubus in 
 Europe. 
 
 P. rubi-idaei (Pers.) Wint. is found on raspberries in Europe. 
 
 P. speciosum Fr. on rose has been separated by Arthur as 
 Earlea speciosa on account of its non-gelatinous teliospore pedi- 
 cel, its large compact caulicolous telia and the absence of uredinia. 
 
 Gymnoconia Lagerheim (p. 355) 
 
 O. Pycnia conic. 
 
 I ( =C8eoma), peridia and paraphyses none. 
 III. Spores as in Puccinia. 
 
 This genus bears a superficial resemblance to Puccinia but is 
 easily distinguished by its naked secial sori. 
 
3G0 
 
 THE FUNGI WHICPI CAUSE PLANT DISEASE 
 
 G. interstitialis (Schl.) Lag.-^-"-'^' -^^ 
 
 0. Pycnia glandular, numerous mostly epiphyllous. 
 
 I (=Caeoma nitens), hypophyllous, sori irregular, confluent; 
 spores orange-red, globose to elliptic, epispore thin, 18-35 x 12-24. 
 
 III. Telia hypophyllous, few, sparse, cinnamon-brown; spores 
 more or less angular, 36-45 x 22-27 [x, pedicel short or wanting. 
 
 Autoecious, on raspberries and blackberries, wild and cultivated, 
 in United States, Canada, Europe and Asia. 
 
 The pycnial stage appears first in spring giving to the leaves 
 and stems a glandular appearance. About two or three weeks 
 
 Fig. 262. — G. interstitialis, cseoma sorus. After Newcomb. 
 
 later the ajcial stage is visible on the lower surface of the leaves; 
 the epidermis soon ruptures and the orange beds of spores show. 
 The pycnia are then fully developed. The affected plants are 
 much stunted and are unproductive but are not killed. The 
 fungous mycelium is intercellular, growing rapidly into formative 
 tissues and perennating -^^ in the woody shoots. The knob-like 
 haustoria penetrate the cells and often lie against the nuclei. The 
 mycelium is especially a])undant in the pith near the bundles. 
 
 The ajciospores may germinate at once and infect susceptible 
 hosts. The teliospore which is less conspicuous and therefore 
 rarely seen is of the Puccinia type. The telia appear in July 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 361 
 
 and August, usually hypophyllous, and the sori are very small 
 and inconspicuous. 
 
 Artificial infection of Rubus with the spores of the Cseoma stage 
 by Tranzschel -^^ gave rise to the telial form, demonstrating 
 the identity of the two. Cultures were also made by Clinton 
 about the same time. 
 
 Xenodochus Sclilecht (p. 355) 
 
 ^ciospores catenulate; uredinia wanting; teliospores short- 
 pedicelled, several celled in linear arrangement. 
 
 X. carbonarium Schl., autoecious on Sanguisorba in Europe. 
 
 Kuehneola Magnus (p. 355) 
 
 iEcia wanting; uredinia pulvinate, telia similar to Phragmidium 
 but with smooth spores with the germ pores apical. 
 K. uredinis (Lk.) Arth. 
 
 II. (=Uredo muelleri.) Uredinia lemon-yellow, minute dots; 
 spores globose to elliptic, about 26 jjl, hyaline, slightly verrucose. 
 
 III. Telia solitary, pale, 250-500 n broad; spores 5 to 6 to 
 12-cclled, epispore hyaline, cells 17-47 x 15-26 At; basidiospores 
 8.5-9.5 M- 
 
 The telia are pale yellowish-white, thus readily distinguishing 
 t'.iem from other Rubus rusts. 
 
 The uredinia are common and sometimes injurious on Rubus. 
 The sori are small and scattered. 
 
 K. gossypii (Lagerh.) Arth. is reported on cotton in British 
 Guiana,-^^ also Florida, Cuba and Porto Rico. 
 
 Gymnosporangium Hedwig f.-oe-^n. 213. 217 (-p 355^ 
 
 Cycle of development including pycnia, secia and telia, with 
 distinct alternating phases; heteroecious and autoecious. Pycnia 
 and other sori subepidermal. 
 
 0. Pycnia deep-seated, usually globoid, generally prominent 
 and conspicuous, at first honey yellow, usually becoming blackish, 
 globose or flattened-globose, with ostiolar filaments. 
 
 I (=Roestelia) erumpent, at first cylindric. Peridium dingy 
 white, usually elongated into a tubular form, membranous, tending 
 
362 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 to rupture by longitudinal slits along the sides; peridial cells im- 
 bricate and often articulated, occasionally hygroscopic, outer walls 
 smooth, rather thin, inner walls smooth, verruculose, verrucose, 
 rugose, or spinulose. iEciospores in basipetal chains with alter- 
 nate barren cells, enclosed in a peridium, globoid to broadly ellip- 
 soid; wall colored, verrucose, usually with numerous, scattered, 
 evident germ pores. 
 
 III. Telia erumpent, naked, usually definite, variously shaped, 
 gelatinous and elastic at maturity, expanding considerably when 
 moistened. Teliospores chiefly 2-celled, in some species 3, 4, or 
 
 Fig. 263. — Gymnosporangium, spore masses just emerging. 
 After Heald. 
 
 5-celled, by transverse septa; walls colored, of various thickness, 
 smooth; pores usually two in each cell, sometimes, 1, 3, or 4, vari- 
 ously arranged; pedicels hyaline, elastic, usually of considerable 
 length, cylindric, rarely carotiform, walls thick, the outer portion 
 swelling and becoming gelatinous to form a jelly-like matryx in 
 which the spores appear embedded. 
 
 All of the species agree in possessing the same spore forms, 
 pycnia, secia, and telia which appear in the same sequence in 
 the different species; also, in the fact with two exceptions, that 
 the aecia grow on pomaceous plants and the telia on Juniperus 
 (with few exceptions). 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 363 
 
 The fficiospores are borne in secia which rest in orange or 
 yellow spots often strongly thickened. Pycnia aliound. The 
 aecium with its thick peridium is erumpent and projects to 
 some distance above 
 the host surface, this 
 character giving rise 
 to the separate form- 
 genus, Roestelia. The 
 peridial margin which 
 may be lacerate or 
 fimbriate is used in 
 specific characteriza- 
 tion. The spores are 
 borne and function as 
 in ordinary secia. 
 They bear several germ 
 pores. 
 
 iEciospores germi- 
 nate at once and if 
 they fall upon suitable 
 coniferous hosts bring 
 about infection. The 
 mycelium penetrating 
 the leaf or brancli 
 often induces large 
 hypertrophy. 
 
 In spring in moist 
 weather the telio- 
 spores are found in 
 spore masses com- 
 
 , r j-v. Fig. 264. — Gymnosporangium teliospores. a, G. cla- 
 
 posecl 01 tne spores, variaeforme; h, G. globosum; c, G. macropus; d, G. 
 which are USUallv nidus-avis; c,G. nelsoni;/,G.clavipes. After King. 
 
 orange or yellow, and of their long gelatinous pedicels. 
 
 Each cell usually bears several germ pores near the septum 
 through one of which the tube emerges. 
 
 The teliospores germinate immediately in situ by typical 
 4-celled promycelia and four basidiospores are produced on each 
 promycelium. 
 
364 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 The basidiospores are capable of infecting only the appropriate 
 alternate host and that when the parts are still young and 
 tender. 
 
 An abnormal development of germ tubes instead of the usual 
 promycelium has been reported in some instances. According 
 to Lloyd & Ridgway ^°^ several crops of basidiospores are pro- 
 duced in one season. 
 
 The various species usually make good subjects with which to 
 study infection. The teliospore masses placed in water soon 
 become covered with basidiospores. Suspensions of these in water 
 applied to susceptible hosts usually give positive results readily. 
 
 G. juniperi-virginianae Lk. ^°^' -^^' ^^^( = G. macropus) Schu. 
 
 0. Pycnia epiphyllous. 
 
 1. ^cia ( =RoesteUa pyrata) chiefly hypophyllous, usually in 
 annular groups, on thickened discolored spots, at first cylindric, 
 
 0.1-0.4 mm. in diameter; 
 i^eridium splitting extremely 
 early, becoming fimbriate to 
 the base, strongly revolute; 
 peridial- cells usually seen 
 only in side view, long and 
 narrow, 10-16 x 65-100 ju, 
 becoming much curved when 
 wet, inner and side walls 
 rather sparsely rugose with 
 ridges extending half way 
 across the side walls; aecio- 
 spores globoid or broadly 
 ellipsoid, 16-24 x 21-31 n, 
 wall light chestnut-brown, 
 2-3 fx thick, finely verru- 
 ' ose. 
 
 III. Telia appearing on 
 globoid or reniform galls 
 5-30 mm. or more in diam- 
 eter, evenly disposed, cylindric or cylindric-acuminate, 1.5-3 mm. 
 in diameter by 10-20 mm. long, golden-brown; teliospores 2-celled, 
 rhombic-oval or narrowly ellipsoid, 15-21 x 42-65 m; slightly or 
 
 Fig. 265. — G. juniperi-virginianae, aecia. 
 After Heald. 
 
THE FUNGI WHICH 6^JSE PLANT DISEASE 365 
 
 not constricted at the septum, wall pale cinnamon-brown, thin, 
 about 1 jLt; pedicel cylindric, 3-5 /j. in diameter; pores two in 
 each cell near the septum. 
 
 I. iEcia on apple both wild and cultivated. 
 
 III. Telia on Juniperus virginiana and J. barbadensis. 
 
 Destructive, particularly in East and South. 
 
 Sporidia are matured in twelve to twenty-four hours after the 
 spore-masses expand by moisture and as soon as the sori begin to 
 dry they are carried away by wind and on suitable hosts infect 
 through the cell walls by appresoria. Two or three crops of sporidia 
 may arise in one season but the first crop is largest.-^* Each crop 
 may result in a corresponding crop of secia. The stage on apple 
 fruits shows as pale-yellow spots of pinhead size about seven 
 to ten days after infection. The spots finally become orange- 
 colored and in a few weeks the pycnia appear as black specks. 
 On leaves hypophyllous cushions 0.5-1 cm. in diameter form on the 
 spots and bear the secia, the mature tubes of which are split and 
 recurved giving a stellate appearance. yEciospores pass back to 
 the cedar in summer and cause infection. The mycelium here 
 remains practically dormant according to Heald ^^* until the fol- 
 lowing spring when the telial galls first become visible. These 
 galls grow throughout the summer, mature in the fall, and give 
 rise to the teliospores during the next spring. The mycelium is 
 thus seen to be biennial. 
 
 G. clavarigeforme (Jacq.) D. C. ^oe. sos. 211 
 
 I. vEcia hypophyllous, fructicolous or caulicolous, usually 
 crowded in small groups 2-3 mm. across on the leaf blades, some- 
 times in larger groups on the veins, petioles and twigs, often 
 densely aggregated on the fruits and occupying part or all of the 
 surface, cylindric, 0.7-1.5 mm. high by 0.3-0.5 mm. in diameter; 
 peridium soon becoming lacerate, usually to base, erect or spread- 
 ing; peridial cells long and narrow, often becoming curved when 
 wet, linear in face view, 18-30 x 80-13 fx, linear or linear-oblong 
 in side view, 15-25 fi thick, outer wall 1-2 n thick, smooth, inner 
 wall and side walls 5-7 n thick, rather coarsely verrucose with 
 roundish or irregular papilla? of varying sizes; seciospores globoid, 
 21-27 X 25-30 fi, wall light cinnamon-brown, 2.5-3.5 n thick, 
 moderately verrucose.- 
 
366 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 III. Telia caulicolous, appearing on long fusiform swellings of 
 various sized branches, numerous, scattered, or sometimes aggre- 
 gated, cylindric, or slightly compressed, 5-10 mm. long by 0.8-1.5 
 mm. in diameter, acutish, or sometimes forked at the apex, 
 brownish-yellow; teliospores 2-celled, lanceolate, 13-20 x 40-80 n, 
 occasionally longer, rounded or narrowed 
 above, usually narrowed below, very 
 slightly or not at all constricted at the 
 septum, wall golden-yellow, thin, about 
 1 n; pores 2 in each cell, near the sep- 
 tum. 
 
 I. JEcia on Crataegus spp., Amelanchier, 
 Aronia, Cotoneaster, Cydonia, and Pyrus. 
 III. Telia on Juniperus communis, J. 
 Fig. 266. — Gymnosporan- oxycedrus, and J. sibirica. Spindle-shaped 
 Stin^Xfpr^Jr:; sweUlngs occur on Juniper branches. 
 Richards. CyUndric spore-masses ooze through rifts 
 
 in the bark. ^Eciospores shed in June germinate at once on Juniper 
 twigs and result in the following year in swellings which often 
 later cause death. In spring the spore-masses emerge and the 
 teliospores germinate in situ. Upon the Rosaceous hosts spots 
 appear eight to fourteen days after infection. Kienitz-Gerloff 
 reports the occasional formation of a germ tube instead of a 
 promycelium. This is, however, to be regarded as an abnormal 
 condition. 
 
 G. globosum Farl. ^os- 213. 215. 216 
 
 O. and I. ^Ecia chiefly hypophyllous and crowded irregularly 
 or rarely in approximately annular groups 2-7 mm. across, cylin- 
 dric, 1.5-3 mm. high by 0.1-0.2 mm. in diameter; peridium soon 
 splitting in the upper part, becoming reticulate half way to base; 
 peridial cells seen in both face and side views, broadly lanceolate 
 in face view, 15-23 x 60-90 fi, linear rhomboid in side view, 13-19 n 
 thick, outer wall about 1.5 ^t thick, smooth, inner and side walls 
 3-5 ^i, thick, rather densely rugose with ridge-like papillae of 
 varying length; aeciospores globoid or broadly ellipsoid, 15-19 x 
 18-25 fx, wall light chestnut-brown, 1.5-2 /x thick, finely verru- 
 cose. 
 
 III. Telia caulicolous, appearing on irregular globoid, gall-like 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 367 
 
 excrescences 3-25 mm. in diameter, unevenly disposed, often 
 separated by the scars of the sori of previous seasons, tongue or 
 wedge-shaped, 1.5-3 mm. broad by 2-5 mm. long at the base and 
 6-12 mm. high, chestnut-brown; teliospores 2-celled, ellipsoid, 
 16-21 X 37-48 n, somewhat narrowed above and below, slightly 
 constricted at the septum, wall pale cinnamon-brown, 1-2 /u, 
 thick; pores 2 in each cell, near the septum. 
 
 I. iEcia on apple, pear, Crataegus, quince, mountain ash. 
 
 III. Telia on Juniperus virginiana and J. barbadensis. Common 
 and widely distributed in eastern America. 
 
 The telial galls are from 0.5 to 2.5 cm. in diameter, very ir- 
 regular. In late spring dark-brown spore-masses, later yellow- 
 orange, 0.5 to 2.5 cm. long appear. 
 
 The Roestelia spots are 0.5-1.0 cm. across. Pycnia blackish 
 above. The secia are on thickened hypophyllous spots, long, 
 slender, soon splitting and becoming fimbriate. Mesospores occur 
 occasionally. The seciospores germinate on the cedar. The 
 mycelium stimulates the hosts to extra formation of parenchy- 
 mateous tissue. 
 
 G. juniperinum (L.) Mart. 
 
 1. JEciix (= Roestelia penicillata [Pers.] Fries.) hj^pophyllous, 
 in annular or crowded groups, 2-5 mm. across on large thickened 
 discolored spots, at first cylindric, 0.5-1.5 mm. high, 0.5-1 mm. in 
 diameter; peridium soon becoming finely fimbriate to base and 
 somewhat twisted or incurved; peridial cells usually seen only in 
 side view, rhomboid, very thick, 30-35 x 60-90 fi, outer wall 
 medium thin, 2-3 n, smooth, inner wall medium thick, 7-10 /x, 
 rugose, side walls very coarsely rugose with thick, somewhat 
 irregular ridges, roundish or elongate ridge-like papillae inter- 
 spersed; seciospores globoid, very large, 28-35 x 30-45 fx, wall 
 chestnut-brown, thick, 3-5 /jl, rather finely verrucose. 
 
 III. Telia caulicolous, appearing on hemispheric swellings 
 (1-4 cm. long) breaking forth along the sides of the larger branches, 
 or on subglobose galls (1.5-2 cm. in diameter) on the smaller 
 branches, applanate, indefinite, usually of considerable size, often 
 covering the whole hypertrophied area, sometimes becoming 
 patelliform when expanded, chocolate-brown; teliospores 2-celled, 
 ellipsoid, 18-28 x 42-61 n, usually slightly narrowed both above 
 
368 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 and below, slightly or not constricted at the septum, wall cinnamon 
 brown, 1-1.5 n, thick; pores usually 3 in upper cell, 1 apical, 2 
 near the septum, in the lower cell 2 pores near the septum. 
 
 and I on apple and mountain ash. 
 
 III. Telia on Juniperus communis and J. sibirica. In Europe. 
 
 The teliospores occur on both twigs and leaves. Marked def- 
 ormation is caused by this stage on leaves and petioles. 
 
 G. clavipes C. & P. '°^ (=G. germinale [Schw.] Kern). 
 
 I. ^cia (=Roestelia aurantiaca) on stems and fruits, crowded 
 on hypertrophied areas of various size on the twigs and peduncles, 
 occupying part or nearly all of the surface of the fruits, cylindric, 
 1.5-3 mm. high by 0.3-0.5 mm. in diameter; peridium whitish, 
 becoming coarsely lacerate, sometimes to base, erect or spreading; 
 peridial cells seen in both face and side views, polygonal-ovate or 
 polygonal-oblong in face view, 19-39 x 45-95 /jl, rhomboid in side 
 view, 25-40 ju, thick, outer wall moderately thick, 3-5 fx, inner wall 
 very thick, 13-23 ix, coarsely verrucose with loosely set, large, 
 irregularly branched papillae, side walls verrucose on inner half 
 similar to inner wall; seciospores globoid, large, 31-32 x 24-39 fi, 
 wall pale yellow, thick, 3-4.5 n, rather coarsely verrucose with 
 crowded slightly irregular papillae. 
 
 III. Telia caulicolous, appearing on slight fusiform swellings, 
 usually aggregated, roundish, 1-4 mm. across, often confluent, 
 hemispheric, 1-3 mm. high, orange-brown; teliospores 2-celled, 
 ellipsoid, 18-26 x 35-51 /x, roundish or somewhat acutish above, 
 obtuse below, slightly or not constricted at the septum, wall 
 yellowish, 1-2 ^t thick, slightly thicker at the apex; pedicles caroti- 
 form, 9-19 fx in diameter near the spore; pores one in each cell, 
 apical in the upper, near the pedicel in the lower. 
 
 I. iEcia on Amelanchier, Aronia, Crataegus, Cydonia, and 
 apple. 
 
 III. Telia on Juniperus communis and J. sibirica. 
 
 G. cornutum (Pers.) Arth. 
 
 A rather uncommon species with I ( = Roestelia cornuta [Pers.] 
 Fries) on Sorbus spp. and III on Juniperus communis and 
 J. sibirica. Ranging from New York to Wisconsin and northward; 
 also in the mountains of Wyoming and Colorado : Europe. Of no 
 considerable economic importance in America. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 369 
 
 G. eUisii (Berk.) Farl. 
 
 I. ^Ecium unknown. III. Telia on Cupressus thyoides. Prob- 
 ably of very small economic importance. 
 
 G. transformans (Ellis) Kern. (=Roestelia transformans 
 Ellis). 
 
 I. iEcia on Pyrus arbutifolia, which is of no economic im- 
 portance. Confined to a small area from Massachusetts to New 
 Jersey. 
 
 III. Telia unknown. 
 
 G. nidus-avis Thax. -'os. 217 
 
 I. iEcia amphigenous, especially fructicolous, cylindric, 2^ mm. 
 high by 0.4-6.7 mm. in diameter; peridium soon becoming irregu- 
 larly lacerate usually to base, slightly spreading; peridial cells, 
 seen in both face and side views, lanceolate in face view, 15-23 x 
 55-88 jj,; linear in side view, 14-18 fx, thick, outer wall 1-.5 n 
 thick, smooth, inner and side walls 5-7 fx thick, coarsely rugose 
 with narrow ridges, with shorter, often roundish papillae inter- 
 spersed; seciospores globoid or broadly ellipsoid, 18-23 x 23-28 /x, 
 wall cinnamon-brown, rather thick, 2.5-4 fx, very finely verrucose, 
 appearing almost smooth when wet. 
 
 III. Telia caulicolous, often dwarfing the young shoots and 
 causing birds' nest distortions, or witches' brooms, usually causing 
 a reversion of the leaves to the juvenile form, sometimes appearing 
 on isolated areas on the larger branches and producing gradual 
 enlargements, solitary or rarely confluent, of variable size and 
 shape, roundish to oval on the young shoots, 1-2 mm. across, oval 
 to nearly elliptic on the woody branches, 1.5-3 mm. wide by 
 2-7 mm. long, pulvinate when young, becoming hemispheric, dark 
 reddish-brown; teliospores 2-celled, ellipsoid, 16-23 x 39-55 /jl, 
 wall pale cinnamon-brown, rather thin, 1-1.5 /x, very slightly 
 thicker at apex; pores one in a cell, apical. Mycelium perennial 
 in leaves, branches or trunks of Juniperus virginiana very com- 
 monly inducing a "bird's nest" distortion. 
 
 I. Mc'ia on Amelanchier and quince. 
 
 III. Telia on Juniperus virginiana. 
 
 G. sabinae (Dicks) Wint. 
 
 O and I (=Roestelia cancellata), on pear in Europe. 
 
 III. Telia on several Junipers. 
 
370 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 The telial mycelium is perennial and causes swellings. From 
 these in spring ooze the gelatinous, transparent spore-masses. 
 
 The mycelium in Juniperus causes increase in wood-bast and 
 rind, thickened twisted tracheids, increase in number and thick- 
 ness of the medullary rays. No mycelium is found in the wood 
 itself. 
 
 G. biseptatum Ell. 
 
 I. iEcia (=RcesteUa botryapites) hypophyllous, usually in 
 groups of 2-8, rarely solitary, borne in gall-like pyriform protuber- 
 ances 1-1.5 mm. in diameter by 1.5-3 mm. high, cylindric, 0.5-0.8 
 mm. in diameter by 2-4 mm. high; peridium soon becoming finely 
 cancellate, not dehiscent at apex; peridial cells cylindric, hyphal- 
 like, 9-14 /i in diameter by 145-190 /z long, often irregularly bent, 
 outer, inner, and side walls of equal thickness, about 1.5-2 ju, 
 whole surface smooth; seciospores globoid, small, 15-17 x 16-22 /x, 
 wall dark cinnamon-brown, rather thick, 2.5-3 fx, moderately 
 verrucose. 
 
 III. Telia caulicolous, appearing on fusiform swellings, scattered, 
 oval or irregular, about 1.5-3 mm. wide by 2-7 mm. long, often 
 confluent, hemispheric, chestnut-brown; teliospores 2 to 4-celled, 
 13-19 X 35-77 fx, usually rounded above, somewhat narrowed be- 
 low, slightly constricted at the septa, wall pale-yellow, 1.1-5 fx 
 thick, pores 2 in each cell, near the septa. 
 
 I. iEcia on Amelanchier. 
 
 III. Teha on Chamsecyparis. 
 
 G. nelsoni Arthur. ^Ecia hypophyllous and fructicolous, usually 
 in small groups 1-2 mm. across, cylindric, 2-4 mm. high by 0.2- 
 0.3 mm. in diameter; peridium whitish, dehiscent at apex and 
 also rupturing more or less along the sides; peridial cells seen in 
 both face and side view, 18-35 x 75-115 ii, linear rhomboid in side 
 view, 16-35 n, thick, outer wall rather thin, 1.5-2 fx, smooth, 
 inner and side walls rather thick, 7-12 ju, evenly and densely 
 verruculose; seciospores globoid, 19-26 x 21-29 ix, wall chestnut- 
 brown, 2-3 fx thick, finely verrucose. 
 
 III. Telia caulicolous, appearing on firm, woody, globose galls 
 0.5-5 cm. in diameter, unevenly disposed, densely aggregated or 
 often separated by the scars of the sori of previous seasons, ir- 
 regularly flattened, about 1-1.5 mm. broad by 1-5 mm. long at the 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 371 
 
 base by 3-4 mm. high, often confluent, light chestnut-brown; telio- 
 spores 2-celled, narrowly ellipsoid, 18-26 x 50-65 /x, narrowed at 
 both ends, slightly constricted at the septum; wall pale cinnamon- 
 brown, 1-1.5 II thick; pores two in each cell, near the sep- 
 tum. 
 
 I. iEcia on Amelanchier, Peraphyllum, quince and pear. 
 
 III. Telia on Juniperus spp. 
 
 Range; Alberta, south to Colorado and Arizona. 
 
 G. japonicum Syd. -^^ 
 
 I. ^Ecia ( = R. koresensis), on Pear. 
 
 III. Telia on Juniperus. 
 
 This form has been imported into America. 
 
 G. torminali-juniperinum (Ed.) Fischer. 
 
 This species has its aecial stage on species of Sorbus and its 
 telia on Juniperus in Europe. It is closely related to G. cor- 
 nutum of the northern part of our own continent, and of 
 Europe. 
 
 G. yamadae Miyabe. Only the aecia of this species have been 
 found. It infests the apple and various other sDecies of Malus in 
 Japan, 
 
 Uromyces Link (p. 355) 
 
 0. Pycnia spherical with minute ostioles. 
 
 1, ^Ecia with peridia, spores without pores. 
 
 II. Urediniospores generally with many germ pores, unicellular, 
 spherical, ellipsoid or variously shaped, usually rough. 
 
 III. Teliospores unicellular, pedicellate, with an apical germ 
 pore. 
 
 The unicellular teliospores may be distinguished from uredinio- 
 spores by their single apical germ pore, also usually by their 
 thicker walls and absence of the roughness so characteristic of 
 urediniospores. 
 
 The genus is a verjdarge one, with hundreds of species, which ex- 
 hibit hetercecism, autoecism, biologic specialization and the various 
 types regarding spore forms that are noted on pages 324-327. 
 
 U. appendiculatus (Pers.) Lev.^^^ 
 
 I. iEciospores angularly globose, whitish, slightly punctulate, 
 
372 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Leaf Tissue 
 
 17-32 X 14-20 IX. II. Urediniospores pale-brown, aculeolate, 24-33 
 X 16-20 M- III. Teliospores elliptical or subglobose, smooth, 
 
 dark-brown, apex much thick- 
 ened, with a small, hyaline, wart- 
 like papilla, 26-35 x 20-26 ju- 
 
 An autoecious eu-type. On 
 Phaseolus, Dolichos and other 
 related legumes. 
 
 The sori usually appear late 
 in the season on leaves, rarely on 
 stems and pods. The mycelium 
 is local. Great difference in 
 varietal susceptibility is noted. 
 
 U. pisi (Pers.) de B.®' 
 
 I. ( =^cidium cyparissia^). 
 
 Fig. 267. — Diagrammatic section of ure- 7^ . j.j. i xu i 1 
 
 dinium of u. appendicuiatus. After ^^cia scattered over the whole 
 Wiietzel. [gg^f surface. Peridia cup-shaped, 
 
 with whitish edges. Spores subglobose or polygonal, orange, 
 
 finely verrucose, 17-26 /x in diameter. 
 
 II. Uredinia roundish, scattered or crowded, cinnamon-brown. 
 Spores subglobose or 
 elongate, j^ellowish- 
 brown, echinulate, 17- 
 20 X 20-25 fi. 
 
 III. Telia roundish 
 or elliptical, blackish. 
 Spores subglobose or 
 shortly elliptical, finely 
 but closely punctate, 
 apex only slightly 
 thickened, 20-30 x 17- 
 20 {X. Pedicels long, 
 colorless, fragile. 
 
 A heteroecious eu- 
 type not found in 
 America: O and I on Euphorbia. 
 
 II and III on Lathyrus, Pisum, Vicia. 
 
 The secial stage dwarfs the host in which it is perennial. 
 
 • Elpidermis 
 ' ' of Leaf 
 
 Spores 
 
 - Leaf Ti55ae 
 Fig 
 
 Young Spore 
 
 268. — Diagrammatic section of teliospores of 
 U. appendicuiatus. After WhetzeL 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 373 
 
 U. fabae (Pers.) De B.-*^ This is an autoecious cu-type whicli 
 causes a rust of tlie broad bean, vetches, peas. 
 
 U. trifolii (Hed.) Lev.--^"'--^ An autoecious eu-type. 
 
 I. yEcia in circular clusters, on pallid spots. Peridia shortly 
 cylindric, flattish, on the stems in elongated groups; edges whit- 
 ish, torn. Spores siibglobose or irregular, finely verrucose, pale- 
 orange, 14-23 n in diameter. 
 
 II. Uredinia pale-brown, rounded, scattered, surrounded by the 
 
 Fig. 2G9. — L roniyces appen- 
 diculatus, teliospore ger- 
 minating. After Tulasne. 
 
 Fig. 270. — Uredini- 
 ospore and telio- 
 spore of Uioniy- 
 ces trifolii. Af- 
 ter Cobb. 
 
 torn epidermis. Spores round or ovate, with tliree or four equa- 
 torial germ pores, echinulate, brown, 20-26 x 18-20 fx. 
 
 III. Telia small, rounded, almost black, long covered by the 
 epidermis. Spores globose, elliptical or subpjTiform, with wart- 
 like incrassations on their summits, smooth, dark-brown, 22-30 x 
 15-20 n. Pedicels long, deciduous. 
 
 Cosmopolitan on white, crimson and alsike clovers. Stages 
 O and I are most common on Trifolium repens, least common on 
 T. incarnatum. Pycnia appear in early spring or even in winter. 
 The seciospores germinate readily in water and give infections which 
 give rise to urediniospores in about two weeks. Urecliniospores 
 maj'' be produced throughout the summer and may even survive 
 the winter. Teliospores are produced in the uredinia or in 
 separate sori late in the season. The teliospores by infection 
 
374 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 give rise to the pycnial and secial stages. Considerable distor- 
 tion arises in parts affected by either stage. 
 
 U. fallens (Desm.) Kern.^^^ A form on crimson, zig-zag and 
 red clover often confused with the last species. 
 
 O and I unknown. 
 
 II. Urediniospores with four to six scattered germ pores. 
 
 III. Teliospores similar to those of U. trifolii. 
 U. medicaginis Pass. 
 
 and I. Pycnia and aecia as in U. pisi. 
 
 II. Uredinia chestnut-brown, spores globose to elliptic, 17- 
 23 n, light-brown. 
 
 Fig. 271. — Uredo stage of U. betse. After Scribner. 
 
 III. Telia dark-brown, spores ovate-elliptic or pyriform 18-28 x 
 14-20. 
 
 A heteroecious eu-type. I, on Euphorbia; in Europe. 
 
 II and III on alfalfa and clovers in Europe and America. 
 
 U. minor Schr. is an autoecious opsis-type, I and III on Trifo- 
 lium montanum. 
 
 U. betaB (Pers.) Tul. ' An autoecious eu-type; on members 
 of the genus Beta both wild and cultivated. In the United States 
 observed only in California. Recorded in Europe, Africa, Australia. 
 
 U. kuhnei Krug. occurs on sugar cane.^^^ 
 
 U. dactylidis Otth. is a heteroecious eu-type; II and III on 
 Phleum, I on Ranunculus, in Europe. 
 
 U. poae Rab. is a heteroecious eu-type; I on Ranunculus and 
 Ficaria; II and III on Poa. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 375 
 
 U. caryophyllinus (Schr.) Wint."''-^^'-' 
 
 I. ^cia on Euphorbia in Europe. 
 
 II. Uredinia sparse, confluent on stems, spores round, elliptic 
 or oblong, 40 x 17-28 n, light-brown. 
 
 III. Teliospores globose, irregular or ovoid, apex thickened 23- 
 35 X 15-22 mm., pedicel 4-10 ju- 
 
 II and III on cultivated carnations and several other members 
 of the genus Dianthus. I on Euphorbia gerardiana. It has been 
 known in Europe since 1789 but was not noted in the United States 
 until 1890 when it was found by Taft at Lansing, Mich. It soon 
 invaded the whole country causing great loss. There is large racial 
 difference in host susceptibility. 
 
 The urediniospores germinate readily in water and serve to 
 propagate the fungus. Studies of the effects of toxic substances 
 upon these have been made by Stevens -^^ and by Stewart.^^'^ The 
 aecial stage has recently been recognized by Fischer ^^^ as JE. 
 euphorbise-gerardianse. 
 
 Less important species are: U. ervi (Wallr.) Plow, an auta?cious 
 eu-type on Vicia in Europe; U. erythronii (D. C.) Pass, an opsis- 
 type occasional on cultivated Lilium in Europe. U. ficariae Schw. 
 is on Ficaria; IT. pallidus Niess. a lepto-type on Cytisus; U. scil- 
 larum (Grev.) Wint. a micro-type on Scilla and Muscari. U. jaf- 
 frini Del. is reported on vanilla; -^^ U. colchici Mas. on Colchinum 
 speciosum in Europe. 
 
 Puccinia Persoon (p. 355) 
 
 O, I, II, as in Uromyces. 
 
 III. Teliospores separate, pedicellate, produced in flat sori, 
 consisting of two superimposed cells each of which is provided 
 with a germ pore. The superior cell has its germ pore, as a rule, 
 piercing its apex; in the inferior or lower the germ pore is placed 
 immediately below the septum. 
 
 Mesospores (p. 327) are not rare. They are merely teliospores 
 with the lower cell wanting, and function as teliospores. 
 
 Some one thousand two hundred twenty-six species are enumer- 
 ated by Sydow ^^ presenting great diversity in spore relation, 
 hetercecism and biologic variation. 
 
376 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 P. cerasi Ces. is a hemi-type on cherries in Southern Europe. 
 
 P. ribis-caricis Kleb. 
 
 I on Ilibes. II and III on Carex. 
 
 Klebahn -^^ differentiates five species of Puccinia on Ribes be- 
 longing to the Ribis-Carex group. These are P. pringsheimiana 
 (I.=jE. grossularise.) P. ribis-pseudocyperi, P. ribis nigri-acutse, 
 P. ribis nigri-paniculatae and P. magnusii. 
 
 P. asparagi D. C.^^^-^^o 
 
 I. Peridia in elongated patches upon the stems and larger 
 branches, short, edges erect, toothed. Spores orange-yellow, 
 round, very finely echinulate, 15-26 /x in 
 diameter. 
 
 II. Uredinia browTi, flat, small, long 
 covered by the epidermis. Spores irregu- 
 larly round or oval, clear-broA\Ti, echinu- 
 late.- 18-25 X 20-30 IX. 
 
 III. Telia black-brown, compact, pul- 
 vinate, elongate or rounded, scattered. 
 Spores oblong or clavate, base rounded, 
 apex thickened, darker, central con- 
 striction slight or absent, deep chest- 
 nut-brown, 35-50 X 15-25 ju- Pedicels 
 persistent, colorless or brownish, as long 
 as or longer than the spores. 
 
 An autoecious eu-type on Asparagus, 
 cultivated and wild. The fungus has 
 been known in Europe since 1805 but did not attract attention 
 in the United States until 1896 in New Jersey ^^^ when it began 
 its devastating westward migration ^^^ across the country reaching 
 California in 1900 or 1901. 
 
 The secial stage appears in early spring; the seciospores may 
 germinate at once or if dry remain viable for several weeks, 
 their germ tubes penetrating the host in most cases stomatally. 
 The uredinia appear in early summer soon after or with the secial 
 stage and, wind borne, distribute the fungus. The uredinio- 
 spores remain viable a few months when dry. The telial stage 
 appears late in the season and germinates only after hibernation. 
 
 Unicellular spores, mesospores, are sometimes met. 
 
 Fig. 272. — Section through 
 black rust pustule, show- 
 ing teliospores of P. as- 
 paragi. After Smith. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 377 
 
 Fiu. 273. 
 
 -Cross-section of aecia of P. asparagi. 
 After Smith. 
 
 P. buUata (Pers.) Schr. is a l^rachy-puccinia which is autcecious 
 on celery, parsley, cHU and other umbellifers. 
 
 P. apii (Wallr.) Cda. also occurs in its uredinial and telial stages 
 on celery. 
 
 P. castagnei Thiim is recorded for celery in France. 
 
 P. allii (D. C.) Ilud. is a hemi-type on cultivated onions. 
 
 P. porri Sow. is an autcecious rust which is sometimes de- 
 structive to onions in y^ n ^n Ci 
 Europe. -><^=#=^^ mocyRX^Br 
 
 P. endiviae Pass."^- 
 occurs on endive in 
 Italy and America. 
 
 P. phragmitis 
 Schum.2^.^-244 
 
 I {=M, rubellum). 
 Peridia on circular 
 red spots 0.5-1.5 cm. 
 in diameter, shallow, 
 edges white, torn. Spores white, subglobose, echinulate, 15-16 n 
 in diameter. 
 
 II. Uredinia rather large, dark brown, elliptical, pulverulent, 
 without paraphyses. Spores ovate or elliptical, echinulate, brown, 
 25-35 X 15-23 n. 
 
 III. Telia large, long, sooty black, thick, often confluent. 
 Spores elliptical, rounded at both ends, markedly constricted in 
 the middle, dark blackish-brown, smooth, 45-65 x 16-25 fx. Pedi- 
 cels very long, 150-200 x 5-8 ijl, yellowish, firmly attached. 
 
 Hetercecious; I on Rumex and rhubarb, II and III on Phrag- 
 mitis. Found only rarely in America,^'*^' ^^* except in the middle 
 west. 
 
 P. cyani (Schl.) Pass, is on cultivated Centaurea. 
 
 P. tragopogonis (Pers.) Cda. 
 
 I. ^cia on the whole plant — leaves, stems, bracts, receptacles 
 ■ — shortly cylindrical, at first mammseform, peridia with whitish, 
 torn edges. Spores rounded, verrucose, orange-yellow, 18-27 fx, 
 sometimes as much as 35 fx. long. Mycelium diffused throughout 
 the host-plant. 
 
 III. Telia brown, few, small, scattered, elliptical or elongate, 
 
378 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 long covered by the epidermis. Spores broadly oval, often 
 almost globose, slightly constricted, apex not thickened, thickly 
 verrucose, brown, 26-48 x 30-35 fx. Pedicels short, colorless, 
 deciduous. Mycelium localized. 
 
 An opsis-type on cultivated Tragopogon. Urediniospores are 
 unknown. The teliospores are often unicellular and are very 
 variable. 
 
 P. taraxaci Plow, is common on dandelion. P. cichorii Pass, is a 
 hemi-type on Cichorium. P. isiacae on Phragmitis is thought to be 
 
 Fig. 274. — P. graminis, telium and germinating 
 teliospore. After Carleton. 
 
 the telial stage of JE. brassicae on cabbage. ^'^^ P. fagopyri Barcl. 
 is found on buckwheat. 
 P. menthae Pers. ^'^ 
 
 I. iEcia with peridia immersed, flat, opening irregularly, edges 
 torn; principally on the stems, which are much swollen, more 
 rarely on concave spots on the leaves. Spores subglobose or 
 polygonal, coarsely granular, pale-yellowish, 17-26 x 26-35 m- 
 
 II. Uredinia small, roundish, soon pulverulent and confluent, 
 cinnamon-brown. Spores irregularly rounded or ovate, echinu- 
 late, pale-brown, 17-28 x 14-19 fi. 
 
 III. Telia black-brown, roundish, pulverulent. Spores ellip- 
 tical, oval, or subglobose, central constriction slight or absent, 
 apex with a hyaline or pale-brown papilla, verrucose, deep-brown, 
 26-35 X 19-23 /x. Pedicels long, delicate, colorless. 
 
 An autoecious eu-type on many mints. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 379 
 
 •r» • • T. *8. 166-182, 246. 306, 322 
 
 P. graminis Pers. ' 
 
 I {=M. berberidis). Spots generally circular, thick, swollen, 
 reddish above, yellow below. Peridia cylindrical, with whitish 
 torn edges. Spores subglobose, smooth, orange-yellow, 15-25 m- 
 
 II. Uredinia orange-red, linear, but often confluent, forming 
 very long lines on the stems and sheaths, pulverulent. Spores 
 elliptical, ovate, or pyriform, with four very marked, nearly 
 equatorial germ pores, echinulate, orange-yellow, 25-38 x 15-20 m- 
 
 III. Telial persistent, naked, linear, generally forming lines on 
 the sheaths and stems, often confluent. Spores fusiform or clavate, 
 constricted in the middle, generally attenuated below, apex much 
 thickened (9-10 n), rounded or pointed, smooth, chestnut-brown, 
 35-65 X 15-20 n. Pedicels long, persistent, yellowish-brown. 
 
 O and I on Berberis and Mahonia. 
 
 II and III on Avena, Hordeum, Secale, Triticum and nearly 
 fifty other grasses. Of great importance on wheat in the Great 
 Plains and along the Ohio. 
 
 This fungus was the subject of the classic researches of de 
 Bary ^^^ begun in 1865 and has since repeatedly served as the basis 
 of fundamental investigations in parasitism, cytology and biologic 
 specialization. That the barberry seciospores can bring about 
 cereal infection seems to have been shown as early as 1816. ^^^ 
 Inoculations in the reverse order were made in 1865. ^^^ Extensive 
 studies by Eriksson ^^"^ are interpreted by him to show that what 
 was formerly regarded as one species must be separated on bio- 
 logic grounds into several races which he finally erects as species, 
 though others do not agree that their rank should be specific. 
 These are: P. graminis secalis. P. graminis avense. P. graminis 
 tritici. P. graminis airse. P. graminis pose. P. phlei-pratensis. 
 
 These words from Butler and Hayman ^^° show the complexity 
 of the status of these biologic forms. 
 
 "Of late years it has become more and more established that 
 parasitic fungi, which are capable like these rusts of living on 
 several hosts, tend to develop 'races' on their different host- 
 species, marked off from each other by definite characters. Some- 
 times the characters are such as are capable of being detected 
 microscopically. Usually, however, the fungi are, to all appear- 
 ance, identical, and differences only appear when their manner of 
 
380 THE FUNGI WHICH CAUSE PLANT DISElASE 
 
 life is carefully studied. The chief of these is the incapacity of a 
 race to attack the host-plants of another race. Such forms as 
 are thus outwardly identical but which show a constant difference 
 in their mode of life are known as "biological" species or. ksformoe 
 speciales. - 
 
 "A speciahzed form is considered to be 'sharply fixed' or 'not 
 sharply fixed' according as it is wholly incapable, or sometimes 
 capable, of attacking the host-plants of the other specialized forms 
 of the same fungus. Thus the P. graminis of wheat (P. graminis 
 f. sp. Tritici) is not sharply fixed, for it can attack barley, rye, 
 &c., sometimes. The P. graminis found on grasses of the genus 
 Agrostis (P. graminis f. sp. Agrostis) is sharply fixed, for it attacks 
 this genus only and does not pass to the other grasses on which 
 it has been tried. 
 
 "But even the not sharply fixed forms, such as the P. graminis 
 of wheat, may be entirely incapable of attacking some of the 
 species which bear other forms of the same fungus. In other 
 words a form may be not sharply fixed in regard to some host- 
 plants and sharply fixed in regard to others. A striking instance 
 of this occurs in India. P. graminis can be divided amongst others 
 into races on wheat (/. sp. Tritici), rye and barley (/. sp. Secalis), 
 and oats (/. sp. Avena). The/, sp. Tritici can attack barley some- 
 times, and did so in four out of sixteen of our inoculations, but it 
 does not, in India at least, attack oats. Hence it is sharply fixed 
 in regard to oats and not sharply fixed in regard to barley. The 
 /. sp. Secalis on barley also does not pass to oats, but infected 
 wheat doubtfully in two out of sixteen inoculations. These two 
 forms are common in India, and the practical bearing of their 
 not passing to oats is considerable, for the /. sp. Avenos has not 
 yet been observed in this country." 
 
 The mycelium branches intercellularly and bears small haus- 
 toria which penetrate the cells. In the barberry it is local. The 
 epiphyllous pycnia appear first followed soon by the mainly 
 hypophyllous secia. The flask-shaped pycnia at maturity bear 
 numerous pycniospores and exserted paraphyses. Their hyphse 
 are orange-tinted, due to a coloring matter in the protoplasm or 
 later in the cell walls. 
 
 The secium originates in the lower region of the mesophyll 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 381 
 
 from a hyphal weft. The fertile branches give rise to chains of 
 spores every alternate cell of which atrophies. The outer row of 
 sporophores and potential spores remains sterile to form the 
 peridium. When young the secium is immersed and globular, 
 at maturity erumpent and forms an open cup. These spores 
 germinate by a tube capable upon proper hosts of stomatal infec- 
 tion and following this of producing the uredinium. 
 
 Urediniospores are produced throughout the season even through 
 the winter under proper climatic conditions. They also remain 
 viable for weeks ^'^^' ^'"^ and doubtless serve hibernation purposes. ^"^ 
 
 Teliospores arise later in the season in the uredinia or in 
 separate teUa. Unicellular teliospores, mesospores, are oc- 
 casionally seen. Tehospores germinate best after normal out- 
 door hibernation, producing the typical 4-celled promycelium, 
 long sterigmata and solitary basidiospores. If under water the 
 usual promycelium becomes abnormal and resembles a germ 
 tube.i^"' 1'^ 
 
 The aecial stage may not occur under certain climatic conditions, 
 and the uredinia alone perpetuate the fungus. -^^' -^"' ^■'^' ^"^ It 
 therefore follows that eradication of the barberry as was at- 
 tempted by legislative enactment in 1660 in Europe and in 1728 
 and 1755 in Connecticut and Massachusetts "^^ does not extermi- 
 nate the rust ^^* (see also ^^'^' ~^). 
 
 Basidiospores were shown by De Bary, ^^^ confirmed by Ward ^^^ 
 and Eriksson, to be incapable of infecting wheat leaves. Suf- 
 ficient such attempts have, however, not been made on young 
 tissue. ^^° 
 
 Jaczewski ^^^ succeeded in securing germination of pycniospores 
 but the resulting mycelium soon died and infection was not at- 
 tained. The same author holds that seciospores may remain 
 viable about a month, the urediniospores a much shorter time. 
 Still hibernation by urediniospores is possible where climatic rela- 
 tions allow the formation of new uredinia during the winter. 
 
 P. rubigo-vera (D. C.) Wint.^^^- '''' '^^^ ''' ' 
 
 I{=M. asperifohum, Pers). Spots large, generally circular, dis- 
 colored, generally crowded. Peridia flat, broad, with torn white 
 edges. Spores subglobose, verrucose, orange-yellow, 20-25 n. 
 
 II. Uredinia oblong or linear, scattered, yellow, pulverulent. 
 
382 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Spores mostly round or ovate, echinulate, with three or four germ 
 pores, yellow, 20-30 x 17-24 m- 
 
 III. Telia small, oval, or linear, black, covered by epidermis, 
 surrounded by a thick bed of brown paraphyses. Spores ob- 
 long or elongate, cuneiform, slightly constricted, the lower cell 
 generally attenuated, apex thickened, truncate or often obliquely 
 conical. Spores smooth, brown, variable in size, 40-60 x 15-20 /x- 
 Pedicels short. 
 
 Heteroecious ; and I on Boraginacese. 
 
 II and III on rye. The teliospores germinate as soon as mature. 
 
 Fig. 275. — P. rubigo-vera, section of uredinium. 
 After Bolley. 
 
 P. triticina Erik, is the most common and widely distributed 
 of all rusts of the United States and is a serious wheat pest in 
 India. ^^° It ordinarily shows only the uredinial stage. The telio- 
 spores germinate the following spring after a resting period. 
 
 Coextensive with wheat culture.^''^ Epidemics are frequent. 
 
 Bolley ^' ^' ^^ (see also ^*'^) has shown it capable of hibernation by 
 urediniospores and by live winter mycelium and it has further been 
 shown that the spores themselves can survive freezing in ice. The 
 secial stage can be entirely omitted. 
 
 This species is combined with P. triticina by Carleton ^^^ and 
 treated as two races. The name P. dispersa is also used to 
 cover the same two species. P. rubigo-vera tritici on wheat and 
 P. rubigo-vera secalis on rye. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 383 
 
 The secial stage of the former of these is not known. Its uredinia 
 survive the severest winters even so far north as the Dakotas. 
 P. coronata Cda.i^^, 248. soe 
 
 I {=JE. rhamni). Peridia often on very large orange swelhngs, 
 causing great distortions on the leaves and peduncles, cylindrical, 
 with whitish torn edges. Spores subglobose, very finely verrucose, 
 orange-yellow, 15-25 x 12-18 m- 
 
 II. Uredinia orange, pulverulent, elongated or linear, often con- 
 fluent. Spores globose or ovate, with three or four germ pores, 
 echinulate, orange-yellow, 20-28 x 15-20 m- 
 
 III. Telia persistent, black, linear, often confluent, long 
 covered by the epidermis. Spores subcylindrical or cuneiform, 
 attenuated below, constriction slight or absent, apex truncate, 
 
 Fig. 276. — P. coronata, various teliospore forms. After Bolley. 
 
 somewhat thickened, with six or seven curved blunt processes, 
 brown, 40-60 x 12-20 m- Pedicels short, thick. 
 
 Heteroecious; I, on Rhamnus frangula. 
 
 II and III on various grasses but not on oats. 
 
 From this form as earlier understood Klebahn has separated 
 P. coronifera Kleb. on evidence derived from inoculations, and 
 made the latter to include these forms with the aecial stage on 
 Rhamnus cathartica and the uredinial and telial stages on Avena, 
 Lolium, Festuca, Holchus, Alopecurus and Glyceria. P. coronifera 
 has been still further divided by Eriksson into eight biologic forms 
 and P. coronata into three such forms.^"'^ 
 
 P. glumarum (Schm.) Er. & Hu.^^^' -^'^ is widely distributed on 
 wheat, rye, barley and a few other grasses in India and Europe 
 but is not known in America.^''^ Its secia are not known. By 
 some this is regarded as a race of P. rubigo-vera. Both 
 uredinia and teliospores have been reported in the pericarp of 
 grains.^® 
 
384 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 P. simplex (Korn.) Er. & He. 
 
 I. Unknown. 
 
 II and III on barley in Europe and seemingly of recent intro- 
 duction into the United States. ^"^ 
 
 One of the least important of the grain rusts. Mesospores are 
 common. 
 
 P, sorghi Schw.260 
 
 I {=M. oxalidis). Peridia hypophyllous, rarely amphigenous, 
 crowded, concentric, epispore smooth, 24-28 /z. 
 
 II. Uredinia amphigenous, numerous, often confluent; spores 
 globose to ovate, 23-30 x 22-26 mm., slightly verrucose. 
 
 
 Fig. 277. — Puccinia sorghi. After Scribner. 
 
 III. Telia amphigenous, black. Spores ovate-oblong or clavate- 
 obtuse, constricted. Epispore thick, 28-45 x 12-17 n, smooth, 
 pedicel long, 5 n, persistent. 
 
 Heteroecious. and I on Oxahs. II and III on Zea. Of little 
 economic importance. 
 
 The relation of the secial stage was demonstrated by Arthur; -*"' 
 it is believed, however, that hibernation is largely by the uredinio- 
 spores. 
 
 P. purpurea C. Amphigenous, spot purplish, sori irregular, 
 dark-brown. 
 
 II. Urediniospores ovate, 35 x 25-30 m, smooth, brown. 
 
 III. Teliospores elongate, ovate, brown, long-pedicellate, 40-45 
 X 22-25 M- On Sorghum in Southern United States and West 
 Indies. 
 
THE P^UNGI WHICH CAUSE PLANT DISEASE 
 
 385 
 
 P. phlei-pratensis E. & H.^^^-^ei- ''o^-^o^ 
 
 I. ^Ecia probably on Berberis, but rarely formed. 
 
 IL Uredinia 1-2 mm. long on leaves and stems, confluent in 
 lines 10 mm. or more long, yellow-brown; spores oblong, pyriform, 
 spiny, 18-27 x 15-19 /z. Mycelium perennial. 
 
 III. Telia in leaves, sheaths and stems, 2-5 mm. long or 
 more, confluent, narrow, dark-brown to black, open or partly 
 
 Fiu. 278. — P. malvacearum. After Holway. 
 
 closed. Spores fusiform or club-shaped, medially constricted, 
 chestnut-brown, apically thickened, 38-42 x 14-16 m- 
 
 II and III on timothy grass. 
 
 This species is closely related to P. graminis and probably a deri- 
 vate from it, but it does not seem capable of infecting the bar- 
 berry under ordinary conditions."^^' -*^ 
 
 Inoculation experiments with timothy rust at Washington, D. C, 
 show that it can be transferred easily to various grasses. Similar 
 results have been obtained by Eriksson in Europe. It is not a 
 well fixed species and by using bridging hosts it can be made to 
 
386 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 transfer to various cereals which it will not attack directly. That 
 such transfers take place in nature to some extent is probable.^°^ 
 
 P. poarum Niess occurs on bluegrass. 
 
 P. malvacearum Mont.'''^'^^ 
 
 III. Telia grayish-brown, compact, round, pulvinate, elon- 
 gate on the stems, scattered, seldom confluent, pale reddish- 
 brown. Spores fusiform, attenuated at both extremities, apex 
 sometimes rounded, constriction slight or absent, apical thickening 
 slight, smooth, yellow-brown, 35-75 x 15-25 /x. Pedicels firm, 
 long, sometimes measuring 120 fx. 
 
 A lepto-puccinia on three species of Althea, seven of Malva, two 
 of Malope; particularly serious on the hollyhock. A native of 
 Chili, it was first known as a pest in Australia; soon afterward in 
 Europe. It seems to have entered the United States sometime 
 prior to 1886 and is now almost universal. The tehospores ger- 
 minate immediately in suitable environment, mainly from the 
 apical cell, or may remain alive over winter and originate the 
 spring infection. The mycelium also hibernates in young leaves. 
 Mesospores are common. 3 to 4-celled teliospores are also met. 
 P. heterogena Lag. is also described on 
 hollyhock from^*^^ South America. 
 P. chrysanthemi Roze.^^e-ses 
 
 II. Uredinia chocolate-brown, single or in 
 circular groups, hypophyllous, rarely epiphyl- 
 lous. Spores spherical to pyriform. Mem- 
 brane spiny and with three germ pores, 17-27 x 
 24-32 /x. 
 
 III. Telia dark-brown hypophyllous. Telio- 
 spores rarely in uredinia, dark, obtuse, apex 
 thickened, membrane thick, finely spiny, 20- 
 25 X 35-43 fjL. Pedicel 1-13^ times the spore 
 length. 
 
 On cultivated Chrysanthemum. Occasion- 
 ally urediniospores like the other uredinio- 
 spores in all other respects but 2-celled are 
 found; a habit unique with this rust. In many places uredinio- 
 spores may be produced continuously and teliospores be but rarely 
 seen, thus in America only urediniospores have been found. It was 
 
 Fig. 279.— p. helianthi, 
 uredinio- and telio- 
 spores. After Cobb. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 387 
 
 first seen in America in 1896 (Mass.) and soon spread over the 
 country. Numerous inoculation trials go to show that it is inde- 
 pendent of the other rusts common on nearly related Compositse.^^^ 
 
 P. arenariae Wint.^°^ 
 
 III. Telia compact, pulvinate, roundish, scattered, often cir- 
 cinate. Spores broadly fusiform or pyriform, summits pointed or 
 rounded, often thickened, base rounded or attenuated, slightly 
 constricted, smooth, pale yellowish-brown, 30-50 x 10-20 ii. 
 Pedicels hyaline, colorless, as long as the spores. 
 
 A lepto-puccinia common on Dianthus. 
 
 P. helianthi Schw. 
 
 0. Pycnia clustered. 
 
 1. Mcia in orbicular spots; peridial margins pale, torn; spores 
 orange, rarely whitish. 
 
 II. Uredinia minute, round, chestnut-brown, spores globose to 
 ovate, 22-26 x 17-22 n, minutely spiny. 
 
 III. Telia round, dark-brown to black; spores rounded at base, 
 slightly constricted, 38-50 x 20-27 n, smooth; pedicel hyaline, 
 equal to or longer than the spores. 
 
 Autoecious on numerous species of Helianthus, probably divis- 
 ible into numerous biologic forms. Imported from America to 
 Europe. 
 
 Arthur ^°^ used fifteen species of Helianthus on which to sow the 
 teliospores of Puccinia helianthi produced on three species. The 
 results are given in table I on page 388. 
 
 In the course of three years' work with this species sixty sowings 
 were made. 
 
 "Looking over the table it will be seen that each set of spores 
 grew upon the species of host from which derived, but not upon 
 the other two species, except that spores from H. loetiflorus sown 
 on H. mollis gave a tardy showing of pycnia, without further 
 development. Also each set of spores grew luxuriantly upon H. an- 
 nuus, and each made a feeble growth upon H. tomentosus, but on 
 all other species they either failed to infect or made a feeble growth, 
 with the single exception that spores from H. Icetiflorus grew well 
 on H. scaberrimus." P. Helianthi thus affords an example of a 
 single species having many races, for which H. annuus acts as a 
 bridging host. 
 
388 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 
 
 Table 
 
 I 
 
 
 
 
 RESULTS OF INOCULATIONS 
 
 OF 
 
 HELIANTHUS 
 
 RUST * 
 
 
 
 
 Teliospores taken from 
 
 
 
 H. mollis 
 
 
 H. grosse- 
 serratus 
 
 H. la^ti- 
 florus 
 
 1. 
 
 H. annuus 
 
 + 
 
 
 + 
 
 + 
 
 2. 
 
 H. decapetalus 
 
 a 
 
 
 
 
 a 
 
 3. 
 
 H. divaricatus 
 
 a 
 
 
 a 
 
 — 
 
 4. 
 
 H. grosse-serratus 
 
 
 
 
 + 
 
 
 
 5. 
 
 H. hirsutus 
 
 — 
 
 
 
 
 
 
 G. 
 
 H. kellermani 
 
 o 
 
 
 a 
 
 — 
 
 7. 
 
 H. liBtiflorus 
 
 
 
 
 
 
 + 
 
 8. 
 
 H. maximiliani 
 
 o 
 
 
 
 
 a 
 
 9. 
 
 H. mollis 
 
 + 
 
 
 O 
 
 — 
 
 10. 
 
 H. occidentalis 
 
 — 
 
 
 
 
 — 
 
 11. 
 
 H. orgyalis 
 
 
 
 
 
 
 
 
 12. 
 
 H. scaberrimus 
 
 
 
 
 
 
 + 
 
 13. 
 
 H. strumosus 
 
 — 
 
 
 
 
 
 
 14. 
 
 H. tomentosus 
 
 — 
 
 
 — 
 
 — 
 
 15. 
 
 H. tuberosus 
 
 
 
 
 O 
 
 O 
 
 + Abundant infection. — Infection, but slow growth and few or no 
 secia formed, o No infection, a Not sown. 
 
 P. violae (Schum) D. C.^^a 
 
 I. JEcisi on the leaves in circular concave patches, often caus- 
 ing much distortion on the stems, flat with white torn edges. 
 Spores subglobose, finely verrucose, orange-yellow, 16-24 x 10-18 fx. 
 
 II. Uredinia brown, small, roundish, scattered, soon naked. 
 Spores roundish or elliptical, brown, echinulate, 20-26 n in diameter. 
 
 III. Teha black, roundish, small, pulverulent. Spores ellip- 
 tical or oblong, slightly attenuated at the base, with an apical 
 thickening, constriction almost absent, brown, 20-35 x 15-20 /x. 
 Pedicels long, deciduous. 
 
 An autoecious eu-type on many species of Viola, throughout the 
 world. Of little economic import. 
 P. convallariae-digraphidis (Soph.) Kleb. is heteroecious; 
 I on Convallaria majalis. Ill on Phalaris. 
 * Adapted from Arthur. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 389 
 
 P. gentianae Strauss is a eu-puccinia on many species of cul- 
 tivated gentians. P. gladioli Cast occurs on gladiolus. P. gran- 
 ulans Kale. & Cke. is on cultivated Pelargoniums in France;-™ 
 P. tulipae Schr. on tulips; P. scillae Lk. on Scilla; P. schroeteri 
 Pass, on Narcissus in Europe. P. pazschkei Diet, is a lepto- 
 puccinia on cultivated saxifrages in Europe. P. horiana Hen. 
 
 Fia. 280.— P. dianthi. Aftor Holway. 
 
 is destructive on Chrysanthemums in Japan.-^^ P. iridis (D. C.) 
 Duby, a hemi-puccinia, is found on many species of Iris. 
 P. cannae Hen. in its uredinial stage is destructive to Cannas 
 in the West Indies. P. persistens Plow, is heteropcious. I on 
 Thalictrum. II and III on Agropyron. P. asteris Duby. is a 
 very common lepto-puccinia on various asters. P. anemones- 
 virginianae Schw. is a lepto-puccinia common on anemone. 
 
 Key to Uredinales Imperfect! (p. 335) 
 
 Spores catenulate 
 
 Peridium absent 1. Caeoma, p. 390. 
 
 Peridium present 
 
 Toothed, body cup-shaped 2. jEcidium, p. 390. 
 
 Fimbriate, body elongate 3. Roestelia, p. 391. 
 
 Irregularly split 4. Peridermium, p. 390. 
 
 Spores not catenulate 5. Uredo, p. 392. 
 
390 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 -^cidium Persoon (p. 389) 
 
 Spores surrounded by a cup-shaped peridium; produced catenu- 
 late in basipetal series. Germination as in Uredo. 
 
 The species are very numerous and belong in the main to Puc- 
 cinia and Uromyces. Most of the forms of economic interest are 
 found under these genera. A few others of occasional economic 
 bearing whose telial stage has not yet been recognized are given 
 below. 
 
 A. brassicae Mont, on Brassica is perhaps identical with Puccinia 
 isiacse. See p. 378. A. tuberculatum E. & K.^^^ is reported as 
 destructive on the poppy mallow. A. pelargonii Thiim. occurs 
 on geraniums; 2^° A. otogense Lindsay on Clematis.^" A. cin- 
 namomi Rac. is serious on the cinnamon tree in Java. 
 
 Caeoma Link (p. 389) 
 
 Sori without a peridium, accompanied by pycnia, with or with- 
 out paraphyses, produced in chains. Germination as in Uredo. 
 
 The forms are mostly stages of Melampsora, Phragmidium or 
 their kin. Those of economic interest are found under Gymno- 
 conia and Melampsora. 
 
 Peridermium Leviell6 (p. 389) 
 
 Pycnia truncate-conic. 
 
 Peridia caulicolous or foliicolous, erumpent, saccate to tubular, 
 lacerate-dehiscent, spores catenulate or at maturity appearing 
 solitary, globose to elliptic or oblong, polyhedral by pressure, 
 yellowish-brown. Epispore always verrucose-reticulate. 
 
 The secial stages of Coleosporium, Cronartium, Pucciniastrum, 
 Melampsorella and Chrysomjoca. 
 
 The peridia usually extend conspicuously above the host sur- 
 face, and rupture irregularly by weathering. 
 
 All of the species grow on the Coniferse, most of them on Pinus 
 on both leaves, branches and bark. On the leaves the aecia are 
 much of the type shown in Fig. 256. When on the woody parts 
 great distortion may be caused by the perennial fungus and much 
 injury result to the wood (see Cronartium quercus, p. 352). 
 
 The mycelium may live intercellularly in rind, bast and wood 
 
 jr^- 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 391 
 
 of pine and continues to extend for years causing swellings of 
 twigs. Pycnia are either subcuticular or subepidermal and the 
 pycniospores often issue in a sweetish liquid. ^Ecia occur as 
 wrinkled sacs emerging from the bark of the swollen places and 
 bear spores perennially. 
 
 A key to some thirty species is given by Arthur & Kern.^^^ 
 So far as it relates to the distribution of the Peridermiums to 
 their telial genera it is as follows : 
 
 Key to Species of Peridermium 
 
 Pycnia subcuticular 
 
 iEcia cylindrical Pucciniastrum. 
 
 iEcia tongue-shaped Melampsorella, Melamp- 
 
 soridium. 
 Pycnia subepidermal 
 
 ^cial peridia one cell thick 
 
 On Pinus Coleosporium. 
 
 On Picea Melampsoropsis. 
 
 On Abies Uredinopsis. 
 
 Pycnia subcorticular 
 JEcial peridia more than one cell thick . . . Cronartium. 
 
 Such forms as are of economic interest and of which the telial 
 stage is known are discussed under Coleosporium, Cronartium, 
 Melampsorella, Melampsoropsis and Pucciniastrum. 
 
 Several other forms are found on pine, spruce and Tsuga. 
 
 Roestelia Rebentisch (p. 389) 
 
 0. Pycnia spherical or cup- 
 formed. 
 
 1. ^cia with strongly de- 
 veloped thick-walled peri- 
 dium, flask-shaped or cylin- Fig. 281 
 dric; spores globose, 1-celled, 
 brown to yellow, catenulate, with several evident germ pores. 
 
 The forms are the acial stages of Gymnosporangiums and 
 occur mostly on Rosaceous hosts. The economic forms will be 
 found under Gymnosporangium. 
 
 ^^ 
 
 R. pyrata, cups showing peridial 
 cells. After King. 
 
392 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Uredo Persoon (p. 389) 
 Spores produced singly on the terminal ends of mycelial hyphse. 
 Germination by a germ-tube which does not produce basidio- 
 spores, but enters the host-plant through 
 the stomata. 
 
 These forms are in the main discussed 
 under their telial genera. 
 
 U. orchidis Wint. and U. satyrii Mass. 
 are in the leaves of cultivated orchids. 
 U. tropaeoli Desm. is found on Tropseolum ; 
 U. arachidis Lag. the peanut ; ^-^ U. auran- 
 tiaca Mont, on Oncidium.^^° U. au- 
 tumnalis Diet, on Chrysanthemums in 
 Japan ^^^ and U. kuhnii (Kr.) Nak. on 
 sugar cane in Java. 
 
 The Auriculariales (p. 323) 
 
 Mycelium septate, forming a gelatinous, 
 irregular and expanded or capitate sporo- 
 carp; hymenium variable, densely beset 
 Fig. 282.— Various hasidia of with basidia, on each segment of which is 
 the lower basidiomycetes, bornc a loug sterigma, with its single 
 
 1, auriculanas; 2, tremellas 007 o 
 
 with longitudinal divisions; spore. 
 
 3, dacryomycetes with un- rr-ii » * 1 • 1 j 1 
 
 divided forked basidium. ihe Auriculariales are mostly sapro- 
 
 phytic and of little economic importance. 
 They embrace some fifty species in two families and are chiefly 
 of interest on account of the form of their basidia Fig. 282, which 
 shows relationship both to the Ustilaginales and to the orders to 
 follow. 
 
 Key to Families op Auriculariales 
 
 Hymenium gymnocarpous 1. Auriculariaceae, p. 392. 
 
 Hymenium angiocarpous 2. Pilacraceae. 
 
 Auriculariaceae 
 
 Key to Tribes or Genera of Auriculariaceae 
 Sporocarp arising from a ton-like base of 
 
 mycelial threads I. Stypinelleae. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 393 
 
 Basidia free on the end of the hyplue 
 
 without saccate cell 1. Stypinella, p. 393. 
 
 Basidia subtended by a saccate cell 2. Saccoblastia. 
 
 Sporocarps crustaceous II. Platygloeeae. 
 
 Sporocarps gelatinous, auriform or caj)- 
 
 shaped III. Auricularieae, p. 393. 
 
 In tribe III, AuriculariesD, there is a single genus, Auricularia. 
 
 Cap more or less cup-shaped or ear-like, jelly-like ])ut firm when 
 wet, horny when dry, the hymenium often veined or folded, but 
 without teeth. The name refers to the cup-like form. 
 
 A. auricula- judiae (L.) Schr. is a very common saprophyte which 
 is occasionally parasitic on elder, elm, and mulberry in Europe. 
 
 In tribe I, few cases of parasitism of any importance are reported. 
 
 Stypinella mompa (Tan.) Lin. is found on the roots of mulberry 
 in Japan. 
 
 Eubasidii (p. 299) 
 
 The Eubasidii represent the higher development of the basidia- 
 fungi and contain the majority of the species. The basidia, 
 the typical club-shaped undivided stalks, bear usually four, 
 sometimes two, six, or eight unicellular spores on a like num- 
 ber of sterigmata and are mostly arranged in hymenia. There 
 is great diversity in the form and size of the sporophore from 
 an almost unorganized mycelial microscopic weft to the large 
 complex structures of the toad stools and puff balls. Conidia 
 and chlamydospores while occasionally present are much less 
 common than in the preceding groups or orders. 
 
 The cells of the sporophore in many forms investigated are 
 binucleate ; ^^ in other forms they arc multinucleate. 
 
 The origin of the binucleate condition often antedates the for- 
 mation of the sporophore and may occur far back in the mycelium, 
 perhaps as far back as the germinating basidiospore itself.^^' ^^' ^^ 
 In the basidial layer, hov\^ever, even of those forms with multi- 
 nucleate vegetative cells, the nuclei are reduced to two so that 
 the general statement is permissible that in the hymenial layer 
 of the Basidiomycetes the cells are binucleate. From such cells 
 two nuclei wander into the basidium primordium where they 
 fuse to one, reducing this cell to a uninucleate condition. This 
 
394 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 nucleus by two mitoses gives rise to four nuclei which wander 
 through the sterigmata into the spores and constitute the four 
 basidiospore nuclei. 
 
 The significance of this phenomenon of fusion in the basidium 
 followed by division, which is wide spread and apparently the 
 
 H 
 
 li 
 
 L 
 
 >t 
 
 >>■ 
 
 
 .\' 
 
 o 
 
 
 -1 --*i 
 
 (- ) 
 
 I 
 
 \ 1 
 
 o 
 
 
 
 
 '^^Ci^, 
 
 Fig. 283. — Stages in the development of the basidium (Agaricus) ; original 
 binucleate condition, followed (E-F) by fusion, and subsequent mitosis N-R, 
 resulting in four spore nuclei. After Wager. 
 
 dominant typical phenomenon among the Basidiomycetes includ- 
 ing both high forms, Agarics, ^^ and low forms, Dacryomycetes,^^ 
 the Uredinales ^^^' ^^' ^^^' ^^^' ^^^ and even the Gasteromycetes 
 (Maire),^^^ is much debated. By some it is regarded as a very 
 much modified type of fertilization, a view to which support is 
 lent by the fact that in some of these fungi, perhaps all, the 
 nuclei multiply by a process of conjugate division. Thus the two 
 nuclei found in the yoimg basidium, although belonging to the 
 same cell may in ancestry be very distantly related. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 395 
 
 Key to Orders of Eubasidii 
 
 Gelatinous fungi with forked basidia 
 
 Basidia clavate, undivided 
 
 Hymenium without stroma, parasites, 
 
 basidia free, strict 
 
 Stroma usually well developed, fleshy, 
 coriaceous, leathery or woody 
 Spores arising from basidia which form 
 a distinct membranous hymenium 
 which is naked at maturity, and 
 frequently covers the surface of 
 gills, pores or spines (Hymenomy- 
 
 cetes) 
 
 Spores arising from basidia enclosed in a 
 definite peridium (Gasteromycetes.) 
 Spores borne in a more or less deli- 
 quescent gleba which is at first 
 enclosed in a peridium, but is at 
 
 maturity elevated on stipe 
 
 Spores remaining within the peridium 
 until maturity 
 Basidia united into a hymenium 
 which lines the walls of irreg- 
 ular cavities 
 Hymenial cavities remaining 
 together in the peridium, 
 their boundaries mostly 
 disappearing at maturity 
 Fleshy until the maturity of 
 the spores, capillitium 
 
 none 
 
 Fleshy when young, at matu- 
 rity filled with dust-like 
 spore-masses mixed with 
 capillitium (puff balls) . . 
 Hymenial cavities separating at 
 maturity from the cup-like 
 peridium (bird-nest fungi) . 
 Basidia uniformly distributed 
 through the peridium or 
 forming skein-like masses . . . 
 
 1. Dacryomycetales. 
 
 2. Exobasidiales, p. 396. 
 
 3. Agaricales, p. 398. 
 
 4. Phallales, p. 462. 
 
 5. Hymenogastrales. 
 
 6. Lycoperdales, p. 464. 
 
 7. Nidulariales. 
 
 i. Sclerodermatales. 
 
396 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 The Dacryomycetales include forms with a gelatinous sporo- 
 phore. They are mostly small, inconspicuous saprophytes, common 
 on decaying wood, leaves, etc. The Hymenogastrales are puff-ball 
 forms, and are very numerous and of very diverse structure. None 
 have been reported as parasitic. The Nidulariales is a small order 
 comprising the curious bird-nest fungi, all saprophytes. The 
 Sclerodermatales are thick-skinned puff balls, mostly subter- 
 ranean, and not known to be parasitic. 
 
 Exobasidiales (p. 395) 
 
 Strictly parasitic, the mycelium penetrating the host and usually 
 causing marked hypertrophy; hymenium unaccompanied by fleshy 
 sporocarp, consisting only of the closely-crowded, clavate basidia 
 which break through the epidermis of the host. 
 
 The basidia bear four, rarely five or six sterigmata and spores. 
 The spores are mostly curved. Conidia are also found in some 
 species. . The basidiospores germinate with a germ tube which pro- 
 duces fine sterigmata and secondary spores capable of budding. 
 The hymenial cells are binucleate, the two nuclei of the basidial cell 
 fusing into one basidium-nucleus. This divides mitotically giv- 
 ing rise to the spore nuclei. 
 
 This order among the basidia fungi is analogous to the Exoas- 
 cales among the ascus fungi. There are two genera and some 
 twenty-five species. 
 
 Key to Genera of Exobasidiales. 
 
 Basidia 6-spored; not gall producers 1. Microstroma, p. 396. 
 
 Basidia 4-spored ; producing galls 2. Exobasidium, p. 396. 
 
 Microstroma Niessl. contains only three species of which 
 
 M. album (Desm.) Sacc. is on oak; 
 
 M. juglandis (Ber.) Sacc. on Juglans and Hicoria. 
 
 Exobasidium Woronin 
 
 Mycelium penetrating the host and causing distinct hyper- 
 trophy, hymenium subcuticular, erumpent, basidia 4-spored, 
 spores elongate. 
 
 There are some twenty species, mostly on members of the 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 397 
 
 Ericaceie. Cultural work and studies in infection are needed be- 
 fore species can l)c properly delimited.^''' 
 
 E. vaccinii (Fcl.) Wor. occurs on Vaccinium vitis idaia, forming 
 large blisters on the leaves, 
 rarely on petioles and stems, 
 discoloration red or purple. 
 The fungus appears as a 
 white bloom on the under 
 surface of the leaf; spores 
 narrowly fusiform, 5-8 x 
 1-2 M. 
 
 Richards ^^ who studied 
 E. vaccinii and E. an- 
 dromedae from inoculations 
 concludes : 
 
 ''Aside from the form of 
 the distortion, E. vaccinii 
 and E. andromedae cannot 
 well be distinguished. The 
 former can produce the same 
 form of distortion on both 
 Gaylussacia and Andromeda 
 and the latter has been made 
 to produce a similar growth 
 on Andromeda. Micro- 
 scopically these forms do 
 not differ. The natural 
 conclusion is that these two 
 species of Exobasidium are 
 one and the same and the form producing large bag-like dis- 
 tortions on Andromeda should be considered a form of E. vac- 
 cinii." 
 
 E. oxycocci Rost causes greater hypertrophy than E. vac- 
 cinii, distorting young twigs and leaves; spores 14-17 x 30 m; 
 smaller conidia often present. The mycelium infests the leaves 
 and stems of the cranberry. ''° Morphologically the species agrees 
 closely with E. vaccinii. Infection experiments are needed. 
 
 E. vexans Mas ^^ causes a serious disease on tea. E. andromedae 
 
 Fig. 284. — Exobasidium andromedae on An- 
 dromeda, showing host cells, mycelium, 
 basidia and spores. After Richards. 
 
398 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 • --c 
 
 '- ~i 
 
 Pk., E. rhododendri Cram,, E. japonicum shirai and E. peckii 
 Hal. are reported on Rhododendron and Andromeda; 
 
 E. azaleae Pk. and several other species on various Rhododen- 
 drons; E. vitis Prill, was noted in France on the grape; '^^ 
 
 E. lauri (Borg) Geyl. is on Laurus. 
 
 E. cinnamomi Petch on cinnamon in Ceylon. 
 
 Agaricales (p. 395) '' ^' "• '*• "> "** 
 
 This is a very large order of over eleven thousand species. 
 The mycelium grows to long distances over or through the sup- 
 porting nutrient me- 
 dium, often forming 
 conspicuous long-lived 
 resistant rhizomorphic 
 strands or sheets, some- 
 times developing sclero- 
 tia or again appearing 
 as a mere floccose weft. 
 The basidia bear four 
 simple spores, in rare 
 cases two, six or eight. 
 Other forms of conidia 
 are found in some spe- 
 cies and chlamydospores 
 may be borne either ex- 
 ternally on the sporo- 
 phore, in the hymenium, 
 or inside of the sporo- 
 phore tissue. In the 
 lowest forms the basidia 
 arise directly from the 
 mycelium without the formation of any definite sporophore but 
 in most species the sporophore is highly complex, consisting of 
 large, stalked or sessile, pseudoparenchymatous structures (toad- 
 stools, mushroom, etc.) on special surfaces of which, the hy- 
 menium, Fig. 286, lies; covering gills or spines or Uning pits or 
 pores. 
 
 The general relation of the basidia to the hymenium and the 
 
 - rac 
 
 Fig. 285. — An agaric (Amanita) sporophore show- 
 ing parts; c, pileus; m, c, striated margin; g, gills; 
 a, annulus; s, stem; v, volva; mc, mycelium. 
 After Peck. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 399 
 
 
 sporophore is shown in Figs. 285, 286. Families are delimited 
 by the character of the sporophore, distribution of the hymenial 
 surfaces, presence of cystidia, size q^ ^rt) rrn ■; 
 and color of spores, and other more IT^Jl-^-Jl-- 
 minor points. \(j )i! f if 
 
 In germination the spore pro- "^'^'"'j ;:-f-^:yr 
 duces a germ tube which develops vV^"^^'^ ^- 
 directly into a mycelium. In many ?-— ^- 
 species the young mycelium is 
 conidia-bearing. 
 
 Cytologically the group conforms 
 to the general description given on 
 pages 393, 394. 
 
 The Agaricales are chiefly of in- 
 terest to pathologists as wood fungi 
 though in a comparatively few in- 
 stances they are found on herbs. 
 Upon wood they may do harm. 
 First, as root parasites, in which 
 case death may follow through in- 
 terference with absorption or an- 
 chorage. Second, as causes of 
 heart rots leading to weakness and 
 eventual overthrow of the tree. 
 Third, as parasites of sap wood, 
 cambium or bark leading to death 
 of a part of the host and often its 
 complete loss. 
 
 In many instances the fungus 
 draws its subsistence from host 
 cells not actually alive and hence strictly speaking they are 
 saprophytes. Nevertheless, since their ultimate effect upon the 
 tree is to cause disease or death, from the practical viewpoint 
 these fungi are pathogenic. Many species, moreover, can start 
 their career on a host plant as saprophytes and after attaining a 
 stage of vigorous vegetative growth become truly parasitic. In 
 most instances they are wound parasites, which cannot gain ac- 
 cess to the inner portions of the host through uninjured tissue 
 
 Fig. 286. — Cross section of the gill 
 showing basidia, sterigmata and 
 spores, also a cystidium stretch- 
 ing from one gill to the next. 
 After Buller. 
 
400 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 
 W ojS " o a^ M 3 «« " 
 w;a cS.M>>^ >^ "^ a. g- 
 
 B'S " E"(D « P a o 03 
 
 S =S . S I '^-^ o =-' c 
 
 S^ a:n ^o 3^ S^-^ o 
 •2« §-53^ =« 2"^ ^ § " ^, 
 
 TpS £ MO) oj^ &S'> S "h 
 
 •S '^-° 
 
 CQ 
 
 
 a . -M OS o G " o 
 § o ^.S ^^ ^< 
 
 ■Ab 
 
 M 
 
 00 >-.^ £.ti <D ??-G^ 
 
 0) £. H b 
 
 c b 
 
 «m^ 
 
 -..H S & o-^'^ 4) S „ g g 
 f^ : ; : : 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 401 
 
 but must make entrance through some wound, as those due to 
 hail, wind, snow, insects, men and other animals, 
 etc., which exposes the inner bark, cambium, sap 
 wood or heart wood without its natural outer 
 protecting tissues. 
 
 Within the tissues the mycelium may cause the 
 disappearance of substances, e. g., Fomes ig- 
 niarius consumes the tannin, or the mycelium 
 may secrete enzymes which penetrate the host to fig. 288. — Tra- 
 long distances. These may dissolve first one com- 
 ponent of the cell, e. g., the lignin, next the 
 most lignified residue, the middle lamella, re- 
 sulting in dissolution of the tissue. In other cases 
 the parts of the cell walls other than the middle 
 lamella are first affected and soon shrink resulting 
 in cracks. Fig. 289. Some fungi cause character- 
 istic color changes particularly in those cell walls 
 which are rich in carbon. Parasitism in this 
 group is old since good examples of agarics 
 growing on wood are found as early as in 
 period. ^^ 
 
 These fungi spread to new hosts by spores borne in various 
 ways; by insects (Trametes radiciperda) animals, 
 wind (Polyporus pinicola) etc., or in a purely 
 vegetative manner by the mycelium which in the 
 form of rhizomorphs (Armillaria mellea) travels 
 through the ground to considerable distances. 
 An excellent summary of the early history of our 
 knowledge of wood destroying fungi is given by 
 
 cheid of pine 
 decomposed by 
 Trametes pini. 
 The primary 
 wall dissolved 
 as far as aa; 
 in the lower 
 part the sec- 
 ondary and ter- 
 tiary layers are 
 only of cellu- 
 lose; c, myce- 
 lium making 
 holes at d and 
 e. After Har- 
 tig. 
 
 the Tertiary 
 
 Fig. 289. — Pine 
 
 1, 338 
 
 traciieid acted Buller, 
 
 porus^schw^- The number of species of Agaricales which af- 
 nitzii. The fgg^, five plants in the waj^s mentioned above is 
 
 cellulose has ^. . ,.,. 
 
 been extracted very great but m many mstances research m this 
 w^aUs^chiefly field has not yet revealed the true relation existing 
 hgnm. Drymg bg^ween the fungi and the woody plants upon 
 cracks. After which they are found growing; whether they 
 occur as parasites or as saprophytes; whether 
 actually injurious or not. The species given below are mainly 
 
402 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 regarded as actually injurious. If more questionable cases were 
 to be included the number would be increased several fold. 
 
 Key to Families of Agaricales 
 
 Basidia loosely aggregated on a mold-like 
 or arachnoid base, formed from loose 
 
 floccose hyphae 1. Hypochnaceae, p. 402. 
 
 Basidia closely aggregated, forming a com- 
 pact layer 
 Hymenium smooth 
 
 Sporocarp effused, resupinate or rarely 
 
 pileate, usually not fleshy 2. Thelephoraceae, p. 405. 
 
 Sporocarp clavate, the upper portion 
 
 only sporogenous, usually fleshy. . 3. Clavariaceae, p. 412. 
 Hymenium variously folded or pitted 
 Hymenium with teeth, tubercles or 
 tooth-like plates which are sporo- 
 genous 4. Hydnaceae, p. 413. 
 
 Hymenium lining pores 
 Pores not easily separating from the 
 pileus, which is commonly 
 
 leathery, corky or punky 5. Polyporaceae, p. 416. 
 
 Pores readily separating from the 
 
 pileus which is fleshy 6. Boletaceae, p. 440. 
 
 Hymenium covering the surface of 
 
 radiating plates 7. Agaricaceae, p. 442. 
 
 Hypochnaceae 
 
 Sporophore poorly developed and often indefinite, of loosely 
 woven floccose hyphae; the basidia clavate, loosely aggregated 
 into an ill-defined hymenium. 
 
 In the simplicity of the sporogenous structures the members 
 of the group approach the Hyphomycetes from which they are 
 separated only by their sporophores which are of the nature of 
 basidia rather than of ordinary conidiophores. 
 
 A small family of some half dozen genera and sixty species. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 403 
 
 Key to Genera of Hypochnaceae 
 
 Spores colorless, smooth, rarely granular 
 Basidia with two sterigmata 
 
 Basidia circulate 1- Helicobasidium. 
 
 Basidia not circinate 
 
 Basidia pyriform, beaked 2. Urobasidium. 
 
 Basidia clavate, not beaked 3. Matruchotia. 
 
 Basidia with 2-4 rarely 6 sterigmata 4. Hypochnus, p. 403. 
 
 Basidia with numerous sterigmata 
 
 Sterigmata small 5. Aureobasidium, p. 405. 
 
 Sterigmata large 6. Pachysterigma. 
 
 Spores colored, mostly spiny 7. Tomentella. 
 
 Hypochnus Ehrenberg. 
 
 Floccose or fungoid, rarely thinly fleshy, spreading over the 
 substratum; basidia clavate; spores colorless, smooth or minutely 
 granular. 
 
 This genus which contains half the species of the family, is 
 
 Fig 290. — H. ochroleucus sporogenous reticulum prior to spore formation. 
 8 basidia, sterigmata, and spores. After Stevens and Hall. 
 
 with difficulty distinguished from Corticium from which it differs 
 in the character of its hymenium. 
 
 H. ochroleucus N. ^''"''^ Sporogenous reticulum of a very close, 
 irregular net work of hyphae variable in thickness; basidia scattered, 
 
404 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 clavate, swollen; sterigmata 4; spores oblong, slightly flattened on 
 the side adjacent to the companion spores, tapering slightly at 
 each end, 4.7-5.8 x 10.5-11.6 /x. A migratory mycelium is 
 present, covering twigs and leaves with a brown felty growth; 
 rhizomorphs white, later buff, about 5.8 /x, septate. Sclerotia 
 are also found. 
 
 The long cottony rhizomorphic strands extend along the twigs, 
 up the petioles and in places aggregate to form brown sclerotia, 
 
 Fig. 291. — H y p o c h ii u s, 
 semi-diagrammatic sec- 
 tion showing develop- 
 ment of hymenium and 
 basidia, with nuclear 
 conditions. After Har- 
 per. 
 
 Fig. 292. — Mycelium 
 of Hypochnus show- 
 ing clamp connec- 
 tions. After Har- 
 per. 
 
 which are especially abundant near the terminal buds. On the 
 leaves Stevens and Hall ^^' '*^ describe a loose network from which 
 the basidia arise. Fig. 295. The species is found on apple, pear, 
 lilac, quince, Vibernum and probably other hosts, and is widely 
 distributed. 
 
 H. cucumeris Frank. 
 
 Fungus gray or brown; basidia elongate, bearing 4 sterigmata; 
 spores ovoid hyaline. Reported on cucumbers ^''' ^^ in 1883. 
 
 H. solani P. & D. is said to be a parasite of potatoes. ^^ It is 
 probably identical with Corticium vagum solani. See p. 407. 
 
 / 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 405 
 
 H. theae Bern, occurs on tea; ^^ H. filamentosus Pat. on live 
 leaves of Caryophyllacese and Amaryllidacese in Quito; H. fu- 
 ciformis (Berk.) McAlp on grasses in Australia. 
 
 An undetermined species of Hypochnus was studied by Eustace^ ^ 
 as the cause of rot of stored apples. Artificial inoculations proved 
 its parasitism, though it was unable to make entrance through 
 sound surfaces. 
 
 The spores are hyaline, smooth, usually obovate, 4-5.5 x 2.5-3.5 n. 
 
 Aureobasidium Viala & Boyer ^^ (p. 403) 
 
 The fungus body consists of delicate, floccose, more or less 
 webby masses of much-branched, septate, golden hyphse; basidia 
 with numerous sterigmata; spores cylindric. 
 
 A single species, A. vitis, V. & B., occurs on grape roots in 
 France and Italy^'' ^" 
 
 Thelephoraceae (p. 402) 
 
 Sporocarp leathery or membranous, (rarely fleshy, corky or 
 punky) resupinate or pileate, simple or compound; hymenophore 
 smooth, warty or wrinkled; basidia numerous, interspersed with 
 spine-like cystidia. 
 
 This is a very large family, but of its eleven hundred species 
 only a few are parasites. 
 
 Key to Genera of Thelephoraceae 
 
 Hymenophore without cj^stidia 
 Hymenophore entirely resupinate 
 Spore membrane colorless 
 Contents colorless 
 Spores sessile 
 Basidia with 2 sterigmata. . . 1. Cerocorticium. 
 Basidia with 4 sterigmata. ... 2. Corticium, p. 406. 
 Basidia without sterigmata. . 3. Protocoronospora,p.409. 
 
 Spores stalked 4. Michenera. 
 
 Contents colored 5. Aleurodiscus. 
 
 Spore membrane colored 
 
 Hymenophore soon gelatinous .... 6. Aldridgea. 
 Hymenophore fleshy-leathery. ... 7. Coniophora. 
 Hymenophore partially free, shelving 
 
 Context of several layers .8. Stereum, p. 409. 
 
406 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Context of only one layer 
 Hymenophore leathery 
 Hymenium not ribbed 
 
 Hymenium almost smooth or 
 with warts 
 
 Basidia continuous 9. Thelephora, p. 410. 
 
 Basidia septate 10. Septobasidium, p. 411. 
 
 Hymenophore smooth 11. Hypoly ssus. 
 
 Hymenium with ribs 
 
 Ribs becoming warty 12. Cladoderris. 
 
 Ribs with warty spines 13. Beccariella. 
 
 Hymenophore not leathery 
 
 Hymenophore gelatinous-fleshy 14. Phlebophora. 
 Hymenophore membranous, rare- 
 ly fleshy or fleshy-leathery 
 Hymenium exterior to the 
 
 hymenophore 15. Craterellus. 
 
 Hymenium inside the hy- 
 menophore 
 Hymenophores mostly soli- 
 tary 
 Hymenophore sessile or 
 
 laterally stipitate 16. Cyphella. 
 
 Hymenophore centrally 
 
 attached - 17. Discocyphella. 
 
 Hymenophores closely 
 
 grouped 18. Solenia. 
 
 Hymenophore with cystidia 
 Cystidia of a single cell 
 Cystidia unbranched 
 Hymenophore of a single layer 
 
 Hymenophore resupinate 19. Peniophora. 
 
 Hymenophore laterally short- 
 stalked 20. Skepperia. 
 
 Hymenophore of several layers. . . 21. Hymenochaete, p. 411. 
 
 Cystidia stellate-branched . 22. Asterostroma. 
 
 Cystidia of several cells 23. Bonia. 
 
 Corticium Persoon (p. 405) 
 
 Hymenophore homogeneous in structure, membranous, leathery 
 or fleshy, almost waxy, rarely approaching gelatinous; hymenium 
 
THE FUxNGI WHICH CAUSE PLANT DISEASE 
 
 407 
 
 arising immediately from the mycelium, smooth or minutely 
 warty; basidia clavate, with four sterigmata; spores small, globose 
 or ellipsoid, with a smooth colorless membrane. 
 
 A genus of some two hundred fifty species, mostly wood inhab- 
 iting. 
 
 One species possesses a mycelium which has long been known 
 in its sterile form as a Rhizoctonia. 
 
 Corticium vagum solani Burt. ''^■^*'' ^^'* 
 
 Hymenophore, white when sporing, poorly developed, of loosely 
 interwoven hyphse; basidia short, cylindric or oblong; spores some- 
 
 FiG. 293. — C. vagum solani Rhizoc- 
 tonia stage. After Duggar. 
 
 Fig. 294. — C. vagum-solani, 
 basidia, sterigmata and 
 spores. After Rolfs. 
 
 what elliptic, often irregular in outline, 9-15 x 6-13 ix. 
 
 Sterile mycelium ( = Rhizoctonia solani = Rhizoctonia violacea)^^ 
 turning yellowish with age, and branching approximately at 
 right angles; often forming sclerotia-like tufts wdth short, broad 
 cells more or less triangular which function as chlamydospores. 
 
 Brown to black sclerotial structures, a few millimeters in diam- 
 eter, consisting of coarse, broad, short-celled hyphae of peculiar 
 and characteristic branching also occur freely, both in nature and 
 in culture, Fig. 293. These cells seem capable of functioning as 
 chlamydospores. 
 
 The hymenophore consists of a dark network of hyphae which 
 changes to grayish-white when sporing. It frequently entirely 
 surrounds the green stems of the host near the ground. The tips of 
 the outermost hyphse are sterigmatate. The spores germinate 
 readily, developing into typical Rhizoctonia mycelium. 
 
 The relation which the various Rhizoctonias which have been 
 described on numerous hosts may bear to the one species under 
 
408 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 discussion is problematic. Much culture and inoculation work is 
 needed. Some of the various hosts upon which a Rhizoctonia 
 apparently closely allied to that of Corticium vagum solani have 
 thus far been found in America are : 
 
 Sugar-beet, bean, carrot, cabbage, cotton, lettuce, potato, 
 radish, sweet potato, pumpkin, watermelon, garden pea, corn, 
 purslane, Solanum verbascifolium, egg plant, pig-weed, spiny 
 pig-weed, Heterotheca subaxillaris, Richardia, Crotalaria, Cy- 
 perus rotundus, Heterotheca lamarckii and Phytolacca decandra, 
 Pinus sps., • Picea. Pseudotsuga, carnation and alfalfa. 
 
 The sterile mycelium was noted in Europe on potato many years 
 ago ; its existence in America has been known since 1890 (Duggar ^^) . 
 Its identity with the genus Corticium was demonstrated in 1904 
 by Rolfs ''^ both by observing the connection between the myce- 
 lium and the basidia on young potato plants and by culture of 
 the typical Rhizoctonia stage from the basidiospores. The parasi- 
 tism of the organism was proved by inoculations made with pure 
 culture by Rolfs.'^^ 
 
 The sterile mycelium (Rhizoctonia) occurs in two forms on 
 the potato, a light-colored actively parasitic form usually some- 
 what deep in the affected tubers and a darker mycelium growing 
 superficially on the host or over the soil. In artificial culture the 
 manner of branching is typical, the young branches running 
 nearly parallel to the main thread and bearing slight constrictions 
 at their bases. 
 
 A key to the species in France is given by Bourdot and Gol- 
 zin.164 
 
 C. laetum (Karst.) Bres. 
 
 Plant body at first salmon-colored, soon fading to a dirty-white; 
 context, of hyphse which are nodose, septate, irregular, 4-10 /x, 
 basidia clavate, 35-50 x 7-12 n; spores oblong ovate, subde- 
 pressed on one side, hyaline, 10-14 x 6-8 fi. 
 
 On fig and apple in Louisiana, and in Europe and in the Northern 
 United States on Alnus, and Corylus. It causes the limb blight 
 of the fig, ^^' ^^^ gaining entrance through dead twigs. While the 
 fungus is usually a saprophyte, once it gains entrance to the host 
 it follows down the branch, covering it with its bright salmon- 
 colored fructification and causing sudden wilting and dying of the 
 
 J" 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 409 
 
 leaves. The cambium layer is the seat of the disease. The fungus 
 spreads rapidly but is not a serious pathogen except in rainy periods 
 in midsummer. 
 
 C. javanicum (Hen.) S. & S. causes disease of coffee and tea; ^^ 
 C. dendriticum Hen. parasitizes orange stems; ''^ C. comedens 
 (Nees) Fr. occurs on oak as a wound parasite; C. zimmermannii 
 S. & Syd. injures many tropical trees; ^° C. lilacino-fuscum Berk. 
 & Curt, occurs on cacao. 
 
 C. chrysanthemi Plow, is reported as the cause of death of 
 cultivated chrysanthemum in England. 
 
 Protocoronospora Atkinson & Edgerton (p. 405) 
 
 Genus as in Corticium, except for the basidia which bear 4-8 
 sessile, oblong or elliptic spores. 
 
 P. nigricans Atk. & Edg.^^ forms narrow elongate spots on vetch 
 pods, stems and leaves. Spot, ol^lique on the pods, 2-5 x 1-2 mm., 
 at first white or with a purple border, later black; subhymenial 
 layer subepidermal two or three cell layers thick; basidia clavate, 
 to subcylindric, 20-30 x 6-8 /x; spores sessile, pale-pink in mass, 
 oblong to subelliptic, hyaline, smooth, granular, continuous, or 
 1-septate in germination, straight or curved. Found on vetch at 
 Ithaca, N. Y., associated with Ascochyta. 
 
 Stereum Persoon (p. 405) 
 
 Hymenophore leathery or woody, persistent, of several layers, 
 sometimes perennial, laterally or centrally attached; hymenium 
 smooth. 
 
 A genus of about two hundred fifty species chiefly wood in- 
 habiting, but a few grow in humus. 
 
 S. hirsutum (Willd.) Pers. 
 
 Hymenophore leathery, firm, expanded, wrinkled, hairy, yellow- 
 ish; the hymenium yellowish, smooth. 
 
 It causes a rot of oak in which the wood appears white-spotted 
 in cross section. 
 
 S. quercinum Potter,^- is found on oak in Europe. 
 
 S. frustulosum (Pers.) Fries, though sometimes found on living 
 trees, is confined to dead wood. It causes a speckled rot of oak 
 wood.^^ Fig. 295. 
 
410 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 S. purpureum Pers. 
 
 Hymenophore expanded, leathery, arched, grayish -white; hy- 
 menium smooth, purple. 
 
 This species is constantly associated with an English and Cana- 
 dian disease of drupaceous and pomaceous trees, manifest by a 
 
 Fig. 295. — Oak timber rotted by Stereum frustulosum. The 
 lighter colored, irregular, small bodies are sporophores. After 
 von Schrenk and Spaulding. 
 
 silvering of the leaves, death of branches and finally of the tree. 
 The causal agency of the fungus has not been fully established.^^ 
 
 Cosmopolitan in distribution. 
 
 S. rugosum Fr. parasitizes the cherry laurel. 
 
 Thelephora Ehrenberg (p. 406) 
 
 Hymenophore leathery, context similar, variable in form, 
 sessile or pileate, even or more commonly plicate; hymenium con- 
 fined to the lower surface or extending all over the hj^meno- 
 phore, smooth or uneven, sometimes warty; basidia numerous, 
 clavate; spores elongate, membrane often dull broAvn, and granular. 
 
 N 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 411 
 
 T. laciniata Pers. injures various trees by its leathery incrustations. 
 
 T. galactina Fr. , .,1 • i 
 
 Resupinate, broadly effused, encrusted, smooth, milky m color. 
 The root rot on oak is in type much like that caused by Armillana 
 
 Fig. 296.— Telephora laciniata. After Clemeuts. 
 
 mellea. It also causes a root rot of apple trees throughout the 
 
 Central States.^^ . , 
 
 Hymenochaetse noxia Berk, is a practically omnivorous fungus 
 attacking hevea, cacao, tea, dadap, castilloa, Caravomca cotton, 
 bread fruit, camphor, throughout the eastern tropics. 
 
 Septobasidium Pat. (p. 406) 
 As Thelephora but with septate basidia. 
 
412 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 S. pedicillata (Schw.) Pat.*'^ 
 
 Resupinate, effused, byssoid, subcompact, light cinnamon- 
 yellow to white, hymenium smooth. 
 
 On oak, palmetto, tupelo, apple, etc. Cosmopolitan. 
 
 Clavariaceae (p. 402) 
 
 Hymenophore fleshy, leathery, cartilaginous or waxy, cylin- 
 dric-clavate, simple or branched often quite large and conspicuous 
 hymenium with cystidia; basidia clavate, with 1 to 4 sterigmata; 
 spores elliptic or fusiform, hyaline. 
 
 There are about five hundred species. One genus only is para- 
 sitic. 
 
 Key to Genera of Clavariaceae 
 
 Hymenophore small, simple 
 Basidia with 1 or 2 sterigmata 
 
 Spores colored 1. Baumanniella. 
 
 Spores hyaline 
 
 Hymenophore expanded above into a 
 
 cap, basidia with 1 sterigma. ... 2. Gloeocephala. 
 Hymenophore clavate, basidia with 
 
 2 sterigmata 3. Pistillaria. 
 
 Basidia with 4 sterigmata 
 
 Hymenophore clavate or filiform. ... 4. Typhula, p. 412. 
 
 Hymenophore capitate, hollow 5. Physalacria. 
 
 Hymenophore usually large, branched, 
 rarely simple 
 Hymenophore mostly round, branches 
 never leaf -like 
 
 Hymenophore fieshy 6. Clavaria. 
 
 Hymenophore not fleshy 
 
 Hymenophore cartilaginous or horny. 7. Pterula. 
 Hymenophore leathery and hairy .. . 8. Lachnocladium. 
 Hymenophore leaf-like 9. Sparassis. 
 
 Typhula graminum Karst. has been reported as injuring wheat. 
 
 Hymenophore fleshy or waxy, delicate, simple or rarely branched, 
 filiform or cylindric, clavate; spores colorless. Sometimes forming 
 sclerotia. Fig. 297. 
 
 T. variabilis Riess. is regarded as a parasite of beets. 
 
 r 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 413 
 
 Hydnaceae (p. 402) 
 
 Sporophore variable in texture, cu- 
 ticular, leathery, corky, felty, fleshy or 
 woody; free and stipitate, shelving 
 or resupinate; the hymenium warty, 
 thorny, spiny or with tooth-like 
 plates; basidia usually 4-spored, rarely 
 1-spored. 
 
 Over five hundred species, mostly 
 very limited in tlieir geographical 
 distribution, and chiefly epixylous, 
 although some are humus-loving. 
 
 297.— Typhula 
 habit sketch; n, 
 
 variabilis, 
 basidium 
 
 and spores. After Winter. 
 
 Key to Gener.\ of Hydnaceae 
 
 Sporophore annual 
 
 Hymenium without a subiculum 1. Mucronella. 
 
 Hymenium with a subiculum. 
 Hymenium with folds or wrinkles 
 
 Crest of the folds entire 2. Phlebia. 
 
 Crest of the folds incised 3. Lopharia. 
 
 Hymenium with granules or warts 
 Granules penicillate, multifid 
 
 Hymenophore fleshy , 4. Kneiffiella. 
 
 Hymenophore firm, not fleshy. ... 5. Odontia. 
 Granules simple 
 
 Hymenium porose, reticulate, 
 
 granular 6. Asterodon. 
 
 Hymenium with obtuse cylindric 
 
 warts 7. Radulum. 
 
 Hymenium with globose hollowed 
 
 warts 8. Grandinia. 
 
 Hymenium with more or less subulate 
 teeth or spines 
 
 Pileus clavaria-like 9. Hericium. 
 
 Pileus not clavaria-like 
 Teeth free, mostly fleshy 
 Teeth rounded. 
 
414 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Spores hyaline 10. Hydnum, p. 414. 
 
 Spores colored 11. Phaeodon. 
 
 Teeth lammeliform 12. Sistotrema. 
 
 Teeth connected at base, coriaceous 
 
 Cystidia none 13. Irpex, p. 415. 
 
 Cystidia present 14. Hydnochaete. 
 
 Sporophore perennial, punky or woody 
 
 Upper surface smooth, or sulcatc 15. Echinodontium, p.415. 
 
 Upper surface zonate 16. Steccherinum, p. 416. 
 
 Hydnum Linnaeus 
 
 Sporophore cuticular, leathery, corky, woody or fleshy, variable 
 in form, resupinate; pileus, shelving, or bushy branched; hymenium 
 beset with pointed spines; basidia with 4 sterigmata; spores hya- 
 line. 
 
 The species of this genus, between two hundred fifty and three 
 
 hundred, are mostly sapro- 
 phytes but a few are true 
 parasites on woody plants. 
 H. erinaceus Bul.^^ 
 Cap 5-30 cm. wide, white, 
 then yellowish or somewhat 
 brownish, the branches form- 
 ing a dense head covered 
 with teeth, fleshy; stem 
 short and stout, 2-8 cm. long 
 and thick, or entirely lack- 
 ing; teeth 3-10 cm, long, 
 slender, densely crowded ; 
 spores globose, clear, 5-6 fi. 
 The name refers to the ap- 
 pearance of the head. 
 It is the cause of a white rot on many deciduous trees, chiefly 
 oaks. The rotted wood is soft and mushy. Numerous large holes 
 filled with masses of light yellowish fluffy mycelium occur in the 
 heart-wood. Sporophores are often absent on the rotted tree. 
 H. septentrionale Fr.^^ 
 Sporophores in bracket-like clusters, up to 20-30 cm. wide by 
 
 Fiu. 298. — Fruiting body of Hydnum erina- 
 ceus in a hollow log. After von Schrenk 
 and Spaulding. 
 
 ^ 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 415 
 
 50-80 cm. long, creamy white in color, texture at first fleshy, be- 
 coming more fibrous; pileus often 3 cm. thick, upper surface al- 
 most plain, slightly scaly, all pilei united behind, teeth slender, 
 often 12 mm. long. 
 
 On sugar maple, })eech, etc., causing rot of the heart-wood. 
 
 H. diversidens Fr. causes white rot of oak and beech in Europe. 
 
 H. schiedermayeri Heuff,®^ injures apple trees in Europe. 
 
 Irpex Fries (p, 414) 
 
 Sporophore shelving or resupinate, hymenium on the lower side, 
 from the first toothed; teeth firm, subcoriaceous, acute, continuous 
 
 Fig. 2'J'J. — 1. flavus. H, habit sketch. After Hennings. 
 
 with the pileus, arranged in rows or reticulately, basally widened 
 and lamellate or even fa void; basidia 4-spored. 
 
 I. fusco-violaceus (Schrad) Fr.^^ is a wound parasite on pine in 
 Europe. 
 
 I. flavus Klotsch is injurious to the Para rubl^er, cloves and 
 coffee; I. destruens to tea. 
 
 I. paradoxus (Schrad) Fr., according to Glazan,^" causes timber 
 rot. 
 
 Echinodontium EUis & Everhart (p. 414) 
 
 Similar to Hydnum but differing in perennial habit; pileus, 
 smooth, woody; cystidia bearing spines. 
 
 E. tinctorium E. & E.^^' ^'^ is the only species. 
 
 Spines brown, 1 cm. long, 134"~2 mm. broad; cystidia subconic, 
 reddish-brown, 20-30 x 6-7 ju- 
 
416 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 On living trunks of Tsuga, Pseudotsuga °°° and Abies in north- 
 western North America. 
 
 Steccherinum S. F. Gray (p. 414) 
 
 Perennial, pileate, sulcate, zonate, radiately subrugose; teeth 
 wide, irregular. 
 
 S. ballouii Banker is the single economic species. 
 
 Campanulate to subdimidiate, more or less intricate, sessile, 
 decurrent to pendent, 1-4 x 1-5 cm. laterally connate up to 10 cm. ; 
 surface velutinous when young, often licheniferous at base, dark 
 olive-brown, drying gray-brown in older parts and seal-brown 
 in younger; margin obtuse, seal brown; substance thin, 1-2 mm., 
 of two layers, the upper harder, somewhat brittle, dark brown, 
 lower softer and lighter colored; hymenium colliculose, golden- 
 yellow, fading to buff or cream; teeth variable, subterete to diform, 
 confluent, papalloid to elongate, usually obtuse, tips brownish, 
 1-5 X 0.5-1 mm. irregularly distributed; spores hyaline broadly 
 elliptic to subglobose, 7-7.2 x 5.5-6.5 /x. 
 
 On Chamaecyparis in New Jersey .^^ According to Ballou ^^ 
 this fungus is devastating the forests of swamp cedar in New Jersey. 
 As it grows only in the tops of the tree and dies with the host, the 
 dead sporophores soon disappearing, it is a species not easily 
 observed. 
 
 Polyporaceae (402) 
 
 Sporophore annual or perennial; context fleshy, tough, corky 
 or woody; hyn^enium poroid or lamelloid, fleshy to woody, rarely 
 gelatinous. 
 
 The sporophores are sometimes fleshy, even edible liut they are 
 more commonly hard and woody, occurring as bracket forms, 
 Fig. 310, on tree trunks. 
 
 Key to Genera of Polyporaceae 
 
 Pores reduced to shallow pits separated by : '^ * ; ; 
 
 narrow ridges, folds or reticulations. . ." I. Merulieae, p. 418Li ; .; . , 
 Pores well developed, variable in size and :^i M 
 
 form II. Polyporeae. 
 
 Sporophore, at least in part gelatinous 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 417 
 
 Sporophore more or less gelatinous 
 
 throughout 1. Laschia. 
 
 Sporophore leathery above, the pores 
 
 gelatuious 2. Glceoporus. 
 
 Sporophore leathery, corky or punky, 
 never gelatinous. Pores minute and 
 rounded or large and angular 
 Sporophore rcsupinate, never shelv- 
 ing 3. Poria, p. 418. 
 
 Sporoi)hore normally pileate, only ac- 
 cidently resupinate 
 Pores usuall}^ small or medium sized, 
 and round 
 Substance of the pileus not con- 
 tinuing between the pores 
 Sporophore at first fleshy, then 
 
 hardening 4. Polyporus, p. 418. 
 
 Sporophore from the first 
 leathery or spongy usually 
 
 annual. 5. Polystictus, p. 426. 
 
 Sporophore from the first more 
 or less corky or punky, 
 
 usually perennial 6. Femes, p. 428. 
 
 Substance of the pileus continued 
 
 between the pores 7. Trametes, p. 437. 
 
 Pores usually large, hexagonal or 
 labyrinthiform rarely bounded 
 by large plates 
 Pores hexagonal 
 Stipe lateral; pores elongate. ... S. Favolus, p. 439. 
 
 Sessile; pores regular 9. Hexagonia. 
 
 Pores labyrinthine, or replaced by 
 plates 
 Sporophore sessile 
 
 Hymenium labyrinthine, be- 
 coming irpiciform 10. Daedalea, p. 439. 
 
 Hjrmenium lamellate, not be- 
 coming irpiciform 11. Lenzites, p. 439. 
 
 Sporophore stipitate, concentri- 
 cally furrowed 12. Cyclomyces. 
 
418 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Merulius lachrymans of the tribe Merulieae is said to parasitize 
 violets. 
 
 Poria Persoon (p. 417) 
 
 Sporophore entirely resupinate, often widely extended, the 
 base leathery to punky, pores small, rounded, covering almost the 
 entire surface. 
 
 A genus of almost three hundred species. 
 
 P. laevigata Fr. causes a white rot of the birch. 
 
 P. vaporaria (Pers.) Fr. is a wound parasite on coniferous trees ^^ 
 especially common on spruce and fir causing a brown rot of the sap 
 wood. 
 
 P. subacida Pers.^* Sporophore effused, determinate; margin 
 pubescent, white; pores minute, subrotund, 2-6 mm. oblique, 
 odor subacrid. A common saprophyte on deciduous and conif- 
 erous trees especially, pine, hemlock, and spruce. Irregular 
 cavities form within the diseased wood and become lined with a 
 tough felt of hyphse, yellow on the inner side. 
 
 P. hypolaterita Berk, causes a tea disease in Ceylon.^^ 
 
 P. vineta Berk, is reported as causing a rot of Hevea in Ceylon.''^ 
 
 Polyporus (Micheli) Paulet (p. 417) 
 
 Sporophore usually annual; simple or compound, rather thick, 
 fleshy, leathery or corky, stipitate or shelving, pores developing 
 from the base toward the margin. Grading into Polystictus on 
 the one hand and approaching Fomes on the other. 
 
 There are about five hundred species. 
 
 P. obtusus Berk.*'^' ^^ 
 
 Pileus somewhat imbricate, large and spongy, at length indurate, 
 dimidiate, sessile, often ungulate, 5-7 x 10-15 x 3-5 cm.; surface 
 spongy-tomentose, hirtose, azonate, smooth, sordid-white to 
 isabelline or fulvous; margin very thick and rounded, sterile, 
 entire, concolorous; context spongy-fibrous, white, indurate with 
 age especially below, 1-2 cm. thick; tubes very long, 2-3 cm., 
 white to isabelline within, mouths large, irregular, often sinuous, 
 1-2 mm. broad, edges thin, "fimbriate-dentate to slightly lacerate, 
 white to isabelline, at length bay and resinous in appearance; spores 
 globose, smooth, hyaline, 6-8 /x; hyphai hyaline, 6 ix; cystidia none. 
 
 s 
 
THE FUNGI WHICH CAl'SE PLANT DISEASE 
 
 419 
 
 It causes a heart-rot of living oaks, occurring as a wound parasite 
 and invading the sap wood when decay is well advanced. It is 
 also found on black locust 
 
 332 
 66, 67, 78, 74. 79, 80 
 
 P. sulphureus (Bui.) Fr. 
 
 Hymenophore cespitose-multiplex, 30-60 cm. broad; pileus 
 cheesy, not becoming rigid, reniform, very broad, more or less 
 stipitate, 5-15 x 7-20 x 
 0.5-1 cm. ; surface finel} 
 tomentose to glabrous, 
 rugose, anoderm, sub- 
 zonate at times, vary- 
 ing from lemon-yellow 
 to orange, fading out 
 with age; margin thin, 
 fertile, concolorous, 
 subzonate, finely to- 
 m e n to s e, undulate, 
 rarely lobed; context 
 cheesy, very fragile 
 when dry, yellow when 
 fresh, usually white in 
 dried specimens, homogenous, 3-7 mm. thick; tubes annual, 
 2-3 mm. long, sulphur-yellow within; mouths minute, angular, 
 somewhat irregular, 3-4 to a mm., edges very thin, lacerate, 
 sulphur-yellow, with color fairly permanent in dried specimens; 
 spores ovoid, smooth or finely papillate, hyaline, 6-8 x 3-5 fx. 
 
 It is common as a cause of red heart-rot of forest and shade 
 trees, conifers and deciduous, and also does damage in the orchard, 
 especially on cherry, apple and pear, and in the forest to oak, chest- 
 nut, poplar, maple, walnut, butternut, alder, locust, ash, pine, 
 hemlock, larch. 
 
 The decayed wood resembles a mass of red-l)rown charcoal and 
 is characterized by radial or concentric cracks in which the fungus 
 forms thin leathery sheets. In dicotyledons the vessels become 
 filled with the fungus. Round gonidia are often formed within 
 the wood. 
 
 P. squamosus (Huds.) Fr. ' ' 
 
 Sporophore of immense size, reaching 50 cm. in breadth and 3 cm. 
 
 Fig. 300. — Polyporus sulphureus. Scattered fruit 
 bodies on living oak. After Atkinson. 
 
420 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 in thickness, usually found in imbricated masses projecting from 
 the trunks of living trees. Pileus subcircular and umbilicate when 
 young, soon becoming flabelliform and explanate; surface ochra- 
 ceous to fulvous, covered with broad, appressed, darker scales 
 
 Fig. 301. — Polyporus squamosus. After Clements. 
 
 which are very close together in young specimens; margin in- 
 volute, thin, entire; context fleshy-tough, juicy, milk-white; very 
 thick, odor strong; tubes decurrent, white or pale yellowish, very 
 short, mouths large, alveolar, 1 mm. or more in diameter, edges 
 thin at maturity, toothed at an early age, becoming lacerate: 
 spores broadly ovoid, smooth, hyaline, 5 x 12 /x; stipe excentric 
 to lateral, obese, reticulate above, clothed at the base with short, 
 
 J' 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 421 
 
 dark brown or black, velvety tomentum, often reduced, variable 
 in length. 
 
 The mycelium causes white rot of nut, ornamental and fruit 
 trees, particularly maple, pear, oak, elm, walnut, linden, willow, 
 ash, birch, chestnut, beech, growing on dead parts of living trees. 
 The hyphse advance most rapidly along the wood vessels and 
 often bear clamp connections. 
 
 181 
 
 A beautiful biological study has been published by Buller ' 
 who states that a single sporophore may produce 11,112,500,000 
 spores and that "the number produced by a single fungus from a 
 single tree in the course of a year may, therefore, be some fifty 
 times the population of the globe." 
 
 He showed the following enzymes to be present in the sporo- 
 phore: laccase, tyrosinase, amylase, emulsin, protease, lipase, 
 rennetase, and coagulase. Pectase, maltase, invertase, trehalase 
 and cytase were not found; It is evident, however, that the my- 
 celium in wood produces cytase and possibly hadromase. 
 
 P. hispidus Bui. 
 
 Pileus thick, compact, fleshy to spongy, dimidiate, sometimes 
 imbricate, compressed-ungulate, 7-10 x 10-15 x 3-5 cm.; surface 
 hirsute, ferruginous to fulvous, azonate, smooth; margin obtuse, 
 velvety; context spongy-corky, somewhat fragile when dry, fer- 
 ruginous to fulvous, blackening with age, 1-1.5 cm. thick; tubes 
 slender, about 1 cm. long, ferruginous within, mouths angular, 
 2-3 to a mm. ferruginous to bay, blackening with age, edges thin, 
 very fragile, lacerate; spores broadly ovoid, smooth, thick-walled, 
 deep-ferruginous, 2-guttulate, 5-6 x 7-8 /x. 
 
 It is common on all kinds of deciduous trees, often injuring fruit 
 trees, especially the apple. 
 
 P. giganteus (Pers.) Fr. has been reported as injurious to the 
 oak. 
 
 P. glivus Fr. is a common saprophyte on deciduous trees and in 
 some cases may be parasitic. 
 
 P. dryophilus Berk. 
 
 Pileus thick, unequal, unguliform, subimbricate, rigid, 7-8 x 10- 
 14 X 2-3 cm. ; surface hoary-flavous to ferruginous-fulvous, becom- 
 ing scabrous and bay with age; margin thick, usually obtuse, 
 sterile, pallid, entire or undulate: context ferruginous to fulvous, 
 
422 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 zonate, shining, 3-10 mm. thick; tubes slender, concolorous with 
 the context, about 1 cm. long, mouths regular, angular, 2-3 to a 
 mm., glistening, whitish-isabelline to dark-fulvous, edges thin, 
 
 Fig. 302. — Decomposition of spruce-timber by Polyporus boiealis. a, a 
 tracheid containing a strong mycelial growth and a brownish yellow fluid 
 which has originated in a medullary ray; at h and c the mycelium is still 
 brownish. At d and e the walls have become attenuated and perforated, 
 the filaments delicate; at / the pits are almost destroyed; at g and h only 
 fragments of the walls remain." The various stages in the destruction 
 of the bordered pits are to be followed from i to r; at i the bordered pit 
 is still intact; at k the walls of the lenticular space have been largely dis- 
 solved, their inner boundary being marked by a circle; at I one side of 
 the bordered pit has been entirely dissolved; at rn and n one sees a series 
 of pits which have retained a much-attenuated wall on one side only — ■ 
 namely, on that which is provided with the closing membrane. In mak- 
 ing the section a crack has been formed in this wall. Between o and r 
 both walls of the pits are found to be wholly or partially dissolved, only 
 at p and q has the thickened portion of the closing membrane been pre- 
 served; at d the spiral structure of both cell-walls is distinctly recogniz- 
 able. These walls when united form the common wall of the tracheid; at 
 t hyphse are seen traversing the tracheids horizontally. After Hartig. 
 
 entire to toothed; spores subglobose, smooth, deep-ferruginous, 
 6-7 jLi; cystidia scanty and short; hyphse deep-ferruginous. 
 
 It causes a disease of oaks. 
 
 P. fruticum B. & C. occurs on living twigs of the orange and 
 oleander in Cuba. 
 
 ^^ 
 
 X 
 
 y 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 423 
 
 
 Fig. 303. — Polyporus bo- 
 rcalis, hymenium with 
 sinuous pores. After At- 
 kinson. 
 
 P. borealis (Wahl.) Fr."' ^^ 
 
 Pileus sessile, subimbricate, dimidiate to flabelliform, often 
 narrowly attached, spongy to corky, very tough, moist and juicy 
 when fresh, 5-8 x 8-12 x 2-4 cm.; surface uneven, soft and spongy, 
 hirtose-tomentose, azonate, white to yellowish; margin thin, white, 
 entire, somewhat discolored on drying: 
 context fibrous-coriaceous above, fibrous- 
 woody below, white, 0.5-1.5 cm. thick; 
 tubes 4-8 mm. long, white to pallid within, 
 mouths angular, irregular, somewhat 
 radiately elongate, sinuous at times, 1-2 
 to a mm., stuffed when young, edges thin, 
 white to ochraceous, dentate to lacerate; 
 spores ovoid, smooth, hyaline, 5-6 x 3-4 fx; 
 hyphae 6-7 fi; cystidia none. 
 
 On pine, spruce, hemlock, balsam pine, 
 etc., as a wound parasite or as a sapro- 
 phyte on dead trees producing a white rot. The mycelium ad- 
 vances longitudinally, radially and tangentially. At certain 
 stages it is very abundant and forms cords in the channels formed 
 by the fungous enzyme. Later these cords disappear. The young 
 mycelium is stout and yellow, later it is more delicate. Dis- 
 solution of the cells begins at the lumen 
 and proceeds outward, the middle lamella 
 persisting last. 
 P. dryadeus Fr.^° 
 
 Sporophore very large, sessile, dimidiate, 
 rarely circular, usually imbricate, applanate 
 or depressed above, convex below, fleshy to 
 spongy-corky, rather fragile when dry, 15- 
 30 X 25-65 X 3-5 cm.; surface very un- 
 even, azonate, opaque, hoary-isabelline, 
 anoderm to very thinly encrusted, sub- 
 shining and bay; margin thick, pallid, entire to undulate, weep- 
 ing; context thick, zonate, subglistening, ferruginous-isabelline to 
 fulvous, 2.5-4 cm. thick; tubes grayish-umbrinous to fulvous 
 within, 5-15 mm. long, slender, very fragile, mouths whitish when 
 young, becoming somewhat resinous in appearance and finally 
 
 Fig. 304. — Polyporus bo- 
 realis, hymenium with 
 rounded pores. After 
 Atkinson. 
 
424 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 bay-brown, at first minute, circular, becoming angular, 4 to a 
 mm., edges thin, fimbriate to lacerate, deeply splitting and 
 separating with age: spores subglobose, smooth, 9-10 x 7-8 /x, 
 the outer wall hyaline, the inner membrane brown; cystidia 15- 
 35 X 5-9 IX. 
 
 It causes rot of oak wood in America and Europe. 
 
 P. amarus Hedg.*^' ^^^ 
 
 Pileus soft and spongy when young, becoming hard and chalky 
 when old, ungulate, often spuriously stipitate from knot-holes, fre- 
 quently large, 5-11 x 10-20 x 6-12 cm.; surface pubescent when 
 young, rimose and chalky when old, at first buff, becoming tan 
 and often blotched with brown when older; margin obtuse, fre- 
 quently having an outer band of darker brown, often slightly 
 furrowed; context creamy-yellow to tan-colored, usually darker in 
 outer layers when old, 4-8 cm. thick; tubes not stratified, brown 
 within, cylindric, 0.5-3 cm. in length, shorter next the margin, 
 mouths circular or slightly irregular, 1-3 to a mm., yellow-green 
 during growth, turning broAvn when bruised or old, becoming 
 lacerate; spores hyaline or slightly tinged with brown, smooth, 
 ovoid, 3^ x 5-8 n, nucleated; cystidia none. 
 
 The cause of "pin rot" or peckiness of incense cedar. 
 
 P. schweinitzii Fr.^^' ^^ 
 
 Pileus spongy, circular, varying to dimidiate or irregular, 15-20 
 cm. broad, 0.5-2 cm. thick; surface setose-hispid to strigose- 
 tomentose and scrupose in zones, ochraceous-ferruginous to ful- 
 vous-castaneous or darker, quite uneven, somewhat sulcate, ob- 
 scurely zonate; margin yellow, rather thick, sterile: context very 
 soft and spongy, fragile when dry, sometimes indurate with age, 
 flavous-ferruginous to fulvous, 0.3-0.7 mm. thick; tubes short, 
 2-5 mm. long, flavous within, mouths large, irregular, averaging 
 1 mm. in diameter, edges thin, becoming lacerate, ochraceous- 
 olivaceous to fuliginous, rose-tinted when young and fresh, quickly 
 changing to dark-red when bruised : spores ovoid, hyaline 7-8 x 3-4 
 jjl: stipe central to lateral or obsolete, very irregular, tubercular 
 or very short, resembling the pileus in surface and substance. 
 
 On coniferous trees especially spruce, fir, pine, larch, arbor \dta3, 
 entering through the root system and extending up the trunk, 
 causing heart-rot. The tracheids exhibit spiral cracks and fissures 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 425 
 
 due to the shrinking of the walls. Fig. 289. Diseased wood is 
 yellowisli and of cheesy consistency; brittle when dry. 
 
 P. betulinus (Bui.) Fr.^^- ss 
 
 Pileus fleshy to corky, compressed-ungulate, convex above, 
 
 plane below, attached by a short umbo behind, varying to bell- 
 shaped when hanging from horizontal trunks, 5-30 x 5-20 x 2-5 
 cm.; surface smoky, covered with a thin, separating pellicle, 
 glabrous, devoid of markings, cracking with age; margin velvety, 
 concolorous, obtuse, projecting nearly a centimeter beyond the 
 
426 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 hymenium: context fleshy-tough, elastic, homogeneous, 3 cm. thick, 
 milk-white; tubes 0.5 cm. long, 2-3 to a mm., sodden-white, sepa- 
 rated from the context by a thin pink layer; mouths very irregular, 
 dissepiments thicker than the pores, obtuse, entire, crumbling 
 away in age, leaving the smooth, white context; spores white, 
 cylindrical, curved, 4-5 m in length. The mycelium penetrates 
 lignified cell walls entering the living cells and causing death. 
 
 On birch it causes a decay of the sap wood similar to that caused 
 by Femes fomentarius. 
 
 P.adustus (Wild.) Fr. is a common saprophyte of deciduous trees. 
 
 Polystictus Fries (p. 417) 
 
 Sporophore leathery, usually thin; pores developing from the 
 center to the circumference of the hymenophore. The thicker 
 forms are cjuite close to some species of Polyporus. 
 
 About four hundred fifty species. 
 
 P. versicolor (L.) Fr.^^' ^^ 
 
 Pileus densely imbricate, very thin, sessile, dimidiate, conchate, 
 2-4 X 3-7 X 0.1-0.2 cm.; surface smooth, velvety, shining, marked 
 with conspicuous, glabrous zones of various colors, mostly laterice- 
 ous, bay or black; margin thin, sterile, entire; context thin, mem- 
 branous, fibrous, white; tubes punctiform, less than 1 mm. long, 
 white to isabelline within, mouths circular to angular, regular, 
 even, 4-5 to a mm., edges thick and entire, becoming thin and 
 dentate, white, glistening, at length opaque-isabelline or slightly 
 umbrinous: spores allantoid, smooth, hyaline, 4-6 x 1-2 n; 
 hyphse 2-6 /x; C3^stidia none. 
 
 Von Schrenk regards this as strictly a saprophyte except when 
 on catalpa, where it causes a heart-rot. It is common on almost 
 any kind of wood. 
 
 Catalpa wood under its action becomes straw-colored and finally 
 soft and pithy. Both cellulose and lignin are dissolved. 
 
 P. sanguineus (L.) Fr. & P. cinnabarinus (Jacq.) Fr. are sapro- 
 phytes on dead parts of live trees. 
 
 P. velutinus (Pers.) Fr. is a common saprophyte which is perhaps 
 sometimes parasitic. 
 
 P. occidentalis Klachb. is recorded as a parasite on Pterocarpus 
 indicus in the Malay peninsula.^^ 
 
 v 
 
 "•mi 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 427 
 
 P. pergamenus Fr.^^ 
 
 Pileus exceedingly variable, sessile or affixed by a short tubercle, 
 dimidiate to flabelliform, broadly or narrowly attached, 2-5 x 2-6 
 X 0.1-0.3 cm.; surface finely villose-tomentose, smooth, white 
 or slightly yellowish, 
 marked with a few nar- 
 row indistinct laterice- 
 ous or bay zones; mar- 
 gin thin, sterile, entire to 
 lobed; context very thin, 
 white, fibrous; tubes 1- 
 
 3 mm, long, white to dis- 
 colored within, mouths 
 angular, somewhat irreg- 
 ular, 3-4 to a mm., 
 usually becoming irpici- 
 form at an early stage, 
 edges acute, dentate, be- 
 coming lacerate, white to 
 yellowish or umbrinous : 
 spores smooth, hyaline. 
 
 It causes a sap wood rot of practically all species of deciduous 
 trees, often on dead trees, less frequently on living trees which 
 have been severely injured. In general the rotten wood resembles 
 that produced by P. versicolor; microscopically it is seen that 
 the fungus attacks chiefly the lignin. 
 
 P. hirsutus Fr. 
 
 Pileus confluent-effused, more or less imbricate, sessile, dimi- 
 diate, applanate, corky-leathery, rather thick, flexible or rigid, 
 3-5 X 5-8 X 0.3-0.8 cm. ; surface conspicuously hirsute, isabelline to 
 cinereous, concentrically furrowed and zoned; margin at length 
 thin, often fuliginous, sterile, finely strigose-tomentose, entire or 
 undulate: context white, thin, fibrous, spongy above, 1^ mm. 
 thick; tubes white, 1-2 mm. long, mouths circular to angular, 
 
 4 to a mm., quite regular, edges thin, firm, tough, entire, white 
 to yellowish or uml^rinous; spores smooth, hyaline, cylindrical, 
 slightly curved, 2.5-3 ^l. 
 
 It is a wound parasite of the Mountain Ash.^^ 
 
 Fig. 306. 
 
 -Polystictus pergamenus. After 
 Clements. 
 
428 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Fomes Fries (p. 417) 
 
 Sporophore sessile, ungulate or applanate; surface varnished, 
 encrusted, sulcate, vinose, or anoderm, rarely zonate; context 
 corky to punky; tubes cylindric, stratiose; spores smooth, hyaline 
 or brown. 
 
 A genus of some three hundred species. 
 
 ■n • • • /T \ r^-u 65, 67, 78, 79 
 
 F. igniarius (L.) Gill. ' ' ' 
 
 Pileus woody, ungulate, sessile, 6-7 x 8-10 x 5-12 cm.; surface 
 smooth, encrusted, opaque, velvety to glabrous, ferruginous to 
 
 Fig. 307. — Fuuica igaiuriuti, frum maple. After Atkinson. 
 
 fuscous, becoming rimose with age; margin obtuse, sterile, fer- 
 ruginous to hoary, tomentose; context woody, distinctly zonate, 
 ferruginous to fulvous, 2-3 cm. thick; tubes evenly stratified, 
 2-4 mm. long each season, fulvous, whitish-stuffed in age, mouths 
 circular, minute, 3-4 to a mm., edges obtuse, ferruginous to ful- 
 vous, hoary when young: spores globose, smooth, hyaline, 6-7 n; 
 spines 10-25 x 5-6 /i. 
 
 It is the cause of a white heart-rot, is one of the most widely 
 distributed forms of wound parasites and occurs on more species 
 of broad-leaf trees than any other similar fungus. Among its 
 hosts are beech, oak, apple, peach, willow, aspen, the maples, birch, 
 butternut, walnut, oak, hickory, alder. 
 
 The first sporophores usually appear at the point of initial 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 429 
 
 infection. The mycelium grows mainly in the heart wood Ijut it 
 may gain entrance through the sap wood or encroach upon the 
 sap wood from the heart wood. Its growth may continue after 
 the death of the host. In early stages it follows the medullary 
 
 HSPw'^-'^' 
 
 
 
 
 
 i 
 
 
 Fig. 308. — A dead beech tree with sporophores of F. fomenta- 
 rius. After voq Schrenk and Spaulding. 
 
 rays. The completely rotted wood is white to light yellow and in 
 it the mycelium abounds in the large vessels and the medullary 
 rays. The walls of the affected wood cells are thin and the middle 
 lamella is often wholly lacking, due to solution of the lignin. 
 
 F. fomentarius (L.) Fr."' " 
 
 Pileus hard, Avoody, ungulate, concave below, 7-9 x 8-10 x 3-10 
 cm. ; surface finely tomentose to glabrous, isabelline to avellaneous 
 
430 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 and finally black and shining with age, zonate, sulcate, horny- 
 encrusted; margin obtuse, velvety, isabelline to fulvous; context 
 punky, homogeneous, ferruginous to fulvous, conidia-bearing, 
 3-5 mm. thick; tubes indistinctly stratified, not separated by lay- 
 ers of context, 3-5 mm. long each season, avellaneous to umbrinous 
 within, mouths circular, whitish-stuffed when young, 3-4 to a mm. ; 
 edges obtuse, entire, grayish-white to avellaneous, turning dark 
 when bruised: spores globose, smooth, very light brown, 3-4 ju; 
 hyphse brown, 7-8 m; cystidia none. 
 
 The mycelium kills the cambium and causes a white rot of the 
 sap wood of deciduous trees, especially beech, birch, elm, maple. 
 The wholly rotted wood is soft, and spongy, light yellow and 
 crumbles into its separate fibers. 
 
 F. everhartii (E. & G.) ''^' ^'' ( = Pyropolyporus prserimosa). 
 
 Pileus woody, dimidiate, ungulate, broadly attached behind, 
 6-10 X 6-15 X 3-8 cm. ; surface glabrous, slightly encrusted, deeply 
 sulcate, not polished, gray to brownish-black, slightly rimose 
 in age; margin obtuse, covered with ferruginous tomentum, be- 
 coming gray and glabrous: context corky to woody, repeatedly 
 zoned, fulvous in dried specimens, 2-3 cm. thick; tubes evenly 
 stratified, 0.5-1 cm. long each season, fulvous, mouths circular, 
 4 to a mm., edges rather thin, entire, ferruginous to fulvous, 
 glistening, the hymenium becoming much cracked in age: spores 
 globose, smooth, ferruginous, 3-4.5 fx; spines abundant, pointed, 
 larger at the base, 15-25 x 6-10 ij.. 
 
 On black oaks, and walnuts causing a rot almost indistin- 
 guishable from that caused by F. igniarius. The mycelium 
 often grows into the living sap wood. 
 
 F. carneus Nees.^^' ^^ 
 
 Pileus woody, dimidiate, varying from cohchate to ungulate 
 often imbricate and longitudinally effused, 2-4 x 6-8 x. 0.5-3 cm.; 
 surface rugose, subfasciate, slightly sulcate, rosy or flesh-colored, 
 becoming gray or black with age; margin acute, becoming obtuse, 
 sterile, pallid, often undulate; context floccose-fibrose to corky, 
 rose-colored, 0.2-2 cm. thick; tubes indistinctly stratose, 1-2 mm. 
 long each season, mouths circular, 3-4 to a mm., edges obtuse, 
 concolorous; spores ellipsoid, smooth, thick-walled, subhyaline, 
 3.5 X 6 ju. 
 
 V 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 431 
 
 On red cedar and arljor vita causing pockets, also on dead 
 spruce and fir. The cellulose is almost all removed from the 
 affected cells of the heart wood. The mycelium is scant and when 
 young is pale and with numerous clamps. It extends horizontally 
 through the tracheids, giving off lateral branches. None is found 
 in the sap wood. 
 
 F. annosus (Fr.) Cke.^^'^^^ ( = Trametes, radiciperda R. Hartig). 
 
 Pileus woody, dimidiate, very irregular, conchate to applanate, 
 10-13 X 5-8 X 0.5-2 cm.; surface at first velvety, rugose, anoderm, 
 light brown, becoming thinly encrusted, zonate, and finally black 
 with age; margin pallid, acute, becoming thicker; context soft- 
 corky to woody, white, 0.3-0.5 cm. thick; tubes unevenly stratified, 
 2-8 mm. long each season, white, mouths subcircular to irregular, 
 3-4 to a mm., edges rather thin, entire, firm, white, unchanging: 
 spores subglobose or ellipsoid, smooth, hyaline, 5-6 x 4-5 m- 
 
 On pine, fir and various deciduous trees, described by Hartig^^ 
 as the most dangerous of all conifer parasites. It is not so plentiful 
 in America as in Europe. 
 
 The sporophores appear near or on the roots, between the 
 bark scales, where the white felted delicate mycelium also occurs. 
 The spores, carried presumably by rodents, germinate upon the 
 bark of roots; the mycelium penetrates to the living cortex, forces 
 its way into the wood and follows up the stem and doAMi the root. 
 The parenchyma cells are killed and browned; the wood becomes 
 violet, later brownish-yellow. The hypha? travel in the cell- 
 lumen and pierce the walls. The lignified parts are dissolved 
 first, later the middle lamella disappears. Eventually the whole 
 root system may become involved and the death of the tree result. 
 
 F. juniperinus (v. Sch.) S. & Sy.^^ 
 
 Pileus woody, ungulate, 3-5 x 5-8 x 5-7 cm. ; surface tomentose, 
 deeply sulcate, ferruginous to gray, at length rough and grayish- 
 black; margin obtuse, velvety, melleous or ferruginous to hoary: 
 context corky to woody, reddish-fulvous, 0.5-1 cm. thick; tubes 
 indistinctly stratified, 0.5-1 cm. long each season, melleous within, 
 reddish-fulvous in the older layers, mouths circular to angular, 
 2-3 to a mm., edges rather, thin, entire, even, melleous: spores 
 reddish-brown, smooth; spines blunt, only slightly projecting. 
 On red cedar. 
 
432 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 In the holes caused by the fungus in the heart-wood is found 
 a velvety mass of reddish-yellow mycelium, glistening with color- 
 less liquid and holding masses of reddish-brown wood fiber. Long 
 white fibers of cellulose with the lignin removed project into the 
 cavities from the ends. 
 
 Structural change begins soon after the mycelium enters a 
 cell lumen. The primary lamella becomes granular and is dissolved 
 by a lignin-splitting enzyme, the secondary lamella becomes white 
 and the cells fall apart. 
 
 The mycelium in newly invaded tissue is nearly hyaline and 
 extends lengthwise. Within the tracheids branches are given off 
 in all directions. 
 
 The sporophore appears after decomposition is considerably 
 advanced. 
 
 F. laracis (Jacq.) Murr.^^^ 
 
 Pileus firm, at length fragile, ungulate to cylindical, 3-8 x 5-10 
 X 4-20 cm.; surface anoderm, powdery, white or slightly yellow- 
 ish, concentrically sulcate, becoming slightly encrusted, tuberculose 
 and rimose; margin obtuse, concolorous: context soft, tough, at 
 length friable, chalk-white or slightly yellowish, very bitter, 
 with the odor of fresh meal, 1-3 cm. thick; tubes evenly strati- 
 fied, concolorous, 5-10 mm. long each season, mouths circular to 
 angular, 3-4 to a mm., edges thin, fragile, white, becoming dis- 
 colored and lacerate, wearing away with age : spores ovoid, smooth, 
 hyaline, 4-5 fx; hypha? 5 /x; cystidia none. 
 
 A wound parasite of the larch, pine and spruce in Europe and 
 America. 
 
 F. ribis (Schw.) Gill.^^ 
 
 Pileus tough, corky, Ijccoming rigid, conchate, laterally connate, 
 3-5 X 5 10 X 0.7-1.5 cm.; surface rough, velvety, anoderm, in- 
 distinctly zoned, ferruginous to umbrinous, becoming glabrous 
 and slightly encrusted with age; margin undulate to lobed, fer- 
 ruginous, furrowed: context punky, fulvous, 3-5 mm. thick; 
 tubes indistinctly stratified, 1-2 mm. long each season, fulvous, 
 mouths circular, 5-6 to a mm., edges rather thin, entire, ferruginous 
 to fulvous, hoary when young: spores globose or subglobose, 
 pale yellowish-brown, smooth, 3-4 x 3 /z; hyphse 2.5 fx; cystidia 
 none. 
 
THE FUNGI WHICH CAUSE PLvVNT DISEASE 433 
 
 This is ;i wound parasite on the heart wood of sassafras and is 
 also found on roots and stems of various shrubby plants including 
 rose, goosel)erry and currant. The fungus fills the large vessels 
 and tracheids with a brown mycelium and dissolves the entire 
 wall locally. 
 
 F. fulvus (Scop) Gill5 
 
 Pileus woody, triquetrous, rarely ungulate, thick and broadly 
 attached behind, 1-3 x. 5-7 x 3-8 cm.; surface smooth, very 
 slightly sulcate, velvety, ferruginous, becoming horny and 
 glabrous and finally nearly black with age; margin subobtuse, 
 ferruginous, velvety; context woody, fulvous, 1-2 cm. thick; 
 tubes evenly stratified, 2-3 mm. long each season, fulvous, mouths 
 circular, 3 to a mm., edges obtuse, entire, ferruginous to fulvous; 
 spores globose, compressed on one side, hyaline, 5.5-6 x 4.5-5 /x; 
 spines fulvous, 15-20 x 7-0 m; hyphffi 2.5 n. 
 
 On plum, birch and other trees. 
 
 The decayed wood is red-brown and crumbles when crushed. 
 
 F. fulvus oleae Lin.^' is injurious on olive in Italy. 
 
 F. nigricans Fr.^"' '■'° is very similar to F. igniarius from which it 
 differs chiefly in the black upper surface and the bluish or blackish 
 hymenial surface of the sporophores. Murrill ^^ regards it as a 
 variety of F. igniarius. 
 
 As a wound parasite it causes a reddish-brown heart-rot of 
 deciduous trees, especially of willow, birch, poplar, beech. 
 
 F. lucidus (Fr.) Bon. causes a cocoanut root-rot. 
 
 F. fraxinophilus (Pk.) Sacc^'- ^^ 
 
 Pileus woody, subtriangular, compressed-ungulate, usually 
 decurrent, 5-10 x 6-12 x 2-4 cm.; surface white, pulverulent or 
 finely tomentose, concentrically sulcate, becoming gray or black 
 and rimose with age; margin tumid, white or yellowish, velvety to 
 the touch; context corky to woody, zonate, isabelline, 0.5-1 cm. 
 thick; tubes evenly but indistinctly stratified, 2-4 mm. long each 
 season, white when young, concolorous with the context in the 
 older layers, mouths white, subcircular, 2 to a mm., edges obtuse; 
 spores broadly ellipsoid, smooth, hyaline, thin-walled, 6-7 x 7-8 
 ju; hyphse light yellowish-brown, 10-12 n; cystidia none. 
 
 It causes a heart-rot of trunk and branches of species of ash. 
 
 The starch in the host cells is lost early by diastatic action in 
 
434 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 advance of the fungus, the nearest hj^phse of which may be several 
 millimeters distant, and is replaced by a decomposition product. 
 The mycelium advances through the medullary rays and spreads 
 through spring and summer bands, abstracting the lignin; the 
 middle lamella dissolves and the cells fall apart. Completely 
 rotted wood is straw-colored, very soft, non-resistant. The young 
 hyphse are very fine and require an immersion less for observation. 
 Clamp connections are frequent. The sporophore appears after 
 the destruction of the wood is considerably advanced. 
 
 F. hartigii All. is very similar to, if not identical with, 
 F. igniarius. 
 
 It produces a white rot of firs and spruces. The mycelium is 
 yellowish with numerous branches which may fill the cavities of 
 the bordered pits of the tracheids. The middle lamella is even- 
 tually dissolved, later the inner walls. 
 
 F. robiniae (Murr.) S. & Sy. ''' '^ 
 
 A large fungus with dark rimose surface and tawny hymenium. 
 Pileus hard, woody, dimidiate, ungulate to applanate, 5-25 x 5-50 
 X 2-12 cm.; surface velvet}^ smooth, soon becoming very rimose 
 and roughened, fulvous to purplish-black, at length dull-black, 
 deeply and broadly concentrically sulcate; margin rounded, 
 velvety, fulvous; context hard, woody, concentrically banded, 
 1-3 cm. thick, fulvous; tubes stratose, 0.15-0.5 cm. long, 50 a 
 mm., fulvous, mouths subcircular, edges entire, equaling the 
 tubes in thickness: spores subglobose, smooth, thin-walled, fer- 
 ruginous, copious, 4-5 fx; cystidia none. 
 
 On black locust causing heart-rot, arising from wound infection 
 of living trees. The very hard wood becomes a soft, yellow to 
 brown mass, spongy when wet. The decay extends out in radical 
 lines from the center, along the large medullary rays, killing the 
 cambium and bark on reaching them. The lignin is first dissolved, 
 later the cellulose. 
 
 The fungus ceases growth on the death of its host. 
 
 F. marmoratus Berk! (=F. fasciatus [Sw.] Cooke.) 
 
 Pileus hard, woody, dimidiate, applanate to ungulate, convex 
 above, 7-10 x 8-15 x 2-6 cm.; surface finely tomentose, at length 
 glabrous, concentrically sulcate, at first mole-colored, changing 
 to umbrinous, and finally avellaneous with black fasciations; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 435 
 
 margin acute to obtuse, isabelline, sterile, undulate or entire; 
 context punky, thin, ferruginous to fulvous, zonate, 3-5 mm. 
 thick, tubes indistinctly stratified, 5-10 mm. long each season, 
 avellaneous within, mouths circular, minute, 4-5 to a mm. edges 
 obtuse avellaneous to umbrinous, becoming darker when bruised: 
 spores subglobose, smooth, light brown, 5-7 ix; hyphae brown, 4-6/i; 
 cystidia none. 
 
 On water oak and orange in Florida,^'* especially abundant on 
 the former. 
 
 F. sessilis (Murr.) Sacc. 
 
 A variable fungus with wrinkled varnished cap and acute margin, 
 found on decaying deciduous trees. Pileus corky to woody, dimidi- 
 ate, sessile or stipitate, imbricate or connate at times, conchate 
 to fan-shaped, thickest behind, thin at the margin, 5 15 x 7-25 
 X 1-3 cm.; surface glabrous, 
 laccate, shining, radiate- 
 rugose, concentrically sul- 
 cate, yellow to reddish- 
 chestnut, at length opaque, 
 dark-brown usually marked 
 near the margin with alter- 
 nating bay and tawny 
 zones; margin usually very 
 thin and acute, often curved 
 downward, often undulate, 
 rarely becoming truncate, 
 white, at length concolorous : 
 context soft-corky or woody, 
 radiate-fibrous, concentri- 
 cally banded, ochraceous- 
 fulvous; tubes 0.52 cm. 
 long, 3-5 to a mm., brown 
 within, mouths circular or 
 angular, white or grayish-brown, edges thin, entire: spores ovoid, 
 obtuse at the summit, attenuate and truncate at the base, verru- 
 cose, yellowish-broAvn, 9-11 x 6-8 m; stipe laterally attached, 
 usually ascending, irregularly cylindrical, 1-4 x 0.5-1.5 cm., re- 
 sembling the pileus in color, surface and substance, often obsolete. 
 
 Fr;. 309. — F. pinicola growing on tlcafl trunk 
 of western hemlock. After von 8chrenk. 
 
436 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 It occurs on oak and maple ®^ as a wound parasite, destroying 
 bark and cambium. This and related species are usually 
 saprophytic. 
 
 F. pinicola (Fr.) Cke.^^ 
 
 Pileus corky to woody, ungulate, 8-15 x 12-40 x 6-10 cm.; 
 surface glabrous, sulcate, reddish-brown to gray or black, often 
 resinous; margin at first acute to tumid, pallid, becoming yellowish 
 or reddish-chestnut: context woody, pallid, 0.5-1 cm. thick; tubes 
 distinctly stratified, 3-5 mm. long each season, white to isabelline, 
 
 Fig. 310. — Fomes applanatus. After Clements. 
 
 mouths circular, 3-5 to a mm., edges obtuse, white to cream-colored; 
 spores ovoid, smooth, hyaline, 6 ix; hyphse 8 m; cystidia none. 
 
 It occurs on conifers; pine, hemlock, spruce, balsam, larch, etc., 
 more rarely on beech, birch and maple, as a wound parasite of 
 the heart wood. The sporophores are often absent until after 
 death of the host. The tracheids bear many holes. The wood 
 carbonizes, the cellulose is destroyed and sheets of mycelium form, 
 particularly within the space occupied by the medullary rays and 
 in tangential crevices. ' " Fig. 309. 
 
 F. applanatus (Pers.) Wallr. 
 
 Pileus hard, woody, dimidiate, applanate, 6-15 x 8-30 x 1-4 cm.; 
 surface milk-white to gray or umbrinous, glabrous, concentrically 
 sulcate, encrusted, fasciate with obscure lines, condia-bearing, 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 437 
 
 usuall}'^ brownish during the growing season from the covering of 
 conidia; margin ol)tuse, broadly sterile, white or slightly cremeous, 
 entire to undulate: context corky, usually rather hard, zonate, 
 fulvous to bay, 5-lQ mm. thick, thinner with age; tubes very 
 evenly stratified, separated l)y thin layers of context, 5-10 mm. 
 long each season, avellaneous to uml^rinous within, mouths circular, 
 5 to a mm., whitish-stuffed when young, edges obtuse, entire, 
 white or slightly yellowish to umbrinous, quickly changing color 
 when bruised: spores ovoid, smooth or very slightly roughened, 
 pale yellowish-brown, truncate at the base, 7-8 x 5-6 /x. 
 
 It is described by Heald ^'^ as the cause of rot of both heart and 
 sap wood of living cotton-wood trees. The invaded medullary 
 rays first lose their starch by digestion. Next the lignin is dis- 
 solved, then the cellulose. 
 
 Von Schrenk regards this fungus as a saprophyte since it grows 
 usually only on outer sap wood that is dead and so far as he ob- 
 served, it does not cause a true disease. 
 
 F. ulmarius Fr. is injurious to elm. 
 
 F. semitosus Berk, causes root rot of Hevea in India. 
 
 F. australis Fr. is a wound parasite on Acacia in Ceylon. 
 
 Trametes Fries (p. 417) 
 
 Sporophore annual, rarely perennial, sessile; context homo- 
 geneous, coriaceous to corky, extending between the tubes, which 
 are circular or irregular. 
 
 There are about one hundred forty-five species. 
 
 T' • : /T-iU \ 17 56, 74, 78, 79 
 
 T. pmi (Thore) Fr. ' ' ' 
 
 Pileus hard, woody, typically ungulate, conchate or effused- 
 reflexed in varieties, often imbricate, 5-8 x 7-12 x 5-8 cm., smaller 
 in varieties; surface very rough, deeply sulcate, tomentose, tawny- 
 brown, becoming rimose and almost black with age; margin rounded 
 or acute, tomentose, ferruginous to tawny-cinnamon, entire, 
 sterile in large specimens: context soft-corky to indurate, homo- 
 geneous, ferruginous, 5-10 mm. thick, thinner in small specimens; 
 tubes stratified, white to avellaneous within, becoming ferrugi- 
 nous at maturity and in the older layers, 5 mm. long each season, 
 much shorter in thin specimens, mouths irregular, circular or 
 daedaleoid, often radially elongate, averaging 1 to a mm., edges 
 
138 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 ferruginous to grayish-umbrinous, glistening when young, rather 
 thin, entire; spores subglobose, smooth, hyaline at maturity, 
 becoming brownish with age, 5-6 x 3-4 ju; spines abundant, short, 
 25-35 X 4-6 /x. 
 
 It occurs on pine, spruce, larch, hemlock, and fir as a wound 
 parasite of the heart wood; it is also on willow in Europe and 
 America. 
 
 The spores are wind-borne and, lodging on unprotected sur- 
 faces, develop a mycelium which grows both up and down, spread- 
 ing most rapidly in a longitudinal direction, or horizontally follow- 
 ing an annual ring. The fungous enzyme first dissolves the lignin 
 leaving the individual tracheids free and of nearly pure cellulose. 
 The cellulose is later dissolved, resulting in holes in the wood. 
 It is found on most of the conifers of the United States as a sapro- 
 phyte. The wood becomes white-spotted. In late stages of decay 
 the entire wood is full of small holes which are lined with a white 
 fungous felt. 
 
 T. ribinophila Murr. is perhaps a parasite on the black locust. 
 
 T. theae Zimm. cause a root- 
 rot of tea in India.^^ 
 T. suaveolens (L.) Fr. 
 Pileus large, subimbricate, 
 dimidiate, sessile, convex above, 
 plane or concave below, 4-6 x 
 5-12 X 1-3 cm.; surface smooth, 
 anoderm, azonate, finely villose- 
 tomentose to nearly glabrous, 
 white to pale-isabelline; margin 
 thick, sterile, entire: context 
 white, punky-corky, 1-2 cm. 
 thick, very fragrant when fresh, 
 with the odor of anise; tubes 5- 
 15 mm. long, white within, 
 mouths circular, 2 to a mm., edges at first very thick, white, entire, 
 becoming thinner and often blackish with age : spores oblong-ovoid, 
 subsinuate, smooth, hyaline, 8-9 x 3-5 fx; hyphse 7 ju; cystidia 
 none. 
 
 On willow. 
 
 Fig. 311. — Favolus europseus. 
 After Lloyd. 
 
THE FUNGI WHICH CAUSE PLAxNT DISEASE 439 
 
 Favolus Fries (p. 417) 
 
 Sporophore leathery, fleshy, or coriaceous, laterally stipitate; 
 hymeiiium with large elongated pores which may even become 
 lamellate, Fig. 311. 
 
 A genus of some seventy species. 
 
 F. europaeus Fr. is a European parasite of fruit and nut trees ; it 
 is also common in America. 
 
 Daedalea Persoon (p. 417) 
 
 Hymenophore epixylous, usually large and annual, sessile, 
 applanate to ungulate; surface anoderm, glabrous, often zonate: 
 context white, wood-colored or brown, rigid, woody, tough or 
 punky: hymenium normally labyrinthiform, but varying to lamel- 
 late and porose in some species: spores smooth, hyaline. 
 
 About seventy-six species. Fig. 312. 
 
 D. quercina (L.) Pers. 
 
 Pileus corky, rigid, dimidiate, sessile, imbricate, applanate, 
 convex below, triangular in section, 6-12 x 9-20 x 2-4 cm.; surface 
 isabelline-avellaneous to cinereous or smoky-black with age, 
 slightly sulcate, zonate at times, tuberculose to coUiculose in the 
 older portions; margin usually thin, pallid, glabrous; context 
 isabelUne, soft-corky, homogeneous, 5-7 mm. thick; tubes laby- 
 rinthiform, becoming nearly lamellate with age in some specimens, 
 1-2 cm. long, 1-2 mm. broad, chalk-white or discolored within, 
 edges obtuse, entire, ochraceous to avellaneous. 
 
 Common on oak and chestnut, often on living trees but 
 growing only on the dead wood. 
 
 Lenzites Fries (p. 417) 
 
 Hymenophore small, annual, epixylous, sessile, conchate; 
 surface anoderm, usually zonate and tomentose: context white or 
 brown, coriaceous, flexible; hymenium lamellate, the radiating 
 gill-like dissepiments connected transversely at times, especially 
 when young: spores smooth, hyaline. Fig. 313. 
 
 About seventy-five species. 
 
440 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 L. abietina (Bui.) Fr. occurs on firs, L. sepiaria (Wulf.) Fr. 
 has been reported as a parasite on pine, spruce, etc., but recent 
 work of Spaulding ^^ shows it to be merely a saprophyte. L. cor- 
 rugata Klot, L. vialis Pk. and L. betulina (L.) Fr. are common 
 
 Fig. 312. — Daedalea quercina on oak. After von ydircnk unci Spaulding. 
 
 saprophytes on deciduous trees; perhaps also parasitic; L. varie- 
 gata Fr. on beech and poplar. 
 
 Boletaceae (p. 402) 
 
 Sporophores fleshy, capitate, centrally or laterally stipitate, 
 rarely actually sessile; hymenium on the under surface only, of 
 tubes which separate readily from the pileus and are united to 
 each other or only closely approximated. 
 
 A family of less than three hundred species. 
 
 Key to Genera op Boletaceae 
 
 Pores adnate to each other I. Boletineae. 
 
 Pores separate tubes II. Fistulineae. 
 
 Sporophore more or less fleshy 1. Fistulina, p. 441. 
 
 Sporophore leathery 
 
 Tubes with a central papilla 2. Theleporus. 
 
 Tubes without papillae 3. Porothelium. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 441 
 
 Fistulina Buller (p. 440) 
 
 Sporophore fleshy, laterally short-stipitate, hymenial sur- 
 face at first granular, then each granule becoming a tube; these 
 are approximate but not united; spores brown in mass. Fig. 314. 
 
 A genus of a half dozen species. 
 
 Fig. 313. — Lcnzites betulina. After Clements. 
 
 F. hepatica (Scha.) Fr. 
 
 ' Cap 8-20 cm. wide, bright-red or red-brown, liver-shaped to 
 shelf-like, more or less lobed, smooth, more or less sticky when 
 wet; flesh containing reddish fibers; stem short, lateral and almost 
 wanting, or sometimes long excentric; tubes pale to yellowish or 
 
442 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 pinkish; spores yellowish to pinkish, ellipsoid, 5-7 x 3-4 ju. 
 It is found on oak and chestnut. 
 
 Agaricacese (p. 402)^^ 
 
 Sporophore usually fleshy, rarely coriaceous or leathery, stip- 
 itate or shelving; stipe variable in development, lateral or central, 
 
 Fig. 314.— Fistulina hepatica. After Clements. 
 
 annulate or not, the entire young sporophore often volvate at 
 first; hymenium lamellate, the lamellae usually free, rarely anas- 
 tomosing, sometimes dichotomous, rarely reduced to ridges or 
 slight folds. 
 
 A family of over twelve hundred species. 
 
 Key to Tribes of Agaricaceae 
 
 Hymenium with the lamellae ridge or fold- 
 like, imperfectly developed I. Cantharellese, p. 443. 
 
 Hymenium with normally developed gills 
 Lamellae sometimes anastomosing, and 
 
 forming meshes IL Paxilleae. 
 
 Lamellae not anastomosing 
 
 Lamellse and often the cap deliquescent 
 
 (in Montagnites withering,) IIL Coprineae. 
 
 Lamellae not deliquescent 
 
 Lamellse thick and fleshy, becoming 
 
 waxy IV. Hygrophoreae. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 443 
 
 Lamellse not fleshy or waxy 
 Substance of the pileus of two 
 kinds of hyphse, one thick, 
 tubular and in bundles, the 
 other thin, single and fre- 
 quently lactiferous V. Lactariese. 
 
 Substance of the pileus of only one 
 
 kind of hyphse 
 
 Sporophore at maturity leathery 
 
 or corky, persistent, rarely 
 
 fleshy 
 
 Lamellae at maturity split 
 
 lengthwise VI. Schizophylleae, p. 444. 
 
 Lamellae at maturity not 
 
 splitting VII. Merasmieae, p. 445. 
 
 Sporophore at maturity fleshy, 
 
 finally putrescent VIII. Agariceae, p. 448. 
 
 Cantharelleae (p. 442) 
 
 This tribe is characterized l^y its low ridge or fold-like lamellae. 
 The hj^menial characters indicate an approach to the Thelephora- 
 ceae. 
 
 Key to Genera of Cantharelleae 
 
 Hymenium on the upper side of the pileus. I. Rimbachia. 
 Hymenium on the under side of the pileus. 
 Hymenium with thin veins 
 
 Veins anastomosing 2. Campanella. 
 
 Veins not anastomosing 3. Arrhenia. 
 
 Hymenium with thick folds 
 
 Substance of the pileus leathery, 
 
 tough 4. Trogia, p. 444. 
 
 Substance of the pileus thin, soft- 
 leathery 
 Sporophore sessile, at first saucer- 
 shaped 5. Leptopus. 
 
 Sporophore laterally stalked, fan- 
 shaped 6. Leptoglossum. 
 
 Substance of the pileus fleshy 7. Cantharellus. 
 
 ^' 
 
444 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Fig. 315. — Trogia faginea. 
 After Hennings. 
 
 Trogia Fries (p. 443) 
 
 Cap thin, leathery, or membranous, persistent, sessile, irreg- 
 ular; hymenium of branched 
 folds, the branches chiefly mar- 
 ginal. 
 
 There are some seven species. 
 T. faginea. (Schr.) v. Sch. 
 Sporophore 1-2 cm. broad, 
 beaker-formed or irregular mar- 
 gined; yellow or orange without, 
 rarely whitish, with fine hairs; 
 ribs concolorous, dichotomous; spores cylindric, 4 x 1-1.5 m, 
 smooth, colorless. 
 
 It injures birch, beech, hazel, etc. 
 
 Schizophylleae (p. 443) 
 
 Sporophore, leathery, persistent, the cleft gills with recurved 
 margins. A group of but four genera and less than a score of 
 species. 
 
 Key to Genera of Schizophylleae 
 
 Sporophore leathery, sessile 1. Schizophyllum, p. 444. 
 
 Sporophore fleshy or membranous, stipitate 
 Stipe central 
 
 Cap thin, membranous 2. Rhacophyllus. 
 
 Cap fleshy 4. CEdemansiella. 
 
 Stipe lateral 3. Pterophyllus. 
 
 Schizophyllum Fries 
 
 Cap woolly, upturned, sessile, epixylous; gills cleft, the mar- 
 gins recoiled; texture leathery. 
 
 About twelve species. Fig. 316. 
 
 S. alneum (L.) Schr. 
 
 Cap 1-4 cm. wide, white or gray-woolly, upturned, attached 
 excentrically, irregularly saucer-shaped* stem lacking; gills grayish 
 to purplish; spores subglol^ose, 2-3 /x. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 It parasitizes sugar cane, horse chestnut, chestnut, mulberry 
 and orange. 
 
 445 
 
 22 
 
 Fig. 31G. — S. alneum. After Clements. 
 
 Marasmieae (p. 443) 
 
 Pileus tough, leathery, thin, membranous, or rarely somewhat 
 fleshy, reviving after drying with the return of moisture. 
 About five hundred fifty species. 
 
 Key to Genera of Marasmieae 
 
 Gills leathery-horny; spores black 1. Anthracophyllum. 
 
 Gills leathery; spores hyaline 
 
 Pileus not distinct from the stipe; sporo- 
 phore trumpet-shaped 
 
 Gills forked, edge blunt 2. Xerotus. 
 
 Gills with a thin edge 
 
 Gills toothed on the margin , 3. Lentinus, p. 445. 
 
 Gills with an even margin 4. Panus, p. 446. 
 
 Pileus distinct from the stipe 
 Annulus wanting 
 
 Pileus firm and dry 5. Marasmius, p. 446. 
 
 Pileus somewhat gelatinous 6. Heliomyces. 
 
 Annulus present 7. Merasmiopsis. 
 
 Lentinus Fries 
 
 Sporophore trumpet-shaped, pileus and stipe not distinct, 
 leathery, pileus central or lateral, gills toothed; spores white. 
 About three hundred forty species. 
 
446 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 L. conchatus (Bui.) Schr. is found on birch, poplar, aspen. 
 L. lepideus ^^^ Fr. on pine, birch, etc. 
 
 Fiu. 317. — Lentinus lepideus. After Clements. 
 
 Panus Fries (p. 445) 
 
 This genus is very close to Lentinus from which it is separated 
 by the character of the gills which have an entire edge. 
 P. stipicus (Bui.) Fr. is perhaps parasitic occasionally. ^°° 
 
 Marasmius Fries (p. 445) 
 
 Sporophore tough, withering, often reviving in renewed moisture; 
 pileus, with few exceptions, regular, thin, leathery, without a veil, 
 sharply cUfferentiated from the stipe, rarely sessile or laterally 
 attached; stipe tough, cartilaginous or horny, without an annulus; 
 gills tough, thin, leathery or membranous, entire margined. 
 
 Some four hundred fifty species of wide distribution, but chiefly 
 small tropical fungi. 
 
 .j»%-.^ 
 
THE FUNGI WHICH CAUSE PLANT DISEASE -447 
 
 Fig. 318. — Marasmius plicatus. After Fulton. 
 
448 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 M. plicatus Wak. 
 
 Pileus submembranous, convex or subcampanulate, glabrous, 
 sulcate-striate, chestnut or light wine-colored; gills rather distant, 
 white, basally attached; stipe slender, glabrous above, white 
 downy below. 
 
 Marasmius parasitism of sugar cane was first described by 
 Wakker in 1895 ^"^ later by Howard. ^°- In these cases M. sacchari 
 or varieties of it were identified. In 1908 Fulton described M. 
 plicatus Wak. as the cause of serious sugar cane troubles in Louis- 
 iana.^*^^ This fungus which exists first as a saprophyte resides 
 primarily in the soil from which it grows over the stools and 
 eventually penetrates living tissue, destroys many roots and 
 smothers the developing buds. The white mycelium is found 
 cementing the lower leaf sheaths to the cane. It is probable that 
 several species are concerned. 
 
 M. sacchari Wak. occurs on sugar cane in the oriental tropics. 
 
 M. hawiiensis Cobb, is reported as associated with the preceding 
 species in Hawaii. M. semiustus B. & C affects the stems, pedun- 
 cles and inflorescence of the banana. M. equicrinis Miill. Banc. 
 causes horse-hair blight of cacao and M. sarmentosus Fr. a simi- 
 lar disease of the tea plant and of forest trees in India. 
 
 Agariceae (p. 443) 
 
 This tribe contains all the gill fungi and is characterized by a 
 fleshy, putrescent sporophore; gills fleshy, rarely tough or leathery, 
 weak, easily broken, not deliquescent, without milky juice. It is 
 the largest tribe of the family. The genera are conveniently 
 grouped as black, brown, rusty, pink or red, and white-spored 
 forms. None of the black-spored species are knowTi as parasites. 
 
 Amaurosporeae (brown-spored series) 
 
 With a volva at base 1. Chitonia. 
 
 Without a volva. 
 
 Veil remaining on the stem as an annulus 
 
 Gills free from the stem 2. Agaricus. 
 
 Gills united with the stem 3. Stropharia. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 449 
 
 Veil remaining attached to the margin of 
 the pileus, often not apparent in very 
 
 old specimens 4. Hypholoma, p. 450. 
 
 Veil inconspicuous or wanting 
 
 Gills free 5. Pilosace. 
 
 Gills decurrent 6. Deconica. 
 
 Gills adnate or sinuate 
 
 Margin of pileus incurved when 
 
 young 7. Psilocybe, p. 451. 
 
 Margin of pileus always straight. ... 8. Psathyra. 
 
 Phaeosporeae (Rusty-spored scries) 
 
 Annulus continuous 
 
 Veil single, forming the annulus 1. Pholiota, p. 452. 
 
 Veil double, forming the annulus and 
 
 deciduous scales on the pileus 2. Rozites. 
 
 Annulus arachnoid, filamentous or evanes- 
 cent, often not apparent in old speci- 
 mens 
 
 Gills adnate; terrestrial 3. Cortinarius. 
 
 Gills decurrent; epiphytal 4. Flammula, p. 452. 
 
 Annulus wanting 
 
 Gills decurrent; stipe with a cartilaginous 
 
 rind 5. Tubaria. 
 
 Gills not decurrent 
 Stipe fleshy 
 
 Without a volva 
 
 Pileus fibrinous or silky - 6. Inocybe. 
 
 Pileus smooth and viscid ■ 7. Hebeloma. 
 
 With a volva , 8. Locellina. 
 
 Stipe with a cartilaginous rind 
 
 Margin of pileus incurved when ^ 
 
 young I 9. Naucoria. 
 
 Margin of pileus straight 
 
 Pileus viscid; gills free \ 10. PluteoIuSo 
 
 Pileus not \nscid; gills attached. .. '11. Galera. 
 
 Rhodosporeae (Pink-spored series) 
 
 Stipe lateral 12. Claudopus. 
 
 Stipe central. i 
 
 Volva present; annulus wanting 13. Volvaria, p. 452. 
 
450 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Volva absent; annulus present 14. Annularia. 
 
 Volva and annulus both wanting 
 
 Gills free from the stipe 15. Pluteus, p. 45 1 . 
 
 Gills adnate or sinuate 
 
 Stipe fleshy 16. Entoloma. 
 
 Stipe with a cartilaginous rind 
 
 Pileus torn into scales 17. Leptonia. 
 
 Pileus papillose, subcam})anulate . 18. Nolanea. 
 Gills decurrent on the stipe 
 
 Stipe fleshy 19. Clitopilus. 
 
 Stipe with a cartilaginous rind 20. Eccilia. 
 
 Leucosporeae (White-spored series) 
 
 Stipe lateral, or none 21. Pleurotus, p. 454. 
 
 Stipe central 
 
 Volva and annulus both present 22. Amanita. 
 
 Volva present; annulus none 23. Amantiopsis. 
 
 Volva absent; annulus present 
 
 Gills free from the stipe 24. Lepotia. 
 
 Gills united to the stipe 
 
 Pileus usually smooth 25. Armillaria, p. 455. 
 
 Pileus floccose 26. Costinellus. 
 
 Volva and annulus Ijoth absent 
 Gills decurrent on the stipe 
 
 Stipe fleshy 27. Clitocybe, p. 457. 
 
 Stipe with a cartilaginous rind 28. Omphalia. 
 
 Gills adnate, stipe with a cartilaginous 
 
 rind 29. Collybia, p. 458. 
 
 Gills sinuate 
 
 Stipe fleshy 30. Tricholoma, p. 460. 
 
 Stipe with a cartilaginous rind 
 
 Pileus membranous, more or less 
 
 striate 31. Mycena, p. 460. 
 
 Pileus very thin, without a pelli- 
 cle 32. Hiatula. 
 
 Hypholoma Fries (p. 449) 
 
 Fleshy; gills attached; annulus imperfect, or none; veil breaking 
 up into fragments which are more or less persistent on the margin 
 of the cap. 
 
 About seventy species. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 451 
 
 H. appendiculatum (Bui.) Karst. is perhaps parasitic, occurring 
 at the bases of hving trees. 
 
 H. fasciculare (Huds.) Fr. is said to grow parasitically upon 
 
 Fui. 319. — Hypoloma appendiculatum. After Clements. 
 
 roots, causing a white rot. It is mentioned as a parasite on rasp- 
 berry roots in Australia. '°^ 
 
 H. lateritium (Scha.) Schr. is also possibly parasitic on trees. 
 
 Psilocybe Fries (p. 449) 
 
 Pileus smooth, margin at first incurved; gills and spores at 
 length brownish or purplish; stipe cartilaginous, hollow or stuffed, 
 veil absent or rudimentary. 
 
 About forty species. Fig. 320. 
 
 P. spadicea (Scha.) Fr. is a weak wound parasite on various 
 woody plants. 
 
 P. henningsii Jung, is said to be occasionally injurious to 
 winter grains ^°^ in Europe. 
 
452 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Pholiota Fries (p. 449) 
 
 Pileus symmetrical, more or less thick, fleshy, with a veil 
 which forms an annulus; gills adnate, becoming rusty at maturity. 
 Fig. 321. 
 
 P. 
 
 aurivilla (Bat.) Quel, and P. 
 deciduous 
 
 Fig. 320. — Psilocybe pennata. 
 After Cooke. 
 
 squarrosa Miill. occur on 
 trees, especially on the 
 apple. 
 
 P. spectabilis Fr. is occasionally 
 parasitic on oaks. 
 
 P. mutabilis (Scha.) Quel, is a root 
 parasite on trees. 
 P. adiposa Fries. 
 
 Cap medium, 5-10 cm. wide, yellow, 
 very sticky when moist, with spread- 
 ing or erect rust-brown scales which 
 sometimes disappear when old, convex 
 to plane; stem 5-15 cm. by 1-2 cm., 
 yellow, paler above and darker, scaly below the more or less im- 
 perfect tufted ring, solid or stuffed; gills adnate, yellowish to rust- 
 colored, broad, crowded; spores rust-colored, elliptic, 7-8 x 5 fx. 
 The name may refer to the sticky cap. 
 
 Chiefly a saprophyte, occasionally on living trees, both decid- 
 uous trees and conifers, as a wound parasite. 
 
 P. destruens Brand, occurs on poplar; P. cervinus Scha. on 
 various trees. 
 
 Flammula Fries (p. 449) 
 
 Pileus fleshy, margin at first incurved; stipe fleshy, fibrous, 
 well marked by the bright yellow or orange colored cap. 
 
 About sixty species. 
 
 F. alnicola Fr. is probably a root parasite. ^°° 
 
 F. penetrans Fr. and F. spumosa Fr. are regarded by Cavara ^°^ 
 as root parasites of forest trees. 
 
 Volvaria Fries (p. 449) 
 Flesh J''; gills free, white, later pink; spores ellipsoid, smooth; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 453 
 
 annulus none; volva present. Easily distinguished from all other 
 pink-spored genera by the volva. Fig. 322, 
 About thirty-six species. 
 
 Fig. 321. — Pholiota adiposa.^ After Clements. 
 
 V. bombycina (Scha.) Quel. 
 
 Cap large, 8-25 cm. wide, all white and silky, more rarely some- 
 what scaly, hemispheric or bell-shaped to convex; stem 8-12 cm. 
 by 1-2 cm., white, smooth, tapering upward, solid, volva large 
 and spreading; gills free, salmon-pink, crowded, spores elliptic, 
 6-7 X 4 /i. It is often parasitic on various trees. 
 
454 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Piute US Fries (p. 450) 
 
 Pileus fleshy, regular; separating easily from the stipe; gills 
 free; volva and annulus both absent; spores elliptic. 
 
 P. cervinus Scha. Fig. 323. 
 
 Cap large, 5-16 cm. wide, usually 
 .'■ome shade of brown, from grayish or 
 yellowish to blackish-brown, more or 
 less fibrous or hairy on the disk, some- 
 times sticky, convex or plane; stem 7- 
 15 cm. by 3^-1 cm., brownish, smooth 
 or black-hairy, solid; gills free, pink, 
 broad; spores pink, rarely greenish, 
 globoid, 7-8 X 5-6 n. 
 
 A common saprophyte which is oc- 
 casionally parasitic. 
 
 Pleurotus Fries (p. 450) 
 
 Pileus laterally sessile, or excentrically 
 stipitate. Fig. 324. 
 
 A genus of about two hundred fifty 
 species. 
 
 P. ostreatus Jacq. 
 
 Cap large, 7-24 cm. wide, white, gray 
 or tan, smooth or more or less scaly in 
 age, convex or plane, shelf or shell- 
 shaped, more or less lobed and torn at 
 the margin; stem short and lateral, or none, white, solid, more or 
 less hairy at base; gills long-decurrent, connected by veins on the 
 stem, white or yellowish ; spores elliptic, 8-10 x 4-5 /x. 
 Common on deciduous trees, mainly saprophytic. 
 P. salignus Schrad. is often parasitic on willow, poplar, mul- 
 berry, etc. 
 P. ulmarius Bui. 
 
 Cap large, 8-15 cm. wide, white, whitish or tan, often brownish 
 toward the center, smooth, often cracked, usually convex, some- 
 times plane; stem long and stout, often nearly central, 5-12 cm. 
 by 2-3 cm., white or tan, smooth or hairy toward the base, solid. 
 
 ^^^^^H^^'^ 
 
 ^^H^j 
 
 ■ 
 
 H^^^f'' 
 
 
 ^f 
 
 K>- 
 
 ^B 
 
 Va 
 
 ^^^^■i^^^*- ^ 
 
 ^^^1^^ 
 
 ^jfl 
 
 ^KmfJm 
 
 wIj 
 
 
 I^^^Hr ^^^ 
 
 ^J^l 
 
 ^^H 
 
 wKm M^ 
 
 w 
 
 ^1 
 
 ^^Kj^jlj^^HM 
 
 bJ 
 
 1 
 
 ^^^l^^^'^l 
 
 ?^'^^ 
 
 1 
 
 ^^■r"' \.-S 
 
 j^% 
 
 'in 
 
 ^BK'''^'^iM 
 
 P^''^'l$'4 
 
 i^^l 
 
 ^^B ^W^ 
 
 1 ■' ,,» 
 
 1^1 
 
 
 1 
 
 1 
 
 ViG.. 322. — Volvaria bomhy 
 cina. After Clements. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 455 
 
 elastic, often curved; gills annexed or sinuate, whitish, broad, 
 close; spores globose, 5-6 fi. 
 
 Parasitic on elm and maple or usually a saprophyte. 
 
 Fig. 323. — Piute us cciviuus. Alter Ciemeuta. 
 
 P. nidulans Pers. occurs on roots of trees in Europe. 
 Other questionable parasites are: P. atrocoeruleus Fr. on wil- 
 low; P. mitis Pers. on pine; P. corticatus Fir. on "poplar. 
 
 Armillaria Fries (p. 450) 
 
 Fleshy, the substance of the pileus and stipe continuous; annulus 
 fixed; gills usually attached, white; spores clavate, ellipsoid or 
 ovate, smooth. 
 
 About sixty species. Figs. 325, 326. 
 
 An extensive list of members of the genus, under the name 
 Agaricus, found growing upon woody plants has been compiled by 
 Wilcox. 1°^ 
 
 A. mellea (Vahl.) Quel."' '"' "' '"' 
 
 Cap large, 3-15 cm. wide, usually honey-colored, but varying 
 through all shades of yellow to bro\vn, typically marked with 
 small tufts of brownish or blackish hairs, especially toward the 
 center, though sometimes woolly or entirely smooth, margin often 
 striate, convex to expanded; stem tall, stout, 3-15 cm. by 6-20 mm., 
 whitish, yellowish, or brownish, especially below the ring, smooth 
 or scaly, hollow or stuffed, ring usually thicldsh and conspicuous, 
 
456 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 but sometimes thin or even lacking; gills touching broadly or 
 running down the stem, Avhitish or yellowish; spores elliptic or 
 rounded, 7-10 m- 
 
 This is a common wound parasite of conifers and deciduous 
 trees, causing a root-rot. It also causes a potato disease in Aus- 
 tralia.^"^ The abundant mycelium is white and extends a meter 
 
 Hi 
 
 HF^^ 
 
 
 ^H 
 
 ■H 
 
 J^m 
 
 ggj^gjj^^y't g^jferaaayg^^gBB 
 
 
 1^^ 
 
 ^^1 
 
 IQSfl 
 
 
 
 ^^^ 
 
 ^^H 
 
 ''■>'^w^|^| 
 
 H|^ 
 
 
 m 
 
 H^ 
 
 R»S^ 
 
 ^^^^^^^n^^ 
 
 
 BS^^I 
 
 ^^^^^^Q 
 
 ^m 
 
 mBM 
 
 ■ffi^^^^^^^^^^H 
 
 H 
 
 ^H 
 
 ^^ 
 
 I^^HsH 
 
 
 |hH 
 
 ^^^^^1^^^^ 
 
 ^^M 
 
 S^^^l 
 
 
 ^1 
 
 ^^^^fflci^A^ 
 
 pl 
 
 ^^^9 
 
 
 H 
 
 H^HRH|BH| 
 
 1 
 
 m 
 
 
 1 
 
 1 
 
 Fig. 324. — Pleurotus ostreatus. After Clements. 
 
 or more through the wood and bark, aggregating under or on the 
 bark to form shining hard gray-black intertangled cords (rhizo- 
 morphs) 1-2 mm. in diameter often reaching out to great distances 
 through the earth. Fig, 326. Sheets of white felt also occur. 
 
 The young mycelium grows into the cambium layer, attacking 
 living cells and often encircling the tree. In the living cortex it 
 presents a characteristic fasciated skin-like appearance. 
 
THE FUNCil WHICH CAUSE PLANT DISEASE 457 
 
 The sporophores are borne in clusters in autumn on the ground 
 or on the Ixark. 
 
 The spores, sowa in phim decoction, develop a mycelium which 
 soon produces rhizomorphs. These advancing give off delicate 
 hypha; which may penetrate into the host. The mycelium spreads 
 
 
 p^BB 
 
 HMM 
 
 
 
 ''■'^#*i|3 
 
 
 ^ - ' s^iC|R|^^pfl^|^^^^HH|^^| 
 
 j% 
 
 
 hhh 
 
 jKV 
 
 ^mKHI 
 
 I^^^H 
 
 5 ^ 
 
 '''V*'\l\\iMll!IL'i!li!ilJjiMMl^^iS 
 
 I^H 
 
 
 ^^^I^^^^^B^^^. ■ «<r_jfl^^^H 
 
 ^ '"^^!^H^^' '-^^B 
 
 Fig. 325. — Armillaria mellea. After Clements. 
 
 most rapidly through the medullary rays and from them into other 
 tissue elements. 
 
 A. fuscipes Fetch causes a root disease of Acacia in Ceylon. 
 
 A. mucida (Schrad.) Quel, is reported as a wound parasite of the 
 beech. 
 
 Clitocybe Fries (p. 450) 
 
 Pileus more or less fleshy, margin at first incurved; stipe fleshy, 
 often becoming hollow; gills decurrent. 
 About ninety species. Fig. 427. 
 
458 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 C. parasitica Wil.^o^ 
 
 Growing in dense clusters; pileus 6-8 cm., convex or umbonate, 
 
 usually minutely scaly, mottled 
 l)uff to yellow-brown in color; 
 gills paler, becoming mottled, 
 at first noticeably decurrent; 
 stipe 10-16 cm. high, up to 
 1 cm. thick, solid, usually 
 curved, darker than the pileus; 
 black rhizomorphs present. 
 
 It differs from Armillaria 
 mellea in having no annulus, 
 and in growing in denser clus- 
 ters. 
 
 The fungus causes a root- 
 rot very similar to that caused 
 by Armillaria mellea. There 
 are present typical subcortical 
 strands, mostly between the 
 cortex and cambium and some- 
 times characteristic subterranean black rhizomorphs adhering 
 close to the cortex of the roots. 
 
 Fungous branches enter the wood chiefly through the medullary 
 rays and there is later rapid vertical growth through the vessels 
 and tracheids. The cell contents are destroyed, the hyphse often 
 forming loops around the nucleus. The sporophores occur in 
 groups at the base of the tree after the disease is well developed. 
 An extensive bibliography is given by Wilcox. ^°'^ 
 
 ^H^" /'-"^-vc" ' 
 
 
 \ 
 
 n ris^ibjli^'^'' x'Swfi 
 
 m 
 
 " % 
 
 „ 1 '.^ZT^wf^^f9lir^w-/it^Jt 
 
 f 
 
 \ 
 
 
 "^ 
 
 
 ^^^^^^^ /Jw" 
 
 
 
 i v^>C--*<y^ M ^ VwlW; /^^ 
 
 
 
 i.j*|r 
 
 
 
 Fiu. 326. — Rhizomorphs of A. mellea. 
 After Freeman. 
 
 Collybia Fries (p. 450) 
 
 Pileus thin, fleshy, margin at first incurved; stipe cartilaginous. 
 
 About two hundred seventy-five species. Fig. 329. 
 
 C. velutipes Curt. 
 
 Cap 2-8 cm. wide, yellow-brown or reddish brown, rarely paler 
 except toward the margin, smooth, very sticky when moist, con- 
 vex to plane or somewhat recurved, often excentric or irregular 
 through pressure. 
 
THE FUNGI WHICH CAI^SE PLANT DISEASE 459 
 
 Fig. 327. — Clitocybe parasitica. After Wilcox 
 
 iG. 328.— Clitocybe parasitica, mycelium entering medullary ray. After Wilcox. 
 
460 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Fig. 329.— Collybia velutipes. 
 Lloyd. 
 
 After 
 
 A common saprophyte which is reported by Stewart ^°^ as the 
 probable cause of death of the horse-chestnut. It has also 
 
 been reported in Europe as a 
 parasite. 
 
 Tricholoma Fries (p. 450) 
 
 Stout and fleshy, stipe 
 ;md pileus of the same sub- 
 stance; gills sinuate or ad- 
 nate. Fig. 330. 
 
 T. rutilans Scha. occurs on 
 pine roots; T. saponaceum Fr. 
 on various tree roots. 
 
 Mycena Fries (p. 450) 
 
 Small; pileus usually bell- 
 shaped, rarely umbilicate, membranous and more or less striate, 
 at first with the straight margin applied to the stipe; gills only 
 slightly toothed, not decurrent or only so by a tooth; stipe slen- 
 der, cartilaginous, usually 
 hollow. Fig. 331. 
 
 A genus of some three 
 hundred species. 
 
 M. epipterygia Scop. 
 
 Five to ten cm. high; 
 pileus 1-2 cm. broad, vis- 
 cid when moist, ovate to 
 conic or campanulate, 
 later more expanded, ob- 
 tuse, the margin striate, 
 sometimes minutely 
 toothed, grayish, in age 
 often reddish; stipe 2 mm. 
 thick, flexuous or straight 
 with soft hairs at the base; gills decurrent by a small tooth, 
 varying in color from whitish through gray to a tinge of blue or red. 
 
 Usually a saprophyte, but injurious to various kinds of trees. 
 Widely distributed in the North temperate zone. 
 
 Fig. 330.— Tricholoma. After Lloyd. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 461 
 
462 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 PhaUales (p. 395) 
 
 Mycelium rhizomorphic ; sporophore with a fertile portion, the 
 gleba, which contains a series of labyrinthine spore chambers, 
 these lined by a hymenium of closely approximated basidia, the 
 supporting tissue parenchymatous, spongy and elastic in texture, 
 forming a receptacle which varies in size and form in the different 
 genera. Except in Rhizogaster the young sporophore is volvate, 
 and at the bursting of the volva immediately assumes its mature 
 size and form. 
 
 An order of less than fifty species of interesting, yet from their 
 foul odor most disagreeable fungi. At present they are regarded 
 as mainly saprophytes. 
 
 Key to Families of PhaUales 
 
 Receptacle stipitate, tubular or cylin- 
 dric, capitate, with the gleba ex- 
 ternal 1. Phallaceae, p. 462. 
 
 Receptacle latticed or irregularly 
 branched, sessile or stalked; gleba en- 
 closed by the receptacle 2. Clathraceae, p. 463. 
 
 Phallaceae 
 
 Key to Genera of Phallaceae 
 
 Gleba borne directly on the upper portion of 
 the stem; no special pileus 
 
 Gleba smooth, even 1 . Mutinus. 
 
 Gleba papillate or uneven 2. Jansia. 
 
 Gleba covered by a rudimentary network 3. Floccomutinus. 
 Gleba borne on the outer surface of a special 
 pileus 
 Pileus even, rugose, or reticulate 
 
 Veil poorly developed or none 4. Phallus, p. 463. 
 
 Veil well developed 
 
 Surface of the pileus regularly reticu- 
 late 5. Dictyophora, p. 463. 
 
 Surface of the pileus irregularly folded 
 
 and convoluted 6. Clautriavia. 
 
 Pileus lamellate 7. Itajahya. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 463 
 
 Phallus Linnaeus (p. 462) 
 
 Stipe cylindric, even, bearing at the apex a 
 smooth, rugose, or reticulate pileus. 
 
 Less than ten species are known. The follow- 
 ing are of economic importance. 
 
 P. impudicus L. 
 
 This is one of the most widely distributed 
 species of the genus, but not so common in 
 America as in Europe. It is reported ^'^ as the 
 cause of a root disease of the grape in Hungary. 
 
 P. rubicundus Bosc. 
 
 Cobb ^^^ has described a disease of sugar cane 
 as due to Ithyphallus coralloides. Lloyd, ^'- 
 however, refers the causal fungus to the present F i g. 332. —Phallus 
 
 1 . , ji i 11 ii 1 impudicus. After 
 
 species, since he considers that all the red Lloyd, 
 forms of "Phallus" constitute a single species. 
 
 Dictyophora Desvaux (p. 462) 
 
 A species of this genus is suspected by Cobb ^^^ as one of the 
 causal fungi in a root disease of sugar cane in Hawaii. 
 
 Clathraceae (p. 462) 
 
 The receptacle consists of a series of arms which are either 
 spreading, erect, or latticed. 
 
 Key to Genera of Clathraceae 
 Receptacle of free arms, or lobes at the sum- 
 mit of the stipe 
 
 Stipe columnar, arms free L Lysurus. 
 
 Stipe enlarged upwards 
 
 Limb of the receptacle with suberect 
 
 lobes 2. Anthurus. 
 
 Limb of the receptacle with radiating 
 
 lobes 3. AsercB. 
 
 Receptacle of simple, erect, columns, apical- 
 ly united and fertile only on their inner 
 side 
 
 Sessile 4. Laternea, p. 464. 
 
 Stalked 5. Pseudocolus. 
 
464 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Receptacle clathral^e or latticed 
 
 Sessile 6. Clathrus. 
 
 Stalked 
 
 Receptacle a simple net 
 
 Stipe simple 7. 
 
 Borne on a series of columns which 
 are united basally into a hollow 
 
 tube 
 
 Receptacle with the network covered 
 
 with knot-like projections 9. Klachbrennera. 
 
 7. Simblum. 
 
 Colus. 
 
 Lateraea Turpin (p. 463) 
 
 Receptacle sessile, of upright, convergent 
 columns, apically united and fertile only on 
 the inner surface. 
 
 L. columnata (Bosc.) Ness, is recorded by 
 Cobb ^^"^ as one of the fungi of the root disease 
 of sugar cane in Hawaii. The species is rather 
 cammon in the Southern United States, South 
 America, the West Indies and Hawaii. 
 
 Lycoperdales (p. 395) 
 
 Mycelium arachnoid to rhizomorphic; sporo- 
 phores from the first appearing as small balls 
 which enlarge to maturity, gleba internal at 
 maturity, becoming a powdery spore-mass; base 
 of the sporophore sterile ; peridium double or single, parenchyma- 
 tous, separating into flakes or breaking regularlj''; fertile hyphse, 
 persistent in the spore mass as a capillitium which is usually at- 
 tached to the columella. 
 
 A single family Lycoperdaceae with species which are usually 
 saprophytes. 
 
 Fig. 333.— Latcr- 
 nea columnata. 
 After Lloyd. 
 
 Key to Genera of Lycoperdaceae 
 
 Outer peridium fragile, more or less decidu- 
 ous, often warty, spiny or scaly 
 Capillitium of an even thickness, not 
 branched 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 465 
 
 Sporophore with a pronounced sterile 
 
 persistent base 1. Lycoperdon, p. 465. 
 
 Sporophore without a pronounced 
 sterile base 
 Inner peridium opening irregularly. . 2. Globaria. 
 Inner peridium opening by a basal 
 pore, the outer peridium break- 
 ing equatorially and the upper 
 half with the attached inner 
 
 peridium forcefully ejected 3. Catastoma. 
 
 Capillitium free, short-branched with 
 pointed ends 
 Sporophore with a pronounced per- 
 sistent sterile base 4. Bovistella. 
 
 Sporophore without a pronounced 
 sterile base 
 Inner peridium papery, opening by an 
 
 apical mouth 5. Bovista. 
 
 Inner peridium thick, breaking 
 
 irregularly, capilhtium spiny. . . 6. Mycenastrum. 
 Outer peridium splitting into star-like re- 
 flexed, persistent segments 
 Inner peridium opening by a single mouth 7. Geaster. 
 Inner peridium opening by several mouths 8. Myriostoma. 
 
 Lycoperdon Tournefort 
 
 Sessile, with a pronounced 
 sterile base; peridium thin, 
 opening regularly by an apical ^^^i- ^y^^^_ 
 
 perforation, smooth, warty or ^^^^^ " ^ 
 spiny; spore-mass and capilli- ^^K- I "^\ 
 
 tium filling the interior of the ^^ ™^ ^ 
 
 sporophore with echinulate 
 spores and even, simple hy- ^m ..^-i 
 
 phiP. 
 
 L. gemmatum Bat. is re- 
 ported by Cavara ^^^ on fir 
 
 trees in Italy, sending its ^^^ 334.— Lycoperdon gemmatum. After 
 
 rhizomorphic mycelial strands Lloyd. 
 
 through cambium and bark causing the destruction of both. 
 
BIBLIOGRAPHY OF BASIDIOMYCETES 
 
 1 Lutman, B. F., Sc. 31: 747, 1910. 
 
 * Dangeard, P., Ser. L. Bot. 3: 240, 1892. 
 3 Harper, R. A., Am. Nat. 44: 544. 
 
 * Harper, R. A., Trans. Wis. Acad. Sci. 12: 483, 1899. 
 
 ' Clinton, G. P., Proc. Boston, Soc. Nat. Hist. 31: 1904. 
 
 " Wolff, R., Der Brand d. Getreides, Halle, 1874. 
 
 ' Brefeld, 0., Unt. Heft £, also Heft, 11: 1895. 
 
 ' Jensen, J. L., Les. Charbon des C^r^ales, July 4, 1889. 
 
 » Prevost, B., Memoir, Paris 29: 1807. 
 
 1° Lobelius, I cones stirpium, 36. 
 
 " Persoon, Synopsis method fung: 224. 
 
 " Jensen, J. L., Om Koen, Brand, 56, 1885. 
 
 " Maddox, F., D. of Ag. Tasmania, 1895, and 1897. 
 
 " Wakagawa, S., Bull. Imp. Cent. Ag. St. Japan 1: 1907. 
 
 15 Brefeld, 0., Klub. d. Landw. z. Berlin, 466, 1903. 
 
 i» Hecke, Zeit. f . Land. Vers, in Oestr. 1904. 
 
 " Hecke, Ber. d. deut. Bot. Ges. 23: 250. 
 
 '8 Freeman, E. M. and Johnson, E. C, B. P. I. 152: 1909. 
 
 1' Arthur, J. C, Stuart, W., Ind. R. 12: 84, 1900. 
 
 2" Kuhn, Hedwigia, 2: 5, 1858. 
 
 » Brefeld, O., Unt. Aus d. Gesamat d. Myk. Heft. 11: 1895. 
 
 "Hori, S., Bull. Imp. Cent. Sta. Japan 1: 73, 1905. 
 
 2» Clinton, G. P., 111. Bui. 47: 1897. 
 
 2" Clinton, G. P., 111. Bui. 57: 1900. 
 
 " Bubak, F., Zeit. Land Vers. Ost. 12: 545. 
 
 "Anderson, P. A., S. C. B. 41: 1899. 
 
 '-' Farlow, W. G., Mass. St. Bd. Agr. R. 24: 164, 1877. 
 
 ^^Thaxter, R., Coim. R. 1899: 129, 1890. 
 
 29 Neger, F. W., Tharand, Fors. Jahr. 60: 222. 
 
 '" Bubak, Zeit. Land. Vers. St. Oest. 477, 1901. 
 
 3' Halsted, B. D., Bull. Torn Bot. Club 17: 95, 1890. 
 
 32 Lagerheim, G. von, J. Myc. 7: 49, 1891. 
 
 •" Nichols, S. P., Trans. Wis. Acad. Sc. 15: 1905. 
 
 *See footnote, p. 53. 
 466 
 
BIBLIOGRAPHY OF BASIDIOMVCETES 467 
 
 '* Marie, R., C. R. 131: 121, 1900. 
 
 '^ Marie, R., C. R. 131: 1246, 1900. 
 
 ="> Harper, R. A., Bot. Gaz. 33: 1, 1902. 
 
 " Wager, H., Ann. Bot. 8: 322, 1894. 
 
 38 Dangeard, P., Le. Bot. 1895. 
 
 3» Richards, H. M., Bot. Gaz. 21: 101, 1896. 
 
 ^o Shear, C. L., B. P. I. 110: 36, 1907. 
 
 *' McRae, W., Agr. Reas. Inst. Pusa. B. IS: July, 1910. 
 
 *^ Viali and Boyer, C. R. 1891: 1148. 
 
 ^^ Seward, A. C., Fossil Plants for Students Botany and Geology 1: 1898. 
 
 '' Noack, Bol. Inst. Agron. Sco. Paulo 9: 1, 1898. 
 
 *' Stevens, F. L., and Hall, J. G., Sc. 26: 724, 1907. 
 
 *" Stevens, F. L. and Hall, J. G., Ann. Myc. 7: 49, 1909. 
 
 '^ Frank, B., Ber. D. deut. Bot. Gez. 1: 62, 1883. 
 
 *« Ilcdw. IS: 127, 1SS3. 
 
 « PriUieux and Delacroix, B. S. M. d. Fr. 5.- 221, 1891. 
 
 '0 Bernard, C., Dept. Agr. Indes Neerland 6: 55, 1907. 
 
 51 Eustace, H. J., N. Y. (Geneva) B. 235: 1903. 
 
 " Viala and Boyer, C. R. 112: 1148, 1891. 
 
 " Peglion, Bull, di Entom. Agr. e. Pat. Veget. 4: 302, 1897. 
 
 " Giissow, H. T., Zeit. 16: 135, 1906. 
 
 "5 Duggar, B. M., N. Y. (Cornell) B. 186: 266, 1901. 
 
 " Rolfs, F. M., Col. B. 91: 1904. 
 
 " Edgerton, C. W., Phytop. 1: 16, 1911, also La. B. 126. 
 
 68 Zimmerman, A., C. Bak. 7; 102, 1901. 
 
 69 Hennings, P., C. Bak. 9: 939, 1902. 
 
 «o Fetch, Jour. Roy. Bot. Card. Ceylon 4: July, 1909. 
 «i Atkinson, G. F. and Edgerton, C. W., J. Myc. 13: 186, 1907, and Sc. 
 N. S. 26: 385, 1907. 
 
 62 Potter, Rept. Trans. English Arboricult. Soc. 105: 1901-1902. 
 
 63 Gussow, H. T., Rept. Expt. Farms Ottawa 110: 269. 
 6* Schrenk, H. von, Bot. Gaz. 34: 65, 1902. 
 
 66 Galloway, B. T., J. Myc. 6: 113, 1891. 
 
 66 Atkinson, G. F., La. Geol. Sur. 335, 1889. 
 
 6' Schrenk, H. von, and Spaulding, P., B. P. I. 149: 1909 
 
 68 Thiimen, v., Zeit. 1: 132, 1891. 
 
 69 Shiljakow, Scripta Bot. Hort. Petrop 3: 84, 1890. 
 
 ^0 Glazan, Bui. Assoc. Vosgienne Hist. Nat. 81*: 1887, 1904. 
 
 " Ellis, J. B. and Everhart, B., Bui. Torrey. Bot. Club, 27: 49, 1900. 
 
 " Banker, H. J., Bull. Torrey. Bot. Club, 36: 341, 1909. 
 
 " Ballou, H. W., Sci. Amer. 99: 454, 1908. 
 
468 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 74 Schrenk, H. von, B. V. P. P. 25: 1900. 
 
 " Petch. T., Trop. Agr. & May. Ceylon Agric. Soc. 28: 292, 1907. 
 76 Fetch, T., Cir. & Agr. Jour. Roy. Bot. Gard. Ceylon 3: 277, 
 1906. 
 " Spaulding, P., Mo. Bot. Gard. R. 16: 109. 
 7« Atkinson, G. F., N. Y. (CorneU) B. 193: 1901. 
 " Schrenk, H. von, Y. B. 1900. 
 
 80 Galloway, B. T. and Woods, A. R, Y. B. 237: 1896. 
 
 81 BuUer, A. H. R., Jour. Ec. Biol. 1906. 
 
 8= Hedgcock, G. G., Mycologia 2: 155, 1910. 
 
 «3 Mayr. H., Bot. Cent. 19: 22, 1884. 
 
 84 Schrenk, H. von, Bur. Forestry, B. 57: 49, 1902. 
 
 86 Kew Misc. Bui. 1910: 95, 1896. 
 
 86 Pollock, J. B., Sc. 31: 754, 1910. 
 
 87 Ellis, J. B. and Galloway, B. T., J. Myc. 5: 141, 1899. 
 8s Schrenk, H. von, B. V. P. P. 21: 1900. 
 
 83 Spaulding, P., Sc. 26: 479, 1907. 
 
 "« Lindroth, J. L., Natur. Zeit. f. Land. u. Fortstwiss, 2: 393, 1904. 
 
 "1 Murrill, Bull. Torrey Bot. Club. 30: 110, 1903. 
 
 »2 Schrenk, H. von, B. B. P. L 32: 1903. 
 
 9' Schrenk, H. von. Mo. Bot. Gard. R. 12: 21, 1901. 
 
 «4 Fawcett, H. S., Fla. R. S8: 1908. 
 
 95 Pollock, J. B., Rept. Michigan Acad. Sci. 7: 53, 1905. 
 
 96 Heald, F. D., Neb. R. 19: 92, 1906. 
 
 97 Maubanc, C, Agr. Prat. Pays. Chands. 5.- 91, 1908. 
 
 98 Spaulding, P., B. B. P. L 214, 1911. 
 
 99 Murrill, Mycologia 3: 23, 1911. 
 
 100 Hennings, P., Zeit. 13: 198, 1903. 
 
 101 Wakker, J. H., C. Bak. 2: 44, 1896. 
 
 102 Howard, A., Ann. Bot. 17: 1903. 
 
 103 Fulton, H. R., La. Bui. 100: 1908. 
 
 104 Kirk, T. W., N. Z. Rept. D. Agr. 437, 1902-5. 
 
 105 Junger Posen, J. R., Zeit. 16: 131, 1906. 
 
 106 Cavara, Staz. Sper. Agr. Ital. 29: 788, 1896. 
 
 107 Wilcox, E. M., Okl. B. 1^9: 1901. 
 
 108 Johnston, T. H., Agric. Gaz. N. S. Wales, 21: 699, 1910. 
 
 109 Stewart, F. C, Bull. N. Y. (Geneva) 328: 361, 1911. 
 
 110 Istvanffy, Zeit. IJ^: 300, 1904. 
 
 111 Cobb, P. A., Hawaii Sugar Planters, Expt. Sta. Div. Path and Phys. 
 Bui. 5: 1906. 
 
 112 Lloyd, C. C, Synopsis of the Known Phalloids 10: 1909. 
 
BIBLIOGRAPHY OF BASIDIOMYCETES 469 
 
 "3 Cobb, N. A., Hawaiian Sugar Planters' Expt. Sta., Div. Path, and 
 Physiol. Bui 6: 1909. 
 
 "* Cavara, F., Stazioni seperim. agrar. ital. 29: 788, 1896. 
 
 11'' Dangeard, P. A., Le Bot. 4: 12, 1894. 
 
 "6 Kellerman, W. A. and Swingle, W. T., Kans. R. 2: 213, 1890. 
 
 1'^ Sclby, A. D., Ohio B. 6^: 115, 1895. 
 
 >ia Pammel, L. H., and King, C. M., la. B. 10/^: 233, 1909. 
 
 119 Hitchcock, A. S. and Norton, J. B. S., Kan. B. 62: 1269, 1899. 
 
 i=« Knowles, E. L., J. Myc. 5: 14, 1889. 
 
 121 Anderson, A. P., Bot. Gaz. 27: 467, 1899. 
 
 1-2 Lang, W., C. Bak. 25: 86, 1910. 
 
 1" Broili, Nat. Zeit. f. Forst u. Land. 8: 335, 1910. 
 
 12^ BoUey, H. L., N. D. B. 1: 9, 1891. 
 
 1" BoUey, H. L., N. D. B. 27: 109, 1897. 
 
 i26Brefeld, 0., Unt. Myk. 5: 1, 1883. 
 
 12^ Brefeld, 0., Unt. Myk. 7: 224, 1889. 
 
 i2« Brefeld, 0., Unt. Myk. 12: 99, 1895. 
 
 1=9 Clinton, G. P., J. Myc. 8: 128, 1902. 
 
 "0 Cornu, M., B., Soc. Bot. Fr. 26: 263, 1897; Ibid, 27: 39, 1880. 
 
 1" Fischer de Waldheim, A., Bring. Jahr., Wis. Bot. 7: 61, 1870. 
 
 132 Fischer de Waldheim, A., Zur Kenntniss dser Entyloma-Arten, 1877. 
 
 1" Gruss, J., Ber. deut. Bot. Ges. 20: 212, 1902. 
 
 13" Herzberg, P., Zopf. Beitrage Phys. Morph. Organ 5: 1, 1895. 
 
 ^^^ Kellerman, W. A. and Swingle, W. T., Kans. B. 12: 7, 1890. 
 
 "« Kellerman, W. A., Kans. B. 23: 95, 1891. 
 
 1" Ktihn, J., Bot. Zeit. 121, 1874. 
 
 138 Kuhn, J., Bot. Zeit. 3/^: 470, 1876. 
 
 139 Maire, R., B. S. M. Fr. U: 161, 1898. 
 1"° Massee, G., Kew B. 153: 141, 1899. 
 
 1^1 Mottareale, G., R. Scuol. Sup. Agr. Portici, 4: 1902. 
 
 i« Pammel, L. H., la. B. 16: 315, 1892. 
 
 1" PriUieux, E., Ann. Sci. Nat. Bot. vi. 10: 49, 1880. 
 
 1" Prillieux, E., B. Soc. Bot. Fr. ^2: 36, 1895. 
 
 i« Schroter, J., Cohn's Beitr. Biol. Pflanz, 2: 435, 1877. 
 
 1" Selby, A. D., Ohio B. 122: 71, 1900. 
 
 i« Setchell, W. A., Proc. Amer. Acad. Arts. Sci. 26: 13, 1891. 
 
 i« Setchell, W. A., Ann. Bot. 6: 1, 1892. 
 
 i« Takahashi, Y., Tok. Bot. Mag. 10: 16, 1896. 
 
 15° Wakker, J. H., Bring. Jahr. Wiss. Bot. 2/-^: 532, 1892. 
 
 1" Wolff, R., Bot. Zeit. 31: 657, 673, 689, 1873. 
 
 152 Magnus, P., Ber. deut. Bot. Ges. 1^: 216, 1896. 
 
470 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 " Griffiths, D., B. P. I. 38: 43, 1903. 
 
 " Setchell, W. A., Bot. Gaz. 19: 185, 1894. 
 
 " Halsted, B. D., N. J. B. 170. 
 
 ^« Cornu, M. B., Soc. Bot. Fr. 30: 130, 1883. 
 
 67 Cunningham, D. D., Sci. Mem. Med. Off. Army India, 3: 27, 1887. 
 
 58 Edgerton, La. B. 126, 1911. 
 
 55 Rech. Basidiomycetes Lons-le-Saumier, 1902. 
 
 «° Duggar, B. M., and Stewart, F. C., N. Y. (Cornell) B. 186: 1901. 
 
 «i Rolfs, F. M., Col. B. 70: 1902. 
 
 «2 Rolfs, F. M., Fla. R. 1905. 
 
 «' Rolfs, F. M., Col. B. 91: 1904. 
 
 «4 Bourdot and Golzin, B. S. M. d. Fr. 37: 223, 1911. 
 
 "5 Edgerton, C. W., La. B. 126: 1911. 
 
 «6 Bary, A. De., Mon. Ber. Akad. Wiss. Berhn, 1865. 
 
 6' Blackman, V. H., New Phytologist, 2: 10, 1903. 
 
 ' Bolley, H. L., Agr. Sci. 5: 263, 1891. Bolley and Pritchard, F. J., 
 Bot. Gaz. 5^; 169, 1911. 
 
 Bolley, H. L., N. D. Agr. Expt. Sta. Bull. 68, 1906. 
 70 Brefeld, Oscar, Untersuchungen, 14: 154, 1908. 
 
 ' Carleton, M. A., Div. V. P. P. B., 16, 1899. 
 
 2 Carleton, M. A., B. P. L B. 63, 1904. 
 
 ' Christman, A. H., Trans. Wis. Acad. Sc. 15: 98, 1904. 
 
 * Eriksson, J. and Henning, Ernst., Die Getreideroste, Stokholm, 1896. 
 
 5 Magnus, P., Ber. deuts. Bot. Ges., 9: 90, 1891. 
 
 8 Schceler, N. P., Landcekomminske Tidender 8: 289, 1818. 
 
 ■' Smith, W. G., Card. Chron. 2: 21," 1884. 
 
 8 Arthur, J. C, Bot. Gaz. 29: 268, 1900. 
 
 5 Blackman, V. H., Ann. Bot. 18: 323, 1904. 
 
 80 Christman, A. H., Bot. Gaz. U: 81, 1907. 
 
 81 Olive, E. W., Ann. Bot. 22: 331, 1908. 
 
 8* Richards, H. M., Proc. Amer. Acad. Arts and Sci. 31: 255, 1895. 
 83 Arthur, J. C, J. Myc. 12: 11, 1906. 
 8^ Arthur, J. C, J. Myc. 8: 51, 1902. 
 85 Arthur, J. C, Bot. Gaz. 35: 10, 1903. 
 8« Arthur, J. C, J. Myc. 11: 8, 1905. 
 8' Arthur, J. C, Torr. Bull. 32: 35, 1905. 
 88 Carleton, M. A., Sc. 13: 249, 1900. 
 89Kurssanow, Zeit. f. Bot. 2: 81, 1910. 
 '0 Eriksson, J., Biol. Cent. 30: 618, 1910. 
 91 Zach, Sitz. d. Kais Ak. d. Wiss. Wien., Math.— Nat. Kl. 119, Ab. 
 
 /.•307, 1910. 
 
BIBLIOGRAPHY OF liASIDIOMYCETES 471 
 
 1" Ward, H. M., Phil. Trans. Bot. 196: 29, 1003. 
 
 '" Arthur, J. C, Results Cong. Int. d. Bot. Vienne, 331, 1905. 
 
 »«* P. Rico. R. 449, 1903. 
 
 '« Arthur, J. C, and Kern, F. D., Torr. Bull. 33: 403, 1906. 
 
 »»« Clinton, G. P., Sc. 25: 289, 1907. 
 
 1" Clinton, G. P., Ct. R. 369, 1907. 
 
 •^« Chittenden, F. L., Jour. Roy. Hort. Soc. London, 33: 511, 1908. 
 
 19^ Galloway, B. T., Bot. Gaz. 22: 443, 1896. 
 
 ^oo Kellerman, W. A., J. Myc. 11: 32, 1905. 
 
 '"i Fraser, W. P., Sc. 30: 814, 1909. 
 
 202 Selby, A. D., 0. B. 21^: 1910. 
 
 ^o' Bolley, L. H., N. D. B. 55: 189, 1903. 
 
 20^ Fischer, E., Zeit. 12: 193, 1902. 
 
 205 Plowright, Zeit. 1: 131, 1891. 
 
 206 Farlow, W. G., Proc. Am. Ac. A. & S. 20: 311, 1885. 
 20' Farlow, W. G., Bot. Gaz. 11: 234, 1886. 
 
 208 Pammel, L. H., la. B. 8^: 1905. 
 
 209 Richards, H. M., Bot. Gaz. U: 211, 1889. 
 
 210 Thaxter, R., Bot. Gaz. 1^: 163, 1889. 
 
 211 Stewart, F. C, N. Y. (Geneva) B. 328: 1911. 
 2i2Biedenkopf, H., Zeit. 4: 321, 1894. 
 
 213 Halsted, B. D., D. Agr. R. 288. 
 21* Heald, F. D., Neb. R. 22: 1909. 
 
 215 Underwood, L. M. and Earle, F. S., Bot. Gaz. 22: 225, 1896. 
 
 216 Pammel, L. H., J. Myc. 7: 102, 1892. 
 21' Thaxter, R., Conn. B. 107: 1891. 
 
 218 Shirae, M., Zeit. 10: 1, 1900. 
 
 219 Whetzel, H. H., N. Y. (Cornell) B. 239: 298, 1906. 
 
 220 Kirk, I. W., New Zeal. D. Agr. R. 13: 405, 1905. 
 
 221 Howell, J. K., N. Y. (Cornell), B. 2J^: 129, 1890. 
 
 222 Pammell, L. H., la. B. 13: 51, 1891. 
 
 223 Kern, F. D., Phyto. ^; 3, 1911. 
 
 224 Lagerheira, G., Svensk. Bot. Tid. 3: 18, 1909. 
 
 225 Cobb, N. A., N. S. Wales, Sydney, 1893. 
 
 226 Arthur, J. C, Bot. Gaz. 16: 321, 1891. 
 22' Stewart, F. C, Geneva R. 15: 461, 1895. 
 
 228 Stewart, F. C, Geneva B. 100: 1896. 
 
 229 Stuart, Wm., Vt. R. 8: 115, 1894. 
 
 230 Stevens, F. L., Bot. Gaz. 26: 377, 1898. 
 
 231 Delacroix, Bull. Soc. M. d. Fr. 18: 14, 1902. 
 
 232 Scribner, F. L., D. Agr. R. 353, 1887. 
 
472 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 2" Transchel, Trav. Mus. Bot. Acad. Sc. St. Pet. 2: 67, 1905. 
 ^^^ Klebahn, H., Zeit. 5: 76, 1895. 
 "^ Halsted, B. D., N. J. B. 129: 1898. 
 "8 Arthur, J. C, Ind. R. 13: 1901. 
 2»^ Smith, R. E., Bot. Gaz. 38: 19, 1904. 
 "8 Smith, R. E., Cal. Bui. 172: 1906. 
 "' Smith, R. E., Cal. Bui. 165: 1905. 
 "0 Stone, G. E. & Smith, R. E., Mass. B. 61: 1899. . 
 2<i Stevens, F. L., Pop. Sc. Mo. May, 1911. 
 2" E. S. R. 16: 380. 
 2« Bates, J. M., J. Myc. 9: 219. 
 2" Bates, J. M., Sc. 16: 138, 1902. 
 2« Trabut, L., Bui. Agr. Alg. & Tun. 13: 355, 1907. 
 "9 Olive, E. W., S. D. B. 109: 1908. 
 =>« Ward, M. H., Ann. Bot. 2: 217, 1888. 
 2« Eriksson & Henning, Zeit. 4: 1894. 
 2« Pritchard, F. J., Bot. Gaz. 52: 169, 1911. 
 
 "0 Butler, E. J. and Hayman, J. M., India D. Ag. R. 1906, Bot. Ser. 1. 
 2^1 Lagerheim, G., Bot. Cent. 54. 324, 1893; Jour. Myc. 7: 327, 1891. 
 2" Barclay, A., Jour. Bot. 30, 1892. 
 
 2" Zukal, H., Untersuchungen iiber die Rostpilzkrankheiten des Get- 
 reides in Oesterreich-Ungarn 10: 16, 1900. 
 
 2" Loverdo, J., Les maladies cryptogamiques des cereales, Paris, 1892. 
 
 «5 Lagerheim, G., Jour. Myc. 7;, 327, 1891. 
 
 "6 Ward, H. M., Ann. Bot. 2: 229, 1888. 
 
 2" Dorset, P. H., Am. Flor. 15: 246, 1899. 
 
 "8 Jaczewski, Zeit. 20: 321, 1910. 
 
 259 Eriksson, J., Ber. d. deut. Bot. Gez. 12: 292, 1894. 
 
 280 Arthur, J. C, Bot. Gaz. 38: 64, 1904. 
 
 2" Arthur, J. C, Sc. 29: 270, 1909. 
 
 2''2 Halsted, B. D., Bull. Torr. Bot. CI. 25: 331, 1898. 
 
 263 Dudley, W. R., N. Y. (Cornell) B. 25: 154, 189,0. 
 
 26" Tabenhaus, J. J., Phytop. 1: 55, 1911. 
 
 286 Eriksson, J., C. V,sk..31: 93, 1911. 
 
 266 Arthur, J. C, Ind. B. 85: 143, 1900. 
 
 267 Jacky, E., Zeit 10: 132, 1900. 
 
 268 Stone, G. E., and Smith, R. E., Mass. R. 9: (Hatch) 1896: 176, 1898. 
 
 269 Arthur, J. C. and Holway, E. W. D., Minn. Bot. St. B. 2: 631, 1901. 
 2'o Chifflot, J., J. Soc. Nat. Hort. Fr. 4: 348, 1907. 
 
 2" Kusano, S., Bull. Coll. Agr. Tokyo Imp. Univ. 8: 27, 1908. 
 272 Clinton, G. P., 111. B. 29: 273, 1893. 
 
BIBLIOGRAPHY OF BASIDIOMYCETES 473 
 
 "3 Newcomb, F. C, J. Myc. 6: 106, 1890. 
 
 "■» Richards, H. M., Proc. Am. Acad. A. & So. 30: 30, 1893. 
 
 2" Tranzschel, W., Hedw. 32: 257, 1893. 
 
 "6 Arthur, J. C, Torreya, 9: 21, 1909. 
 
 2" Kirk, T. W. and Cockayne, A. H., N. Zeal. D. Agr. R. 16: 108, 1908. 
 
 "8 Cook, M. C, Jour. Roy. Hort. Soc. London, 26: 1901. 
 
 2" Bartlett, A. W., R. Bot. Card. British Guiana, 20: 1906-1907. 
 
 280 Montmartini, L., Atti. Inst. Bot. Univ. Pavia, 1904. 
 
 281 Kusano, S., Bull. Co. Imp. Tokyo, 1908. 
 
 282 Pettis, C. R., Forest Quart. 7: 231, 1909. 
 
 283 Hennings, P., Zeit. 12: 129, 1902. 
 
 284 Stewart, F. C, Geneva, T. B. 2: 62, 1906. 
 
 285 Spaulding, P., B. P. I. Circ. 38: 1909. 
 
 286 Spaulding, P., B. P. I. Bui. 206: 19II. 
 28V Hedgcock, G., Sc. 31: 751, 1910. 
 
 288 Shear, C. L., J. Myc. 12: 89, 1906. 
 
 289 Farlow, W. G., Anniv. Mem. Boston Soc. Nat. Hist. 1880. 
 29oldem, R. ii;343, 1898. 
 
 291 Kuhn, J., Bot. Zeit. 27: 540, 1869. 
 
 292 Freeman, Ann. Bot. 16: 487, 1902. 
 
 29' Ward, H. M., Ann. Bot. 16: 233, 1902. 
 294 McAlpine, D., Vict. D. Ag. 5: I, 1891. 
 296 Kusano, S., Coll. Agr. Imp. Univ. Tokyo, 1908. 
 
 296 Roze, B. S. M. Fr. 88: 1900. 
 
 297 IClebalin, H., Ber. d. Deut. Bot. Gaz. 8. 59. 1890. 
 
 298 Klebahn, H., Hedw. 29, 27, 1890. 
 
 299 Tubeuf, K., C. Bak. 7, 445. 
 3ooHaLsted, B. D., N. J. R. 391, 1893. 
 '01 Halsted, B. D., N. J. R. 279, 1892. 
 
 302 Lloyd, F. E. and Ridgway, C. S., Ala. B. D. Agr. 39: 1911. 
 
 303 Johnson, E. C, B. P. I. 22J^: 1911. 
 
 304 Trelease, Wm., Trans. Wis. Acad. 131, 1882. 
 306 Kern, F. D , Torrya 9: 4, 1909. 
 
 306 Freeman, E. M. and Johnson, E. C, B. P. I. 216: 1911. 
 
 307 Eriksson, J. P., Ark. f. Bot. Stockholm 8: 1909. 
 
 308 Arthur, J. C, Proc. Soc. Prom. Agr. Sc. 23: 1902. 
 
 309 Arthur, J. C, J. Myc. 11: 53, 1905. 
 
 310 Stewart, F. C, N. Y. (Geneva) B. 328: 1910. 
 «ii Klebahn, Zeit. 2: 18, 1902. 
 
 312 Eriksson, J., Kung. Svens, Vet.— Akad. Hand. B. 317: 6, 1904. 
 
 313 Sappin-Trouffy, P., C. R. 116: 211 and 1304, 1894. 
 
474 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 "* Dangeard, P. A., C. R. 116: 267, 1893. 
 '1^ Pairault, G. and Raciborski, M., Jour. d. Bot. 9: 318, 1895. 
 "6 Istvanffi, G., Ber. d. Deut. Bot. Gez. 1895. 
 317 Juel, Pring. Jahr. 1898. 
 "8 Maire, C. R., Paris, 1900, July 9. 
 '1' Maire, C. R., Paris, 1900, Dec. 24. 
 320 Olive, E. W., Phyto. 1: 139, 1911. 
 "1 McAlpine, D., Ag. Vict. B. U: 1891. 
 
 3" Montemartini, Atti d. Ell. Inst. Bot. Univ. di. Pavia, 5: 1897. 
 323 Fischer, E., C. Bak. 28: 139, 1910. 
 3" Selby, A. D., 0. B., 139: 1903. 
 3" South, F. W., W. Ind. Bull. 2: 83, 1911. 
 
 326 Wolff, R., ^cidium pini and sein Zusammenhang mit Coleosporium 
 senecionis, Regia, 1876. 
 
 3" Clinton, G. P., J. Myc. 8: 128, 1902.. 
 
 328 Fetch, T., Cirs. and Agr. Jour. Roy. Bot. Gard. Ceylon 5: 89, 1910. 
 
 329 Pennington, L. H., R. Mich. Ac. Sc, 9. 
 
 330 B. P. I. Circ. 35, 8, 1909. 
 
 331 Spaulding Mo. Bot. Gard. R. 17, 53, 1906. 
 
 332 Y. B. U. S. D. Agr. 588, 1907. 
 
 333 V. Schrenk, Cont. Shaw School Bot. No. 14, 45, 1899. 
 
 334 Hedgcock, Sc. 29: 913, 1909. 
 336 Mycologia, 157, May, 1910. 
 
 336 Hedgcock, Sc. 29, 913, 1909. 
 
 337 Y. B. U. S. D. Agr. 587, 1907. 
 
 338 Buller J., Ec. Biol, 1: 1, 1905. 
 
 339 Spaulding in Mo. Bot. Garden Report, No. 17. 
 3« See Indian Forestry, 36: 559-562, 1910. 
 
 3" Scholz Verhandl. K. K. Zool. Bot. Gesell. Wien. 47; 541-557, 1897. 
 3" Vermont Agricultural Experiment Repor. 342-347. 
 313 Plowright, C. B., B. M. S. Trans. 90: 1904. 
 3" Y. B. U. S. D. Agr. 587, 1907. 
 3« Lagerheim, G. J. Myc. 7: 44. 
 
FUNGI IMPERFECTI (p. 64) 
 
 In the preceding pages it has been repeatedly evident that one 
 species of fungus may have two, even several different types of 
 spores; in the Erysiphales the perithecial form and the conidial; 
 in the Peronosporales oospores and conidia; in the Sphseriales the 
 ascigerous form and several conidial forms; in the Basidiomycetes 
 the basidial form and various conidial forms; in the Uredinales 
 spring and summer stages and teliospores. In comparatively 
 few instances among the many thousand species of fungi are all 
 of the different spore forms belonging to the species known to 
 man. In very many cases the lower or conidial forms are known 
 without any higher spore form (ascigerous, basidial, or sexual form), 
 being known to be genetically connected with them, though it seems 
 very probable, reasoning by analogy, that these conidial forms 
 really constitute part of the life cycle of some fungus which em- 
 braces also a higher form of spore. It is probable, indeed certain, 
 that some of these conidial forms at present possess also higher, as 
 yet unknown, forms of fructification. It is likewise probable that 
 in many cases the conidial form, though it does not now possess 
 any higher spore form, did in its not remote phylogeny possess 
 such forms; indeed that all of them are phylogenetically related to 
 fungi which produced one of the higher types of spores. 
 
 In some cases even in the absence of the higher spore it is possible 
 to refer the fungus to its proper order as for example is the case 
 with the conidial forms of the Peronosporales, the summer or spring 
 forms of the Uredinales, or the Oospora forms of the Erysiphales. 
 
 Regarding many thousands of other conidial forms such refer- 
 ence is impossible or hazardous, since from the conidial form the 
 form of the higher spore can be inferred with only a small degree of 
 accuracy or not at all. For example, the conidial form known as 
 GlcEosporium in the higher form of some of its species proves to be 
 a Glomerella, in other cases a Pseudopeziza; some Fusariums 
 prove to belong to the life cycle of Nectria, others to that of Neocos- 
 mospora, etc. 
 
 475 
 
476 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 In plant pathology and in systematic mycology it becomes 
 necessary to classify, for convenience of reference and designation, 
 these multitudinous conidial forms of which the higher spore 
 form is as yet unknown, which may exist now or which may have 
 existed only in the more or less remote past. From analogy it 
 is probable that most of them pertain to the Ascomycetes, though a 
 few may find place among other classes. 
 
 This whole group of forms, which is characterized chiefly by the 
 imperfection of our knowledge of them, is classed together under 
 the name Fungi Imperf ecti. 
 
 The Fungi Imperfecti are in a temporary way divided into 
 orders, families, genera and species as are other fungi, with full 
 recognition of the fact that future research will result in many 
 cases in the disclosure of higher spore forms and the consequent 
 removal of species to their proper place in the general scheme of 
 classification. 
 
 Recognizing the tentative nature of the genera in the Fungi 
 Imperfecti these are spoken of as "form-genera." 
 
 Pathologically, the Fungi Imperfecti are of high importance, often 
 occurring on leaves, stems, fruit, wood, bark, etc., as active parasites, 
 though very many are also saprophytes. Upon leaves they are 
 particularly common causing diseased areas known as "leaf spots." 
 
 The Fungi Imperfecti display three principal types of fructifi- 
 cation, pycnidia, acervuli and hyphae. 
 
 Pycnidia are more or less spherical, hollow sporocarps on the 
 inside of which conidia are borne on stalks (conidiophores) arising 
 from the base or base and sides. Figs. 349, 354. The pycnidium 
 may be of various colors though it is most commonly black or dark; 
 it may be superficial or imbedded, and with or without a beak 
 (rostrum). The opening for the escape of the spores (ostiole) may 
 be narrow, or wanting or it may be very large, round, irregular, 
 etc. The walls vary from extremely delicate to very thick, smooth 
 or variously provided with hairs, spines, etc. 
 
 As need arises, it is common to speak of micro-pycnidia, and 
 macro-pycnidia. Pycnidia with very small spores are sometimes 
 called spermogonia especially if the spores do not germinate, a cus- 
 tom to be deprecated. 
 
 The acervulus may be regarded as a pycnidium without its wall. 
 
THE P^UNGl WHICH CAUSE PLANT DISEASE 477 
 
 It consists of a close bed of short conidiophores. Figs. 371, 379. 
 Acervuli may be small or large, subepidermal, subcortical or super- 
 ficial and may or may not be provided with hairs (setae) Fig. 370, 
 of various kinds. An acervulus with a well marked basal stroma 
 is known as a sporodochium. Fig. 435. If the sporodochium stalk 
 is markedly developed the structure becomes a coremium. It is 
 sometimes quite difficult to distinguish between a pycnidium 
 with an extremely large ostiole, or one with a very thin wall, and 
 the acervulus. For such purposes thin longitudinal sections are 
 most useful. 
 
 Hyphae are conidiophores which grow free for some distance 
 above their supporting substratum and in more loose form than in 
 the acervuli, so that the terminal parts at least stand out as sep- 
 arate threads. Figs. 383, 384, 396, 410. 
 
 The hyphae may be simple and short, or long and much branched. 
 When the hyphse are very short and closely crowded to form a 
 sporogenous cushion the condition of an acervulus is approached 
 and confusion arises. 
 
 The conidia borne in the pycnidia, acervuli or on the hyphse are 
 of as various forms and types as is well conceivable and are made 
 the chief basis for subdivision of orders into form-genera. They 
 may be simple or compound, of almost any color, and may be borne 
 in bisipetal succession in chains, or solitary, or in groups at the 
 apices of the conidiophores. 
 
 The following scheme of Saccardo presents the confessedly 
 artificial groups into which conidia may for convenience be divided. 
 
 Scheme of Spore Sections. 
 
 Amerosporso: spores 1-ceIIcd, not stellate, spiral or filiform. 
 
 Hyalosporse: spores hyaline or clear, globose to oblong, continuous. 
 
 Phceosporse: spores dark, yellow to black, globose to oblong, con- 
 tinuous. 
 Didymosporse : spores, 2-celled. 
 
 Hyalodidymse: spores hyaline, 2-celled. 
 
 Pha^odidymse : spores dark, 2-celled. 
 Phragmosporae: spores 3 to many-celled by cross septa. 
 
 Hyalophragmiae: spores hyaline, 3 to many-celled. 
 
 PhaBophragmise: spores dark, 3 to many-celled. 
 
478 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Dictyosporse : spores septate, both crosswise and lengthwise, i. e., 
 muriform. 
 Hyalodictyse: spores hyaUne, muriform. 
 Phaeodictyse: spores dark, muriform. 
 Scolecosporse : spores needle-shaped to filiform, continuous or septate. 
 Helicosporae: spores spirally twisted, hyaline or dark, continuous or 
 
 septate. 
 Staurosporae: spores stellate or radiate, hyaline or dark, continuous 
 or septate. 
 
 The mode of bearing spores and the color of the fungus both of 
 which it is seen are made the basis of classification have been shown 
 by Stevens and Hall ^ and others ^ to depend largely on environ- 
 ment, while the septation of the spores, also a fundamental char- 
 acter in present classification, depends often on the age of the 
 spores or on other factors. Many spores are unicellular until 
 germination begins but then become typically 2-celled; e. g., 
 Gloeosporium, Such conditions have led to much inaccuracy in 
 description and doubtless to undue multiplication of form- 
 species. 
 
 It has been quite customary, probably to some extent excusably 
 so, to describe as new a form-species when no form-species pre- 
 viously described for the same host or its near botanical kin could 
 be regarded as identical with it. Thus a Septoria found on Vitis 
 would ordinarily be regarded as new unless some of the Septorias 
 already described on some of the Vitacese seemed to be the same, 
 even though indistinguishable from dozens of Septorias on other 
 families of plants. This course has led to enormous multiplica- 
 tion of so-called species in these form-genera giving rise to such 
 form-genera as Septoria, Cercospora, and Phyllosticta with species 
 numbering more than 900, 500, 800, respectively. 
 
 The condition is much as is depicted by Cobb:' "Is a fungus 
 species newly found on a peach? Call it new and name it pruni. 
 Same genus on the grape — name it ampelinum. On the apple? 
 New, call it mali. On banana? Christen it musse. What next? 
 Sparrow in a pear tree. Passer pyri?" 
 
 Many of the form-genera are purely artificial — not at all well 
 founded, e. g., Phoma is separated from Phyllosticta only by the 
 supposed inability of the latter to grow on structures other than 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 479 
 
 leaves, a distinction which has been shown to be quite untenable." 
 It is evident that much careful study by cultures and cross in- 
 oculations is needed to reveal the true status in these Fungi. 
 
 Since the conception of species is here most loose the form species 
 given below must be regarded as purely tentative. The names are 
 to serve merely as handles for convenience in treating of the 
 various parasites and in only comparatively few instances do 
 they signify that they are really species. In many cases forms 
 appearing under two or more names may prove eventually to be 
 identical while in other cases forms may need to be su]> 
 divided. 
 
 Key to Orders of Fungi Imperfect! 
 
 Conidia produced in pycnidia 1. Sphseropsidales, p. 479. 
 
 Conidia not in pycnidia 
 
 Hyphse innate within the matrix 2. Melanconiales, p. 537. 
 
 Hyphse somewhat superficial, often floccose 3. Moniliales, p. 564. 
 Conidia or other special reproductive cells 
 
 unknown 4. Mycelia sterilia, p. 659. 
 
 The Sphaeropsidales 
 
 Conidia in pycnidia which open by pores or slits, superficially 
 resembling the perithecia of the Ascomycetes. 
 
 The Sphffiropsidales are preeminently leaf-spotting fungi though 
 many of them grow on fruit or stems causing blight, rot, cankers 
 etc. The vast majority are saprophytes or parasitic on tissues of 
 weak vitality, but not a few are active parasites. 
 
 Key to Families of Sphaeropsidales 
 
 Pycnidia globose, conic, or lenticular 
 Pycnidia membranous, carbonous or 
 
 coriaceous, black 1- Sphaerioidaceae, p. 480. 
 
 Pycnidia fleshy or waxy, light colored. 2. Nectrioidaceae, p. 526. 
 Pycnidia more or less dimidiate, irregular 
 
 or shield-shaped, black 3. Leptostromataceae^ p. 528. 
 
 Pycnidia cup-shaped or patelliform, black. 4. Excipulaceae, p. 533. 
 
480 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 The Sphserioidaceae (p. 479) 
 
 Pycnidia globose, ovate, or clavate, leathery to carbonous, 
 black or dark brown, opening by a pore, superficial, erumpent or 
 covered; stroma present or absent; conidia variable in form, 
 color, and division. 
 
 The family is subdivided according to its spores as indicated 
 below. 
 
 Key to Sections op Sphaerioidaceae 
 
 Conidia globose to elongate, straight or 
 falcate, 1 to many-celled 
 Conidia 1-celled, globose, ovate or elon- 
 gate I. Amerosporae. 
 
 Conidia hyaline 1. HyalosporaB, p. 480. 
 
 Conidia colored 2. Phaeosporae, p. 500. 
 
 Conidia 2-celled, ovate to elongate. ... II. Didymosporae. 
 
 Conidia hyaline 3. Hyalodidymae, p. 505. 
 
 Conidia colored 4. Phaeodidymae, p. 509. 
 
 Conidia 3 to many-celled, by transverse 
 
 septa, elongate III. Phragmosporae. 
 
 Conidia hyaline 5. Hyalophragmiae, p. 513. 
 
 Conidia colored 6. Phaeophragmiae, p. 514. 
 
 Conidia muriform, ovate to elongate. . IV. Dictyosporae. 
 
 Conidia hyaline 7. HyalodictyaB. 
 
 Conidia colored 8. Phaeodictyae, p. 516. 
 
 Conidia filiform, 1 to many-celled, hyaline 
 
 or colored V. 9. Scolecosporae, p. 517. 
 
 Conidia cylindric, spirally coiled, 1 to 
 
 many-celled, hyaline or colored VI. 10. Helicosporae. 
 
 Conidia stellate, 1 to many-celled, hyaline 
 
 colored VII. 11. Staurosporae. 
 
 Sphaerioidaceae-Hyalosporae 
 
 Spores hyaline, 1-celled, spherical, elliptical or long. 
 
 Key to Genera of SphaerioidaceaB-HyalosporaB 
 
 Stroma none; pycnidia separate. 
 Pycnidia smooth 
 Conidia borne singly 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 481 
 
 Conidia unappendaged 
 Pycnidia free in tlie substratum; sub- 
 iculuin none 
 Pycnidia not beaked, oi^ening by a 
 pore, or irregularly 
 Not growing on other fungi 
 Pycnidia opening by a regular pore 
 Pycnidia more or less sunken in the 
 substratum 
 Pycnidia globose, etc. not spindle- 
 shaped 
 Pycnidia borne on dark colored 
 spots, or on wood, globose 
 Conidiophores simple or nearly 
 so 
 Pycnidia rather large 
 Pycnidia at first covered, 
 then erumpent 
 Spores under 15 M 
 
 On leaves only 1. Phyllosticta, p. 483. 
 
 Not on leaves 2. Phoma, p. 490. 
 
 Spores over 15 M 3. Macrophoma, p. 493. 
 
 Pycnidia from the first super- 
 ficial 4. Aposphseria, p. 494. 
 
 Pycnidia very small, closely 
 aggregated on dark spots 
 
 on the leaf 5. Asterostomella. 
 
 Conidiophores branched 6. Dendrophoma, p. 494. 
 
 Pycnidia scattered, superficial, 
 circular, conidia elongate or 
 
 cyhndric 7. Crocicreas. 
 
 Pycnidia globose ; conidiophores 
 
 circinate 8. Pyrenotrichum. 
 
 Pycnidia horizontal, free, cylin- 
 
 dric 9. Glutinium. 
 
 Pycnidia opening irregularly, or 
 operculate 
 
 Spores globose 10. Mycogala. 
 
 Spores elongate or ellipsoid 
 
 Pycnidia operculate 11. Piptostomum. 
 
 Pycnidia opening irregularly 
 
482 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Spores pointed 12. Sclerotiopsis. 
 
 Spores blunt 13. Plenodomus. 
 
 On Erysiphacese 14. Cicinnobolus, p. 494. 
 
 Pycnidia beaked 15. Sphaeronema, p. 494. 
 
 Pycnidia on a subiculum 
 Conidia ovate or elongate 
 Subiculum of simple hyphae 
 
 Pycnidia free 16. Byssocystis. 
 
 Pycnidia sunken in the subiculum. . 17. Chaetophoma, p. 495. 
 
 Subiculum radiate 18. Asteroma, p. 496. 
 
 Conidia Y-shaped 19. Ypsilonia. 
 
 Conidia appendaged 20. Neottiospora. 
 
 Conidia in chains 
 Conidial chains separate and simple ... 21. Sircoccus. 
 Conidial chains connected, often form- 
 ing a net 22. Pecia. 
 
 Pycnidia appendaged or hairy 
 Appendages simple 
 Pycnidia with short simple tubercles; 
 
 conidia irregular in outline 23. Muricularia. 
 
 Pycnidia with long bristles; conidia 
 regular 
 Bristles septate, usually covering the 
 entire pycnidium, conidia cylin- 
 
 dric fusoid, usually curved 24. Vermicularia, p. 496. 
 
 Bristles usually only at the apex; 
 conidia ovate, elongate or cylin- 
 
 dric, straight 25. Pyrenochaeta, p. 497. 
 
 Appendages stellate at the apex 26. Staurochaeta. 
 
 Pycnidia stromatic, superficial or sunken 
 Pycnidia single on the stroma 
 Pycnidia with a single chamber 
 
 Conidiophores filiform 27. Phomopsis, p. 493. 
 
 Conidiophores indistinct or absent 
 
 Stroma indistinct 28. Plenodomus. 
 
 Stroma rather well developed 29. Sclerophoma. 
 
 Pycnidia typically with more than one 
 
 chamber 12. Sclerotiopsis. 
 
 Pycnidia with well developed stroma, free 
 or buried 
 Pycnidia with separate mouths 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 483 
 
 Pycnidia single on the stroma 30. Dothiopsis. 
 
 Pycnidia several on each stroma 
 Conidia separate from each other 
 Pycnidia scattered irregularly 
 Stroma sharply defined, globose, etc. 
 Pycnidial chambers appearing as 
 
 enlargements from without ... 31. Anthracoderma. 
 Pycnidial chambers not as above 
 Stroma valsoid 
 Conidia straight 
 
 Conidia large, fusiform 32. Fusicoccum, p. 498. 
 
 Conidia small, ovate, clavate or 
 cylindric 
 Conidia ovate or clavate, very 
 
 small 33. Cytosporella, p. 498. 
 
 Conidia larger, ovate, or elon- 
 gate 
 Pycnidia superficial or sub- 
 superficial 
 
 Conidiophores simple 34. Dothiorella, p. 499. 
 
 Conidiophores branched. ... 35. Dothiorellina. 
 
 Pycnidia deep seated 36. Rabenhorstia. 
 
 Conidia allantoid 37. Cytospora, p. 499. 
 
 Stroma pulvinate 38. Fuckelia, p. 500. 
 
 Stroma indefinite, on black spots on 
 
 the host plant 39. Placosphseria. 
 
 Pycnidia regularly arranged on the 
 
 stroma around a sterile center. . . 40. Lamyella. 
 
 Conidia adhering basally in fours 41. Gamosporella. 
 
 Pycnidia on each stroma with a com- 
 mon ostiole 
 Stroma globose or flask-shaped; conidia 
 
 curved 42. Torsellia. 
 
 Stroma conic-truncate, conidia elongate 
 
 cylindric, straight 43. Ceuthospora, p. 500. 
 
 Stroma thin, effuse; conidia curved to 
 
 allantoid 44. Plagiorhabdus, p. 500. 
 
 Phyllosticta Persoon (p. 481) 
 Pycnidia immersed, erumpent or with the beak piercing the 
 
484 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 epidermis, lenticular to globose, thin membranous, opening by 
 a pore; conidia small, ovate to elongate, continuous, hyaline or 
 green; conidiophore short or almost obsolete. On leaves. 
 
 In part=Guignardia, Valsonectria, Mycosphaerella. 
 
 The genus is a very large one of some eight hundred forms, few of 
 which have been adequately studied. It differs from Phoma only in 
 that it is foliicolous while Phoma is caulicolous, a distinction which 
 
 Fig. 335. — P. solitaria. 1, section through apple; 4, spores 
 from apple blotch showing appendages; 6-7, germinating 
 spores; 9, mycelium from corn-meal cultures. After Scott 
 and Rorer. 
 
 is not consistently maintained and which is untenable for generic 
 limitation (see p. 478). 
 
 The fungus produces leaf spots by killing or weakening the 
 leaf tissue with its mycelium. The spots are circular or subcircular, 
 unless rendered angular by obstruction by veins, and the pycnidia 
 may usually be seen with a lens in old spots unless the color of the 
 leaf forbids. Similar effects follow on fruits. 
 
 P. ampelopsidis E. & M. on Ampelopsis is probablj'^ identical 
 with P. labruscae =Guignardia bidwellii. See p. 238. 
 
 P. bellunensis Mart, on elm = Mycosphaerella ulmi. See p. 249. 
 
 P. brassicae (Carr.) West on cabbage, etc. = Mycosphaerella bras- 
 siaecola.^ See p. 249. 
 
 P. labruscaB Thiim. on the grape =Guignardia bidwellii. See 
 p. 238. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 485 
 
 P. tabifica Prill is perhaps identical with Mycospharella tabifica, 
 though Potebnia'' questions this. See p. 247. 
 
 P. maculiformis (Pers.) Sacc. on chestnut = My cosphaerella 
 maculiformis. See p. 249. 
 
 P. solitaria E. & E.^' ^ 
 
 Perithecia minute, immersed, the ostiole only erumpent; conidia 
 broadly elliptic, 8-10 x 5-6 n, surrounded by a mucilaginous sheath. 
 
 It is the cause of apple fruit blotch and of cankers and leaf spots. 
 On the fruit it was first reported by Clinton ^ in 1902. The fruit 
 spots show a characteristic fringed appearance owing to the 
 imequal advance of the mycelium which is limited to the outer- 
 most fruit cells. In the fruit the pycnidia develop subepidermally. 
 
 Fig. 336. — P. solitaria. 1-month-old colony on apple agar. After 
 Scott and Rorer. 
 
 The fungus was grown in pure culture and its identity on twig, 
 leaf and fruit was shown by cross inoculation. 
 
 P. persicae Sacc. is common on peach leaves. 
 
 P. piricola Sacc. & Speg. is foimd on apple and pear. 
 
 P. limitata Pk.^° is reported as the cause of an apple leaf spot. 
 
 Spots round minute, 2-6 mm., brown or reddish; pycnidia epiph- 
 yllous, black, few, punctiform; spores ellipsoid, 7-8 x 4 ju. P. mali 
 P. & D. occurs on apple and pear. 
 
 P. pirina Sacc.^^ 
 
 Spots variable; pycnidia epiphyllous, punctiforjn, lenticular, 
 100-130 n, context loosely cellular, brown; conidia ovoid to 
 ellipsoid, 4-5 x 2-2.5 ijl. 
 
 This was long regarded as the chief factor causing the common 
 leaf spot on the apple and pear. Recent work throws doubt on this. 
 
486 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 P. circumscissa Cke. 
 
 Amphigenous; spots orbicular, reddish-brown, at length de- 
 ciduous; pycnidia scattered, minute; conidia elliptic, 8 x 2 )u. 
 
 Spots and shot holes are formed on drupaceous hosts. 
 
 P. prunicola Sacc.^- 
 
 Spots subcircular, epiphyllous, sordid-brownish or ochraceous, 
 margin subconcolorous; pycnidia scattered, punctiform; conidia 
 ovoid to ellipsoid, 5 x 3 ju. 
 
 It is foimd on Prunus, causing leaf spots in Europe, America 
 and Australia. Scurf is also produced on apple bark. 
 
 P. armenicola Far. is associated with an apricot fruit disease. 
 
 P. grossulariae Sacc. grows on Ribes grossularia. 
 
 P. fragaricola D, & R. is widespread in Europe on the strawberry. 
 
 P. vitis Sacc. and P. succedanea (Pass.) All. are found on grape 
 in Europe. 
 
 P. vialae R. & G. also parasitizes the grape. 
 
 P. bizzozeriana Mass. in Hungary produces a grape disease 
 superficially resembling black rot.^^ 
 
 P. putrefaciens Sh. occurs on cranberry. 
 
 P. oleae Pet. and P. insulata Mont, cause leaf spots on the olive. 
 
 P. cannabinis Kirch forms spots on hemp leaves; 
 
 P. humuli Sacc. & Speg. on the hop. 
 
 P. bataticola E. & M. Pycnidia scattered, minute, black; spots 
 small rounded, whitish with a purple margin; conidia ellipsoid, 
 5 X 2iu. Leaf spots are produced on the sweet potato. 
 
 P. nicotiana E. & E. 
 
 Spots brown, reddish, zonate; pycnidia 200 n, black; conidia 
 3.5-5 X 1.5 jLt. It causes leaf spots of tobacco;^* 
 
 P. tabaci Pass, also occurs on Nicotiana. 
 
 P. medicaginis (Fcl.) Sacc. occurs on alfalfa; ^^ 
 
 P. japonica Miy. and P. miuria Miy. parasitize rice. ^^ 
 
 P. betae Oud. 
 
 Spots grayish-ochre, large and irregular; pycnidia epiphyllous, 
 minute, densely clustered, browTiish, subimmersed; conidia elliptic, 
 5-6 X 3 iu. 
 
 It is mentioned by Stewart ^'^ as the cause of leaf spots of beets. 
 
 P. malkoffi Bub. causes cotton leaf spots in Bulgaria. 
 
 P. cofifeicola Del. and P. comoensis Del. are on coffee; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 487 
 
 P. cinnamoni Del. on cinnamon leaves; 
 
 P. hevea Ziinm. on Para rubber. 
 
 P. hortorum Speg.^^' ^^ 
 
 Spots circular, indefinite, fulvous, gray in the center, amphig- 
 enous, at last falling away; pycnidia in the center of the spot, 
 minute, 80-90 n, globose-lenticular, thin, membranous, dull 
 f usco-olivaceous ; conidia elliptic to ovoid, rounded at the ends, 
 4-6 X 2-2.5 M- 
 
 It produces spots on leaves and fruit of egg plant in Europe 
 and America. 
 
 P. chenopodii Sacc.^° 
 
 Spots irregular, scattered or confluent, ochraceous, fuscous 
 margined; pycnidia lenticular, punctiform, 50 n; conida oblong- 
 elliptic, 5 X 3 /x. A leaf spot is produced on spinach. 
 
 P. apii Hals.^^ forms brown spots on leaves of celery; pycnidia 
 punctiform, black; conidia elliptic to ovate oblong. 
 
 P. phaseolina Sacc. 
 
 Spots irregularly scattered, subcircular, 2-10 mm., deep rusty 
 brown, becoming lighter in center and darker margined; pycnidia 
 scattered, 70-90 n; conidia ovoid oblong, 4-6 x 2-2.5 ju. 
 
 It causes spotting of bean and cowpea.^^^ 
 
 P. cucurbitacearum Sacc. 
 
 Spots epiphyllous or amphigenous, sordid, whitish ; pycnida punc- 
 tiform, 80-100 fx, lenticular; conidia oblong, 5-6 x 214 M, curved. 
 
 On muskmelon, cucumbers and other cucurbs, spotting the 
 leaves. ^'' -'--^ 
 
 P. citrullina Chester "^ is also reported on melons, ^^^ 
 
 P. maculicola Hals.^^ produces spots in Dracsena and related 
 plants. 
 
 P. hedericola Dur. & M. and P. hederacea (Arc.) All. cause 
 spots on Hedera leaves,-^' ''^^ 
 
 P. rosae Desm. and P. argillaceae Bres. occur on roses. 
 
 P. rosarum Pass, causes a black spot on roses in New South 
 Wales. 
 
 P. althaeina Sacc.^^ 
 
 Spots irregular, with a dark browTi margin; pycnidia few, 
 lenticular, 90 /x, ochraceous; conidia ovate-oblong, 6-7 x 3-4 /i- 
 
 On hollyhock in Italy, France and America. 
 
488 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 P. idaecola Cke. forms spots on cultivated species of Sida and 
 Hibiscus. 
 
 P. dianthi West, grows on Dianthus leaves. 
 
 P. primulaecola Desm. occurs on Primula leaves.^^ 
 
 Amphigenous; spots large, white, light margined; pycnidia epiph- 
 yllous, numerous, prominent, globose, black; conidia subglobose. 
 
 P. violae Desm.-^' ^ 
 
 Amphigenous, spots white, round; pycnidia numerous, minute, 
 brown; spores minute, subcylindric, 10 fi long. 
 
 Common, causing leaf spots on pansy and violet. 
 
 P. hydrangeae E. & E.^^ 
 
 Spots 1.5-1 cm. or more, rusty brown, margin narrow, raised, 
 at first shaded with purple; pycnidia epiphyllous, lenticular, 
 100-115 m; conidia oblong, 10-12 x 2.5-3.5 ii. 
 
 On Hydrangea causing leaf spots. 
 
 P. syringae West, is common on lilac. 
 
 P. halstedii E. & E. 
 
 Amphigenous, spots roundish, reddish-brown, \i-V/i cm. con- 
 centrically zonate, pycnidia few, lenticular, 100-150 /x, immersed; 
 conidia broadly fusoid-oblong, 15-20 x 5-7 ^u. Causing a leaf spot 
 of the lilac. 
 
 P. cruenta (Fr.) Kick. 
 
 Spots subcircular, reddish, becoming paler in the center; pycnidia 
 gregarious or scattered, globose-lenticular, dark olivaceous; conidia 
 ovate-oblong, 14-16 x 5.5-6.5 /x; conidiophores, cylindric, 10-12x4/i. 
 
 It causes leaf spots of cultivated Solomon's Seal. 
 
 P. cyclaminis Brun. occurs on cyclamen; 
 
 P. digitalis Bell on digitalis. 
 
 P. chrysanthemi E. & D.^e 
 
 Spots purplish-brown, pycnidia 80-100 ju; conidia 4-5 x 2.5-3 ju. 
 
 It causes leaf spots on cultivated chrysanthemums. 
 
 P. leucanthemi Speg. is occasionally found in spots of chrysan- 
 themum leaves. 
 
 P. richardiae Hals.-^ is common as a leaf spotter of the calla 
 lily but has not been satisfactorily descril)ed. 
 
 P. opuntiae Sacc. & Speg. occurs on various of the Cactaceae; 
 
 P. liliicola Sacc. on lily; 
 
 P. vincae minoris B. & K. on Vinca minor; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 489 
 
 P. pteridis Hals, causes blighting of cultivated Pteris; "^ 
 
 P. narcissi Aderh. of narcissus. ^° 
 
 P. cavarae Trinch. produces white spots on leaves of Anthurium.^^ 
 
 P. dracaenae causes spots on Dracsena leaves. 
 
 P. funckia Hals. Pycnidia 75-150 ix, straw colored. 
 
 The cause of leaf spots of cultivated Funkias.^'^ 
 
 P. dammarae is found on Dammara in Italy; 
 
 P. nobilis Thum. on Laurus. 
 
 P. ulmicola Sacc. 
 
 Spots indefinite, ochraceous, margin concolorous; pycnidia gre- 
 garious, punctiform, 70-80 ijl, lenticular; conidia oblong ellipsoid, 
 6-3 M- It infests elm leaves. ^^ 
 
 P. acericola C. & E^- 
 
 Spots irregular, fuscous, brown margined; pycnidia densely 
 scattered on the central part of the spot, subepidermal, flask- 
 shaped, dark brown, 120 ju; conidia ovate, 8-9 x 5-6 /jl. 
 
 It causes serious leaf spotting of maples throughout the United 
 States. 
 
 P. aceris Sacc. forms small spots on maple leaves. 
 
 P. paviae Desm. 
 
 Spots indeterminate, reddish, lighter margined; pycnidia 
 epiphyllous, black; conidia cylindric-elliptic, 11-12 ^ long. It 
 is said to be common on J^sculus.^^ 
 
 P. sphaeropsidea E. & E.^^ 
 
 Epiphyllous; spots reddish-browTi, margin lighter, scattered 
 or confluent, 1-2 cm.; pycnidia scattered, immersed, punctiform, 
 erumpent above, subepidermal; conidia globose to broadly ellip- 
 soid, hyaline, 12-15.5 x 8-10 n. 
 
 It causes serious leaf spotting of chestnuts throughout the 
 United States. 
 
 P. tiliae Sacc. & Speg. is found on Tilia. 
 
 P. minima (B. & C.) E. is on Negundo. 
 
 P. catalpae E. & M. 
 
 Spots, rounded, brown, 3-6 mm., often confluent; pycnidia 
 subcuticular, small, black, scattered, 112 x 84; conidia ovate, 5-7 x 
 2.5-4.5 IJL. It causes leaf spots on Catalpa.^"* 
 
 P. magnolias Sacc. causes leaf spots on Magnolia; P. viridis E. & 
 K. on ash; P. ilicina Sacc. on the cork oak. 
 
490 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 An unidentified species has been reported on watermelon ^^ as 
 cause of considerable injury. Halstead mentions also an undeter- 
 mined species on oats.-^ Pycnidia 150-250 {j,; spores 12-18 x 
 6-7 /i, pyriform. 
 
 Phoma (Fries) Desmaziere (p. 481) 
 
 The genus as at present recorded contains over 1200 forms. 
 It is indistinguishable from Phyllosticta (see p. 484) except that 
 it is caulivorous. Several species are regarded as conidial forms 
 of Diaporthe, Mycosphaerella, etc. 
 
 P. reniformis on grape =Guignardia bidwellii. See p. 238. 
 
 P. albicans Rob. & Desm. on chicory =Pleospora albicans. 
 See p. 260. 
 
 P. betae Fr. on beet = Mycosphaerella tabifica. See p. 247. 
 
 P. bohemica Bub. & Kab. on fir tree needles = Rehmielliopsis. 
 See p. 276. 
 
 P. ambigua (Nitz.) Sacc. on pear = Diaporthe ambigua. See 
 p. 279. 
 
 P. sarmentella Sacc. on hop = Diaporthe sarmentella. See 
 p. 279. 
 
 P. persicae Sacc. 
 
 Pycnidia scattered to gregarious, glol^ose lenticular, /e- /b mm. ; 
 conidia oblong ovoid, 8-3 x 2 /x, conidiophores cylindro-conical, 
 equal in length. 
 
 It produces constriction and death of peach twigs.^^ 
 
 P. mall S. & S.^^' '' 
 
 Pycnidia gregarious, subcuticular, depressed, ostiole erumpent; 
 conidia oblong-f usoid, 2-3 x 5-8 /x. 
 
 It attacks the wood of young apple trees and also causes a decay 
 of the fruit. 
 
 P. cydoniae Sacc.^^ 
 
 Pycnidia subgregarious, depressed, ostiole obtuse or erumpent, 
 conidia elliptic oblong, 8-9 /x long; conidiophores short. 
 
 A form causing rot of quince fruit was provisionally referred 
 to this species l^y Halsted. 
 
 P. limonis Thiim. & Boll. P. citri Sacc. and P. aurantiorum 
 (Rab.) Sacc. occur on citrous fruits; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 491 
 
 P. pomarum Thiim. on pomaceous fruits in Europe. 
 
 P. myxiae Far. is associated with an apricot fruit spot. 
 
 P. omnivora McA. is described as the cause of AustraUan wither 
 tip of the orange '^° while to P. citricarpa McA is attributed another 
 common Austrahan citrous fruit disease. 
 
 P. mororum Sacc. is on Morus. 
 
 P. tuberculata McA. causes a disease of grape berries in Aus- 
 traha."*^ 
 
 P. lophiostomoides Sacc. is common and perhaps parasitic on 
 cereals. 
 
 P. hennebergii Kiihn produces brown spots on the glumes of 
 wheat and leads to some injury to the grain.'*" 
 
 P. solanicola P. & D.'*^ causes a disease of potato ^^^ stems in 
 France. 
 
 P. solani Hals.^^ 
 
 Pycnidia innate, depressed, oblong; conidia oblong. 
 
 On egg plant causing damping-off of seedlings. 
 
 P. subcircinata E. & E. 
 
 Pycnidia black, 70-90 m; conidia 5-6 x 2-2.5 n. 
 
 Spots are produced on bean pods. 
 
 P. sanguinolenta Rost.^^ 
 
 Pycnidia scattered, subglobose; conidia ellipsoid, 4-6 x 1.5-3 
 /jl; surrounded by a slime which gives the spore-mass a violet-red 
 color. 
 
 As the cause of a rot of carrot roots it has been reported in New 
 Jersey. 
 
 P. oleraceae Sacc.''^"^^ 
 
 Pycnidia scattered, globose depressed, papillate, sunken in 
 the tissues, 34"/^ mm.; conidia oblong, subcylindric, medially 
 constricted, apically obtuse, 5-6 x 2 )u. 
 
 Manns notes this fungus causing a serious cabbage disease in 
 Ohio. The pycnidia are sparse on oval sunken diseased areas on 
 the stems, and bacterial invasion follows soon in leaves, cam- 
 bium and xylem. The cambium is rapidly destroyed and the 
 plant collapses. Bos ^^ and Quanjer ^^ have demonstrated the 
 pathogenicity of the fungus. 
 
 P. napobrassicae Rost. causes rot of mangolds in Den- 
 mark; ^^''^ also recently reported from Canada. ^^ 
 
492 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 P. apiicola Speg. is recorded on celery.^- 
 
 P. brassicse Thiim. on cabbage is probably identical with 
 P. oleraceae. 
 
 P. roumii Fron. is said to cause a serious cotton disease in 
 Africa. ^^ 
 
 P. batatae E. & H.^^ 
 
 Pycnidia blackish, gregarious, immersed; conidia terete, ovoid; 
 conidiophores slender. The cause of dry rot of sweet pota- 
 toes. 
 
 P. chrysanthemi Vogl. is found on leaves of chrysanthemum 
 causing them to wilt. 
 
 P. malvacearum West is noted on European hollyhocks; 
 
 P. devastatrix Berk, on cultivated lobelias ; 
 
 Fig. 337. ^P. olcracea. A, showing pycnidia with spores stream- 
 ing out; B, section; C, spores. After Manns. 
 
 P. dahlias Berk, on stems and flowers of Dahlia. 
 
 P. cyclamenae Hals, is given as the cause of Cyclamen leaf spots 
 but without ample description. 
 
 P. oleandrina Del. is on the rose, laurel, etc. 
 
 P. pithya Sacc. seems to be parasitic on the fir causing con- 
 rtriction and death of twigs. 
 
 P. strobi (B. & Br.) Sacc. is prevalent on white pine in Europe. 
 
 P. strobilinum P. & C. is closely related to the above. 
 
 P. sordida Dur. & M. occurs on Carpinus. 
 
 P. ribesia Sacc. Pycnidia collected, erumpent, spores oblong- 
 fusoid, 10 X 33^ iu, hyaline. In branches of Grossularise. 
 
 Several undetermined species have been reported, among them 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 493 
 
 one on snapdragon,'^'^ another on Clematis roots,''^ and one on ap- 
 ple «' 
 
 Phomopsis Saccardo " (p. 482) 
 
 As in Phoma, but with hooked conidiophores. A small genus. 
 
 P. aloeapercrassae Trinch. is reported on scapes and flowers of 
 the aloe in Italy. 
 
 P. stewartii Pk. 
 
 Perithecia gregarious, commonly occupying grayish or bro\\'n 
 spots, thin, subcutaneous, at length erumpent, depressed, minute, 
 V3-V2 mm. broad, black; spores of two kinds, first ; filiform, curved, 
 flexuous or uncinate, hyaline, 16-25 x 1-1.5 m, second; oblong or 
 subfusiform, hyaline, commonly binucleate, 8-12 x 2-3 m; 
 sporophores slender, equal to or shorter than the spores. 
 
 The fungus with its filiform spores only was noted as a parasite 
 on Cosmos by Halsted who referred to it as a species of Phlyctaena.^' 
 It has been noted in New York by Stewart, ^^ and is destructive 
 both in the greenhouse and in the open. 
 
 Macrophoma Berlese & Voglino (p. 481) 
 
 As in Phoma, but the ostiole of the pycnidium not papillate, 
 and the pore smaller; conidia over 15 m long; conidiophores sim- 
 ple, short or filiform. 
 
 About one hundred seventy-five species. 
 
 M. hennebergii (Kahn) Berl. & Vogl. causes a serious disease 
 on wheat in Sweden .^^ 
 
 The fungus which appears in the Uterature as M. curvispora 
 Pk. is in reality Gloeosporium malicorticis, see 
 p. 542, and that referred to as M. malorum 
 is Myxosporium corticolum. See p. 546. 
 
 M. vestita Prill. & Del. attacks cacao in 
 Ecuador. ^ ^^ 
 
 M. dalmatica (Thiim.) B. & V. parasitizes the ^^^ sss.Im. curvi- 
 olive; M. taxi B. & V. attacks the leaves of ^P°corXr^" ^^' 
 Taxus; M. abietis M. & H. is associated with 
 a fir disease; M. manihotis Hem. is on cassava; M. ligustica Mag- 
 nag on Hydrangeas; M. helicinia Magnag on ivy. 
 
494 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 M. reniformis (V. & R.) Car. is reported on grapes in Algiers, 
 Italy and Russia. 
 
 Aposphaeria Berkley (p. 481) 
 
 Pycnidia globose, carbonous, with a papillate ostiole, erum- 
 pent or superficial; conidia elongate to globose; conidiophores 
 very short or absent. 
 
 One hundred species are recognized. 
 
 An undetermined species was found by Stevens -^ in New York 
 ,and New Jersey in 1892, causing diseased spots on strawberry 
 leaves. 
 
 Dendrophoma Saccardo (p. 481) 
 
 ■ Pycnidia superficial or subepidermal and erum- 
 .pent, carbonous; ostiole papillate; conidia elongate; 
 conidiophores branched. 
 
 A genus of some fifty species, chiefly sapro- 
 phytes. 
 
 D. marconii Cav. occurs on hemp stems; D. con- Fig. 339.— Den- 
 vallariae Cav. on leaves of Convallaria majalis; n^d^iopTor'es 
 D. valsispora Penz on living lemon leaves. ^"^^j. ^I'l'^'gl 
 
 Cicinnobolus Ehrenberg is frequently met as a cher. 
 parasite on the mycelium of the Erysiphales. 
 
 Macrodendrophoma salicicola on Salix = Physalospora gregaria. 
 See p. 252. 
 
 Sphaeronema Fries (p. 482) 
 
 Pycnidia superficial or not, pyriform, cylindric or globose, 
 rostrum long; conidia ovate or elongate. 
 
 Some seventy-five species, chiefly saprophytes, have been de- 
 scribed. 
 
 S. phacidioides Desm. on clover =Pseudopeziza trifolii. See 
 p. 148. 
 
 S. fimbriatum (E. & H.) Sacc^^' ^^ 
 
 Pycnidia globose, 100-200 fx, surrounded by septate, hyaline 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 495 
 
 hyphse, rostrum, 20-30 ix long, apically fimbriate; conidia globose- 
 elliptic, 5-9 /x. 
 
 The fungus grows in the sweet potato producing dark, almost 
 black spots in the skin. The tissue below becomes olive-green. 
 The dark mycelium is found penetrating 
 through and between cells of the dis- 
 eased area where numerous olivaceous 
 conidia are also present. The elon- 
 gated beaks of the pycnidia rise like a 
 small forest from the surface of the 
 potato. 
 
 In artificial culture the mycelium is 
 dark, abundantly septate and with nu- 
 merous oil globules. Long multiseptate ., 
 conidiophores with light colored tips fiq. 340.— S. fimbriatum; 1, 
 arise from the medium. From these pycnidium sending forth 
 
 spores; 2, hyaline conidia; o, 
 
 hyaline conidia are produced, appar- oHve conidia. After Halsted 
 ently endogenously. Fig. 340, Oliva- 
 
 ceus, globose to elliptical, Fig. 340, conicUa are formed within the 
 medium on branches of the mycelium in much the same manner. 
 The pycnidia develop in about nine days after inoculation and the 
 conidia are extruded from the fimbriate mouth of the long ros- 
 trum. 
 
 Inoculations proved the pathogenicity of the organism, 
 typical black rot appearing in about three weeks after infec- 
 tion. 
 
 S. adiposum Butler causes a black rot of sugar cane. 
 
 S. pomarum Sh. is on cranberry. 
 
 S. spurium (Fr.) Sacc. on Prunus is often reported as Dematium 
 prunastri. 
 
 S. oryzae Miy. is on rice.^® 
 
 Chaetophoma Cooke (p. 482) 
 
 Pycnidia superficial, very small, on a subiculum of interwoven 
 hyphse; conidia ovate or elliptic, very small. 
 Some forty species, chiefly American. 
 C. glumarum Miy. parasitizes rice in Japan. ^^ 
 
496 THE FUNGT WHICH CAUSE PLANT DISEASE 
 
 Asteroma De Candolle (p. 482) 
 
 Pycnidia very small, globose, erumpent, often on a mass of 
 hyphae; conidia ovate or short eylindric. In part =Gnomonia. See 
 p.. 274. 
 
 About forty species chiefly parasitic. 
 
 A. padi (D. C.) Grev. on Prunus=Gnomonia padicola. See 
 p. 275. 
 
 A. geographicum (D. C.) Desm. occurs on various species of 
 Pomacese; 
 
 A. punctiforme Berk, on the rose; 
 
 A. stuhlmanni Hen. on bananas and pineapples in Africa. 
 
 A. codisei All. is said to be a serious parasite of Codiaium.®' 
 
 Vermicularia Fries (p. 482) 
 
 Pycnidia superficial, or erumpent, globose depressed, to globose 
 clavate, leathery or carbonous, black, ostiolate or not, beset 
 with rather long, stiff, septate, dark colored bristles; conidia 
 
 cylindric-fusoid, often curved. 
 
 Some one hundred thirty 
 
 species, chiefly saprophytes. 
 
 V. dematium (Pers.) Fr. 
 
 Pycnidia erumpent, superficial, 
 
 80-120 fjL, conic, then depressed, 
 
 often confluent, black, spines 
 
 pale at the ends, 150-200 x 5 ju; 
 
 conidia cylindric-elongate, 20 x 
 
 i\S\Sd 4-6 n, apically rounded, curved. 
 
 Fig. 341. -V. dematium. c, a nearly Commonly a Saprophyte, this 
 mature "perithecium;" s, spores; fungus Occasionally causes as- 
 
 -"t liypilSB. Al lGP XV66Q. cc -r • 
 
 paragus disease.''^ In Europe it 
 is reported as the cause of much loss to the ginseng crop. On 
 this plant it produces a stem anthracnose. The fungus was 
 isolated and its cultural characters studied by Reed.^^ 
 
 V. trichella Fr. 
 
 P3^cnidia ovate, small, black, spines long, at the apex of the 
 pycnidium; conidia fusoid, curved, pointed, 16-25 x 4-5 /x. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 497 
 
 On living parts of many fruit hosts, as well as ivy and other 
 woody plants.^^ 
 
 V. melicae Fcl. grows on Melica; 
 
 V. microchaeta Pass, on camellia. 
 
 V. circinans Berk.^^' ^^ 
 
 Spots orbicular; pycnidia arranged concentrically, small, setae 
 long; conidia oblong, curved, obtuse. 
 
 On onions the fungus appears as small black dots on the scales. 
 These later become encircled by rings of black pycnidia. Stone- 
 man found no true pycnidium; this would indicate relationship 
 of the organism with Volutella rather than with Vermicularia. 
 
 V. varians Due. is described by Ducomet as the cause of a scab- 
 like disease of tomato and potato.^^ 
 
 V. subeffigurata Schw. Pycnidia large, scattered, dark, sub- 
 elevated; spines unequal. On carnation leaves. 
 
 V. telephii Karst.^^ 
 
 Pycnidia scattered, erumpent, superficial, spherical, dark, 100- 
 150 fx; conidia fusoid bacilliform, acutely curved, 
 22-32 X 4 /x. 
 
 On leaves and stems of cultivated Sedums. 
 
 V. concentrica Lev. is reported by Halsted -^ |||^ ^ 
 
 as causing unsightly spots on Dracaena. 
 
 V. denudata Schw. A Vermicularia referred 
 to as probably this species is reported as dam- S42 — P 
 
 aging to Kentucky blue grass in Dakota.^*^ chaeta berbeiidis, 
 
 V, .... ri 1 • J. J 1 conidiophoro and 
 
 . polygoni-virgmica Schw. is reported by conidia: After Ai- 
 
 Reed & Cooley on rhubarb. i^« l^^'^^^^- 
 
 An undetermined species is reported as injurious to the potato.^^ 
 
 Pyrenochaeta de Notaris (p. 482) 
 
 Pycnidia globose-clavate, erumpent, leathery or carbonous, 
 black, bristly, ostiolate; conidia ovate, elongate or cylindric; 
 conidiophores branched. 
 
 A genus of some thirty species. 
 
 P. phloxidis Mas. is common just above ground on living stems 
 of Phlox causing cankers. 
 
 P. ferox Sacc. is found on potato stems. 
 
 P. oryzae Miyake ^^ occurs on rice in Japan. 
 
498 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Fusicoccum Corda (p. 483) 
 
 Stroma subepidermal, several-chambered, erumpent, leathery, 
 black; conidia fusoid, straight and usually large. 
 
 Some forty species, several of which are regarded as conidial 
 forms of Diaporthe and Gnomonia. 
 
 F. veronense Massal on Sycamore and Oak = Gnomonia veneta. 
 See p. 274. 
 
 F. viticolum Red. on grape =Cryptosporella viticola. See p. 280. 
 
 Fig. 343. — F. viticolum, compound pycnidium, germinating spores, pa- 
 raphyses. After Reddick. 
 
 F. amygdali Del. causes a spot disease of almond twigs in 
 Europe. 
 
 F. bulgarium Bub. is described as the cause of a grape disease in 
 Austria.^- 
 
 F. perniciosum Briosi & Farm, on chestnut =Melanconis 
 modonia Tul. See p. 281. 
 
 Cytosporella Saccardo (p. 483) 
 
 Stroma tuberculate or cushion-form, immersed, then erumpent, 
 leathery, black, lighter within; conidia clavate or ovate, usually 
 quite small. Some twenty-five species. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 499 
 
 C. cerei, Poll, is on Cereus; 
 
 C. citri Maynag. on oranges; 
 
 C. damnosa Pet. on pine; all in Italy. 
 
 C. persicae Schw. is reported on young peach branches. 
 
 Cytospora Ehrenberg (p. 483) 
 
 Stroma superficial or erumpent, tubercular, with irregular 
 chambers; conidia elongate allantoid. 
 Ascigerous forms belonging to Valsa are 
 known. 
 
 Some two hundred species, chiefly 
 saprophytes. 
 
 C. palmarum Cke. is on palms. 
 
 C. ceratophora Sacc. is the suspected 
 cause of a blight of Japanese chestnuts.^^ 
 
 C. acerina Aderh. causes disease of Acer in Europe. ^'^ 
 
 C. sacchari Butler is found on sugar cane in Bengal. 
 
 Dothiorellina Bubak with the one species D. tankoffiii Bub. has 
 recently been described as the cause of disease of the mulberry. ^^^ 
 
 Fig. 344. — Cytospora. Sec- 
 tion through a stroma. 
 After Chester. 
 
 Dothiorella Saccardo (p. 483) 
 
 Pycnidia erumpent, on a stroma, leathery, ostiole papillate or 
 not; conidia ovate or elongate. 
 
 Some seventy species, chiefly saprophytes. 
 
 D. ribis (Fcl.) Sacc, on a wide range of hosts =Diaporthe stru- 
 mella. See p. 279. 
 
 Fig. 345. — D. mori. A'', section of stroma, 0, conidio- 
 phores and conidia. After Allescher. 
 
 D. mori Berl. and D. populi Sacc. are perhaps parasitic on Morus 
 and Populus respectively. 
 
 An unidentified species is reported by Duggar on currant as 
 the cause of cane blight. Inoculations using the conidia have 
 produced the disease. See also p. 283. 
 
500 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Fuckelia Bonordin (p. 483) 
 
 Stroma erumpent, globose-pulvinate, substipitate, dark without, 
 lighter within, with several angular pycnidial locules; conidia 
 elliptic. 
 
 A single species F. ribis Bon. on currants in Europe is a conidial 
 form of Cenangium vitesia. See p. 151. 
 
 Ceuthospora Grevielle (p. 483) 
 
 Stroma coalescing, erumpent, cushion-shaped, leathery, many- 
 chambered, all chambers opening by a common pore; conidia 
 elongate cylindric, mostly straight. 
 
 Some twenty-five species, chiefly saprophytes. 
 
 Fig. 346.— C. cattlcyaj, a 
 p y c n i d i u m. After 
 Delacroix. 
 
 Fig. 347. — Plagiorhabdus 
 oxycocci on cranberry. 
 After Shear. 
 
 C. cofifeicola Del. is of questionable parasitism on coffee; 
 C. cattleyae Sacc. & Syd. on orchids. 
 
 Plagiorhabdus oxycocci Shear has been reported on cran- 
 berry. ^^^ 
 
 Sphaerioidaceae — Phaeosporae (p. 480) 
 
 Conidia 1-celled, dark, globose, ovoid or oblong. 
 
 Key to Genera of Sphaeropsioidaceae — Phaeosporae 
 
 Pycnidia separate >> 
 
 Pycnidia without mycelium or subicle 
 Pycnidia smooth, not hairy 
 Conidia in chains, globose 1. Sirothecium. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 501 
 
 Conidia not in chains 
 Pycnidia sessile, splioroid 
 
 Pycnidia beaked 2. Naemosphaera. 
 
 Pycnidia not beaked 
 
 Conidia spindle-form, with 
 
 both ends light colored . . 3. Hypocenia. 
 Conidia globose to elliptic 
 Pycnidia opening irregu- 
 larly 4. Harknessia. 
 
 Pycnidia opening bj' a regu- 
 lar ostiole 
 Conidia large, ovate to 
 
 elliptic 5. Sphaeropsis, p. 501. 
 
 Conidia very small, glo- 
 bose to ellipsoid. ... 6. Coniothyrium, p. 503. 
 
 Pycnidia stipitate, clavate 7. Levieuxia. 
 
 Pycnidia hairy or setose 8. Chaetomella. 
 
 Pycnidia with distinct mycelium or 
 subicle 
 Pycnidia astomous, in a dark subicle. . 9. Capnodiastrum. 
 
 Pycnidia perforate 10. Cicinnobella. 
 
 Pycnidia cespitose or in a stroma 
 
 Pycnidia in dense erumpent clusters 11. Haplosporella. 
 
 Pycnidia not as above, in a definite 
 stroma 
 Stroma applanate or effuse, foliicolous. 12. Discomycopsis. 
 Stroma dot-like, discoid or hemi- 
 spheric 
 
 Stroma dot-like, immersed 13. Melanconiopsis. 
 
 Stroma discoid to hemispheric 
 
 Stroma discoid; spores large 14. Nothopatella. 
 
 Stroma pulvinate; spores minute, 
 
 catenulate 15. Cytoplea. 
 
 Stroma hemispheric ; pycnidia 
 
 circinate 16. Weinmannodora. 
 
 Sphaeropsis Leveille 
 
 Pycnidia immersed, erumpent, globoid, black, leathery, mem- 
 branous, with the ostiole papillate; conidia ovate or elongate, 
 conidiophores rod-like. 
 
502 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 About two hundred species several of them important plant 
 pathogens. 
 
 S. malorum Pk. 6°' -• "^"^^ 
 
 Mycelium sooty-brown; pycnidia erumpent, usually surrounded 
 by broken epidermis, apically somewhat depressed; conidia oblong 
 elliptic, brown, usually about twice as long as broad, 22-32 x 10-14 
 H, varying in size with host and part attacked. 
 
 On apple, pear, quince, hawthorn; on twigs causing canker or 
 blight; on fruit causing rot and on leaves causing spots'. 
 
 
 '; "■■■ ?' 
 
 ?k 
 
 
 >; 
 
 
 ' 
 
 ■ii 
 
 
 
 t 
 
 
 .^ 
 
 
 
 i.&>-L'4 
 
 !' 
 
 
 Fig. 348. — S. mahjium, /*, dark colored mycelial 
 threads among the cells of the fruit; d, a 
 pycnidium, which has pushed through the epi- 
 dermis, c, and is giving off dark colored spores, e; 
 B, mature spores germinating in water. After 
 Longyear. 
 
 This is one of the common causes of pomaceous fruit rots and 
 of leaf spot in the United States. Its occurrence in leaf spots was 
 noted in 1898,^^ and in 1902 Clinton ^'^ recognized it as their cause. 
 Cultures were obtained from diseased leaf spots bj^ Scott & Rorer ^^ 
 and by inoculations the ability of the fungus to cause spots was 
 definitely proved. 
 
 This fungus was reported by Paddock ^^ as the probable cause 
 of apple twig blight and canker and cross inoculation between 
 twigs and fruit proved the identity of the fungus on these two parts. 
 
 The mycelium is very dark or olivaceous and abounds in the 
 rotten pulp of affected fruit, also in diseased bark, and is even 
 
THE FUNdl WHICH CAUSE PLANT DISEASE 503 
 
 present in wood though extencUng Init si)aringly into woody 
 tissue. 
 
 A pycnidial fungus agreeing with S. malorum morphologically 
 has been shown by Shear ^- to be a conidial form of the aseigerous 
 fungus Melanops ( = Botryospliseria), see p. 284. 
 
 S. pseudodiplodia (Man.) G. & M. **^' ^^ causes an apple disease 
 in Europe. 
 
 S. mori Berl. parasitizes Morus; 
 
 S. ulmiS. &R. the elm; 
 
 S. magnoliae Magnag. the Magnolia in Italy; 
 
 S. japonicum Miy. rice in Japan. ^^ 
 
 S. vincae S. & W. 
 
 Pycnidia gregarious or scattered, globose, immersed, black, 
 small, 260-300 At; ostiole papillate, erumpent; conidia ovate, 
 ovate-oblong or subpyriform, 17-28 x 10-14 n. On Vinca.-^'* 
 
 Many other forms are recorded on various hosts but their 
 parasitism is questionable. 
 
 Coniothyrium Corda (p. 501) 
 
 Pycnidia subcortical, erumpent or not, globose or depressed, 
 ostiole papillate, black, leathery to car]3onous; spores small, 
 ellipsoid, conidiophore reduced or absent. 
 
 More than one hundred fifty species. 
 
 C. pyriana (Sacc.) Shel. is common on apple leaf spots but is not 
 regarded as their cause.^ 
 
 C. concentricum (Desm.) Sacc. occurs on Yucca, Dracsena, etc. 
 
 C. tumefaciens Gus.^'' is described as the cause of a rose canker. 
 
 C. melastorum (Berk.) Sacc.^^ is on sugar cane. 
 
 C. fuckelii Sacc.^^ 
 
 Pycnidia superficial, scattered, dark, 180-200 n, globose- 
 depressed; conidia numerous, globose to short-elliptic, 2.4-5 x 
 2-3.5 fx. 
 
 The European form is reported on dead and dying branches and 
 a form closely allied to it, probably identical, has been studied in 
 New York as tlie cause of a raspberry cane-blight. This fungus 
 and no other was present and typical disease followed inoculation. 
 The organism was recovered in pure culture. Both new and old 
 canes died within two months after inoculation. 
 
504 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 This is a conidial form of Leptosphseria coniothyrium. See 
 p. 257.^^^ 
 
 The same fungus was reported by Stevens & HalP^ and was 
 studied by O'Gara^^ and determined by inoculation and cross 
 inoculating, using pure cultures, to be the cause of rose and apple 
 canker and apple fruit rot. 
 
 C. diplodiella (Speg.) Sacc^^"* 
 
 Pycnidia minute, subcuticular, erumpent, brown, 100-150 ix; 
 conidia ovoid to elliptic, 7-11 x 5.5 (x; conidiophores simple or 
 branched, hyaline, filiform. 
 
 This is the cause of a v/hite rot of grapes and has been reported 
 
 Fio. 349. — C. diplodiella, section through 
 pycnidium. After Scribner. 
 
 by Viali & Ravez as belonging to the ascigerous genus Carrinia.^ 
 See p. 263. 
 
 Though probably of American origin it was first recognized 
 in Italy in 1878. In 1887 it caused alarm in France and it was 
 first noted in America in the same year. The mycelium is abundant 
 in the affected pulp and sometimes upon the seeds. Peduncles 
 are often killed. The pycnidia are subcuticular, first pink, then 
 white, later brown. 
 
 C. scabrum McA. is the cause of black scurf of citrous fruit 
 in Australia. 
 
 C. coffeae Zimm. is on coffee in Java. 
 
 C. vagabundum Sacc. causes premature fall of leaves of goose- 
 berries. 
 
 C. japonicum Miy., C. brevisporum Miy. and C. anomale 
 Miy. are found on rice in Japan.''' 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 505 
 
 C. wernsdorffiae Kock occurs on roses. 
 C. hellebori C. & M. is found on hellebore. 
 
 Sphserioidaceae— Hyalodidymae (p. 480) 
 Conidia hyaline, 1-septate, ovoid, ellipsoid or oblong. 
 
 Key to Genera of Sphaerioidaceae— Hyalodidymae 
 
 Pycnidia separate 
 Pycnidia not beaked 
 Pycnidia in discolored areas, maculicole 
 Pycnidia immersed, then erumpent, 
 perforate 
 
 Conidia muticate 1- Ascochyta, p. 506. 
 
 Conidia with setse at the apex. ... 2. Robillarda. 
 
 Pycnidia superficial, astomous 3. Pucciniospora. 
 
 Pycnidia not maculicole 
 
 Pycnidia hairy 4. Didymochaeta. 
 
 Pycnidia smooth 
 
 Conidia with an appendage at each 
 end 
 Conidia with 1 or more bristles . 5. Darluca. 
 Conidia with cap-like append- 
 ages 6. Tiarospora. 
 
 Conidia muticate 
 
 Conidiophores 1-spored 
 
 Pycnidia without subicle 7. Diplodina, p. 509. 
 
 Pycnidia on a cobwebby subi- 
 cle, phyllogenous S. Actinonema, p. 508 
 
 Conidiophores several to many- 
 
 gpored 9. Cystotricha. 
 
 Pycnidia beaked 10- Rhynchophoma. 
 
 Pycnidia in a stroma 
 Stroma effuse 
 
 Stroma consisting of two distinct 
 
 layers H- Thoracella. 
 
 Stroma of a single layer 12. Placosphaerella. 
 
 Stroma verruciform 
 
 Stroma superficial bi Patzschkeella. 
 
 Stroma erumpent l-l- Cytodiplospora. 
 
506 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Ascochyta Libert (p. 505) 
 
 Usually producing definite spots; pycnidia globose-lenticular, 
 ostiolate; conidia ovate. 
 
 About two hundred fifty species. 
 
 A. pisi Lib.2i' ^i- 92=Mycosph8erella pinodes."*^^ See p. 250. 
 
 Spots variable in size, roundish, yellowish with brown margin; 
 
 pycnidia centrally located, black, of angular cells, 5-7 ijl; ostiole 
 
 rounded, surface reddish brown; conidia 
 
 slightly constricted at the septum, oblong, 
 
 12-16 X 4-6 ju; exuded spore-mass brown. 
 
 On peas, beans, vetch, Cercis, etc. The 
 pycnidia are visible on the dead areas of the 
 stems, leaves, pods or seeds. The mycelium 
 hibernates in affected seeds, reduces their 
 germinating power and carries the fungus 
 over to the succeeding crop. 
 Fig. 350.— a. citri, ^' boltshauseri Sacc. on bean in Swit- 
 zerland ^^ is closely related to the last 
 species. 
 
 A. armoraciae Fcl. is on horse radish, causing leaf spots; 
 A. ellisii Thiim. on grape; 
 
 A. brassicae Thiim. on cabbage, forming large dull patches; 
 often quite injurious. 
 A. rhei E. & E. 
 
 Spores finally constricted and 1-septate, 7-12 x 3.5-4 /x, hyaline. 
 On rhubarb. 
 A. viciae Lib. 
 
 Epiphyllous; spots roundish, reddish, margin elevated, orange 
 red; pycnidia minute, clustered, black, 90-100 n; conidia 
 oblong-ovate, obtuse, slightly constricted, 12-15 x 4-5 n; exuded 
 mass white. On Vicia. 
 A. nicotianae Pass.^^ 
 
 Spots between the veins, irregularly scattered, brown; conidia 
 oblong ovate, constricted at the septum. On tobacco. 
 A. parasitica Faut. 
 
 Spots whitish; epiphyllous; pycnidia small, black. Conidia el- 
 liptic, 3-4 X 6-10 n. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 507 
 
 This is found associated with rust sori on malvaceous hosts. ^^' ^^ 
 
 A. polemonii Br. & Cav. occurs on Polcmonium. 
 
 A. piniperda Lin. is parasitic on fir leaves. 
 
 A. aquilegiae Iloum. spots columbine leaves. 
 
 A. beticola P. & D. is on beet leaves; 
 
 A. orobi Sacc. on sainfoin; and A. oryzae Catt. on rice in Italy. 
 
 A. lactucae Rost. is on lettuce; 
 
 A. aesculi Bub. & Kab. on ^^culus in Europe; 
 
 A. pallida Bub. & Kab. on Acer in Europe; 
 
 A. pruni Bul3. & Kab. on the cherry in Europe; 
 
 A. populicola Bub. & Kab. on the Silver Poplar in Europe; 
 
 A. dianthi Berk, on Dianthus and other pinks; 
 
 A. violae Sacc. causing spots on violet leaves; 
 
 A. digitalis Fcl. on digitalis; 
 
 A. iridis Oud. on Iris. 
 
 A. juglandis Bolt, causes spots on leaves of Juglans;^^ 
 
 A. aspidistras Mas. on Aspidistra. 
 
 A. fragariae Sacc. 
 
 Perithecia partly immersed, black, 100-125 n; conidia fusiform 
 to cylindric, constricted, 14-27 x 4-5.5 /jl. 
 
 This was reported by Dudley ^"^ as occurring in injurious form 
 near Rochester, N. Y., causing spots, at first red, later brown, 
 on strawberry leaves. 
 
 A. primulae Wail.^^ 
 
 Epiphyllous; pycnidia on discolored spots, scattered, depressed 
 globose, 100-110 /x, pale brown, papillate ostiolate; conidia cy- 
 lindric, obtuse, 5-6 x 2-2.5 fx. On Primula. 
 
 A. chrysanthemi Stev.°^ 
 
 Pycnidia few, immersed, early erumpent, single or scattered, 
 hemispheric, amber-colored, 100-200 n; ostiole central, small, 
 often raised bj^ a neck, dark-bordered; conidia oblong, straight 
 or irregular, 3-6.2 x 10-20 n, apically obtuse, septum often ob- 
 scure, sometimes more than one; not constricted till germination. 
 
 It causes blighting of ray flowers of chrysanthemums. 
 
 A. medicaginis Bres. 
 
 Spots small, angular, pale, clustered; pycnidia sublenticular, 
 apiculate, pale, becoming black, 200 x 160 n, context parenchy- 
 matous; conidia oblong, obtuse, scarcely constricted, 10-12 x 4- 
 
508 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 4.5 IX. According to Stewart, French & Wilson, spots are caused 
 on alfalfa.^^ The American form is distinct from the European 
 and has been described under the name A. imperfecta Pk.'^^^ 
 
 A. lycopersici Brum. 
 
 Spots red or brown, large, rounded or irregular; pycnidia sparse, 
 minute, black; conidia oblong, constructed, 8-10 x 2.5 ^i. 
 
 Spots are produced on leaves and fruits of egg plant. 
 
 A. caulicola Lau. causes injury to Melilotus alba.^°^ 
 
 A. cookei Mas. is reported on Sweet William. 
 
 A. corticola McA. is the cause of lemon l^ark-blotch in Australia, 
 killing the trees. ^°^ 
 
 A. graminicola Sacc. occurs on grasses and grains; 
 
 Fig. 351. — Actinonema rosae. 8, branching strand of superficial 
 mycelium; 4, spores. After Southworth. 
 
 A. manihotes Hen. on cassava in Africa. 
 A. tremulae Sacc. occurs on aspen; 
 A. melutispora B. & Br. on ash. 
 
 Actinonema Fries (p. 505) 
 
 Pycnidia very small, not ostiolate, with a radiating mycelial 
 growth on the surface of the host; conidia elongate, on short 
 conidiophores. 
 
 A genus of about fifteen species, chiefly leaf parasites, 
 
 A. rosae (Lib.) Fr.^^' ^^^ 
 
 Spots rounded or irregular, black or purple, epiphyllous, often 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 509 
 
 confluent, marginally fimbriate, the radiating fibers arachnoid, 
 white, distinctly branched; pycnidia tuberculariform, scattered 
 or confluent, black; conidia oblong, constricted, 18-20 x 5. n; 
 conidiophores short. 
 
 This fungus was first described in 1826. It is common on rose 
 leaves. The mycelium is in part subcuticular, in part deeper. 
 The subcuticular part is visible through the cuticle, consisting 
 of radiate strands each composed of several parallel hypha3. From 
 this mycelium branches penetrate deep into the leaf. The dark 
 color of the leaf spots is due to discoloration of the contents of the 
 diseased cells; the mycelium itself having little or no color. 
 
 A. tiliae All. causes defoliation of Tilia. 
 
 A. fagicola All. occurs on beech leaves; 
 
 A. fraxani All. on ash. 
 
 Diplodina Westendorp (p. 505) 
 
 Pycnidia immersed or erumpent, globose; ostiole papillate, 
 black, small; spores elongate. 
 It differs from Diplodia only 
 in the hyaline spores. 
 
 About eighty species chiefly 
 saprophytes. 
 
 D. citrullina (C. O. Sm.) 
 Gres. on cucurbs=Mycosph8e- 
 rella cirullina. See p. 246. 
 
 D. castaneae P. & D. in- 
 jures chestnut leaves, and 
 
 causes cankers on the shoots in France, resulting in serious 
 loss.^°2 
 
 D. parasitica (Hart.) Prill, occurs on the basal leaves of young 
 shoots of spruce causing defoliation. 
 
 D. salicina C. & M. causes tips of willows to die. 
 D. corticola A. & S. is found on cacao in Africa. 
 
 Fig. 352. — D. castanese, pycnidium and 
 spores. After Delacroix. 
 
 Sphaerioidaceae-Phaeodidymae (p. 480) 
 Conidia dark, 1-septate, ovoid to oblong. 
 
510 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Key to Sphaerioidaceae-Phaeodidymse 
 
 Pycnidia separate 
 Pycnidia beaked 
 
 Pycnidia hairy 1. Rhynchodiplodia, p. 510. 
 
 Pycnidia smooth 2. Pellioniella. 
 
 Pycnidia not beaked 
 
 Pycnidia hairy 3. Chaetodiplodia, p. 510. 
 
 Pycnidia smooth 
 
 Conidia with a mucous layer, 
 
 very large 4. Macrodiplodia. 
 
 Conidia without a mucous laj'cr 
 Pycnidia erumpent, conidia 
 muticate 
 Conidia less than 15 m long. 5. Microdiplodia, p. 510. 
 Conidia 15 ju or more long. 6. Diplodia, p. 511. 
 Pycnidia superficial, lignicole. 7. Diplodiella, p. 512. 
 Pycnidia cespitose or in a stroma 
 
 Pycnidia cespitose 8. Botryodiplodia, p. 513. 
 
 Pycnidia in a stroma 
 
 Pycnidia and subicle enclosed in a 
 
 hemispheric stroma 9. Lasiodiplodia, p. 513. 
 
 Pycnidia without subicle, in a 
 
 globose stroma 10. Diplodiopsis. 
 
 Rhynchodiplodia Briosi & Farneti 
 
 Pycnidia rostrate, pilose ; conidia oblong. 
 
 A single species, R. citri B. & F., causes disease of the lemon. 
 
 Chaetodiplodia Karsten 
 
 Pycnidia erumpent, globose, ostiolate, black, membrano- 
 carbonous, hairy or bristly; conidia elongate. 
 
 A genus of about ten species, chiefly saprophytes. 
 C. vanillae Zimm. is on vanilla. 
 
 Microdiplodia Allescher 
 
 Pycnidia subcuticular, erumpent, membranous to subcarbon- 
 ous, globose or depressed, minutely ostiolate; conidia ovoid to 
 oblong, small, (under 15 n.) 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 511 
 
 More than twenty-five species, chiefly saprophytes. 
 M. anthurii Trinch. occurs on Anthurium. 
 
 Diplodia Fries (p. 510) 
 
 Pj^cnidia immersed, erumpent, carbonoiis, black, usually 
 ostiolate-papillate; conidia ellipsoid or ovate; conidiophores 
 needle-shaped, simple, hyaline. 
 
 Over four hundred fifty species, many of them saprophytes. 
 
 D. zeae (Schw.) Lev.^"^"^'^^ 
 
 On ears and stalks of corn, pycnidia borne on the husks, cobs, 
 stalks and rarely the grains, gregarious, small, lenticular to flask- 
 shaped or irregular, papillate; conidia elliptic, straight or curved, 
 constricted or not, 25-30 x 6 ju. 
 
 It occurs as the cause of a very serious drj^ rot of ear corn. 
 
 The actual growing mycelium is hyaline and much branched. 
 
 Pycnidia in the cob are principally on the scales which surround 
 the inner ends of the kernels and are set in a dense mass of white 
 mycelium. On dead stalks 
 the pycnidia form below 
 the rind, particularly at 
 the nodes, breaking 
 through during the follow- 
 ing summer, and extruding 
 the spores in cirri. 
 
 The fungus was studied 
 extensively by Burrill & 
 Barrett ^°^ and inoculations 
 were made using pure cul- 
 tures. Spores placed under 
 the husk or in the silk, or sprayed upon plants in suspensions, re- 
 sulted in disease. 
 
 Smith and Hedges ^°^ report that infection is often by way of the 
 root system, the mycelium reaching the grains through the stem 
 and from the cob. 
 
 D. macrospora Ea. 
 
 Pycnidia scattered, large, erumpent, carbonous; conidia elon- 
 gate, irregularly clavate, curved or constricted, 70-80 x 6-8 //. 
 
 Fig. 353.- 
 nel 
 
 -Pycnidia of Diplodia, from corn ker- 
 After Burrill and Barrett. 
 
512 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 This is responsible for a corn mold similar to that caused by 
 the last species. ^°^ 
 
 Other parasitic species are : 
 
 D. oryzae Miy. on rice; 
 
 D. cerasorum Fcl. on cherries; 
 
 D. aurantii Catt. on oranges; 
 
 D. mori West, on Morus; 
 
 D. gongrogena Temme on Populus in Germany; 
 
 D. sapinea (Fr.) Fcl. on conifers; 
 
 D. pinea Kick, on pine leaves in Europe; 
 
 D. coffeicola Zimm. on coffee; 
 
 D. perseana Del. on the avocado. 
 
 D. opuntiae Sacc. is sometimes a serious pest of the cactus. 
 
 D. citricola McA. occurs in Australia on lemon twigs, stems 
 and green fruit. ^°^ 
 
 D. destruens McA. is on orange and lemon leaves in Australia; ^°^ 
 
 D. heteroclita D. & M. on Citrus in Algiers. ^"^ 
 
 D. cacaoicola Hen. does much injury to cacao and sugar 
 cane ''*^ in the West Indies. 
 
 D. natalensis Ev. causes a serious black rot of citrus fruits in the 
 Transvaal; ^°^ 
 
 Pycnidia scattered, covered, later erumpent, black; papillate 
 150-180 n; spores elliptical, 1-septate, not constricted, dark, 24 
 X 15 fx, exospore with striated bands. 
 
 A Diplodia which cannot be distinguished from this was studied 
 l)y Fawcett and Burger and is reported as the cause of gum- 
 mosis of peach and orange in Florida. "^^ Pure culture inoculations 
 and cross inoculation showed the same fungus able to cause the 
 disease on both hosts. 
 
 D. rapax Mas. is the cause of a stem disease of Para rubber. 
 
 D. epicocos Cke. grows on the coconut and an undetermined 
 species attacks ripe pineapples. 
 
 Diplodiella Karsten (p. 510) 
 
 Pycnidia superficial, globose, ostiolate papillate, black, smooth, 
 rather carbonous; conidia elliptic. 
 
 About twenty-five species, chiefly saprophytes on wood. 
 D. oryzae Miy. is found on rice. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 513 
 
 Botryodiplodia Saccardo (p. 510) 
 
 Pycnidia botryose-confluent, erumpent, stromatic, membrano- 
 carbonous, black, usually ostiolate-papillate ; conidia elongate or 
 ovate. 
 
 Over thirty species, chiefly saprophj^es. 
 
 An unnamed species of this genus is given by Butler as the 
 probable cause of a coconut palm disease in India. ^°^ 
 
 Lasiodiplodia Ellis & Everhart (p. 510) 
 
 Pycnidia collected on a stroma, 2 0^ ^ ^ 
 covered with a brown mycelium, paraph- ir_,', 
 
 yses among the conidiophores. Other- z;^^" -^ 
 
 wise as in Diplodia. 
 
 Two species, both parasites. 
 
 L. tubericola E. & E.^i" 
 
 Pycnidia globose, 250-305 n; stro- 
 matic mass about 1 mm. in diameter; co- ^ 
 nidia elliptic, 18-22 x 11-14 ju, not con- ^\- 
 stricted; conidiophores short; paraph- ^-r 
 yses 45-55 n long, overtopping the '-'■^^=^^ 
 
 conidia. ■^'"^- 354.-^Lasiodiplodia tu- 
 
 bericola. Perithecium, pa- 
 It was found on sweet potatoes from raphyses and spores. After 
 
 Java which were brought to the 
 Louisiana Experiment Station in 1894. 
 L. theobromae (Pat.) G. & M. is a wound parasite of Hevea. 
 
 Sphaerioidacese-Hyalophragmiae (p. 480) 
 Conidia hyaline, 2 to many-septate, oblong to fusoid. 
 
 Key to Genera of Sphaerioidaceae-Hyalophragmiae 
 
 Pycnidia more or less globose 
 Subicle none 
 
 Conidia appendaged at apex 
 
 Setse 1 1 . Kellermania. 
 
 Setae 3 2. Bartalinia. 
 
514 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Conidia muticate 3. Stagonospora, p. 514. 
 
 Subicle present, dark, phyllogenous 4. Asterostomidium. 
 
 Pycnidia elongate to cylindric 5. Mastomyces, p. 514. 
 
 Stagonospora Saccardo 
 
 Pyenidia superficial or erumpent, 
 globose, ostiolate-papillate, black, 
 membranous or subcarbonous ; co- 
 nidia elongate, 3 or more-celled. 
 
 Over one hundred species, chiefly 
 saprophytes; differing from Hen- 
 dersonia only in the hyaline conidia. 
 
 S. carpathica Batumi. 
 
 Spots circular, 1-3 mm., light 
 browTi with a narrow darker border; 
 pycnidia 120-180 ju; conidia escaping 
 in a gelatinous mass, straight or 
 M, 2 to 5-celled, frequently slightly 
 
 Fig. 355. — Stagonospora. C, pyc- 
 nidium in section. D, spores 
 After Corda. 
 
 slightly curved, 14-28 x 4 
 constricted.^^ It causes leaf spots on alfalfa. 
 S. iridis Mass. occurs on iris. 
 
 Mastomyces Mont. 
 
 Pycnidia gregarious, separate, erumpent, elongate, papillate- 
 ostiolate; conidia fusiform, 3-septate. 
 
 There are two species, one of which, M. friesii Mont., is 
 probably the conidial form of Scleroderris ribesia, see p. 155, the 
 cause of a relatively unimportant currant disease of Europe. 
 
 Sphserioidaceae-Phaeophragmiae (p. 480) 
 Conidia hyaline, 2 to several-septate, oblong to fusoid. 
 
 Key to Genera of Sphaerioidaceae-Phaeophragmiae 
 
 Pycnidia separate 
 Pycnidia not beaked 
 
 Conidia free from each other 
 Conidia muticate 
 
 Pycnidia papillate or subastomous 
 
 Pycnidia with flattened base 1. Macrobatis. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 515 
 
 Pycnidia globose, without flat- 
 tened base but on a stellate 
 
 superficial subicle 2. Couturea. 
 
 Pycnidia without a subicle, 
 erumpent 
 
 Pycnidia hairy 3. Wojnowicia. 
 
 Pycnidia smooth 4. Hendersonia, p. 515. 
 
 Pycnidia opening widely, with an 
 operculum 
 Pycnidia superficial, dark, hairy 5. Angiopoma. 
 Pycnidia immersed, pale, smooth 6. Lichenopsis. 
 Conidia appendaged 
 
 Conidia 1-ciliate at each end 7. Cryptostictis, p. 516. 
 
 Conidia 1-ciliate at base 8. Urohendersonia. 
 
 Conidia with a round or cup-like 
 
 appendage at each end 9. Santiella. 
 
 Conidia united in groups 
 
 Conidia united into a fascicle 10. Eriosporina. 
 
 Conidia stellately united 11. Prosthemium. 
 
 Pycnidia beaked 12. Pseudographium. 
 
 Pycnidia in a stroma 13. Hendersonula, p. 516. 
 
 Hendersonia Berkley 
 
 Pycnidia immersed, erumpent or not, 
 globose with a papillate ostiole or depressed, 
 membranous or subcarbonous; conidia elon- 
 gate or fusoid, 2 to many-septate. 
 
 Some two hundred fifty species, chiefly 
 saprophytic, although there are several para- 
 sitic species. 
 
 H. mail Thiim. 
 
 Epiphyllous; pycnidia disciform, large, 
 scattered, black, on brownish, orbicular, 
 violet-margined spots; conidia clavate, apex 
 rounded, base somewhat acute, not constricted, 12-14 x 4-5 m- 
 
 On leaves of apple in Europe and America. 
 
 H. piricola Sacc. is on pear; H. cydonae C. & E. on quince; 
 
 H. acicola INI. & T. causes a pine leaf disease.^^^ 
 
 H. cofifeae Del. is on coffee; 
 
 Fig. 356. — Hender- 
 son i a, hymenium 
 and spores. After 
 Starback. 
 
516 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 H. oryzae Miy. on rice; 
 
 H. notha Sacc. & Br, on Juniperus leaves; 
 
 H. togniniana Poll, on Cycas. 
 
 H. foliicola (Berk.) Fcl.^^^ 
 
 Pycnidia epiphyllous, broA\Tiish-black, subglobose, subelliptic 
 or irregular; conidia elliptic to clavate, obtuse, 3 to 5-septate; conid- 
 iophores filiform, radiating. On Juniperus and Pine. 
 
 Cryptostictis Fuckel (p. 515) 
 
 Pycnidia erumpent, globose or depressed, 
 ostiolate; conidia elongate, 2 or more septate, 
 subapically appendiculate with a long hyaline 
 bristle. It differs from Hendersonia chiefly in 
 spore characters. 
 
 A small genus of eleven species, chiefly sapro- 
 
 FiG. .357.— Cryptos- phytes. 
 
 tictis, spores. Af- Q^ cvnosbati (Fcl.) Sacc. and 
 
 ter Starback. ^ , .-^ \ r, 
 
 C. caudata (Preu.) Sacc. occur on the rose, 
 the former on the fruit and branches forming wounds. 
 
 Hendersonula Speg. (p. 515) 
 
 Stroma black, irregular; ostioles punctiform; spores ellipsoid, 
 several-celled, colored. In part =Plowrightia. 
 
 A form on the plum=Plowrightia morbosa. See p. 218. 
 
 Sphaerioidaceae-Phaeodictyse (p. 480) 
 
 Conidia dark, muriform, oblong to ovoid, rarely radiate or 
 cruciate. 
 
 Key to Genera of Sphaerioidaceae-Phaeodictyae 
 
 Pycnidia separate 
 
 Conidia not reticulate 
 
 Pycnidia on bark, erumpent 1. Camarosporium, p. 517. 
 
 Pycnidia on wood, superficial 2. Cytosporium. 
 
 Conidia reticulate 3. Endobotrya. 
 
 Pycnidia merely locules in a stroma 4. Dichomera. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 517 
 
 Camarosporium Schulzer von Miiggenburg (p. 516) 
 
 Pycnidia immersed, erumpent, separate, 
 globose, ostiolate, papillate, carbonous or 
 submembranous; conidia ovate to fusiform, ^ 
 
 muriform, with 2 to many cross walls. 
 
 Over one hundred twenty species, chiefly Pf^ f^-L 
 saprophytes. V^ i^"^ 
 
 C. fissum (Pers.) Star, causes injury to ^' ^'^ 
 
 roses. ' ^ 
 
 C. viticola (Cke. & H.) Sacc. is reported on 
 
 grape; Fig. 358. — Camaro- 
 
 C. CI T\T sporium, spores. 
 
 . men Sacc. on MorUS. After Starback. 
 
 Sphaerioidaceae-Scolecosporae (p. 480) 
 
 Conidia hyaline or light colored, elongate-fusoid, rod-shaped 
 or filiform, continuous or septate. 
 
 Key to Genera of Sphaerioidaceae-Scolecosporse 
 
 Pycnidia separate 
 
 Pycnidia membranous or carbonous 
 Pycnidia superficial 
 Pycnidia hairy 
 
 Conidia single on the conidiophores 1. TrichocoIIonema. 
 Conidia ternate on the conidio- 
 phores 2. Gamospora. 
 
 Pycnidia smooth 
 
 Pycnidia beaked 3. Cornularia. 
 
 Pycnidia not beaked 
 
 Conidia usually expelled in a ball 4. CoUonema. 
 Conidia not expelled in a ball. . 5. Septorella. 
 ycnidia immersed or erumpent 
 
 Pycnidia hairy, maculicole 6. Trichoseptoria, p. 518. 
 
 Pycnidia smooth 
 
 Pycnidia beaked 7. Sphaerographium. 
 
 Pycnidia not beaked 
 
 Pycnidia maculicole, mainly 
 phyllogenous 
 
 Conidia hyaline 8. Septoria, p. 518. 
 
 Conidia colored 9. Phaeoseptoria, p. 525. 
 
518 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Pycnidia not maculicole 
 
 Pycnidia complete at top, 
 
 usually papillate 10. Rhabdospora, p. 525. 
 
 Pycnidia more or less incom- 
 plete at top 
 Pycnidia gaping, showing a 
 
 gelatinous spore mass. 11. Gelatinosporium. 
 Pycnidia not exposing a ge- 
 latinous mass 
 
 Pycnidia foliicole 12. Phleospora, p. 525. 
 
 Pycnidia rami-caulicole. . 13. Phlyctaena. 
 Pycnidia suberose, incomplete, often pale 
 
 Pycnidia cespitose 14. Micropera. 
 
 Pycnidia merely gregarious 15. Micula. 
 
 Pycnidia in a stroma 
 Conidia 4 to 6-fasciculate on a conidio- 
 
 phore 16. Eriospora. 
 
 Conidia separate 
 
 Conidia setose-penicillate 17. Dilophospora, p. 525. 
 
 Conidia muticate 
 
 Stroma superficial, setose 18. Septodothideopsis. 
 
 Stroma erumpent or immersed 
 Pycnidia distinct in the stroma, 
 
 conidia hyaline 19. Cytosporina, p. 526. 
 
 Pycnidia as locules in the stroma, 
 
 conidia colored 20. Septosporiella. 
 
 Trichoseptoria Cavara (p. 517) 
 
 Pycnidia separate, erumpent, on spots, membranous, hairy; 
 conidia needle-shaped, septate. 
 
 A single species. T. alpei Cav.^^^ is reported by Cavara as 
 injurious to lemon fruits in Italy. 
 
 Septoria Fries (p. 517) 
 
 Pycnidia immersed, usually on leaf spots, globose lenticular, 
 ostiolate, membranous, black; conidia narrowly elongate to fili- 
 form, multiseptate, hyaline, conidiophores very short. 
 
 Over nine hundred species, all parasitic, several of them of 
 considerable economic importance but most of them occurring on 
 non-economic hosts. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 519 
 
 In part=Mycosph3erella, Leptosphcpria. 
 
 The genus is a very large one similar to Phoma and Phyllosticta 
 except in its spore form and in the ostiole which is frequently 
 very large. Septoria and Phleospora are distinguished only by 
 the lesser development of the walls of the latter and many species 
 which in early stages pass as Phleospora would in older stages be 
 classed as Septoria. 
 
 Septoria and Rhabdospora are distinguished only by the part 
 of the host affected, stem or leaf, and many forms in these two 
 genera are undoubtedly identical. 
 
 S. pisi West, is on peas. 
 
 S. piricola Desm. on pear and apple = My cosphserella sentina. 
 See p. 246. 
 
 S. populi Desm. on Populus=Mycosph8erella populi. See p. 250. 
 
 S. phlogis Sacc. & Speg. on Phlox =Leptosph2eria phlogis. See 
 p. 258. 
 
 S. ribis Desm.^^^ 
 
 Hypophyllous; spots small, irregular, bounded by the leaf veins, 
 brownish-purple ; pycnidia in- 
 nate, minute, convex, brownish- 
 black; cirri in mass reddish; co- 
 nidia elongate, linear, curved, 
 50 fjL long. 
 
 On gooseljerry and currant, 
 causing leaf spots and defolia- 
 tion. 
 
 S. aciculosa E. & E. Fig. 359.— S. nbis, a pyemdium and 
 
 Pycnidia innate to superficial, ^p"^*^^- ^^t^'" ^^""gyear. 
 
 grouped, minute, amphigenous; conidia needle-shaped, continuous, 
 15-20 x 0.75 ^l. 
 
 It is found on the strawberry. 
 
 S. fragariae Desm. 
 
 Epiphyllous; spots suborbicular, brown, wdth reddish-brown 
 margin; pycnidia minute, innate, prominent, brownish; cirri white; 
 conidia cylindric, obtuse, 3-septate. 
 
 Perhaps =Mycosph8erella fragariae. See p. 244. 
 
 On strawberry, cultivated and wild, forming circular leaf 
 spots. 
 
520 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 S. cerasina Pk.^^^ 
 
 Spots scattered or confluent, minute, subangular, b^o^\^l or 
 reddish-brown; pycnidia pale, collapsing; conidia filiform, straight 
 or curved, 50-75 jj. long. On cherry. 
 
 S. pruni E.^^^ 
 
 Spots dark brown, dry, subrotund, soon breaking out, 1-3 mm. ; 
 pycnidia brown, immersed, 60 m; conidia linear, obtuse, 4 to 
 6-septate, 30-50 x 2 /x. On plum. 
 
 S. limonum Pass, and S. sicula Penz, occur on citrus; 
 
 S. glaucescens Trab. on the mandarin; 
 
 S. loefgreni N. on oranges in Brazil; 
 
 S. ampelina B. & C. on the grape. 
 
 S. longispora Sh. (not Miy.) is found on the cranberry.^^^ 
 
 S. graminum Desm.^^^"^^^ 
 
 Spots slightly elongate, pale, fuscous-margined, limited by the 
 leaf veins; pycnidia seriate or scattered, brownish; conidia very 
 slender, straight or curved, non-septate, but multiguttulate, 
 55-75 X 1-1.3 /x. 
 
 This is a frequent saprophyte or weak parasite on wheat, oats 
 and numerous wild grasses. Under some conditions it becomes 
 an injurious parasite, especially upon winter wheat. 
 
 S. tritici Desm. is closely Hke S. graminum. ^^^ 
 
 It is associated with Leptospheeria tritici on wheat. See 
 p. 258. 
 
 S. glumarum Pass, is also found on wheat. 
 
 S. nodorum Berk, occurs, particularly at the nodes, on the same 
 host. 
 
 S. secalina Jancz. is on wheat and rye leaf sheaths; 
 
 S. avenae Frank, on leaves of oat. 
 
 S. longispora Miy. (not Shear) and S. curvula Miy. are on 
 rice. 
 
 S. betaB West. 
 
 Spots pale brown, white in the center, brownish-margined; 
 pycnidia epiphyllous, minute, black, prominent; conidia cylindric, 
 straight or curved, white in mass. 
 
 It was noted by Humphrey ^^^ causing a beet leaf spot. 
 
 S. citruUi E. & E. 
 
 Spots small, round, white, scattered; pycnidia mostly solitary, 
 
THE FUNGI WHICH CAUSE PLAxNT DISEASE 
 
 521 
 
 one in the center of each spot, but slightly prominent; conidia 
 cylindric or clavate-cylindric, 10-25 x 1.5-2 jx. 
 
 On watermelon leaves. 
 
 S. cucurbitacearum Sacc. is also on cucurbits. ^^ 
 
 S. cannabina Pk. is on hemp producing leaf spots. 
 
 S. nicotianae Pat. is reported from France as the cause of tobacco 
 leaf spotting. ^^"^ 
 
 S. dolichi B. & C. 
 
 Spots white, with a broad, light brown margin; conidia straight, 
 subfusiform, 3-septate, 40 /x. On cowpeas.^^^ 
 
 S. medicaginis Rob. & Desm. is on alfalfa. 
 
 Spots whitish, angulate-subcircular, confluent; pycnidia len- 
 ticular, 70-90 m; conidia slender, vermiform, tortuous, 60-70 x 1 /i, 
 septate. 
 
 S. petroselini Desm. 
 
 Spots brown, in age white, amphigenous; pycnidia epiphyllous, 
 minute, olivaceous, promi- 
 nent; conidia filiform, straight 
 or curved, 35-40 x 1-2 ju- On 
 parsley. 
 
 S. petroselini apii Br. & 
 
 CaV.25' 122-126 
 
 This common and very de- 
 structive fungus on celery 
 leaves was first described in 
 Italy by Cavara and in 
 America it was early noted 
 by Chester ^^s and Halsted.^'^ 
 The pycnidia are abundant in 
 the leaf spots and in the case 
 of stored celery they are 
 found scattered over the blanched petioles 
 a host variety. 
 
 S. lycopersici Speg.^^' ^"^' ^^^ 
 
 Spots large, often confluent and covering the entire leaf, sordid 
 cinereous, subindeterminate ; pycnidia scattered, hypophyllous, 
 lenticular-hemispheric, prominent, membranous; conidia elongate, 
 cylindric, 70-110 x 3.3 ^i, pluriseptate. 
 
 Fig. 360. — S. petroselini apii. Pycnidiuni 
 showing spores oozing through the ostiole. 
 After Jensen. 
 
 Essentially it is only 
 
522 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 The cause of leaf spots of tomato. It was noted in New Jersey 
 about 1893 ^^'^ and in Ohio in 1896.^-^ It is one of the serious 
 tomato pests. 
 
 S. lactucae Pass.''^" 
 
 Spots irregular, brownish, angulate, sometimes destroying the 
 entire leaf, pycnidia minute, punctiform, scattered, 90 n in 
 diameter, conidia filiform, straight or curved, 25- 
 30 X 1.7-2 n. 
 On lettuce. 
 
 S. consimilis E. & M.^^ 
 
 Distinguishable from the preceding by the more 
 indefinite spots, slightly larger pycnidia (90-100 n) 
 and longer conidia (30-45 x 2-2.5 n). It causes 
 brown spots on lettuce leaves. 
 Fig. ^.-Spores S. armoraciae Sacc.^^ 
 of s. lycopcrsici. Spots irregular, ochraceous; pycnidia puncti- 
 form, grouped in the center of the spot, 60 n; 
 conidia filiform, curved, 15-20 x 2-2.5 fx, 1 to 3-septate. On 
 horseradish causing leaf spot. 
 
 S. antirrhini Desm. attacks the snapdragon severely. ^-^ 
 S. rosae Desm. is on rose; 
 S. hydrangese Bizz. on cultivated hydrangea; 
 S. iridis C. Mass. on Iris. 
 S. cyclaminis Dur. & M. on cyclamen. 
 S. sedi West. 
 
 Epiphyllous; spots circular, gray to gray-brown; pycnidia mi- 
 nute, numerous, brown, scattered, erumpent; conidia cyHndric, 
 straight or curved, 5-guttulate; cirri white. On cultivated Sedum. 
 S. hederae West, is on Hedera; 
 
 S. rostrupii Sacc. & Syd. and S. varians Jaff. on chrysanthe- 
 mum; as is also: 
 
 S. chrysanthemella Cav. ' Spots ochraceous, dark mar- 
 gined; pycnidia epiphyllous, punctiform; conidia 40-50 x 2.5-2 n, 
 obscurely septate. 
 
 It causes damping off of chrysanthemum cuttings and spotting 
 of the leaves. ^^^ 
 S. dianthi Desm.^^ 
 Spots yellowish, oblong, roundish or irregular; pycnidia globose, 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 523 
 
 depressed, brownish-black; cirri white; conidia elongate, cylindric, 
 curved, obtuse, 30-45 x 4 /x. 
 
 It is the cause of a common and injurious leaf spot of the car- 
 nation. The pycnidia are visible as dark specks on the blanched 
 background of the spot. 
 
 S. azaleae Vogl. 
 
 Spots reddish-yellow; pycnidia amphigenous, immersed, globose 
 to depressed, black; conidia oblong cylindric, filiform, straight or 
 curved, 1 to 3 or more septate, constricted slightly at the septa, 
 12-18 X 1.5-2.5 At; conidiophores cylindric, short, 3-5 m long. 
 
 On Azalea. 
 
 S. divaricatae E. & E. 
 
 Spots whitish, amphigenous, confluent, purple-bordered; pyc- 
 nidia numerous, epiphyllous, lenticular, 100-120 n, dull black; 
 conidia 18-30 x 0.75-1 /x, nearly straight, non-septate, finely 
 guttulate. 
 
 It frequently injures cultivated phlox. ^* 
 
 S. narcissi Cass, is on Narcissus. 
 
 S. exotica Speg. is on Veronicas in cultivation. 
 
 S. fairmanii E. & E. 
 
 Spots amphigenous, scattered, subangular, 3-4 mm. dark 
 brown, limited by the veins, with a narrow dark margin; pycnidia 
 epiphyllous, scattered, rather numerous, black, subprominent, 
 100-112 ijl; conidia filiform, slightly curved, guttulate, 30-45 x 
 1.5-2 M. 
 
 It parasitizes hollyhock leaves. ^^ 
 
 S. parasitica Fau. 
 
 Spots amphigenous, white; pycnidia punctiform, innate; conidia 
 cylindric, 30-40 x 3.5-4 n. 
 
 The conidia are broader than in the preceding species and the 
 gross appearance is quite different. It is found associated with 
 rust sori on hollyhock. ^^ 
 
 S. helianthi E. & K. 
 
 Spots brown, definite, 2.5-7.5 mm. with a yellowish elevated 
 margin; pycnidia epiphyllous, immersed, brown, collapsing, 105 fx; 
 conidia linear-filiform, 3 to 5-septate, 30-70 x 2-3 /x-^^" 
 
 On sunflower leaves. 
 
 S. majalis Aderh. causes a leaf spot of lily-of-the-valley; 
 
524 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 S. oleandrina Sacc. In leaf spots of oleander. 
 
 S. veronicae Desm. 
 
 Spots amphigenous, small, subrotund, brownish or grayish, 
 becoming white, border umbrinous; pycnidia epiphyllous, glo- 
 bose, prominent, pale brownish-black; conidia elongate, slender, 
 straight or flexuose. 
 
 It is parasitic on cultivated Veronicas.^* 
 
 S. caraganae Hen. is on Caragana. 
 
 S. ochroleuca B. & C. 
 
 Spots scattered, suljorbicular, pale, brown margined; pycnidia 
 central, minute, scattered, hypophyllous, pale, collapsing; conidia 
 fusoid-filiform, curved, continuous or 1-septate, 25 ^ long. 
 
 In leaf spots on chestnut. 
 
 S. castanicola Desm. and S. castanea Lev. are on chestnut; 
 S. nigro-maculans Thiim. on walnuts and horse-chestnut; 
 
 S. aesculi Lib. and S. hippocastani B. & Br. on horse- 
 chestnut. 
 . S. pseudoplatini R. & D. occurs on sycamore and maple; 
 
 S. fraxani Desm. on ash; 
 
 S. cercidis Fr. on Cercis; 
 
 S. tiliae West, on I'ilia; 
 
 S. curvata (R. & B.) Sacc. on Robinia leaves. 
 
 S. spadicea P. & C.^^^ causes a common twig blight of 
 pine. 
 
 Pycnidia not spot-forming, late, becoming slightly erumpent 
 on inner surface of browning needles, scattered, membranous, 
 fuscous-olivaceous, subimmersed, 190-225 m in diameter. Spores 
 hyaline, cylindrical, slightly curved or flexuous, apex acute, 
 1-septate, rarely constricted at septum, 3-4 x 30-45 ju- Conidio- 
 phores short. 
 
 S. ulmariae Oud. Pycnidia minute, immersed, spores cylindric, 
 curved, hyaline, continuous, 5.0 x 2.5 /x. On Spirea. 
 
 S. cornicola Desm. 
 
 Spot orbicular, margin dark purple; pycnidia epiphyllous, few, 
 black; spores cylindric, curved, 35-40 x 2-2.5 fx, obsolete 2 to 4- 
 ^septate, hyaline. On Cornus. 
 
 S. parasitica Hart, is found on young spruce buds killing the 
 lateral shoots. 
 
THE FUx\GI WHICH CAUSE PLANT DISEASE 525 
 
 Phaeoseptoria Miyabe (p. 517) 
 
 As in Septoria but with colored conidia. 
 P. oryzae jMiy. is on rice in Japan. 
 
 Rhabdospora Montaigne (p. 518) 
 
 Pycnidia innate, erumpent, globose or depressed, brown or 
 black; conidia as in Septoria. 
 
 Similar to Septoria, but on stems. 
 
 R. coffeicola Del. and R. coffeae Del. are on coffee; 
 
 R. theobromaB A. & S. on cacao; 
 
 R. oxycocci Sh. on cranberry. 
 
 R. rubi E. Pycnidia black, subglobose, innate, erumpent, 
 scattered, 100-195 /jl; conidia linear, curved, 3 to 4-septate, 40- 
 45 X 3 Ai. On blackberry. 
 
 Phleospora Wallroth (p. 518) 
 
 Pycnidia innate, imperfectly developed, and chiefly formed of 
 modified host tissue; conidia elongate-fusoid, thick, 2 to many- 
 septate. About twenty-five species of leaf parasites. 
 
 This genus closely approaches the Melanconiales in structure. 
 Several forms have been shown to be allied to Mycosphserella, e. g., 
 P. ulmi to M. ulmi. 
 
 P. mori (Lev.) Sacc. on Morus=CyHndrosporium mori =My- 
 cosphsella. 
 
 P. moricola (Pass). Sacc. on Morus is a conidial form of 
 Septoglceum mori. 
 
 P. aceris Lib. is found on maple and sycamore leaves; 
 
 P. oxycanthae Desm. on hawthorn leaves; 
 
 P. caraganae Jacz. on Caragana.^^^ 
 
 Dilophospora Desmazieres (p. 518) 
 
 Pycnidia globose, ostiolate, usually stromatic ; conidia cylindric, 
 unicellular, with hair-like appendages at each end. 
 In part =Dilophia. 
 D. graminis Desm. =Dilophia graminis. See p. 257. 
 
526 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Cytosporina Saccardo (p. 518) 
 
 Stroma valsoid, cushion-formed or tubercular; pycnidia sunken, 
 the ostiole erumpent; conidia filiform, curved, 1-celled. 
 
 Twenty species of bark and wood inhabiting fungi. 
 
 These are, in part at least, conidial forms of the Valsacese. 
 
 C. ribis Miy.^^^ occurs on currant and gooseberry bushes in 
 Holland attacking the cortex, later the wood, and killing the 
 shoots. 
 
 Nectrioidaceae (p. 479) 
 
 Pycnidia fleshy or waxy, light colored, globose, rarely cup- 
 shaped or hysterioid; stroma present or absent; conidia various, 
 usually hyaline. 
 
 This group contains some twenty-five genera none of which are 
 serious plant pathogens. Some are conidial forms of the ascigerous 
 fungi Aschersonia and Polystigma. 
 
 Key to Subfamilies and Groups of Nectrioidaceae 
 
 Pycnidia globose, ostiolate I. Zythieae. 
 
 Conidia 1-celled 
 
 Hyaline 1. Hyalosporae, p. 526. 
 
 Dark colored 2. Phaeosporae. 
 
 Conidia two-celled hyaline 3. Hyalodidymiae. 
 
 Conidia 3 to several-celled, hyaline 
 
 Elliptic to fusoid 4. Hyalophragmiae. 
 
 Bacillar to filiform 5. Scolecosporae. 
 
 Pycnidia cupulate or hysterioid II. OUuleae. 
 
 Zy thie se-Hy alosporae 
 
 Conidia hyaline, continuous, ovoid to elliptic. 
 
 Key to Genera of Zythiaceae-Hyalosporse 
 
 Pycnidia separate 
 Pycnidia smooth 
 Pycnidia beakless 
 Conidia in chains 1 . Sirozy thia. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 527 
 
 Conidia not in chains 
 
 Pycnidia on creeping hyphsD 2. Eurotiopsis. 
 
 Pycnidia without mycelium 
 Conidia spiny or cihate 
 
 Conidia spiny 3. Roumegueriella. 
 
 Conidia with several cilia at 
 
 apex 4. Ciliospora. 
 
 Conidia smooth 
 
 Pycnidia single-walled 
 Pycnidia more or less papil- 
 late 5. Zythia, p. 527. 
 
 Pycnidia with crateriform 
 
 ostiole 6. Libertiella. 
 
 Pycnidia cup-shaped 7. Lemalis. 
 
 Pycnidia with outer circum- 
 
 scissile wall 8. Dichlaena. 
 
 Pycnidia beaked 9. Sphaeronemella. 
 
 Pycnidia hairy or spiny 
 
 Pycnidia densely beset with conoid 
 
 1-cellcd setse 10. Muricularia. 
 
 Pycnidia with slender bristles or hairs 
 
 Hairs fasciculate 11. Collacystis. 
 
 Hairs separate 
 Hairs everywhere but at the apex 12. Chaetozythia. 
 Hairs only around the wide ostiole 13. Pseudozythia. 
 Pycnidia cespitose or in a stroma 
 
 Pycnidia cespitose, beaked; conidia in 
 
 chains 14. Treleasiella. 
 
 Pycnidia in a stroma 
 
 Stroma more or less pulvinate 
 
 Conidia fusoid 15. Aschersonia. 
 
 Conidia globose 16. Munkia. 
 
 Stroma fruticose, branched; conidia 
 
 bacillar 17. Hypocreodendron. 
 
 Zythia Fries 
 
 Pycnidia erumpent or superficial, globose, with more or less 
 evident papillate ostioles, white or bright colored; conidia ovate 
 or elongate. 
 
 Some twenty species. 
 
528 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Z. fragarise Lail). Is said to cause a strawberry disease. 
 
 Leptostromataceae (p. 479) 
 
 Pycnidia membranous or carbonous, black, more or less dis- 
 tinctly dimidiate, scutiform, astomous, ostiolate or cleft, erumpent 
 or superficial. Over two hundred species. 
 
 Key to Sections of Leptostromataceae. 
 
 Conidia l-celled 
 
 Hyaline 1. Hyalosporae, p. 528. 
 
 Colored 2. Phaeosporae, p. 531. 
 
 Conidia 2-celled 
 
 Hyaline 3. Hyalodydimae. 
 
 ■ Colored 4. Phaeodidymae. 
 
 Conidia 3 to several-celled 
 
 Hyaline 5. Hyalophragmiae, p. 531. 
 
 Colored 6. Phaeopharagmiae. 
 
 Conidia 1 to several-celled, filiform 7. Scolecosporae, p. 532. 
 
 Leptostromataceae-Hyalosporae 
 
 Conidia hyaline, l-celled, globose to ovoid. 
 
 Key to Genera of Leptostromataceae-Hyalosporse 
 
 Pycnidia separate 
 Pycnidia astomous or variously perforate, 
 but not cleft 
 Conidiophores lacking 
 Pycnidia on a subicle 
 
 Subicle of fumaginous hyphse 1. Eriothyrium. 
 
 Subicle of broad fibers 2. Trichopeltulum. 
 
 Pycnidia without subicle 
 Conidia muticate 
 
 Pycnidia stellately divided or 
 
 cleft 3. Actinothecium. 
 
 Pycnidia depressed-clypeate, not 
 
 stellate 4. Leptothyrium, p. 529. 
 
 Conidia setulose at each end 5. Tracyella. 
 
 Conidiophores present, cylindric 6. Piggotia, p. 530. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 529 
 
 Pycnidia more or less, clearly cleft length- 
 wise 
 
 Pycnidia elongate or lanceolate 7. Leptostroma, p. 530. 
 
 Pycnidia subcircular 8. Labrella, p. 530. 
 
 Pycnidia in a stroma 
 
 Stroma phyllogenous 9. Melasmia, p. 530. 
 
 Stroma growing on animal hairs 10. Trichophila. 
 
 3C' 
 
 Fig. 362.— Lepto- 
 thyrium o x y- 
 cocci. Four 
 spores. After 
 Sheai. 
 
 Leptothyrium Kunze & Schweinitz (p. 528) 
 
 Pycnidia superficial or erumpent, dimidiate, scutiform, mem- 
 brano-carbonous, black, coalescing or scattered, ostiole variable, 
 structure cellular; conidia ovoid-oblong to fusoid. 
 Some one hundred species. 
 
 In part=Gnomonia and Gnomoniella. 
 L. alneum (Lev.) Sacc. on alder = Gnomoniella 
 tubiformis. See p. 274. 
 
 L. pomi (M. & F.) Sacc.i=^«' ^^^ 
 Forming minute superficial black spots; pycnidia 
 differentiated in late winter, 25-100 ju; conidia el- 
 liptic, 12-14 X 2-3 IX. The mycelium of the spots breaks away 
 and probably functions as a reproductive body. 
 
 The fungus is common in sterile form on pomaceous fruits but 
 the sporing stages are rarely found. 
 
 L. periclymeni Desm., L. acerinum Ktz. and L. buxi Pass, are 
 on Lonicera, acer and box respectively. 
 L. oxycocci Sh. ^^^ 
 
 Pycnidia black, dimidiate, amphigenous, scattered, subco- 
 riaceous- to coriaceous, irregularly subglobose, 
 subepidermal, erumpent, rupturing irregularly; 
 conidia subfusoid, sometimes slightly curved, 
 pseudoseptate, 10-15 x 2.5-3 /x; conidiophores 
 simple, straight, tapering, slightly longer than 
 
 Wmm?' 
 
 Fig. 363.— Lepto 
 
 thyrium oxycocci. j-u„ p^nidiq 
 Section of a pyc- ^"^ COniQia. 
 
 nidium, showing Qn Cranberry. 
 
 its dimidiate char- _ , , . -r^ ^ 
 
 acter. After L. macrothecium Fcl. 
 
 '^' strawberry disease. 
 
 is said to cause a 
 
 L. peonae Br. & Cav. is on peony leaves. 
 
 L. parasiticum Poll, is on Cereus stems in Italy. 
 
530 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 An undetermined species has been reported as a "fly speck" on 
 cabbage. ^^^ 
 
 Piggotia Berkley & Brown (p. 528) 
 
 Pycnidia applanate, inequilateral, thin-membranous, later with 
 a stellate cap which is thrown off forcibly; conidia elongate or 
 cylindric. 
 
 A genus of less than ten species. 
 
 P. astroidea Berk. & Br. parasitizes elm leaves. 
 
 P. fraxini B. & C. 
 
 Perithecia hypophyllous; spores oblong, 5-7 /x long. On ash, 
 causing leaf spot. 
 
 Leptostroma Fries (p. 529) 
 
 Pycnidia dimidiate, subsuperficial, applanate, elongate, black, 
 more or less hysterioid; conidia ovate, elongate or allantoid. 
 In part = Hysteriaceae. There are some sixty species. 
 L. larcinum Fcl. on larch = My cosphserella larcina. See p. 249. 
 L. piricola B. & S. occurs on the pear; 
 L. punctiforme Wallr. on willow. 
 
 Labrella Fries (p. 529) 
 
 Pycnidia black, round, often indefinite; spores long, fusiform, 
 or spherical, hyaline, continuous. 
 
 L. piricola Bres. & Sacc. is on pear leaves; 
 L. coryli (Desm. & Rob.) Sacc. on Corylus. 
 
 Melasmia Levielle (p. 429) 
 
 Pycnidia dimidiate, carbonous, black, often on an effused black 
 stroma; conidia allantoid. 
 
 In part = Rhytisma. Over twenty species. 
 
 M. acerina Lev. is the conidial form of Rhytisma acerinum. 
 See p. 158. M. punctata S. & R. and M. salicina Lev. of the two 
 corresponding Rhytismas. See p. 158. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 531 
 
 Leptostromataceae-Phaeosporae (p. 528) 
 Conidia globose to oblong, 1-celled, dark. 
 
 ICey to Genera of Leptostromataceae-Phaeosporae 
 
 Pycnidia separate 
 
 Pycnidia on a dark subicle, radiately de- 
 hiscent 1. Asterostomella. 
 
 Pycnidia not on a subicle 
 
 Conidia conglobate, verrucose 2. Discomycopsella. 
 
 Conidia not conglobate, smooth 3. Pirostoma, p. 531. 
 
 Pycnidia in a stroma 
 Stroma membranous 
 
 Pycnidia distinct, exserted 4. Peltostroma. 
 
 Pycnidia merely locules, immersed. ... 5. Lasmenia. 
 Stroma carbonous; locules many, 
 
 immersed 6. Poropeltis. 
 
 Pirostoma Fries 
 
 Pycnidia separate, shield-shaped, rounded or elongate, leathery, 
 conidia globose to ellipsoid. 
 
 A genus of less than five species. 
 
 P. farnetianum Poll, occurs on Pandanus in Italy. 
 
 Leptostromataceae-Hyalophragmiae (p. 528) 
 Conidia oblong to fusoid, hyaline, 2 to several-septate. 
 
 Key to Genera of Leptostromataceae-Hyalophragmiae 
 
 Pycnidia astomous or ostiolate, not cleft 
 Conidia muticate; pycnidia with creeping 
 
 hyph^e 1. Asterothyrium. 
 
 Conidia ciliate 
 
 Conidia fusoid, 1-ciliate at each end. . 2. Discosia, p. 531. 
 Conidia cruciate, each arm 1-ciliate. . 3. Entomosporium, p. 532. 
 Pycnidia rimose dehiscent 4. Cystothyrium. 
 
 Discosia pini Heald has been reported as a parasite on pine 
 hypocotyls. 
 
532 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Entomosporium Levielle (p. 531) 
 
 Pycnidia depressed, sul)globose, not ostiolate, black; conidia 
 4-celled, cruciate, each arm 1-ciliate. 
 
 A genus of three species of parasites. In part=Fabrea. 
 
 E. mespili (D. C.) Sacc. =F. mespih. See p. 150. 
 
 E. maculatum Rev. on pear and quince = F. maculata. See 
 p. 149. 
 
 E. thumenii (Cke.) Sacc. occurs on hawthorn. 
 
 Leptostromataceae-Scolecosporae (p. 528) 
 Conidia usually hyaline, linear or filiform, continuous or septate. 
 
 Key to Genera of Leptostromataceae-Scolecosporae 
 
 Pycnidia astomous or opening variousl^y 
 Pycnidia with a round ostiole; conidia 
 
 catenulate 1. Crandallia. 
 
 Pycnidia astomous or irregularly dehis- 
 cent 
 Pycnidia with radiate-fimbriate mar- 
 gin 2. Actinothyrium. 
 
 Pycnidia not radiate-fimbriate 
 
 Pycnidia of two kinds, small simple, 
 
 and large and loculate 3. Brunchorstia, p. 532. 
 
 Pycnidia of one kind 
 Conidia muticate 
 • Pycnidia corrugate, not hairy; 
 
 conidia not separating 4. Melophia. 
 
 Pycnidia hairy; conidia separat- 
 ing into joints 5. Chaetopeltis. 
 
 Conidia ciliate-penicillate at 
 
 apex 6. Giulia. 
 
 Pycnidia elongate, longitudinally cleft 7. Leptostromella, p. 533. 
 
 Brunchorstia Eriksson 
 
 Pycnidia erumpent, irregular in form, the smaller occurring 
 singly, the larger as chambers in a stroma, opening by an irregular 
 pore; conidia filiform, septate. A single species. 
 
 B. destruens Erik, on pine=Cenangium abietis. See p. 151. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 533 
 
 Leptostromella Saccardo (p. 532) 
 
 Pycnidia at first covered, at maturity apparently superficial, 
 depressed convex, subcarbonous, dark colored; conidia bacillar 
 or filiform, continuous or sep- 
 tate. 
 
 About twenty species, chiefly 
 of no economic importance. 
 
 L. elasticae E. & E. 
 
 Spots large, more or less el- 
 liptic, whitish, sordid, purplish 
 margined; pycnidia epiphyllous, j,,^_ 364.-Lcptostroi^i eiasticse. 
 hysterioid, 0.5-0.7 mm.; longi- After stone and Smith, 
 
 tudinally dehiscent; conidia oblong, hj^aline, continuous, 12-15 x 
 4-5 fj.; conidiophores 12-15 x 3-4 n; obtuse, subolivaceous. 
 
 The cause of leaf spots of Ficus elastica.-^^^ 
 
 Excipulaceae (p. 479) 
 
 Pycnidia membranous to carbonous, black, cup-shaped, patel- 
 late or hysterioid, at first more or less spherical but at length widely 
 open, erumpent or superficial, glabrous or hairy. 
 
 Key to Sections of Excipulaceae 
 
 Conidia globose to fusoid, continuous 
 
 Hyaline I. Hyalosporae, p. 533. 
 
 Colored II. Phasosporae. 
 
 Conidia 1-septate, hj^alinc III. Hyalodidymae, p. 53G. 
 
 Conidia 2 to several-septate 
 
 Hyaline IV. Hyalophragmiae. 
 
 Colored V. Phaeophragmiae. 
 
 Conidia filiform or bacillar VI. Scolecosporae, p. 536. 
 
 Excipulaceae-HyalosporaB 
 
 Conidia hyaline, continuous, globose to oblong. 
 
534 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Key to Genera of Excipulaceae-Hyalosporae 
 
 Pycnidia pilose or setose 
 Conidia muticate; pycnidia cupulate. ... 1. Amerosporium, p. 534. 
 Conidia ciliate; pycnidia cupulate 
 
 Conidia several-ciliate at apex 2. Polynema. 
 
 Conidia 1-ciliate at each end.- 3. Dinemasporium, p. 535. 
 
 Pycnidia smooth or nearly so 
 
 Pycnidia more or less cup-shaped, or dis- 
 ciform 
 Pycnidia black 
 
 Pycnidia composed of conglutinate 
 
 dark hyphae 4. Godroniella. 
 
 Pycnidia with cellular context 
 
 Pycnidia cup-like when mature, 
 sometimes obconoid 
 Conidiophores simple 
 
 Pycnidia cup-shaped 5. Excipula. 
 
 Pycnidia terete-conic 6. Catinula. 
 
 Conidiophores branched 7. Heteropatella. 
 
 Pycnidia subglobose, disciform or 
 verruciform 
 Pycnidia subglobose, irregularly 
 
 dehiscent and coUabent .... 8. Dothichiza, p. 535. 
 Pycnidia disciform, often im- 
 perfect and covered by 
 
 epidermis 9. Discula, p. 535. 
 
 Pycnidia verruciform; conidia 
 
 mucose-involute 10. Agyriellopsis. 
 
 Pycnidia purple 11. Lemalis. 
 
 Pycnidia hysterioid or valvately gaping 
 
 Pycnidia widely hysterioid 12. Psilospora. 
 
 Pycnidia valvately gaping 
 
 Conidiophores typically branched. . . 13. Sporonema, p. 535. 
 Conidiophores simple or none 14. Pleococcuin. 
 
 Amerosporium Spegazzini 
 
 Pj'cnidia subcupulate, setulose, conidia cylindric to ellipsoid. 
 Some twenty-five species, chiefly saprophytes. 
 A. oeconomicum E. & T. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 535 
 
 Spots orbicular, 2-6 mm., white above with a reddish border, 
 mostly entirely reddish below; pycnidia epiphyllous, erumpent, 
 conic-hemispheric, broadly perforate above, beset with straight, 
 spreading, grayish-black, septate bristles, 100-150 x 4 /*; conidia 
 oblong-fusoid, 18-27 x 4 /x. 
 
 Very common on cowpea leaves in circular spots, with dark 
 pycnidia in concentric circles on white background/^^ 
 
 Dinemasporium Levielle (p. 534) 
 
 Pycnidia cupuliform, superficial, black, with dark bristles; 
 conidia elongate or allantoid, with apical spines. 
 Some thirty species, chiefly saprophytes. 
 D. oryzae Miy. is on rice.^^ 
 
 Dothichiza Libert (p. 534) 
 
 Pycnidia erumpent, roundish, somewhat disculate, irregularly 
 dehiscent; conidia elongate or cylindric. In part =Cenangium. 
 About eleven species, chiefly saprophytes. 
 D. populea S. & B. parasitizes poplar.^"*" 
 
 Discula Saccardo (p. 534) 
 
 Pycnidia disciform-patellate, imperfectly differentiated from 
 the substratum; conidia ellipsoid, elongate or cylindric. 
 Some twenty-five or thirty species, chiefly saprophytes. 
 D. platani (Pk.) Sacc.=Gnomonia veneta. See p. 274. 
 
 Sporonema Desmazieres (p. 534) 
 
 Pycnidia subepidermal, erumpent, at first 
 closed, then opening radiately; conidia ovate 
 or cylindric. 
 
 Some sixteen species, chiefly saprophytes. 
 
 S. platani Baum on Platanus=Gnomonia Fig. 365. — Sporonema 
 
 ircr,o+o Qoo t^ 97/L oxycocci on cranberry 
 
 veneta. feee p. Z/4. leaf_ After Shear. 
 
 S. phacidioides Desm.=Pseudopeziza tri- 
 
 folii. See p. 148. 
 
 S. oxycocci Sh.'^^ 
 
 Pycnidia amphigenous, excipuliform, thickened at the base, 
 
536 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 gradually disappearing above, immersed, erumpent, depressed- 
 globose, gregarious or scattered, 50-100 m, sometimes collapsing 
 rupturing irregularly by a slit or triangular split; conidia cylindric, 
 straight, 17-19 x 3-4 //; conidiophores simple, oblong to subglobose, 
 about 34 the length of the spore, or less. On cranberry. 
 S. pulvinatum Sh. is also on cranberry. 
 
 Excipulaceae-Hyalodidymae (p. 533) 
 Conidia hyaline, 1-septate, oblong or fusoid. 
 
 Key to Genera of Excipulaceae-Hyalodidymae 
 
 Pycnidia discoid or patellate 
 
 Pycnidia discoid, veiled; conidiophores 
 
 simple 1. Discella, p. 536. 
 
 Pycnidia patellate, subsuperficial; conid- 
 iophores branched 2. Pseudopatella. 
 
 Pycnidia hysterioid or irregularly gaping 
 
 Pycnidia hysterioid, elongate 3. Scaphidium. 
 
 Pycnidia globose, then irregularly gaping; 
 
 conidia catenulate 4. Siropatella. 
 
 Discella Berkley & Broome 
 
 Pycnidia disco-patellate, imperfectly formed; conidia fusoid 
 or oblong. Some twelve or fifteen species, chiefly saprophytes. 
 
 D. cacaoicola A. & S. is on cacao in Africa. 
 
 The Excipulaceae-hyalophragmias, ExcipulacesB-phaeophragmiae 
 contain no important parasites. 
 
 Excipulaceae-Scolecosporae (p. 533) 
 
 Conidia typically hyaline, bacillar or filiform, continuous or 
 septate. 
 
 Key to Genera of Excipulaceae-Scolecosporae 
 
 Pycnidia separate 
 
 Conidia separating at the joints 1. Schizothyrella. 
 
 Conidia not separating 
 Pycnidia discoid, covered, erumpent, 
 
 margin lacerate; conidia filiform. . 2. Protostegia. 
 
THE FUNGI WPIICH CAUSE PLANT DISEASE 537 
 
 Pycnidia mostly cupulate, not lacerate; 
 
 coniclia hamate 3. Oncospora. 
 
 Pycnidia in a stroma 
 
 Pycnidia pezizoid 4. Ephelis, p. 5.'57. 
 
 Pycnidia superficial 5. Pseudocenangium. 
 
 Ephelis Fries 
 
 Stroma black, subeffused, sclerotioid; pycnidia pezizoid, sunken, 
 in the stroma; conidia cylindric to filiform. 
 
 Some seven species, chiefly of no economic importance. 
 It is a conidial form of Balansia. See p. 209. 
 
 Melanconiales (p. 479) 
 
 Mycelium internal; true pycnidia never developed, the conidio- 
 phores form a stratum; strata typically bearing conidia in acervuli 
 which are immersed or erumpent, black or light colored, waxy, 
 corneous or even submembranous, accompanied by setae or not; 
 conidia variable. 
 
 The common name " anthracnose" is applied to any disease 
 caused by a member of this order. 
 
 A single family Melanconiaceae which contains about forty-five 
 genera and over twelve hundred species. 
 
 Key to Sections of Melanconiaceae 
 
 Conidia globose to elongate 
 Conidia continuous 
 
 Hyaline I. Hyalosporae, p. 538. 
 
 Colored II. Phaeosporas, p. 553. 
 
 Conidia 1-septatc 
 
 Hyaline III. Hyalodidymae, p. 555. 
 
 Colored IV. Phaeodidymae, p. 556. 
 
 Conidia 2 to many septate 
 
 Hyaline V. Hyalophragmiae, p. 556. 
 
 Colored VI. Phaeophragmiae, p. 557. 
 
 Conidia muriform, dark VII. Phaeodictyae. 
 
 Conidia long-cylindric to filiform VIII. Scolecosporse, p. 561. 
 
 Conidia stellate IX. Staurosporae. 
 
538 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Melanconiaceae-Hyalosporse (p. 537) 
 Conidia hyaline, 1-celled, globose to oblong, rarely dilute colored. 
 
 Key to Genera of Melanconiaceae-Hyalosporae 
 
 Conidia muticate 
 Masses, or acervuli, not setose 
 Conidia not catenulate 
 Conidia not allantoid 
 Masses bright colored, subtremel- 
 
 loid 1. Hainesia. 
 
 Masses gray to black, rarely 
 
 bright colored, waxy or horny 
 
 Growing, for the most part, on 
 
 leaves or fruits 2. Glceosporium, p. 539. 
 
 Growing usually on twigs of trees 
 
 or shrubs 3. Myxosporium, p. 546. 
 
 Masses black, discoid, horny 4. Melanostroma. 
 
 Conidia allantoid 5. Naemospora, p. 547. 
 
 Conidia in chains 
 Masses oblong, hysterioid, dark, 
 
 hard 6. Hypoderinium, p. 547. 
 
 Masses discoid, pulvinate or conoid 
 
 Masses bright colored, soft 7. Myxosporella. 
 
 Masses dark to black 
 Conidiophores repeatedly 
 branched 
 Masses discoid; conidiophores 
 
 dichotomous 8. Blennoria. 
 
 Masses depressed-pulvinate; 
 
 conidiophores verticillate 9. Agyriella. 
 Conidiophores simple 
 
 Masses scutellate, olive or 
 
 ashen 10. Myxormia. 
 
 Masses truncate, black below, 
 
 pale above 11. Bloxamia. 
 
 Masses setose at margin; conidiophores 
 
 short, fasciculate 12. ColIetotrichum,p.547. 
 
 Conidia aristate with a branched awn at 
 
 apex 13. Pestalozziella. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 539 
 
 Gloeosporium and Colletotrichum are prominent in pathology as 
 the "anthracnose fungi" and cause many important diseases. The 
 two genera, separated only by the occurrence or non-occurrence of 
 setae, contain many species which have been transferred from one 
 of these genera to the other on this character, which is to some ex- 
 tent a variable one depending upon the supporting medium, con- 
 ditions of growth and the particular strain of the fungus under 
 observation. 
 
 Many form-species have been described solely on a basis of 
 the hosts affected. Subsequent culture study, and cross inocula- 
 tion has often failed to sustain these species so that many forms 
 that were formerly considered as distinct are now grouped under 
 one name. No satisfactory disposition of these forms can be made 
 until their ascigerous stages are known and compared and their 
 biologic relations investigated. 
 
 Such work as has been done (see page 267) leads rather to con- 
 solidation than to segregation of species. 
 
 For sake of clearness and convenience, mention is made below 
 of many form species of these two genera under their old names, 
 though the evidence now is that in many instances they should be 
 consolidated with other species. 
 
 Gloeosporium Desmazieres & Montaigne (p. 538) 
 
 Conidial layer subepidermal, disciform or pulvinate, usually 
 erumpent, pale or fuscous; conidia ovate, rarely oblong; conidio- 
 phores needle-shaped. 
 
 In part=Glomerella, Pseudopeziza, Gnomoniella, Gnomonia, 
 Trochila, Physalospora, Calospora. 
 
 There are over three hundred species of parasites, many of 
 them very important pathogens. The spores in germination 
 commonly form dark colored, thick-walled chlamydospores and 
 usually l)ecome 1-septate. 
 
 G. rufomaculans (Berk.) Thiim. on a large variety of hosts = 
 Glomerella rufomaculans. See p. 264. 
 
 G. melengonea E. & H. is reported on egg-plant fruits in New 
 Jersey ;^^ G. orbiculare Berk, on cucurbs; 
 
 G. fructigenum Berk, on many fruits. 
 
 G. laeticolor Berk, on peaches and apples and G. versicolor 
 
540 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 541 
 
 B. & C. on peaches are probably all identical with Glomerella 
 rufomaculans. 
 
 G. salicis West, on Salix=Pseudopeziza salicis. See p. 148. 
 
 G. piperatum E. & E. on pepper = Glomerella piperata. See 
 
 p. 269. 
 
 G. cylindrospermum (Bon.) Sacc. on Alnus = Gnomoniella tubi- 
 
 formis. See p. 274. 
 
 G. vanillse Cke. on orchids =Calospora vanillse. See p. 280. 
 G. macropus Sacc. on Cattleya=Physalospora cattleya. See 
 
 p. 253. 
 
 G. cinctum B. & C. on orcliids=Glomerella cincta. See p. 269. 
 G. paradoxum (de Not.) Fcl. on Hedera=Trochila craterium. 
 
 See p. 157. 
 
 G. cingulatum Atk. on privet = Glomerella cingulata. See 
 
 p. 268. 
 
 G. psidii Dei. on guava= Glomerella psidii. See p. 270. 
 
 G. atrocarpi Del. on Atrocarpus= Glomerella atrocarpi. See 
 
 p. 273. 
 
 G. nervisequum (Fcl.) Sacc. on sycamore =Gnomonia veneta. 
 
 See p. 274. 
 
 G. ribis (Lib.) M. & D. on Ribes=Pseudopeziza nbis. See 
 
 p. 148. 
 
 G. bicolor M. Cal. occurs on grapes in Australia. 
 
 G. ampelophagum (Pass.) Sacc.^^^"^^^ 
 
 Spots subcircular often confluent, from cortex of the berry, cen- 
 ters gray; margin dark or red. Acervuli subepidermal, minute, col- 
 lected; conidia oblong, ellipsoid or ovoid, 5-6 x 2-3 /x, hyaline. 
 
 Small dark spots are produced on fruit, leaf or cane of grape. 
 These later enlarge and show white centers with dark or even red 
 borders. The mycelium lies just below the epidermis. On shoots 
 the cambium is killed and cankers develop. Two kinds of spores 
 have been found by Viala and Pacottet^^^ one very small and linear, 
 the other larger and in Phoma-like pycnidia. Common in the 
 eastern United States and Europe. 
 
 G. depressum Penz. is on Citrus. 
 
 G. spegazzinii Sacc; and G. intermedium Sacc. grow on Citrus 
 fruits; G. citri Mas., G. hendersonii B. & Br. on oranges causing 
 leaf scorch in England, and Trinidad. 
 
542 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 G. variabile Laii. grows on Ribes alpinum. G. curvatum 
 Oud. is described as a currant parasite. 
 G. malicorticis Cor.^^ 
 
 Caulicolous; spots brownish, slightly depressed, irregular in 
 outline; acervuli minute, erumpent; conidia elliptic, curved, 
 
 hyaline or greenish-tinged, 
 granular, 24 x 6 ju- 
 
 On apples in northwestern 
 United States. Neofabrea has 
 been reported as genetically 
 connected. ^^^ 
 
 G. cydoniae Mont, is re- 
 corded as a parasite on the 
 quince. 
 
 G. musarum C. & M. is a 
 common wound parasite on 
 bananas. 
 
 Acervuli innate; erumpent, 
 gregarious, rose-tinged; conidia 
 elongate-ellipsoid, ends 
 rounded, 10-12 x 4-5 fx, gran- 
 ular. A variety, importatum, 
 is also recognized. 
 G. diospyri E. & E. 
 Acervuli on yellowish dis- 
 colored areas, innate, erumpent, epiphyllous, on the leaf veins, mi- 
 nute, tuberculiform, pale; conidia ovate, granular, 6-14 x 5-7 /x. 
 On persimmon. 
 G. fragariae (Lib.) Mont. 
 
 Spots indeterminate, red, epiphyllous; acervuli applanate, 
 rugulose, black; conidia cylindric, 4 to 5-guttulate. 
 On strawberries but not usually troublesome. 
 G. amygdalinum Brizi.^^^ occurs on the green fruit of the al- 
 mond in Italy. 
 
 G. venetum Speg.^^* "^'^^^ 
 
 Caulicolous or foliicolous; spots orbicular or elliptic, border 
 raised, darker, 2-3 mm. in diameter; conidia oblong, elliptic, 
 5-7 x 3 /i, in mass amber-colored. 
 
 Fig. 367. — G. malicorticis; a, acervulus; 
 E, germinating spore. After Cordley. 
 
THE FUNGI WHICH' CAUSE PLANT DISEASE 543 
 
 The fungus occurs on all aerial parts of the raspberry and is 
 wide-spread in Europe and America causing serious disease. On 
 canes small purple spots first show near the ground, enlarge and 
 soon develop ashen centers. The leaf spots are small, often 
 scarcely 1 mm. in diameter. 
 
 G. mangiferae Hen. is found on mango leaves in Cuba 
 and other West Indian Islands. 
 
 G. olivarum d'Alm. parasitizes olive fruit in Europe. 
 
 G. minus Sh. is on cranberry. ^^" 
 
 G. myrtilli All. is injurious to Vaccinium myrtillus. 
 
 G. cofifeanum Del. occurs on coffee in Java; 
 
 G. pestis Mass. on yam leaves in Fiji. 
 
 G. trifolii Pk.i'^^-i^^ 
 
 Spots subcuticular, brown, suborbicular, concentrically zonate; 
 conidia oblong to cylindric, obtuse, 15-23 x 4-6.3 fi. 
 
 The fungus was first observed in America and what was regarded 
 as the same was later seen in Europe as the cause of dying of stems 
 and leaves of clover. 
 
 G. caulivorum Kirch. ^^' 
 
 Caulicolous, spots forming long dark streaks, more or less sunken, 
 blackish-bordered; acervuli minute; conidia curved, more or less 
 pointed, 12-22 x 3-5 ju. 
 
 This was said by Kirchner (see ^^^) to be the cause of the more 
 serious European anthracnose affecting stem, fruit and leaf of 
 clover. Fulton ^^^ in 1910 reported it in America and showed that 
 pure cultures of the fungus readily produced infection in wounds or 
 even on un wounded succulent parts when in humid air. The conidia 
 have been knowTi to live twelve months. 
 
 G. morianum Sacc. is on alfalfa. 
 
 G. medicaginis E. & K. 
 
 Acervuli scattered, innate, blackish, rather large, visible on both 
 sides the leaf, opening below; conidia oblong, cylindric, granular, 
 subhyaline, more or less narrowed at the middle, 15-20 x 3-4 n. 
 
 On withered leaves and stems of alfalfa, defoliating the lower 
 part of the stem. 
 
 G. manihotis Hen. is found on Cassava in Africa. 
 
 G. lagenarium (Pass.) Sacc. on cucumbers is probably identical 
 with CoUetotrichum lindemuthianum. 
 
544 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 G. concentricum Grev. causes spotting of leaves of cabbage, 
 cauliflower, etc. 
 
 G. cattleyae (P. & D.) Sacc. grows on leaves of Cattleya; 
 G. dianthi Cke. on carnation in England. G. clematidis Sor. is 
 found on cultivated clematis stems j^''^ 
 
 G. rosae Hals.^^ is reported by Halsted on rose canes causing 
 injury similar to that of G. venetum on the raspberry. 
 
 G. mezerei Cke. is on Daphne. 
 
 G. affine Sacc. grows on various orchids and Hoya. G. oncidii 
 Oud. on Oncidium. 
 
 G. euphorbias Hals, is on clusters and stems of spurge."^ 
 
 G. stanhopeicola Hen., G. laeliae Hen. and G. pallidum Karst. 
 & Har. are on orchids; G. helicis (Desm.) Oud. on English ivy. 
 
 G. cactorum Ston. occurs on a number of species of cacti; 
 
 G. beyrodtii Klitz on Vanda; 
 
 G. opuntiae E. & E. on Opuntia; 
 
 G. elasticae C. & M. on Ficus; 
 
 G. bruneum Fetch, and G. alborubrum Fetch, on Hevea. 
 
 G. rhodendendri Br. & Cav. forms yellow spots on various 
 species of Rhododendron. 
 
 G. aquilegiae Thiim is on Aquilegia. 
 
 G. violaB B. & Br.i8 
 
 Spots pale, becoming whitish; acervuli very thin, solitary; 
 conidia yellowish. Causing leaf spots on cultivated violets. 
 
 G. cytisi B. & Br. is on laburnum; 
 « G. bidgoodii Cke. is on Oncichum; 
 
 G. pelargonii C. & M. on Felargonium. 
 
 G. crotonis Del. occurs on Codiaum. 
 
 G. soraurianum All. also on Codiseum leaves and described as 
 a dangerous parasite is perhaps identical with G. crotonis. 
 
 G. anthuriophilum Trinch. causes spots on Anthurium leaves. 
 
 G. begonias Magnag. is on begonias in Italy. 
 
 G. fagicolum Fass. is widespread and destructive to beech 
 in Germany. 
 
 G. umbrinellum B. & Br. is found on Quercus; 
 
 G. inconspicuum Cav. on elm; 
 
 G. theas-sinensis Miy. and G. theas Zimm. on tea in Japan and 
 Africa. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 545 
 
 G. allescheri Bres. and G. nanoti P. & D. (xx-ur on 
 Palms. 
 
 G. tiliaeOud. is a serious parasite on the twigs, petioles and leaves 
 on the linden in Denmark. 
 
 G. tiliaceum (AU.)^''^ said to be distinct from the above occurs 
 in Germany on Tilia. 
 
 G. juglandis (Lib.) Mont, causes a common, and serious leaf 
 blight of the butternut. ■^•'^ 
 
 G. fagi (D. & R.) West is on Fagus; 
 
 Spots subcircular, fuscous above, olivaceous, vitreous be- 
 neath; acervuh small, prominent, honey-colored; conidia oblong 
 ovate, 15-20 x 7-8 n, minutely 1 to 3-guttulate; conidiophores 
 fasciculate, cylindric, fuscous. 
 
 G. apocryptum E. & E. causes a nursery disease of maples 
 and of )30x elder. ^""^ 
 
 Acervuli numerous, minute, mostly hypophyllous, on dead areas 
 of the leaf; conicUa very variable in size, 5-12 x 23/2-5 n, oblong 
 to narrowly elliptic. 
 
 G. betularum E. & M. 
 
 Spots rounded, 2-3 mm., blackish margined; acervuli amphig- 
 enous, brownish, 120-140 fx, becoming cupulate; conidia hyaline, 
 obovate, 9-10 x 5-6 /x- 
 
 It is common on leaves of American birches. 
 
 Other common species on deciduous trees are: 
 
 G. tremulas (Lib.) Pass, on Populus; 
 
 G. betulinum West, on beech; 
 
 G. alneum West, on alder; 
 
 G. carpini (Lib.) Desm. on Carpinus; 
 
 G. coryli (Desm) Sacc. on Corylus; 
 
 G. quercinum West, on oak; 
 
 G. nervicolum Massal on oak. 
 
 G. kawakamii Miy. is found on Paulownia in Japan causing 
 witches' brooms. 
 
 G. saccharini E. & E. 
 
 Acervuli minute, numerous; spores oblong-fusoid, 6-7 x 1.5-3 n, 
 hyaline, continuous. On maple. 
 
 G. caryss E. & D. =Gnomonia caryse.^*^ 
 
 Spots suborbicular, 1-2 cm., margin subdefinite; acervuli 
 
545 
 
 THE FUNGI WHICH CAUSE PLAxNT DISEASE 
 
 hypophyllous, numerous, 75-150 n; spores allantoid, continuous, 
 7-10 X 1.5-2 /I. On Carya. 
 
 G. berberidis Cke. 
 
 Hypophyllous; acervuli collected, numerous; spores ovoid, 
 5 X 3 IX. On Barberry. 
 
 G. tamarindi Hem. is on tamarinds, in Africa. 
 
 G. canadense E. & E. 
 
 Spots amphigenous, center pale, border brownish; acervuli few, 
 
 Flu. 368. — M. corticolum, on apple twig. Alter 
 Edgerton. 
 
 180-200 m; spores ovate-oblong, hyaline, 10-14 x 3.5-4.5. 
 On white oak. 
 
 Myxosporium Link (p. 538) 
 
 Acervuli immersed or superficial, indefinite, pallid or reddish; 
 conidia ovate, hyaline or pale, conidiophores slender-cylindric. 
 
 Some seventy species, some of which are important pathogens. 
 
 In part=Gnomonia. See p. 274. 
 
 M. valsoideum (Sacc.) All. on sycamore =Gnomonia veneta. 
 See p. 274. 
 
 M. corticolum Edg. 
 
 Acervuli erumpent, originating under several layers of cortex, 
 1-2 mm. in diameter, scattered over the diseased area; conidia 
 straight or curved, cylindric, very densely granular, 18-36 x 6-9 
 M, oozing out of the pores in white cirri; conidiophores very 
 short. Very similar to an immature Sphseropsis malorum but 
 considered distinct by Stewart and his associates. ^^ 
 
 It forms bark cankers in pear and apple in America. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 547 
 
 M. longisporum Edg.^''^ 
 
 Acervuli erumijent, subcorticular, variable in size up to 1.5 mm., 
 scattered over the host in poorly defined rows; conidia straight 
 or curved, 30-48 x 12-15 n, oozing out in white cirri; conidio- 
 phores very short. 
 
 On twigs of Liriodendron. 
 
 Other parasitic species are: 
 
 M. piri Fcl. on pear; M. mali Bres. on apple; M. abietinum 
 Rost. on conifers; M. devastans Rost. on beech; M. lanceola S. & 
 R. on oak; M. carneum Lib. on beech twigs. 
 
 Naemaspora Persoon (p. 538) 
 
 Acervuli subgelatinous, indefinite, bright colored; conidia 
 allantoid, short, with a bristle at each end. 
 
 N. crocea (Bon.) Sacc. is reported by Massee as the cause of 
 die-back of peach shoots in England. ^^^ 
 
 Hypodermium Link (p. 538) 
 
 Acervuli subcuticular, erumpent, elongate, black; conidia ovate- 
 oblong, catenulate. 
 
 H. orchidearum Cke. is on Cymbidium. 
 
 Colletotrichum Corda (p. 538) 
 
 Acervuli innate erumpent, discoid or elongate, dark, surrounded 
 with long black setae; conidia terete to fusoid; conidiophores short. 
 
 The genus is distinguished from Gloeosporium by the presence 
 of setae, a somewhat unreliable character. See p. 539. 
 
 In part=Glomerella and Pseudopeziza. See pp. 264, 147. 
 
 Some eighty species, several of them very important plant path- 
 ogens. 
 
 C. gossypii Sout. on cotton =Glomerella gossypii. See p. 271. 
 
 C. cincta Ston. on orchids =Glomerella cincta. See p. 269. 
 
 C. rubicolum E. & E. on red raspberry =Glomerella rubicolor. 
 See p. 270. 
 
 C. lindemuthianum (Sacc. & Magnus) Briosi & Cavara.^*' ^^°' 
 
548 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Spots subelliptic to irregular, depressed, brownish; acervuli 
 scattered, surrounded by a few not very conspicuous black seta?; 
 conidia oblong, ends rounded, straight or curved, 15-19 x 3.5-5.5 
 ;u; conidiophores cylindric, simple, 45-55 ju. 
 
 This fungus, generally known as C. lindemuthianum, is accord- 
 
 ^nnmcmse Conker 
 
 Starcli Grains 
 
 Fig. 369. — C. lindemuthianum. Showing relation of the fungus 
 to the tissues of the bean. To the left above is a diagram of 
 a section across a bean pod through a canker. The drawing 
 below is a much enlarged largely diagrammatic view of a por- 
 tion of this same section. It shows how the mycelial threads 
 of the fungus may penetrate the seed coat and enter the 
 starchy tissue of the seed, there to remain dormant until the 
 following sea.son. On the left is a spore germinating and pene- 
 trating the epidermis. To the right a magnified view of spores, 
 one germinated. After Whetzel. 
 
 ing to the cultural studies of Shear & Wood (see p. 267), probably 
 a variety of Glomerella rufomaculans. See p. 264. 
 
 On the bean it attacks stems, leaves, cotyledons, or the pods, 
 producing sunken spots of dead tissue which bear the numerous 
 pink acervuli. It has l3een sho■\^^l that the mycelium on the fruit 
 may penetrate through the pericarp and into the seeds beneath 
 and there hibernate. 
 
 C. lagenarium (Pers.) E. & H. ^^^ is probably identical with 
 C. lindemuthianum. It is described as the cause of spots on fruit 
 leaves and stems of cucumbers, watermelons, squash, pumpkins 
 and citron. 
 
 C. oligochaetum Cav. grows on cucurbs, attacking all parts. ^^^ 
 Probablv=C. lindemuthianum. 
 
THE FUNGI WHICH CAUSE PLAxNT DISEASE 549 
 
 C. carica S. & H.'^' '^^ 
 
 Acervuli brown, becoming black, hemispherical, numerous, 
 small, 85-250 ju, bearing 1-12 (or often 0) long, slender, irregular 
 setae which are dark throughout, acute, rigid, septate, 2-6 x 22- 
 106 iJL, conidia regular, oblong, obtuse, 3.5-6.6 x 8.7-20; conidio- 
 phores slender, 1-2 x 45 /x, hyaline. 
 
 It is the cause of a decay of figs in the United States. 
 
 C. ampelinum Cav. is on grape leaves. 
 
 C. glceosporioides Penz. 
 
 Acervuli sparse or scarcely gregarious, subepidermal, erumpent, 
 dark, cylindric, setae continuous or few-septate, dark colored, 
 40-90 X 5-6 fji, conidia cylindric, straight, 16-28 x 4-6 /x; co- 
 
 70. — C. carica. 5, conidiospores, spores and seta', 1, lilac 
 produced on germ tubes. After Stevens & Hall. 
 
 nidiophores densely fasciculate, cylindric, rounded apically, 
 tenuous, 18-25 x 4-5 ju. 
 
 It causes "wither tip" of orange, pomelo and lemon, ^^"'^^^ spots 
 on citrus leaves, lime canker, and anthracnose of stem and flower 
 with great financial loss in Florida, West Indies, South America, 
 Australia, Malta and many other localities. 
 
 In "wither tip" the fungus enters through the terminal bud or 
 from leaves. On lemons attack is through bruises. Acervuli are 
 found on leaf, twig or fruit, breaking through the epidermis. 
 Cross inoculation on the various hosts and with the different forms 
 of the disease demonstrated the identity of all. Smith ^^^ has 
 questioned the casual relation of this fungus as regards "wither- 
 tip" as it occurs in California. 
 
 C. falcatum Went. 
 
 Acervuli poorly defined, setae irregularly arranged, cuspidate, 
 
550 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 100-200 X 4 /i, brownish; conidia falcate, 25 x 4 /i; conidiophores 
 ovoid, 20 X 8 fx., hyaline to fuscous. 
 
 This is believed to be the chief cause of the red rot of sugar- 
 cane. ^^^ It was reported in the United States by Edgerton,^^^ 
 also b}'' Stevens. ^^® Inoculation experiments indicate that it is 
 distinct from C. lineola, on sorghum and Johnson grass, which it 
 resembles morphologically. 
 
 C. cereale Manns. ^^^ 
 
 Spots circular to ovoid, 30 mm.; acervuli dark brown, or black; 
 setse few or many, dark brown to black, at base 6-8 /x thick, 
 tapering to a length of 60-120 n, continuous or 1 to 2-septate; 
 
 Fiu. 371. — C. cereale, acervulus showing mycelium, sete, conid- 
 iospores and spores. After Manns. 
 
 conidia 18-26 x 3-4 ju, spindle to boat-shaped, 2 to several- 
 guttulate; conidiophores, very short, 12-6 x 1-2 ix. 
 
 This fungus is parasitic on the roots, stems, blades and spikes 
 of rye, wheat, oats, barley, emmer, orchard grass, timothy, blue 
 grass and chess. The disease causes a premature ripening and 
 shrivelling of the grain. Superficially the diseased heads present 
 the same appearance as those attached bj' scab (Fusariose) but 
 no pink over-growth is present, nor is the presence of the disease 
 always apparent, as it was found on numerous heads of grain which 
 appeared to be healthy. Morphological studies indicate that all 
 the hosts mentioned above are affected by the same fungus. This 
 was confirmed by cross inoculations in the case of wheat and 
 emmer. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 551 
 
 C. trifolii Bain.i7s-i8o 
 
 Spots dark, depressed; aeervuli erumpent, scattered or gre- 
 garious; conidia straight, ends rounded, 3-4 x 11-13 (jl; conidio- 
 phores cylindric or fusoid, hyaline; setae few or many, continuous 
 or uniseptate, dark, paler apically, 4-7 x 39-62 n, sinuous, or 
 nodose. 
 
 It occurs as an anthracnose producer on stems, rarely on leaves, 
 of clover and alfalfa causing very serious injury. In general ap- 
 pearance it is much like Gloeosporium caulivorum. 
 
 C. spinaciae E. & H.^" 
 
 Spots roundish, dirty-white, or greenish, 2-4 mm., with a slightly 
 raised border; aeervuli amphigenous, punctiform, 40-75 fj., with 
 3-12 erect or spreading bristle-like setae, 60-75 x 4-4.5 fx, sub- 
 bulbous at base, subhyaline, subacute above, dark brown below; 
 conidia subfalcate, fusoid, 2 to 4-guttulate, 14-20 x 2.5-3 ju, ends 
 subacute; conidiophores short. 
 
 It produces blotches on spinach leaves. 
 
 C. phomoides (Sacc.) Ches.^^' ^e. 154-157. isi 
 
 Spots depressed, circular, slightly discolored, center black, 
 5-10 mm., later irregular and confluent; aeervuli abundant, 
 densely gregarious, rusty brown to black, applanate, 95-150 n; 
 setffi abundant, fuliginous, generally curved, septate, 65-112 /x; 
 conidia oblong, 16-24 x 4 n, ends subacute; conidiophores 
 short, slender, 30-40 n high, arising from a well developed 
 stroma. On tomato. 
 
 This is a common cause of ripe rot of tomatoes. The fungus was 
 studied in culture by Stoneman ^^ who reported it as somewhat 
 different from G. rufomaculans, though Edgerton ^^® thought the 
 apple and tomato forms the same. Work by Gueguin ^^^ throws 
 doubt on the American form on tomato being identical with the 
 European form known as G. phomoides. Chester ^^^' ^^- has 
 reported what he regarded as the last species as setigerous. 
 
 C. nigrum, E. & H.^^- ^^ 
 
 Spots blackish, depressed; decaying; aeervuli numerous, su- 
 perficial; setae numerous, slender, setae pointed; conidia ob- 
 long. 
 
 This form which appears quite different from G. piperitum was 
 described from New Jersey by Halsted. 
 
552 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 C. malvarum Br. & Casp.^^^ (-=c. althgea.) 
 
 Epiphyllous and caulicolous; spots brown, sunken; acervuli 
 erumpent; setae dark brown, abundant, 1 or 2-septate, usually 
 colorless below, 60-109 x 3-5 jx, appearing after the conidio- 
 phores which are colorless, cylindric, tapering slightly and apically 
 rounded, slightly longer than the conidia; conidia irregular, oblong, 
 granular, flesh-colored in mass, 11-28 x 5 ^t. 
 
 It is described by Southworth ^^^ as the cause of anthracnose of 
 the hollyhock. The fungus closely resembles C. -lindemuthianum 
 but cross inoculations on the bean failed to produce disease though 
 on hollyhock inoculations succeeded easily. 
 
 C. schizanthi Jensen & Stewart was found on greenhouse 
 Schizanthus plants in Ithaca.^^^ 
 
 C. agaves Sacc. 
 
 Spots pale; acervuli conic; setse few, 90-100 x 5-6 n, brownish 
 ochraceous, 2 to 3-septate, conidia 22-26 x 4-5 ju; conidiophore 
 subramose, fuscous at base. On sisil hemp and agave.^^^ 
 
 C. bletiae Hals, fs on Bletia. 
 
 C. violae-tricoloris R. G. Sm.i^^^^^ 
 
 Spots pale-yellow on leaves. Dead areas on petals occur with 
 more or less deformity of blossom. Spots at first orbicular and 
 definite, later confluent and irregular, acervuli numerous, 50- 
 150 ju, often confluent; stroma usually poorly developed; setae 
 mostly single or in pairs, 20-70 ^t, deep brown, 1 to 2-septate, 
 tapering gradually to a point; conidia oblong or slightlj'' curved, 
 ends blunt, 20 x 5 m; conidiophores short, hyaline. 
 
 It causes spotting of pansy leaves in several states and leads 
 to failure to bloom. 
 
 C. anthurii Del. occurs on Anthurium; 
 
 C. luxificum H. & D. on cacao in the West Indies; 
 
 C. elasticae (C. & M.) Koo. on Ficus. 
 
 C. primulae Hals.-^ is reported as causing a leaf disease of the 
 primrose. 
 
 C. kentiae Hals, is on palms. ^^ 
 
 C. omnivorum Hals. 
 
 Spots dry, irregular in outline; conidia 20-28 x 3-5 n, falcate; 
 setae elongate, acute, black. 
 
 On Aspedistra and other plants.-'' 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 553 
 
 C. camelliae Mas. is on tea. 
 
 C. antirrhini Stcw.^^*^ 
 
 Spots depressed, elliptic or orbicular, often confluent, 3-10 mm, 
 acervuli numerous, crowded; stroma well developed; conidia 
 16-21 X 4 /i, straight or curved, ends rounded; conidiophores 
 short; setse abundant, dark brown, 50-100 n, simple," mostly 
 straight and tapering uniformly to a subacute point. 
 
 It attacks the stems and leaves of the cultivated snapdragon 
 producing sunken spots. 
 
 C. cyclamenae Hals, is on Cyclamen; 
 
 C. dracaenae Hals, on Dracaena; 
 
 C. cofifeanum N. is on coffee; ^^^ 
 
 C. heveae Fetch, on Hevea in India; 
 
 C. cradwickii Banc, on cacao pods; 
 
 C. brachytrichum Del. on cacao leaves; 
 
 C. theobromae A. & S. and C. theobromicolum Del. are on 
 cacao. 
 
 C. incarnatum Zimm. is on Hevea and vanilla; 
 
 C. macrosporum Sacc. on vanilla; 
 
 C. pollaccii Ma^Tiag. on Japanese loquot in Italy; 
 
 C. hedericola Lau. on Hedera. 
 
 Undetermined species of Colletotrichum have been reported 
 on asparagus, ^^ carnation,^'' pear,^^ and many other hosts. 
 
 Melanconiaceae-Phaeosporae (p. 537) 
 Conidia dark, continuous, globose to oblong or fusoid. 
 
 Key to Genera of Melanconiaceae-Phaeosporae 
 
 Conidia solitary on the conidiophores 
 
 Conidia globose or oblong 1. Melanconium, p. 554. 
 
 Conidia fusoid, often arcuate 
 
 Conidiophores not swollen at base. ... 2. Cryptomela. 
 
 Conidiophores swollen at base 3. Basiascum. 
 
 Conidia in chains 
 
 Conidial chains separate 4. TruUula, p. 554. 
 
 Conidial chains in a niucose head 5. Thyrsidium. 
 
554 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Melanconium Link (p. 553) 
 
 Acervuli subcutaneous, conic or discoid, black; conidia elongate 
 to globose-oblong, erumpent in black masses; conidiophore sim- 
 ple. In part=Trichosph8eria. See p. 228. 
 More than one hundred fifty species. 
 M. fuligineum S. & V. Cav.^^ 
 
 Acervuli scattered or gregarious, at first gray-cinereous, then 
 brownish, subepidermal, erumpent; conidia ovoid to ellipsoid, 
 inequilateral, acute, 9-12 x 4-6 ix, olive, guttulate; conidiophores 
 filiform, from a well developed stroma. 
 
 It causes the important bitter rot of ripening grapes, especially 
 the white varieties, occurring also on shoots 
 and peduncles. Acervuli appear on the 
 surface of the rotted berries. The myce- 
 lium penetrates even to the seeds. 
 
 Southworth suggested in 1891 ^^^ that 
 this and Gloeosporium are congeneric but 
 Atkinson ^^° who studied the fungus in pure 
 1^ culture thinks them generically distinct. 
 Fig. 372.— m. fuligineum. Noack ^^^ who studied what he regarded as 
 
 After Atkinson. ., , • i -ht <• i- • ,i ■ •, • 
 
 the typical M. luligmeum says that it is 
 preceded by and belongs to a Gloeosporium-form. 
 
 M. pandani Lev. is a common parasite on Pandanus in green- 
 houses, killing the branches. 
 
 M. sacchari Mass.^-^ 
 
 Acervuli numerous, collected in indeterminate pallid orbicular 
 spots; conidia cylindric, 10-15 x 3-4 n, straight or slightly curved, 
 olivaceous, smooth. 
 
 In leaves, sheaths and culms of sugar cane. The cause of the 
 rind disease. 
 
 TruUula Cesati (p. 553) 
 
 Acervuli subcuticular, erumpent, discoid-pulvinate, or conical- 
 depressed, black; conidia oblong-cylindric, catenulate; conidio- 
 phores long, bacillar, simple or branched. 
 
 Some twenty species, of trifling economic importance. 
 
 T. vaniUae Hen. is on vanilla in Africa. 
 
THE FUNGI WHICH CAUSE PLAx\T DISEASE 555 
 
 Melanconiaceae-Hyalodidymae (p. 537) 
 Conidia hyaline, 1-septate, ovoid to fusoid. 
 
 Key to Genera of Melanconiaceae-Hyalodidymae 
 
 Conidia mutic 
 
 Saprophytic, on stems and fruits 1. Septomyxa. 
 
 Biogenous, typicahy on leaves 2. Marssonia, p. 555. 
 
 Conidia 3 to 4-ciliate at each end 3. Gloesporiella. 
 
 Marssonia Fisch 
 
 Acervuli globose-discoid, pale, conidia ovate to elongate. In 
 part =Gnomonia, Trochila, Pseudopeaiza, 
 
 Some seventy-five species, all leaf parasites, several of eco- 
 nomic importance. 
 
 M. castagnei (D. & M.) Sace. on Populus = Trochila popularum. 
 See p. 157. 
 
 M. juglandis (Lib.) Sacc. on walnut =Gnomonia 
 leptostyla. See p. 275. 
 
 M. populi (Lib.) Sacc. 
 
 Spots suborbicular, epiphyllous, separate or con- 
 fluent, browTi, darker margined, acervuli convex _, ^_., ,, 
 
 ' ' . . . Fig. 3/3. — M.per- 
 
 to applanate, fulvous; conidia obovate to subpyri- forans, conidio- 
 form, 20 x 12 n, constricted at the septum, spor/sf ^AfVer 
 straight or curved. Selby. 
 
 It is common on leaves of Populus as the cause of blighting 
 of lateral twigs. It is injurious in nurseries.^® 
 
 M. panattoniana (Berl.) Mag. is found on lettuce in Italy; 
 
 M. secalis (Oud.) Mag. on rye; 
 
 M. martini S. & E. on oak; 
 
 M. potentiilae (Desm.) Fisch as the cause of a disease of the 
 strawberry in Europe. 
 
 M. rosae Trail causes premature fall of rose leaves. 
 
 M. perforans, E. & E.^^s 
 
 Spots small; irregular, 1-2 mm., pale, soon deciduous; acervuli 
 
556 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 (^ 
 
 100-120 n, or by confluence larger; 
 conidia abundant, clavate or wedge- 
 shaped, 11-15 X 2.5-3 Ai. 
 
 The cause of leaf perforations of 
 /^^ lettuce. 
 A (r\ M. violae.(Pass.) Sacc.^^^ 
 
 ^ 1 (// Discoloration of the host slight; 
 
 ._-^_^ JII!^^ acervuU numerous, scattered, small; 
 
 ~ conidia curved, or straight, 15-18 x 
 
 5-6 M> septum usually excentric. 
 Small spots are produced on violet 
 
 FiQ. 374. — Marssoniu violae. 
 
 Spores and conidiophores. leaVCS. 
 
 After Jones and Giddings. -^^ medicaglnis Vors. is on alfalfa. 
 
 Melanconiaceae-Phaeodidymae (p. 537) 
 Conidia dark, 1-septate, ovoid to fusoid. 
 
 Key to Genera of Melanconiaceae-PhaeodidymaB 
 
 Conidia solitary 
 
 Conidia muticate 1. Didymosporium, p. 556. 
 
 Conidia 1 to 3-ciliate at apex 2. Neobarclaya. 
 
 Conidia catenulate, connected by hyaline 
 
 isthmi 3. Bullaria. 
 
 Didymosporium Nees 
 
 Acervuli rounded or elongate, covered, erumpent; conidia elon- 
 gate or fusoid. A genus of less than twenty species. 
 D. salicinum Vuill is on poplar. 
 
 Melanconiaceae-HyalophragmiaB (p. 537) 
 Conidia hyaline, 2 to several-septate, oblong to fusoid or clavate. 
 
 Key to Genera of Melanconiaceae-Hyalophragniiae 
 
 Conidia separate 
 Conidia muticate 
 Conidia oblong or fusoid, masses usually 
 
 pale 1. Septogloeum, p. 557. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 557 
 
 Conidia long-clavatc; masses dark. ... 2. Rhopalidium. 
 Conidia 1 to several-ciliate, usually at the 
 
 apex 3. Pestalozzina. 
 
 Conidia united at base into a radiate or stel- 
 late group 4. Prosthemiella. 
 
 Septogloeum Saccardo (p. 556) 
 
 Acervuli very small, subepidermal, erum- 
 pent, pallid; conidia oblong. Some twenty- 
 five species of leaf parasites. 
 
 S. hartigianum Sacc. attacks maple, killing 
 very young twigs. 
 
 S. ulmi Fr. is found on elm leaves =Phylla- 
 chora ulmi. (?) 
 
 S. mori Lev. on mulberry = My cosphserella 
 mori. (?) 
 
 S. cydoniae (Mont.) Pegl. is on the 
 quince; 
 
 S. manihotis Zimm. on manihot in Java. 
 
 S. arachidis Rac. is seriously injurious to ^ 
 the peanut in Java.^^^ 
 
 S. profusum E. & E. is found on Corylus; 
 
 S. fraxini Hark, on ash. 
 
 I G. 375. — Septo- 
 gloeum acerinum, 
 conidiospores and 
 conidia. After Sac- 
 cardo. 
 
 Melanconiaceae-Phaeophragmiae (p. 537) 
 Conidia dark, 2 to several-septate, oblong to cylindric. 
 
 Key to Genera of Melanconiaceae-phasophragmiae. 
 
 Conidia mutic 
 
 Conidia separate, not in chains 
 
 Conidia oblong or elongate, not stellate 
 Conidia curved-attenuate, i. e., hya- 
 line-rostrate 
 Conidia dark, except the hyaline 
 
 beak 1. Scolecosporium. 
 
 Conidia with 2 inner cells opaque, 
 
 others clear 2. Toxosporium, p. 558. 
 
558 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Conidia oblong, not rostrate 
 
 Conidia cirrhose protruded. ...... 3. Stilbospora. 
 
 Conidia not protruded 4. Coryneum, p. 560. 
 
 Conidia stellate-lobed, lobes several- 
 septate 5. Asterosporium 
 
 Conidia in chains 
 Conidia connected with filiform isthmi 6. Seiridium. 
 
 Conidia chains without isthmi 7. Seiridiella. 
 
 Conidia ciliate 
 
 Conidia ciliate at apex alone 
 
 Conidia 1-cihate 8. Monochaetia, p. 558. 
 
 Conidia several-ciliate 9. Pestalozzia, p. 558. 
 
 Conidia 1-ciliate at each end 10. Hyaloceras. 
 
 Toxosporium Vuillemin (p. 557) 
 
 Acervuli sublenticular, erumpent, scattered, minute, black; 
 conidia curved, beaked at each end, central cells dark, apical hya- 
 line; conidiophores short, simple. 
 
 T. abietinum Vuill.^^^ causes drying out of Abies leaves in 
 Europe. 
 
 Monochaetia Saccardo 
 
 As in Pestalozzia except that the conidia bear only a single 
 seta. About sixty species. 
 
 M. pachyspora Bubak. is common on Castanea, causing large, 
 circular, dead leaf spots with the acervuli showing in somewhat 
 concentric circles. 
 
 Pestalozzia de Notaris 
 
 Acervuli subcutaneous, erumpent, discoid or pulvinate, black; 
 conidia elongate, colored or the end cells hyaline, with several 
 hyaline sette on each end. 
 
 A genus of over two hundred species of various habit, some of 
 considerable economic importance. 
 
 P. hartigii Tub. causes disease of tree and shrub seedlings in 
 nurseries, constricting the stem just above the soil and resulting 
 in death. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 559 
 
 Fig. 376. — P. funeioa. 
 B. A young mycelium, 
 of an older myceliuna. 
 
 A. Spores. 
 
 C. Hypha 
 
 After Reed. 
 
 P. funerea Desm. 
 
 Acervuli scattered, punctiform, blackish, subepidermal, erum 
 
 pent; stroma depressed, white; 
 
 conidia oblong, fusoid, 5-celled, 
 
 constricted at the septa, the three 
 
 central cells fuscous, the others 
 
 hyaline, 22-32 x 6-8 m, with 2-5 
 
 recurved hyaline spines, 10-15 x 
 
 0.7-1 fx; conidiophores short, 5-9 x 
 
 1-1.5 tx. 
 It is found on various conifers 
 
 causing disease and is a common 
 
 saprophyte. In America it causes 
 
 a stem spot or anthracnose of ginseng,^"* girdling the petioles. 
 
 The culture characters were studied by Reed.^^® 
 P. guepini Desm. var. vaccinii Sh.^^'' 
 
 Acervuli minute, punctiform, convex, black, subepidermal, 
 
 erumpent; conidia el- 
 liptic and somewhat 
 unequilateral, about 
 20 fx long; central cells 
 dark, the two end cells 
 hyaline, the apical cell 
 with 3-4 filiform setae 
 22-35 n long, the basal 
 with a short hyaline 
 appendage, 6-12 /x. 
 
 Common on fallen 
 leaves of cranberries, 
 and associated with 
 rot of the berries. It 
 
 T. „_- D ^ , . ... is common on tea 
 
 biG.S7t. — Pestalozzia guepini vaccinn; a, a eonidium 
 
 having an apical appendage with three branches; CaUsing a SCrioUS dis- 
 b, a conidium having an apical appendage with , ^ ,,. 
 
 four branches; c, a germinating conidium; d, a ger- Case, alSO On Uamellia, 
 
 minating conidium sending out two germ tubes, "^/ron^r^lir. /~* i + ^ n c. 
 
 After Shear. IViagnolia, V^ 1 1 r U S, 
 
 Rhododendron. 
 P. uvicola Speg.^^^ 
 Acervuli globose, lenticular, black, subepidermal, erumpent. 
 
560 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 300-400 n; conidia fusiform, 5-celled, the three median oUvaceous- 
 fuscous, the others hyahne, 35 x 8-10 fx, inferior appendage 25-30 
 X 1 jjL, superior group 8-10 x 1 /x. 
 
 It is described as the cause of rot of grape berries and of a leaf 
 spot of the vine. 
 
 P. aloea Trinch. occurs on aloe in Italy; 
 
 P. clusiae Griff. & Mont, on Clusia leaves in France; 
 
 P. richardiae Hals, sometimes disfigures calla leaves. 
 
 P. tumefaciens Hen. is found on Abies causing galls. 
 
 P. gongrogena Temme causes galls and cankers on willow; 
 
 P. fuscescens Sor. parasitizes cultivated Corypha; 
 
 P. fuscescens var. sacchari Wak. is on sugar cane. 
 
 On palms occur P. palmicola S. & S., P. palmarum Cke., and 
 
 P. phoenicis Grev. 
 
 P. inquinans C. & Hark is on eucalyptus in California; 
 
 P. stictica B. & C. on sycamore and linden; 
 
 P. suffocata E. & E. and P. discosioides E. & E. on roses. 
 
 P. lupini Sor. on Lupinus cotyledons. "°° 
 
 Coryneum Nees. (p. 558) 
 
 Acervuli discoid or pulvinate, subcutaneous, erumpent, black, 
 compact; conidia oblong to fusoid. 
 
 Some seventy-five species. 
 
 C. modonia (Sacc.) Griff. & Maub. on chestnut=Melanconis 
 modonia Tul. See p. 281. 
 
 C. juniperinum E. on juniper =Exosporium juniperinum.^"^ 
 
 C. beyerinckii Oud. 
 
 Acervuli minute, punctiform, black, gregarious; conidia borne 
 on a parenchymatous pulvinate stroma, stipitate, oblong, ovate, 
 light olivaceous, 3 to many-septate, slightly constricted at the 
 septa or not, cells not all of the same size. 
 
 Ascospora beyerinckii is said by Vuillemin to be the ascigerous 
 stage. See p. 236. It is reported as injurious to peaches, caus- 
 ing blight and shot-hole in California ^°^ and to apricots, cherries 
 and peaches in Africa. It is close to and perhaps identical with 
 Clasterosporium carpophilum. 
 
 The acervuli occur as black specks near the centers of the leaf 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 561 
 
 spots but since diseased tissue soon drops out they are often diffi- 
 cult to find. Bark spots are often sterile. Late in the season spores 
 abound scattered on the surfaces of twigs, especially at rough 
 places, as near leaf scars. Spores near bud scales penetrate them 
 with a mycelium and kill the buds or if on bark they enter the 
 twig and produce dead spots. 
 
 C. foliicolum Fuckel.-«=^ 
 
 Spots epiphyllous, ochraceous, indefinite; acervuli punctiform, 
 erumpent; conidia ellipsoid-oblong, 17 x G-7 n, 3-septate, con- 
 
 FiG. 378. — C. beijerinckii. Longitudinal section of a pustule. 
 After Smith. 
 
 stricted at the septa, olivaceous, lower cell subhyaline, stalk 
 subhyaline, 15-20 x 1.25 fi. 
 
 It is present as a saprophyte on apple leaf spots and causes 
 cankers on twigs and branches. 
 
 C. camellias Mas. is reported on cultivated Camellia. 
 
 C. mori Namura causes mulberry twig blight in India. ^°^ 
 
 The Melanconiaceae-Hyalodictyae and Melanconiaceae-Phseod- 
 ictyae containing only three genera have no parasitic species of 
 importance. 
 
 Melanconiaceae-Scolecosporae (p. 537) 
 
 Conidia cylindric, filiform or suballantoid, hyaline, mostly con- 
 tinuous. 
 
562 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Key to Genera of Melanconiaceae-Scolecosporae 
 
 Conidia allantoid 1. Naemospora. 
 
 Conidia bacillar to filiform 
 
 Conidia fasciculate at the apex of the 
 
 conidiophores 2. Trichodytes. 
 
 Conidia solitary- 
 Masses white or pale, foliicolous; conidia 
 
 filiform 3. Cylindrosporium,p. 562. 
 
 Masses gray or dark, usually ramicolc; 
 
 conidia falcate 4. Cryptosporium, p, 564. 
 
 Masses bright-colored, saprophytic; 
 
 conidia falcate 5. Libertella, p. 564. 
 
 Cylindrosporium Unger 
 
 Acervuli subepidermal, white or pallid, disciform or siibeffuse; 
 conidia filiform, continuous, hyaline, straight or curved. 
 
 About one hundred species of 
 parasites, several of them of con- 
 siderable economic importance. 
 
 C. mori Berl. on Morus=Myco- 
 sphserella morifolia. See p. 249. 
 
 C. castanicolum (Desm.) Berl. 
 on Castanea=Mycosphserella macu- 
 liformis. See p. 249. 
 C. padi Kavst:-"'"--''^ 
 Hypophyllous; spots angular, sub- 
 fuscous; acervuli subepidermal caus- 
 ing elevations; conidia curved, 
 cylindric, 48-60 \ 2 fx; conidio- 
 phores minute, produced in great abundance. 
 
 This is the cause of the most common, familiar, widespread and 
 destructive shot-hole disease of the cherry and plum. When on 
 the peduncles the fruits are dwarfed and ripen unevenly. The 
 diseased leaf tissue usually falls away, resulting in "shot-holes." 
 Acervuli abound. 
 
 Arthur found a Phoma associated with this fungus and later 
 asci in the same pycnidia. He believed these forms all con- 
 
 FiG. 379. — C. padi, section of acer- 
 vulus. After Pammel. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 563 
 
 nected but confirmation of such conclusion has not been ad- 
 duced. Connection with Coccomyces has also been reported. ^^^ 
 
 C. tubeufiana All., also on Prunus is closely like C. padi. 
 
 C. pomi Brooks.211-212 
 
 Acervuli pallid, subeffuse, at first subepidermal, then erumpent; 
 conidia granular, filiform, straight or 
 flexuose, 15-80 x 2-2.5 /x. 
 
 It is reported as common from 
 New Hampshire to Virginia and Michi- 
 gan on apples of almost all varieties, 
 causing small, dry, sunken, brown fruit 
 spots; a disease which had hitherto 
 been referred to a variety of causes. 
 The fungus was studied in numerous pi^. 380.— Cyiindrosporium 
 culture media and its pathogenicity was Sdaf ^'"uTtures.™'' iTt ^ r 
 proved by inoculations. Brooks. 
 
 C. chrysanthemi E. & D.^^ 
 
 Spots subindefinite, 1 cm. or more broad, black; acervuli innate, 
 amphigenous, 100-170 n; conidia fusoid straight, 50-100 x 3-4. 5;u. 
 
 The fungus causes dark blotches on the leaves of chrysanthemum. 
 
 C. clematidis E. & E. 
 
 Spots amphigenous, reddish-brown, round or subangular, 1-3 jx; 
 acervuli comparatively few, epiphyllous, immersed, scattered; co- 
 nidia fusoid-linear, 75-80 x 2.5-3 ix, somewhat curved, exuding in a 
 white mass. It causes leaf spot of Clematis. ^^ Later is described 
 a variety jackmanii which differs from the species in the acervuli 
 not being confined to the spots, which are less definite, and exud- 
 ing a black mass of spores which are themselves hyaline. 
 
 C. humuli E. & E. 
 
 Spots amphigenous, mostly hypophyllous, small, angular, limited 
 by the veinlets, rusty brown; acervuli minute, black, amphigenous; 
 fconidia nearly cylindric, granular, 40-50 x 3 m, oozing out in a 
 white mass. 
 
 The cause of leaf spots of hops.^^ 
 
 Other parasitic forms are : 
 
 C. saccharinum E. & E. on maple; 
 
 C. colchici Sacc. on Colchicum; 
 
 C. inconspicuum Wint. on lily; 
 
564 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 C. orni (Pass.) Pegl. and 
 
 C. viridis E. & E. on ash; 
 
 C. quercus Sor. on oak; 
 
 C. cercosporoides E. & E. on tulip tree. 
 
 An unidentified Cylindrosporium is reported from New Jersey 
 and New York as causing spots of tomato with considerable in- 
 jury. 
 
 It is possible that this was in reality Septoria lycopersici.^^' ^''° 
 
 Cryptosporium Kunze (p. 562) 
 
 Acervuli discoid-conic, covered by a peridium, erumpent, form- 
 ing a pseudo-pycnidium from the substratum; conidia fusoid- 
 falcate, large, continuous, typically stipitate. 
 
 Some forty species, chiefly saprophytes. 
 
 C. leptostromiforme Kiihn forms black stromata on lupine. 
 
 C. minimum Lau. is the cause of a rose stem disease and of 
 cankers. 
 
 Libertella Desmaziere (p. 562) 
 
 Acervuli covered, irregularly and tardily erumpent, conidia 
 filiform, falcate, elongate, continuous. 
 
 Some twenty species, chiefly saprophytes. 
 
 L. rubra Bon. on Prunus =Polystigma rubrum. See p. 208. 
 
 L. ulcerata Mas. causes cankers on fig trees in greenhouses.^^* 
 
 Moniliales (p. 479) 
 
 The Moniliales differ from the Sphseropsidales in the ab- 
 sence of the pycnidium and from the IVIelanconiales in their 
 somewhat loose, separate hyphce, not innate and closely aggregated 
 as in the Melanconiales. There are genera on the boundaries 
 between these orders which are difficult to place, as for example 
 Coryneum, some species of which are often put in Helmin- 
 thosporium; Vermicularia which sometimes is confounded with 
 Volutella, etc. 
 
 The order is one of very great diversity and contains a multitude 
 of forms. Many are only saprophytes while some are aggressive 
 parasites. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 565 
 
 Key to Families of Moniliales 
 
 Hyphae in more or less loose cottony 
 masses 
 HyphsD and conidia clear or bright 
 
 colored I. Moniliaceae, p. 565. 
 
 Hyphse and conidia typically both dark; 
 
 one or the other always dark II. Dematiaceae, p. 594. 
 
 Hyphse compactly united or forming a 
 
 globose to cylindric body which is 
 
 often stalked 
 
 Hyphal body cylindric to capitate, 
 
 stalked, i. e., a synnema or cory- 
 
 mium III. Stilbaceae, p. 632. 
 
 Hyphal body more or less globose, 
 
 sessile, i. e., a sporodochium IV. Tuberculariaceae, p. 638. 
 
 Moniliaceae 
 
 Hypha3 hyaline or bright colored, more or less fragile, lax, not 
 cohering in fascicles; conidia concolorous, hyaline or bright colored. 
 
 Key to Sections of Moniliaceae 
 
 Conidia globose, ovate, oblong or short- 
 cylindric 
 
 Conidia continous 1. Amerosporae, p. 565. 
 
 Conidia two-celled 2. Didymosporae, p. 585. 
 
 Conidia three or more-celled 3. Phragmosporae, p. 588. 
 
 Conidia muriform 4. Dictyosporae, p. 592. 
 
 Conidia cylindric, spiral or convolute, 
 
 usually septate 5. Helicosporae. 
 
 Conidia of several stellately grouped cells. . 6. Staurosporae, p. 593. 
 
 Moniliaceae-Amerosporae 
 
 Conidia continuous, globose or ovoid to short cylindric. 
 
 Key to Groups of Moniliaceae-Amerosporae 
 Hyphae very short, or obsolete, little dif- 
 ferent from the conidia 
 
 Conidia not in chains 1. Chromosporieae, p. 566. 
 
 Conidia in chains 2. Oosporeae, p. 567. 
 
566 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Hyphse elongate and distinct from the 
 conidia 
 Conidiophores simple or little branched, 
 apically swollen 
 
 Conidia solitary 3. Hartigielleae, p. 570. 
 
 Conidia in heads 
 
 Conidia not in chains 4. Cephalosporieae, p. 570. 
 
 Conidia in chains 5. Aspergilleae, p. 572. 
 
 Conidiophores much-branched, conidia 
 not in heads 
 Conidia borne irregularly on simple 
 or branched but not inflated or 
 
 verticillate conidiophores 6. Botrytideae, p. 574. . 
 
 Conidia borne on verticillately 
 
 branched conidiophores 7. Verticilliae, p. 583. 
 
 Conidiophores with inflated nodes upon 
 
 which clusters of conidia are borne 8. Gonatobotrytideae. 
 
 Chromosporieae (p. 565) 
 HyphsB short or obsolete, conidia not in chains. 
 
 Key to Genera of Chromosporieae 
 
 Conidia solitary, at least not capitate 
 Saprophytic 
 
 Hyphse almost none 
 
 Conidia separate 1. Chromosporium. 
 
 Conidia joined in twos or threes, 
 
 not catenulate 2. Selenotila. 
 
 Hyphse very short, branched, septate 3. Coccospora. 
 
 Entomogenous 4. Massosporao 
 
 Phytogenous 
 In fungi 
 
 Conidia ovoid, smooth 5. Myceliophthora, p. 567. 
 
 Conidia globose, verrucose 6. Coccosporella. 
 
 In leaves, hyphse vermiform-tortuous 7. Ophiocladium, p. 567. 
 Conidia capitate; hyphse lacking; biophil- 
 
 ous 8. Glomerularia. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 567 
 
 Myceliophthora Costant (p. 566) 
 
 Sterile hyphse creeping, simple or somewhat branched, bearing 
 conidia at the apex; conidia solitary, 
 acrogenous, ovoid. ^■^^m^^(^ 
 
 A single species M. lutea Costant. ^^^^^^o 
 
 causes disease of cultivated mush- ^^IwM-^ 
 
 rooms in France. ^^^ ■ — \f — \(W^i^4^§^^ , — ir- 
 
 Ophiocladium Cavara (p. 566) ^vOU^^^-v^^'^ 
 
 Fertile hyphse fasciculate, tor- ^ '\< \C»~\\ V a( 
 
 tuose; COnidk acrogenous, ellip- Fig.381.— O. hordeiaccrvulusand 
 ' o 7 r- spores. After Cavara. 
 
 tic. 
 
 Two species of which one, O. hordei Cav., parasitizes barley. 
 
 Oosporeae (p. 565) 
 Hyphffi short or obsolete, conidia in chains. 
 
 Key to Genera of Oosporeae 
 
 Conidial chains arising in the hyphse 
 
 Conidial branches simple, arcuate 1. Malbranchea. 
 
 Conidial branches dichotomous, not 
 
 arcuate 2. Glycophila. 
 
 Conidial chains arising at the apex of the 
 
 hyphse 
 . Conidia globose, elliptic, or ovate 
 Conidia all of equal size 
 
 Sterile hyphse very short or none. . . 3. OSspora, p. 568. 
 Sterile hyphse evident, rarely none 
 Conidia not connected by an 
 isthmus 
 Growing within the substratum 
 
 Haustoria none 4. Monilia, p. 568. 
 
 Haustoria present 5. Oidiopsis. 
 
 Growing on the surface of living 
 
 plants 6. Oidium, p. 569. 
 
 Conidia connected by an isthmus . 7. Paepalopsis. 
 
 Apical conidium larger 8. Halobyssus. 
 
 Conidia fusoid, acute at each end 9. Fusidium, p. 568. 
 
568 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Conidia cylindric or cuboid 
 
 Hyphse nearly obsolete; conidia cylin- 
 dric 10. Cylindrium. 
 
 Hyphse distinctly present 
 
 Conidia cylindric. 11. Polyscytalum. 
 
 Conidia cuboid 12. Geotrichum. 
 
 Oospora Wallroth (p. 567) 
 
 Fertile hyphse short, sparingly branched, 
 slender; conidia catenulate, globose to ovoid, 
 hyaline or dilute-colored. 
 
 Over one hundred species, chiefly saprophytes. 
 
 O. scabies Thax.^i". 217. 219-224 
 
 Vegetative hyphse rarely 1 n thick, curved ir- 
 regularly, septate or falsely septate, branching; 
 aerial hyphse at first white, then grayish, 
 evanescent, breaking up into bacteria-like 
 spores. 
 
 Isolation and inoculation in pure culture by 
 Thaxter showed this to be the cause of the 
 Fig. 382 — uospora. common American form of scab of Irish potato, 
 
 After Baccardo. 
 
 beet, turnip, etc. 
 O. abietum Oud. causes defoliation of firs in Europe.^^^ 
 
 Fusidium Link (p. 567) 
 
 Hyphse short, simple, not well differentiated from the conidia 
 which are fusoid, catenulate, acute at the ends, hyaline or dilute- 
 colored. In part =Nectria. See p. 201. 
 
 A poorlj'' understood genus of over 50 species. 
 
 F. candidum Link, on various trees=Nectria ditissima. See 
 p. 203. 
 
 Monilia Persoon (p. 567) 
 
 Hyphse erect, branched, forming a dense mycelial felt, which 
 produces numerous conidiophores; conidia catenulate, hyaline or 
 light-colored, ovate or lemon shaped. In part=Sclerotima. See 
 p. 136. 
 
 Some fifty species. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 569 
 
 M. fructigena Pcrs. on stone and pome fruits =Sclero.tinia 
 fructigena. See p. 139. 
 
 M. cinerea Bon. on stone and pome fruits =Sclerotinia cinerea. 
 See p. 137. 
 
 M. cinerea Bon. on Prunus padus=Sclerotinia padi. See p. 140. 
 
 M. cinerea Bon. on Vaccinium oxycoccus=Sclerotinia oxycocci. 
 See p. 140. 
 
 M. laxa A. & R. on apricots =Sclerotinia laxa. See p. 137. 
 
 M. linhartiana Sacc. on medlars and quinces ^^=Sclerotinia 
 linhartiana. See p. 141. 
 
 M. crategi Diedicke on Crataegus =Sclerotinia crategi. See 
 p. 143. 
 
 M. seaveri Reade on Prunus =Sclerotiiiia seaveri.^^^' ^^^ See 
 p. 140. 
 
 M. fimicola Cast. & Matr. is a parasite of mushrooms, Clitocybe 
 and Pleurotus. 
 
 Oidium Link (p. 567) 
 
 On the surface of Hving leaves; hj^phse branched, white, bearing 
 erect, simple conidiophores with catenulate, ovoid conidia. 
 
 About fifty species. 
 
 These conidial fungi in the main belong to the Erysiphales 
 though some forms are placed in Oidium which clearly do not 
 belong to that ascigerous order. Salmon states that there are 
 some forty-four apparently Erysiphaceous Oidiums listed; but 
 that twenty-five of these grow on plants known to be the hosts 
 of ascus bearing Erysiphacese. 
 
 O. fragariae Harz.=S. humuli. See p. 175. 
 
 O. leucoconium Desm.=S. pannosa. See p. 176. 
 
 O. balsamii Mont.=E. polygoni. See p. 177. 
 
 O. ambrosise ThUm.=E. cichoracearum. See p. 178. 
 
 O. monilioides Link.=E. graminis. See p. 179. 
 
 O. tuckeriBerk.=U. necator. See p. 181. 
 
 O. crataegi Grogn.=P. oxyacanthse. See p. 183. 
 
 O. farinosum Cke.=P. leucotricha. See p. 184. 
 
 The following may also be mentioned : 
 
 O. erysiphoides Fr. on hop, clover, cucumber, etc.; 
 
 O. chrysanthemi Rab. on chrysanthemums; 
 
570 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 O. mespilinum Thiim on Mespilus; 
 
 O. tabaci Thiim on tobacco; 
 
 O. verbenas T. & B. on Verbenas. 
 
 O. quercinum Thiim has been reported as the cause of much 
 injury to oaks in Europe since 1907. The identity of the Oidium 
 causing the epidemic is, however, much questioned. By some it is 
 regarded as a stage of Microsphsera alni, by others it is set up 
 under a separate name as O. alphitoides G. & M.^^^' ^'® 
 
 Hartigielleae (p. 566) 
 
 One genus, Hartigiella Sydow. The species H. laricis (Hart.) 
 
 Syd. causes fall of needles of larch. 
 
 Cephalosporieae (p. 566) 
 Hyphae elongate; conidia in heads. 
 
 Key to Genera of Cephalosporieae 
 
 Conidia globose or oblong 
 
 Conidia sessile on the head or nearly so 
 Fertile hyphse inflated at apex 
 Apical vesicle globose-inflated 
 
 Conidia sessile, not mucus-covered 
 Vesicle verrucose or muriculate 
 
 Fertile hyphee simple 1. CEdocephalum. 
 
 Fertile hyphse sigmoid, much 
 
 branched 2. Sigmoideomyces. 
 
 Vesicle hexagonally areolate. ... 3. Rhopalomyces. 
 Conidia on stalks, mucus-covered . 4. Gliocephalus. 
 Apical vesicle clavate or lobed 
 Vesicle disk-shaped, stellate- 
 
 lobed 5. Coronella. 
 
 Vesicle clavate or subpalmate. ... 6. Buseella. 
 Fertile hyphse not inflated at apex 
 Conidial head covered with mucus 
 
 Fertile hyphse simple 7. Hyalopus. 
 
 Fertile hyphse with verticillate 
 
 branches at tip 8. Gliobotrys. 
 
 Conidial head without mucus 
 Fertile hyphse with one head 
 Conidia not separating 9. Papulospora. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 571 
 
 Conidia separating 
 
 Head elongate 10. Doratomyces. 
 
 Head globose or slightly clavate 
 
 Sterile hyphse scanty 11. Haplotrichum. 
 
 Sterile hyphse long, decum- 
 bent 12. Cephalosporium, p. 571. 
 
 Fertile hyphse with 2 to several heads 
 Conidia upright on verticillate 
 
 conidiophores 13. Ccemansiella. 
 
 Conidia in more definite heads 
 Fertile hyphse simple, with 3 to 
 several heads of conidia on 
 
 spines 14. Botryosporium, p. 571. 
 
 Fertile hyphse several times 2 to 
 
 3-fid 15. Trichoderma. 
 
 Conidia borne on little stalks or sterig- 
 mata 
 
 Fertile hyphse simple 16. Corethropsis. 
 
 Fertile hyphse verticillate branched . . 17. Spicularia. 
 Conidia short cylindric 
 
 Conidia without mucus 18. Cylindrocephalum. 
 
 Conidia covered with mucus 19. Acontium. 
 
 Cephalosporium Corda 
 
 Hyphse creeping, conidiophores short, erect, not apically swollen. 
 Conidia spherical or ovate, hyaline or slightly colored. 
 
 The small spored condial forms often associated with Fusarium 
 (microconidia) belong to this form-genus. 
 
 Botryosporium Corda 
 
 Hyphse assurgent, simple or forked, elongate, irregularly later- 
 ally branched; fertile branches simple, with three or more short 
 apical branches which end in heads of conidia; conidia globose to 
 ovate. 
 
 A genus of only about ten species. 
 
 B. diffusum (Grev.) Cda. has been reported as parasitic on Cas- 
 uarina; 
 
 B. pulchrum Cda. on wheat and radish. 
 
 B. longibrachiatum (Oud.) Maire on various green-house plants. 
 
572 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Aspergilleae (p. 566) 
 Hyphae well developed; conidia in heads, catenulate. 
 
 Key to Genera of Aspergilleae 
 
 Fertile hyphse inflated at apex 
 Fertile hyphse simple or nearly so 
 
 Sterigmata of apical vesicle none or 
 simple 
 
 Conidia terminal on sterigmata 1. Aspergillus, p. 572. 
 
 Conidia lateral and terminal on ster- 
 igmata 2. Dimargaris. 
 
 Sterigmata verticillately branched. ... 3. Sterigmatocystis, p. 573, 
 Fertile hyphse dichotomous, branches 
 
 curved 4. Dispira. 
 
 Fertile hyphse little or not at all inflated 
 Fertile hyphse verticillately branched at 
 tip 
 Tips equally verticillate; conidia doli- 
 
 form 5. Amblyosporium. 
 
 Tips unequally verticillate; conidia 
 globoid 
 Conidia without mucus 
 
 Conidiophores slender 6. Penicillium, p. 573. 
 
 Conidiophores swollen, conidia en- 
 closed in mucus 7. Gliodcladium, p. 574. 
 
 Fertile hyphse not verticillate at tip 8. Briarea. 
 
 Aspergillus (Micheli) Link 
 
 Hyphse effused, creeping; conidiophores erect, simple, capitate; 
 conidia catenulate; sterigmata none or indistinguishable from the 
 conidia. 
 
 The conidia are often found, the asci but rarely. 
 
 A. fumigatus Brizi, is held responsible by Brizi^^'' for pathological 
 changes in wheat seed which rendered them incapable of germina- 
 tion. 
 
 A. ficuum (Hen.) Weh. and A. phoenicis (Cda.) Lind. occur on 
 figs. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 573 
 
 Sterigmatocystis Cramer (p. 572) 
 
 As in Aspergillus but with the sterigmata branched in whorls 
 at the apex. 
 
 S. niger Van Tiegh. 
 
 Hyphse slender, conidiophores erect, 800-1000 x 11-16 n, thick- 
 walled, hyaline or dark above, the apical globose swelling black; 
 basidia 40 n long, radiately arranged, sterigmata obclavate, 8- 
 
 FiG. 3S3. 
 
 -B. pulchrum. After 
 Corda. 
 
 Fig. 384. — Aspergil- 
 lus. From Strass- 
 burger et al., Text 
 Book of Botany. 
 
 10 fi long; conidia globose, 3.4-4.5 n, minutely verrucose, violet- 
 brown, catenulate. On tobacco. 
 
 S. ficuum (Reich.) Hen. 
 
 Conidia globose, 3.8 n, dark violet, thick-walled, smooth. 
 
 In the fruits of figs in Asia Minor and United States. 
 
 S. luteo-nigra Lutz. is injurious to cacao in the tropics. 
 
 Penicillium Link (p. 572) 
 
 Hyphse creeping; conidiophores erect, apicallj' irregularly ver- 
 ticillate-penicillately branched; conidia catenulate, spherical, or 
 
574 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 elliptical, hyaline or variously colored. For the ascigerous stage 
 
 see page 167. 
 
 The conidial stages of many Penicilliums have been given 
 
 searching investigation and comparative study by Thom.^^^ 
 
 P. glaucum Lk. 
 
 Hyphffi effused, creeping, septate, interwoven, white, conidio- 
 
 phores penicillate, branches single or in pairs, erect, forked; conidia 
 
 globose to broadly elliptic, smooth, hyaline, 
 
 with a tinge of green, 4 fx. 
 
 It is the cause of rot of ripe oranges, lemons, 
 
 apples, etc. 
 
 P. italicum Weh. is described as a wound 
 
 parasite on oranges by Massee. It is very 
 
 similar in appearance to P. glaucum but a 
 
 Fig. 385.— Penicillium. little greener; conidia elliptic-oblong, 7-9 x 4 /x. 
 After Bref eld. t» j- -4. j. /t^ \ o 
 
 P. digitatum (Fr.) Sacc. 
 
 Similar to the preceding species in habit but the conidia are 
 white in mass, 4-6 fx. Often associated with, and similar in effects 
 to P. glaucum. 
 
 P. olivaceum Weh. is found on citrous fruits; 
 
 P. luteum Zuk. on apple. 
 
 An undetermined species is reported as the cause of a white dry 
 rot of sweet potatoes. ^^° 
 
 Various other species of the genus occur on fruits and vegetables 
 causing their decay. 
 
 Gliocladium Corda (p. 572) 
 
 Hyphae effused, spreading; conidiophores and conidia as in 
 Penicillium but the conidia surrounded Vjy a mass of mucus. 
 
 A genus of only about ten species. 
 
 G agaricinum C. &. M. arrests growth and breaks the pilei of 
 mushrooms. 
 
 Botrytideae (p. 566) 
 
 Conidiophores elongate, simple or branched but not inflated, 
 and the branches not verticillate; conidia borne variously, globose 
 or ovate to elliptic. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 575 
 
 Key to Genera of Botrytideae 
 
 Conidia smooth or scarcely roughened 
 Saprophytic or apparently so, often real 
 parasites 
 Conidia typically pleurogynous 
 Fertile hyphae 2 to several-furcate. . . 1 . Haplaria. 
 Fertile hypha) simple or nearly so 
 
 Conidia globose or ellipsoid 2. Acladium. 
 
 Conidia short cylindric 3. Cylindrotrichum. 
 
 Conidia acrogenous or pleurogynous 
 Some intermediate joints of the hy- 
 phiB swollen and denticulate, 
 
 conidia-bearing 4. Physospora. 
 
 Intermediate joints equal 
 
 Conidia-bearing hypha) of two sorts, 
 
 the upright alone denticulate 5. Blastomyces. 
 
 Conidia-bearing hyphse of one sort 
 
 Fertile hyphse simple or nearly so 
 
 Hyphffi not denticulate; 
 
 conidia solitary 
 
 Hyphse forming a crust-like 
 
 stratum 6. Hyphoderma. 
 
 Hyphse loose, cobwebby. . . 7. Acremonium, p. 577. 
 Hyphse denticulate ; conidia 
 usually grouped 
 Hyphse everywhere denti- 
 culate, bearing conidia 
 
 only at tip 8. Xenopus. 
 
 Hyphse denticulate or pro- 
 liferous at tip alone 
 Apex denticulate, many- 
 
 spored 9. Rhinotrichum. 
 
 Apex inflated-ampuUi- 
 
 form, 1-spored 10. Olpitrichum 
 
 Fertile hyphse branched 
 Conidia globose to ovoid 
 Both sterile and fertile 
 hyphse procumbent 
 Sterile hyphse intracellu- 
 lar 11. Hartigiella. 
 
576 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Sterile hyphse superficial 
 Fertile hyphse vaguely 
 branched 
 Conidia acro-pleuro- 
 
 gynous 12. Sporotrichum, p. 577. 
 
 Conidia on a one- 
 sided synipo- 
 
 dium 13. Monopodium. 
 
 Fertile hyphaj dichoto- 
 mous; conidia ac- 
 rogenous on spine- 
 like branches 14. Langloisula. 
 
 Fertile hyphse eriect or as- 
 cending 
 Conidia solitary acrogen- 
 ous 
 Fertile hyphse spiny- 
 branched at apex. 15. Plectothriz. 
 Fertile hyphse not 
 
 spiny-branched. . . 16. Monosporium. 
 Conidia loosely grouped 
 about the apex 
 Conidia not involved 
 in mucus 
 Conidia on inflated 
 
 muriculate apices 17. Phymatotrichum. 
 Apices not muricu- 
 late or inflated. 18. Botrytis, p. 578. 
 Conidia involved in 
 
 mucus 19. Tolypomyria. 
 
 Conidia fusoid to cylindric 
 Fertile hyphse mostly pro- 
 cumbent 20. Sporotrichella. 
 
 Fertile hyphse erect or as- 
 cending 
 Conidia fusoid on the 
 upper side of curved 
 
 branches 21. Martensella. 
 
 Conida acrogenous 
 Conidia-bearing 
 
 branches terete. . . 22. Cylindrophora. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 577 
 
 Conidia-bcaring 
 
 branches ellipsoid 23. Cylindrodendrum. 
 Biogenous 
 
 Conidia smooth 
 
 Cateuulate 24. Ovularia, p. 582. 
 
 Solitary 25. Ovulariopsis, p. 582. 
 
 Conidia densely spiny 26. Ramulaspera. 
 
 Conidia muricate or tuberculose-stellate 
 Conidia globose 
 Conidia merely muricate 
 
 Hyphse loose, cobwebby 27. Sepedonium. 
 
 Hyphse woven into a subgelatinous 
 
 pellicle 28. Pellicularia, p. 382. 
 
 Conidia setose at apex as well as muri- 
 cate 29. Chaetoconidium. 
 
 Conidia tuberculose-stellate 30. Asterophora. 
 
 Acremonium Link (p. 575) 
 
 Hyphae subsimple, procumbent; conidiophores simple, short; 
 conidia solitary, hyaline or light colored, 
 oval to ellipsoid. 
 
 A genus of some ten species. 
 
 An undetermined species is recorded by _ 
 Humphrey -''• ^-^ as causing disease of cucum- '^f/p'l 
 bers in IVIassachusetts. I' \i 
 
 Sporotrichum Link (p. 576) 
 
 Fig. 386. — Acremonium. 
 
 Hyphse widely spreading, much branched; After Saccardo. 
 conidiophores simple, short; conidia solitary or in groups on 
 separate sterigmata, ovoid or subglobose. 
 
 Over one hundred twenty-five species are described, most of 
 which are saprophytes. 
 
 S. pose Pk. 
 
 Hyphee creeping, interwoven, branched, continuous or sparingly 
 septate, variable in thickness, 2.5-6 n, hyaline, forming a loose 
 cottony stratum; conidia of two kinds; microconidia, globose or 
 broadly ovate, 4-12 /x; macroconidia abundant, elongate elliptic to 
 ovate elliptic, 1 rarely 2-septate, about three or four times as 
 large as the microconidia. 
 
578 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 The form is an atypical one in 
 that it produces two kinds of 
 spores; one kind which is usually 
 septate 
 
 Heald ^-^ also Stewart and Hodg- 
 kiss ^^"^ have described it as the 
 cause of bud rot of carnations, while 
 the latter authors also mention it 
 in connection with a disease known 
 as "silver top" of June grass in 
 Fig. 3S7.--S. pojE. 11. Hyphabear- which the paiiicles wither as they 
 
 ing conidiophores and macroco- * *' 
 
 nidia. 13, Hypha bearing co- expand, tliough the autliors express 
 
 nidiophores and microconidia. , , , , • , , i i i , • 
 
 After Heald. doubt as to its actual causal relation 
 
 to the disease. A mite appears to 
 be the carrier of the spores. Cultural studies and cross-inoculation 
 showed the fungus form on the two hosts to be identical. 
 
 Botrytis (Micheli) Link (p. 576) 
 
 Hyphse creeping; conidiophores simple or more or less markedly 
 dendritic branched, erect, branches various, thin and apically 
 pointed, thick and obtuse or cristate; conidia variously grouped 
 at the apex of the branches, never in true heads, continuous, 
 globose, elliptic or oblong, hyaline or light colored. 
 
 In part =Sclerotinia. See p. 136. 
 
 A genus of some two hundred or more species, several of them 
 of great economic importance. 
 
 This form-genus contains manj'^ parasites on various hosts. 
 In some instances they are known to include ascigerous stages, 
 (Sclerotinia), in their life cycle; in others no such relation is known, 
 though it has often been assumed on quite untenable grounds. 
 Specific limitations are but poorly understood and the relations 
 between the various forms and between these forms and the as- 
 cigerous stages are in a state of much confusion c. f. (p. 137). In 
 some instances the same conidial stage is claimed by different in- 
 vestigators as belonging to two distinct ascigerous species, a 
 manifest impossibility, (e. g., S. fuckeliana and S. libertiana with 
 B. cinerea.) „ - 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 579 
 
 The more prominent forms as described are given below, recog- 
 nizing that some of them may be co-specific. 
 
 T, • r> 231-243 
 
 B. cinerea Pers. 
 
 Hyphae slender, constricted at septa, gregarious, simple or 
 sparsely branched, erect, cinereous, conidia globose, pale. 
 
 A form which occurs on the grape is usually referred to 
 S. fuckeliana though there is not entire agreement on this point. 
 On the grape the Botrytis develops its mycelium in the berries 
 and produces dense tufts of conidia over their surfaces. The 
 sclerotia form within the fruits. Leaves and 
 canes are also affected, (see p. 140). 
 
 On the lily Ward^^^ in a classic study de- 
 monstrated the parasitism of the fungus show- 
 ing its action to be dependent upon toxins and 
 enzymes. The type in this case deviated some- 
 what from the usual B. cinerea in that its 
 spores were a little larger than is usual, but it 
 nevertheless seemed to be this species. No 
 ascigerous stage was found. 
 
 On Cyclamen and Primula Wehmer^^^ re- 
 ports a similar case.-^° The fungus has also 
 often been reported on the cultivated gera- Fig. 388.— b. cinerea. 
 
 ^ After Smith. 
 
 nium. 
 
 On lettuce Humphrey, -^^ Jones, ^^^ Bailey,^^' and many others 
 have reported a greyish mold on the leaves due to a Botrytis 
 which is often cited as B. cinerea though it appears to form no 
 ascigerous stage. The affected part of the leaf collapses and is 
 covered with a conspicuous growth of the conidiophores and coni- 
 dia. Small sclerotia are produced in considerable abundance 
 when on artificial media but they, on germination, bear clusters, 
 dense bushy tufts, of conidiophores. That this form on lettuce 
 ever produces ascophores is doubtful. 
 
 Smith describes a case in which linden stems beginning at the 
 ground were parasitized by B. cinerea. The bark appeared to be 
 first affected and sclerotia formed in the cortical parenchyma. 
 Similar cases are on record regarding the rose, various conifers, 
 grape (Brizi) Aesculus, Prunus. In all of these cases the Botrytis 
 seems to be B. cinerea and without ascophores. 
 
580 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Numerous studies ^^^ of the power of B. cinerea to infect growing 
 tissue have been made with the conclusion that it is a weak parasite 
 and that to become aggressively parasitic it must first develop 
 a vigorous mycelium saprophytically. Attempts to immunize 
 plants against its attack have been made with partial suc- 
 cess.^*^ 
 
 Extensive studies of the condition of sclerotia and conidia forma- 
 tion by B. cinerea (from grape) were made by Reidemeister.^^^ 
 He concludes that sclerotia form on all media favorable to growth 
 of the fungus. They are on an average 5-8 mm. in diameter, 
 smaller under conditions of poor nutriment, high osmotic pressure 
 or strong transpiration. The}'' are often found in concentric rings 
 and their formation is induced by the presence of various agents 
 which inhibit groAvth. Conidia are formed under condition of 
 energetic transpiration and on media of high osmotic tension. 
 Conidia and sclerotia vary inversely in production. Appressoria 
 develop on all media where sclerotia grow and are favored by 
 substances which inhibit growth. Conidia are suppressed by 
 conditions favoring the formation of appressoria. 
 
 B. depraedens Cke. is a pest of the sycamore. 
 
 B. fascicularis (Cda.) Sacc.^^ 
 
 Cespitose, minute, brownish; hyphae erect, fasciculate, flexuose, 
 brown, or semi-pellucid, branches hyaline; conidia in subglobose, 
 white heads, oblong, large. 
 
 A mold of egg-plants is attributed to this fungus by Hal- 
 sted. 
 
 An undetermined Botryiis is reported on carnation by Atkinson 
 and another on Ribes.^^* 
 
 B. parasitica Cav. 
 
 Hyphse cinereous, sparse, erect, inflated at base; conidia ovate, 
 large, short-pedicillate, on short branches, heads umbellate, hya- 
 line or dilute, cinereous, 16-20 x 10-13 n. 
 
 This is said by Halsted ^Ho be the form found on lilies, parti- 
 cularly the bulbs, in New Jersey. It was first reported by Cavara 
 in Italy and is widespread and destructive. 
 
 B. poeoniae Oud. 23. 245. 246 
 
 Mycelium in the parenchyma of the host, hyphse erect, 0.25- 
 1 mm. high, protruding through the stomata, branches spirally 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 581 
 
 arranged, simple, or branched; conidia, numerous, in heads 12-15 
 H across, oblong or ovate-oblong, 16-18 x 7-7.5 /x, hyaline or di- 
 lute colored. 
 
 It is reported as the cause of considerable injury to peonies in 
 different parts of the United States. The greenish-black flat 
 sclerotia are found inside the stems. 
 
 It is mentioned by Bos -^^ as parasitic on young peony stems and 
 on lily-of-the-valley and lilac. 
 
 B. longibrachiata Oud.222. 248 
 
 White, sparse, cespitose, 1.5-2 mm. high; mycelium creeping, 
 branched; fertile hyphse, verticillate, hyaline, much branched 
 and apically inflated; conidia numerous, hyaline, oval, 4.5-5.5 x 
 2.5/1. 
 
 It was reported by Thaxter ^-" as the cause of stem rot of to- 
 bacco in the curing house. The affected stems are covered with 
 white velvety patches of mycelium which soon spread to the 
 veins. 
 
 The same fungus is reported by Aderhold on ferns. ^'^^ 
 
 This is perhaps a form of B. cinerea. 
 
 B. douglassi Tub. on fir may be B. cinerea and=Sclerotinia 
 fuckeliana. See p. 140. 
 
 B. citricola Brizi, closely related to B. cinerea, attacks oranges 
 and citrus fruits resulting in mummies. 
 
 B. diospiri Brizi attacks the persimmon fruit near time of ripen- 
 ing and prevents maturity. 
 
 B. patula S. & Ber.^^" 
 
 Cespitose, minute, greyish- white, spots cottony, suborbicular; 
 fertile hyphse assurgent, continuous, filiform, branching, panicu- 
 late; conidia large, globose or globose-elliptic. 30 /i in diameter, 
 light yellow. On raspberries. 
 
 B. infestans (Hazsl.) Sacc. is common on hemp in Europe. It 
 sometimes is associated with Sclerotinia libertiana which has led 
 some to assume its connection with that fungus; but no such 
 genetic relation is probable. 
 
 B. galanthina Lud. occurs on snowdrops. It is said to belong to 
 Sclerotinia galanthina, see p. 141, but the asci have not been seen. 
 
 Undetermined species are reported on carnations, Ribes and 
 mangold. 2^^ 
 
582 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Ovularia Saccardo (p. 577) 
 
 Hyphse, simple, or sparingly branched, erect, apically simple 
 or dendritically branched; conidia globose or 
 ovoid, solitary, rarely in short chains. 
 Over seventy-five species, all parasites. 
 O. necans (Pass.) Sacc. produces spots on 
 quince leaves in Italy and France; 
 
 O. canaegricola Hen. on economic species of 
 
 Fig. 389.— Ovularia. Rumex ; 
 
 After Sorakin. Q. armoraclae Fcl. on horseradish; 
 
 O. interstitialis B. & Br. and O. primulana Thiim. on primrose 
 leaves; 
 
 O. vicias (Frank.) Sacc. on Vicia; 
 
 O. corcellensis Sacc. on Primula; 
 
 O. alnicola Cke. on Alnus; 
 
 O. rosea Fcl. on willow; 
 
 O. villiana Mag. on lemons; 
 
 O. syringae Berk, on lilac. 
 
 O. citri B. & F. causes the white rust of lemons in Sicily.^^'^ 
 
 A lemon disease in Australia has been credited by McAlpine ^^^ 
 to O. citri McAlpine. 
 
 O. medicaginis Br. & Cav. is on alfalfa; 
 
 O. exigua (W. Sm.) Sacc. on clover. 
 
 Ovulariopsis Patouillard & Hariot (p. 577) 
 
 Similar to Ovularia, except in the solitary, acrogenous, sub- 
 clavate conidia. 
 
 Sterile hypha creeping, conidiophores erect, simple, septate, at 
 apex with a single 1-celled hyaline, subclavate conidium. 
 
 A small genus of leaf parasites, in part conidia of the Erysi- 
 phacese (Phjdlactinia). See p. 187. 
 
 O. ulmorica Del. causes a mildew of mulberries.^^^ 
 
 Pellicularia Cooke (p. 577) 
 
 Hyphse creeping, branched, septate, in a subgelatinous pellicle, 
 conidia sessile. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 583 
 
 A single species. P. koleroga Cke. causes a coffee leaf rot in 
 India and has been reported by Fawcett -^^ as causing serious leaf 
 blight of the same host in the West Indies. 
 
 Verticillieae (p. 5G6) 
 Conidia acrogenous, on verticillate branches of the conidiophore. 
 
 Key to Genera of Verticillieae 
 
 Conidia solitary or loosely grouped, not in 
 chains 
 Conidia-bearing branches very short, am- 
 
 pulliform 1. Pachybasium. 
 
 Conidia-bearing branches terete or longer 
 Conidia globose to ovoid 
 Tips of branches clavate, in twos 
 
 rectangularly 2. Verticilliopsis, p. 584. 
 
 Tips of branches not as above 
 
 Conidia conglutinate into a stra- 
 tum 3. Corymbomyces, p. 584. 
 
 Conidia not conglutinate 
 
 Conidia separating readily from 
 
 the tips 4. Verticillium, p. 584. 
 
 Conidia separating with dif- 
 ficulty from the tips 5. Cladobotyrum. 
 
 Conidia cylindric or elongate 
 
 Conidia-bearing branches or sporo- 
 phores 1-spored 
 
 Sporophores straight 6. Acrocylindrium. 
 
 Sporophores uncinate 7. Uncigera. 
 
 Sporophores scveral-sporcd 
 Sporophore inflated verrucose at 
 
 apex 8. Calcarisporium. 
 
 Sporophore incurved, with seriate 
 
 conidia below 9. Coemansia. 
 
 Conidia capitate or densely spicate, not in 
 chains 
 Conidia sessile 
 
 Conidia capitate, involved in mucus 
 
 Fertile hyphse smooth 10. Acrostalagmus, p. 584. 
 
 Fertile hyphaj asperate 11. Gloeosphaera. 
 
584 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Conidia densely spirally spicate at 
 
 apices 12. Clonostachys. 
 
 Conidia on small stalks 13. Sceptromyces. 
 
 Conidia in chains 14. Spicaria, p. 585. 
 
 Verticillium Nees (p. 583) 
 
 Hyphse creeping; conidiophores erect, verticellately branched; 
 conidia borne singly at the apex of the branchlets, globose-ovoid, 
 hyaline or light colored. 
 
 A genus of some seventy-five species, which are in the main 
 conidia of various species of Hypocreales. See p. 196. 
 
 V. albo-atrum McA. is a weak wound parasite of the potato. 
 
 Verticilliopsis Cast (p. 583) 
 
 Fertile hyphse with verticillate branches, 2 or 3 at each node; 
 fertile branches clavate; conidia in heads, surrounded by a slime. 
 A monotypic genus. 
 
 V. infestans Cast, infects mushrooms in culture. 
 
 Corymbomyces Appel & Strunk (p. 583) 
 
 Sterile hyphse creeping; fertile hypha3 erect, septate, dichoto- 
 mous corymbose; conidia ellipsoid, clustered in gelatinous masses 
 at the apex of the branches. 
 
 A single species, C. albus Appel & Strunk. on cacao in Africa. 
 
 Acrostalagmus Corda (p. 583) 
 
 Hyphse creeping; conidio- 
 phores erect, septate, richly 
 verticillately branched; conidia 
 borne in slimy heads on the 
 s|[^ ^^^^S^^^^^ enlarged end of the secondary 
 branches. 
 
 About fifteen species. 
 
 Fig. 390.— Cross-section of a vascular ^' ^^^US Preu. 
 
 bundle. Acrostalagmus threads in the Hyphse cespitose, efifuse, slen- 
 vessels. After Van Hook. , i • 
 
 der, subangular, contmuous or 
 
 septate, conidiophores, 200-220 x 1.7-2 n, erect; fertile branches 
 
 continuous, straight or curved; conidia in spherical heads, 9-10 n 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 585 
 
 in diameter, numerous, minute, elliptic oblong, 3.3-3.4 x 1-1.5 m, 
 hyaline. 
 
 It causes a wilt of ginseng. The vascular bundles are yellowed 
 and the ducts plugged by the 
 mycelium. Entrance is apparently 
 through the leaf scars. The fungus 
 was isolated by Van Hook ^^® and 
 cultural studies made. In a later 
 article Rankin ^"'^ has discussed what 
 appears to be this fungus under the 
 name A. panax. 
 
 A. vilmorinii Gue.^^^'^^^ causes a 
 disease of China asters and a species 
 closely related, one of cacao fruits. 
 
 Spicaria Harz (p. 584) 
 
 Hj'phse creeping; conidiophores 
 erect, much branched; conidia apical, fig. 391.— Spore-bearing stalks of 
 catenulate, ovate or elongate, hyaline fp^o^eraJe^borL^in heads"and?r: 
 
 or dilute colored. held together at first by a coat 
 
 of slime. After Van Hook. 
 
 About ten species. 
 
 S. solani Hart, is said to produce effects on the potato much 
 like those of Fusarium solani. '^^^ 
 
 S. colorans v. Hall, the cause of cacao cankers is probably a 
 conidial stage of Calonectria cremea. See p. 205. 
 
 Moniliaceae-Didymosporeae (p. 565) 
 
 Conidia hyaline, or bright colored, 1-septate, ovoid oblong or 
 short fusoid. 
 
 Key to Genera of Moniliaceae-Didymosporeae. 
 
 Conidia not in chains 
 Saprophytic or on fungi 
 Conidia smooth 
 Fertile hyphse simple or nearly so 
 Hyphte inflated at apex or joints 
 Hyphse denticulate, inflated at 
 
 apex; conidia fusoid 1. Diplorhinotrichum. 
 
586 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Hyphse inflated at both apex 
 
 and joints 2. Arthrobotrys. 
 
 Hyphse not inflated 
 Conidia spirally pleurogynous 3. Haplariopsis. 
 Conidia solitary, acrogenous 
 or capitate 
 Conidia capitate at apex. . . 4. Cephalothecium, p. 586. 
 Conidia solitary at apex 
 
 Fertile hyphse long 5. Trichothecium. 
 
 Fertile hyphse very short 6. Didymopsis. 
 Fertile hyphse branched 
 
 Branching irregular 7. Diplosporium. 
 
 Branching verticillate 8. Diplocladium. 
 
 Branching dichotomous; sterig- 
 
 mata subternate 9. Cylindrocladium. 
 
 Conidia echinulate; conidial cells un- 
 equal 10. Mycogone, p. 587. 
 
 Biophilous 
 
 Conidia obliquely beaked 11. Rhynchosporiuni,p. 587. 
 
 Conidia not beaked 
 Hyphse mostly simple, not spirally 
 
 twisted 12. Didymaria, p. 587. 
 
 Hyphse simple, spirally twisted ... 13. Bostrichonema. 
 Conidia catenulate 
 
 Fertile hyphse simple, short 14. Hormiactis. 
 
 Fertile hyphffi verticillately branched. . 15. Didymocladium. 
 
 Cephalothecium Corda 
 
 HyphsB prostrate ; conidiophores erect, 
 simple, septate, conidia apical, siibcapi- 
 tate, oblong to pyriform, hyaline. 
 Five species, chiefly saprophytes. 
 C. roseum Cda.^^*^^^^ 
 Cespitose in subrotund, rose colored 
 spots, fading with age, byssoid; hyphse 
 Fig. 392.— Spores of Cepha- creeping, branched; conidiophores erect, 
 Eistir '°''''°'' ^^^^"^ simple, continuous, hyaline; conidia 
 oblong-ovate, constricted at the septum, 
 capitate, light rose. 
 It is often found following apple scab gaining entrance through 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 587 
 
 the injured cuticle and causing rot. A ring of pink conidiophores 
 and conidia is formed around tlie margin of the scab. Inoculation 
 tests showed the fungus unable to penetrate through sound cuticle 
 though it readily made entrance through wounds. It has been 
 occasionally reported on living twigs and leaves and as a common 
 saprophyte has long been known. The first account of it in America 
 was from New York -^° in 1902 though it was described in 1899 as 
 injuring pears in Germany."®" 
 
 Mycogone Link (p. 586) 
 
 Hyphse intricately branched; conidiophores 
 short, lateral; conidia unequally 2-celled, the 
 upper larger, echinulate. 
 
 There are about fifteen species of mycogenous 
 fungi which are probably conidial stages of Hy- 
 pomyces. See p. 200. 
 
 M. perniciosa Mag."^^' -®^ 
 
 White throughout, byssoid, deforming the 
 host; conicUophores short; conidia solitary, 
 more or less pyriform, almost colorless, 17- 
 22 X 9-12 n. 
 
 It is reported by Mrs. Patterson as the 
 cause of a mushroom disease in America. 
 A verticillium conidial stage was present but 
 no ascigerous form. 
 
 M. rosea Link, also occurs on mushrooms. 
 
 Rhynchosporium Heinsen (p. 586) 
 
 On leaf spots; hypha? filiform, hyaline, creeping, septate; conid- 
 iophores erect, with incurved branches, hyaline, apically denticu- 
 late; conidia short-cylindric, with a short oblique beak, medially 
 septate, hyaline. A monotypic genus. 
 
 R. graminicola Hein. occurs on rye, wheat, and barley in Europe. 
 
 Didymaria Corda (p. 586) 
 
 Conidiophores simple, conidia borne apically, ovate, hyaline. 
 
 About twenty species of leaf parasites. 
 
 D. prunicola Cav, produces spots on plum leaves. 
 
 Fig. 393. — Mycogone, 
 conidiophores and 
 conidia. After Sac- 
 cardo. 
 
588 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Moniliaceae-Phragmosporae (p. 565) 
 
 Conidia hyaline or bright colored, 2 to several-septate, oblong, 
 fusoid or elongate. 
 
 Key to Genera of Moniliaceae-Phragmosporae 
 
 Fertile hyphte very short and little dif- 
 ferent from the conidia 
 Conidia in chains, cylindric or oblong.. 1. Septocylindrium, p. 589. 
 Conidia not in chains 
 
 Sporophore 3-celled, upper cell much 
 
 inflated 2. Milowia. 
 
 Sporophore not inflated, sometimes 
 obsolete 
 Conidia ciliate at apex and upper 
 
 septum 3. Mastigosporium, p. 590. 
 
 Conidia not ciliate 
 
 Hyphse lacking; conidia not ag- 
 gregate 4. Fusoma, p. 590. 
 
 Hyphse distinct; conidia ag- 
 gregate 
 Conidia in mucose glomerules . 5. Rotaea. 
 Conidia in fascicles, not mu- 
 cose 6. Paraspora. 
 
 Fertile hyphse manifest and distinct from 
 the conidia 
 Saprophytic 
 
 Conidia solitary or at least not capi- 
 tate 
 Fertile hyphse simple 
 
 Sterile hyphse lacking 7. Dactylella. 
 
 Sterile hyphse abundant 8. Monacrosporium. 
 
 Fertile hyphse branched 
 
 Hyphse verticillately branched. . 9. Dactylium. 
 Hyphse irregularly branched. . . 10. Blastotrichum. 
 Conidia capitate 
 Fertile hyphse vesiculose at tip. . . 11. Cephaliophora. 
 Fertile hyphse not swollen 
 
 Hyphse simple, sterile lacking . . 12. Dactylaria. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 589 
 
 HyphiE verticillate; sterile hy- 
 
 phcc present 13. Mucrosporium. 
 
 Parasitic 
 
 Conidia mucose-conglobate, allan- 
 
 toid, often continuous 14. AUantospora. 
 
 Conidia not mucose-conglobate 
 Conidia ovate-cylindric or elon- 
 gate, often catenulate 15. Ramularia, p. 590. 
 
 Conidia obclavatc-pyriform 16. Piricularia, p. 591. 
 
 Septocylindrium Bonardin (p. 588) 
 
 Conidiophores very short, scarcely distinct from the conidia, 
 or in parasitic species distinct but short and inflated or dentic- 
 ulately sublobate at the apex; conidia oblong or cylindrical, one 
 to many-septate, catenulate, the chains often branched. 
 
 About thirty species, a few of them of economic impor- 
 tance. 
 
 S. areola (Atk.) P. & C.-''' ''' 
 
 Spots amphigenous, pale, becoming darker in age, 1 to 10 mm., 
 angular, limited by the veins of the leaf, conidiophores amphig- 
 enous, fasciculate, sub- 
 nodose, branched or not, ^i( 
 
 several times septate, 
 hyaline, 25-75 x 4-7 ju; 
 conidia oblong, usually 
 abruptly pointed at the 
 ends, catenulate or not, 
 14-30 X 4-5 /x, hyaline. 
 
 Leaf spots are pro- 
 duced on cotton. The F^«- 394.— S. areola. After Atkinson. 
 conidia and stalks are so a])undant on the undersides of spots as 
 to give them a frosted appearance. 
 
 S. rufomaculans (Pk.) P. & C. 
 
 Spots numerous or confluent and even covering the entire leaf, 
 reddish; conidiophores very short, hypophyllous, cespitose; conidia 
 catenulate, variable, ellipsoid-oblong to cylindric, hyaline, 8-16 x 
 3-4 n. 
 
 It is somewhat injurious on buckwheat in America.^^^ 
 
590 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 S. radicicolum Aderh ^''^ is reported by Aderhold as the cause of 
 death of roots of Prunus and Pyrus. 
 
 Mastigosporium Riess (p. 588) 
 
 Conidiophores short, stipitate, continuous, hyaline, conidia fu- 
 soid, large, 3-septate, hyaline, with apical and subapical bristles. 
 A small genus in part = Dilophia. 
 
 Fusoma Corda (p. 588) 
 
 Mycelium obsolete or poorly developed; conidia innate, fusiform 
 separate. 
 
 F. parasiticum Percival, causes a wilt of hops.^^^ 
 
 Ramularia Unger (p. 589) 
 
 Conidiophores fasciculate, simple or with short, scattered 
 branchlets, often flexuose, nodulose, or denticulate towards the 
 apex, hyaline or light colored; conidia acrogenous or acropleuro- 
 gjTious on the denticulations, hyaline, sometimes subcatenulate, 
 oblong, cylindric, typically many-septate. 
 
 About three hundred species. In part =Mycosph8erella. See 
 p. 243. 
 
 R. tulasnei Sacc. on strawberry =Mycosph8erella fragariae. See 
 p. 244. 
 R. armoraciae FcL^^ 
 
 Spots amphigenous, subochraceous becoming gray; conidiophores 
 fasciculate, continuous, subsimple, 40-50 x 
 2.5-3 ju; conidia rod-shaped, obtuse, hyaline, 
 15-20 X 3-4 n. 
 On horseradish causing leaf spots. 
 R. taraxaci Karst, 
 
 Hypophyllous, spots purple-margined, hyphse 
 35-45 X 2-3 /x, spores bacillar, simple, straight, 
 hyaline, 18-30 x 2-3 fx. 
 
 Fig. 395. — R. armora- ^ , , ,. 
 
 cite. After Sac- On dandelion. 
 
 ^^^^^- R. spinaciae Nip. is on spinach; 
 
 R. betas Rost. on beet; 
 
 R. necator Mas. on cacao; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 591 
 
 R. geranii (West.) Fcl. on cultivated geraniums 
 
 R. primulae Thiim. 
 
 Spots rounded-angular, subochraceous, emarginate; conidio- 
 phores amphigenous, 50-60 x 5 ix, continuous, somewhat denticu- 
 late, rarely branched; conidia fusoid-cylindric, 20-30 x 3-6 ii, con- 
 tinuous or 1-septate. On Primula.-^ 
 
 R. lactea (Desm.) Sacc. is on violets; 
 
 R. heraclei (Oud.) Sacc. on cultivated Heracleums; 
 
 R. onobrychidis P. & D. on leaves of sainfoin. 
 
 R. cynarae Sacc. causes loss of artichokes in France and Africa. 
 
 R. coleosporii Sacc. is on sweet potato in Porto Rico.^^^ 
 
 R. modesta Sacc. is recorded for the strawberry. 
 
 R. narcissi Chit, and R. vallambrosae Br. & Cav. cause disease 
 of leaves and stalks of Narcissus.-™ 
 
 R. goeldiana Sacc. kills twigs of coffee. 
 
 Piricularia Sacc. (p. 589) 
 
 Conidiophores simple, rarely branched, 
 conidia obclavate to pyriform, 2 to many- 
 septate, solitary acrogenous, hyaline. 
 
 A small genus of parasites. 
 
 P. grisea (Cke.) Sacc.^^^'^^^ produces 
 pallid or water-soaked, spots on culms 
 and leaves, with age greyish; conidio- 
 phores in clusters of two or five from 
 the stomata, simple or rarely sparingly 
 branched, greyish, septate; conidia sin- 
 gle, terminal in scorpioid cymes, ovate, 
 2-septate, 24-29 x 10-12 n. 
 
 It causes death of rice plant tissue and 
 the disease called "blast." If affected 
 leaves or stalks be placed in a damp at- 
 mosphere for about a day a delicate 
 
 greyish fungus, the sporing mycelium appears. The fungus grows 
 well in culture and applied to the rice plants gives rise to the 
 typical disease spots. This species was originally described on 
 Digitaria sanguinalis and the form on rice has been called 
 
 Fig. 396. — Piricularia grisea. 
 a, conidiophores. h, ger- 
 minating spores. After 
 Fulton. 
 
592 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 P. oryzae; but morphological characters and inoculation experi- 
 ments indicate their identity on various other grasses. 
 
 P. caudata A. & S. occurs on cacao. 
 
 To the Moniliaceae-scolecosporae belongs only one genus : 
 
 Cercosporella Saccardo 
 
 Hyaline throughout; conidiophores simple or branched; conidia 
 filiform, many-septate. Distinguished from Cercospora only in 
 color. The genus contains some seventy species 
 of parasites. 
 
 C. persicae Sacc.^^^ 
 
 Conidiophores cespitose, on discolored areas, 
 filiform, 2 to 3-branched, continuous; conidia 
 40-60 X 1-5 fi, torulose. 
 
 The conidia develop in abundance on the 
 lower sides of leaf spots of peach causing a 
 frosty mildew. 
 
 C. narcissi Bond, occurs on Narcissus; 
 C. inconspicuus (Wint. & Hohn) on lily. 
 J ^ C. pastinacae Karst. 
 
 Fig. 397. — C. per- Spots amphigenous, fuscus or whitish; conidia 
 card'o. ^^*^^ ^^°" filiform, somewhat curved, slender, attenuate, 
 
 50-90 X 2 M- 
 On parsnip and other Umbelliferse. 
 C. albo-maculans E. & E. 
 
 Spots orbicular, white, dark-margined, conidiophores amphige- 
 nous, cespitose, 8-12 x 2 ju, hyaline, continuous; conidia cylindric, 
 40-68 X 2-2.5 /x, straight or curved, 3-septate. 
 A common cause of pale spots on turnip leaves. 
 
 Moniliaceae-Dictyosporeae (p. 565) 
 
 Conidia hyaline or bright colored, muriform, globose, ovoid 
 or cubic. 
 
 Key to Genera of Moniliaceae-Dictyosporese 
 
 Saprophytic 
 
 Hyphse much-branched; conidia elliptic 
 
 or globose, cells uniform 1. Stemphyliopsis. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 593 
 
 Hyphse little-branched; conidia six-lobed 
 and sarcinceform, central cell larger, 
 
 colored, lobes hyaline 2. Synthetospora. 
 
 Parasitic 3. Hyalodema, p. 593. 
 
 This group contains but one important pathogen, Hyalodema 
 evansii Mag., recently described by Magnus -''^ on Zizyphus in 
 Africa. 
 
 The Moniliaceae-Helicosporae contain no important parasites. 
 
 Moniliaceae-Staurosporae (p. 565) 
 
 Conidia hyaline or bright colored, stellate, radiate or forked, 
 septate or continuous. 
 
 Key to Genera of Moniliaceae-Staurosporae 
 
 Hyphse lacking; conidia trident-shaped. ... 1. Tridentaria. 
 Hypha; present 
 
 Conidia globose to cylindric, permanently 
 attached to 2 or 3 divergent sterig- 
 
 mata 2. Tetracladium. 
 
 Conidia themselves stellate or radiate 
 Conidia bilobate-forked; lobes parallel, 
 
 contiguous 3. Pedilospora. 
 
 Conidia narrowly digitate 4. Prismaria. 
 
 Conidia 3 to 4-radiate 
 
 Conidia ciliate at the apex 5. Titaea, p. 593. 
 
 Conidia muticate 
 
 Conidia 3-radiate 6. Trinacrium. 
 
 Conidia 4-radiate 
 
 Fertile hyphaj very short, simple 7. Tetracium. 
 Fertile hyphse branched 8. Lemonniera. 
 
 Titeae Saccardo 
 
 Conidiophores simple, continuous; conidia subradiately 4 to 5- 
 celled, the cells unequal in size. 
 
 A small genus of little economic importance. 
 
 T. maxilliformis Rost. has been found on the roots of clover in 
 Denmark. 2^^ 
 
594 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Dematiaceae (p. 565) 
 
 Hyphse dark or black, cobwebby, loose, usually rigid, not coher- 
 ing in definite fascicles; conidia typically dark and concolorous, 
 but sometimes the hyphse are dark and conidia clear, or the conidia 
 dark and the hyphse clear. This family parallels the Moniliacese 
 and certain intermediate forms must be sought in both. 
 
 Key to Sections op Dematiaceae 
 
 Conidia globose, ovate, oblong or short 
 cylindric 
 
 Conidia continuous 1. Amerosporae, p. 594. 
 
 Conidia 2-celled 2. Didymosporae, p. 601. 
 
 Conidia 3 or more-celled 3. Phragmosporae, p. 608. 
 
 Conidia muriform 4. Dictyosporae, p. 615. 
 
 Conidia long, filiform or vermicular 5. Scolecosporae, p. 625. 
 
 Conidia cylindric, spiral or convolute, typi- 
 cally septate 6. Helicosporae. 
 
 Conidia of several stellately grouped cells. . . 7. Staurosporae. 
 
 D ematiacese-Amerosporse 
 
 Conidia continuous, globose to oblong. 
 
 Key to Subfamilies of Dematiaceae-AmerosporSB. 
 
 Conidiophores very short, scarcely distin- 
 guishable from the mycelium 
 
 Conidia borne singly 1. Coniosporieae, p. 595. 
 
 Conidia catenulate 2. Toruleae, p. 595. 
 
 Conidia in heads or racemes 3. Echinobotryeae. 
 
 Conidiophores manifest and distinct from 
 the mycelium and spores 
 Conidia dark, rarely subhyaline 
 Conidia not in chains 
 
 Conidia capitate 4. Periconiese, p. 597. 
 
 Conidia verticillate, or at least lat- 
 eral 5. Anthrinieae. 
 
 Conidia borne singly on short 
 
 lateral branches 6. Trichosporieae, p. 598. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 595 
 
 Conidia solitary, acrogcnous 7. Monotosporeae, p. 600. 
 
 Conidia in chains 8. Haplographieae, p. 600. 
 
 Conidia hyaline 
 
 Conidia acrogcnous on short hctcromor- 
 phic conidiophorcs at tlie lower 
 part or bases of erect hyphai 
 
 Conidia single or catenulate 9. Sarcapodieae. 
 
 Conidia in heads 10. Myxotrichelleae. 
 
 Conidia on hypha? of the same kind 
 
 Conidia in heads 11. Stachylidieae. 
 
 Conidia in chains 12. Chalarieae. 
 
 Conidiosporieae (p. 594) 
 Conidia not catenulate, conidiophores short. 
 
 Key to Genera of Coniosporieae 
 
 Conidia spherical, elliptic or discoid 1. Coniosporium, p. 595. 
 
 Conidia elongate 2. Fusella. 
 
 Coniosporium Link 
 
 Hyphse very much reduced; conidia dark, 
 globose, ovoid or discoid, borne on short hya- 
 line conidiophores. '^ 
 
 .,..,.« . ^ • n 1, Fig. 398. — Conio- 
 
 About eighty-five species, chiefly saprophytes. sporium. After 
 C. onobrychidis Mag. occurs on sainfoin; Saccardo. 
 
 C. filicinum Rost. on Pteris and other ferns. 
 
 Toruleae (p. 594) 
 Conidia in chains. 
 
 Key to Genera of Toruleae 
 
 Conidia of two sorts, macroconidia catenul- 
 ate 
 
 Microconidia glomerate 1. Heterobotrys. 
 
 Microconidia internal, catenulate 2. Thielaviopsis, p. 5C6. 
 
 Conidia all alike 
 Hyphce dark 
 
 Chains breaking up readily 
 Conidia globose or ovoid 3. Torula, p. 597. 
 
596 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Conidia clavate 4. Gongromeriza. 
 
 Chains breaking up with difficulty 
 
 Chains curved 5. Gyroceras. 
 
 Chains straight or nearly so 6. Hormiscium. 
 
 Hyphse hyaline 7. Monilochaetes, p. 597. 
 
 Thielaviopsis Went. -'' (p. 595) 
 
 Hyphse creeping, subhyaline; conidiophores simple, septate; 
 conidia of two kinds; macroconidia catenulate, ovate, fuscous; 
 
 ■T. ethaoeticus. 
 Wakker and 
 
 Fig. 400.— Torula. 
 Saccardo. 
 
 After 
 
 microconidia cylindric, hyaline, catenulate within the conidiophore. 
 In part=Trichosphaeria. 
 
 Only two species, both of economic importance. 
 
 T. paradoxa (d. Seyn) v. Hohn (=Chalara paradoxa.) 
 
 Macroconidia 16-19 x 10-12 /x; microconidia 10-15 x 3.5-5 /jl. 
 
 It is the cause of a pineapple rot, in which role it was first de- 
 scribed in 1886; and of a sugar cane disease.'" 
 
 In addition to micro and macrospores the fungus possesses a 
 pycnidial form. With variation of the substratum the spores vary 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 597 
 
 considerably from the typical. In disinfection tests Patterson and 
 Charles ^^ showed the macrospores to be considerably more resist- 
 ant than the microspores, also that fumigation kills superficial 
 spores and spores placed in incisions in the fruit. 
 
 T. podocarpi Pet. is known from Podocarpus roots.^^^ 
 
 Torula Persoon (p. 595) 
 
 Hyphae decumbent; conidiophores short, scarcely different 
 from the conidia, which are catenulate, breaking away singly or in 
 groups, dark to black, oblong to fusoid, smooth or roughened. 
 
 Some one hundred fifty species, chiefly saprophytes. 
 
 T. exitiosa d. Seyn is said to cause much injury to chestnuts. 
 
 T. sphaerella Cke. causes a sooty mold of coffee. 
 
 Monilochaetes Ellis & Halsted (p. 596) 
 
 Hyphae brown; conidiophores obsolete or very short, conidia 
 like; conidia in chains, moniliform, dark; some chains interspersed 
 with larger conidia. 
 
 Monotypic and poorly known. 
 
 M. infuscans Ell. & Hals.^^'' 
 
 The mycelium grows subepidermally in sweet potato roots 
 causing discoloration and withering. The conidiophores arise 
 from the surface bearing their simple chains of conidia. 
 
 Periconieae (p. 594) 
 Conidia dark, capitate. 
 
 Key to Genera of Periconieae 
 
 Fertile hyphse simple, but often with short 
 apical branches 
 Hyphse with apical branches or conidio- 
 phores 
 
 Parasitic 1. Periconiella. 
 
 Saprophytic 
 Apex with heterogeneous conidio- 
 phores 
 Apex swollen; conidiophores 3 to 4 2. Haplobasidium. 
 
598 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Apex not swollen; conidiophores 
 
 many 3. Stachybotrys. 
 
 Apex short-branched, rarely simple 
 Apex short-branched or simple 
 
 Apex not swollen 4. Periconia, p. 598. 
 
 Apex swollen 5. Stachybotryella. 
 
 Apex capitate-branched; branches ' 
 2 to 3-furcate and spine- 
 bearing 6. Cephalotrichum. 
 
 Hyphse without apical branches or co- 
 nidiophores 
 
 Conidia globose 7. Trichobotrys. 
 
 Conidia boat-shaped curved; hypha) 
 
 dark-ringed 8. Camptoum. 
 
 Conidia fusoid, sometimes subhya- 
 
 line 9. Acrotheca. 
 
 Fertile hyphse branched below the apex 
 Hyphse forked below apex; conidia ob- 
 long 10. Synsporium. 
 
 Hyphse repeatedly dichotomous; conidia 
 
 globose or elliptic 11. Dicyma. 
 
 Periconia Bonordin -^^ 
 
 Hyphffi creeping, or obsolete; conidiophores simple, dark, 
 apically fertile; conidia globose*, fuscous, solitary on short sterig- 
 raata. Fig. 401. 
 
 Some forty species chiefly saprophytes. 
 
 Trichosporieae (p. 594) 
 Conidia dark, borne singly on short lateral branches. 
 
 Key to Genera of Trichosporieae 
 
 Hyphse loose, typically saprophytic 
 
 Hyphse vesiculose-inflated here and there 
 
 Conidia-bearing vesicles pleurogynous. 1. (Edemium. 
 
 Conidia-bearing vesicles acrogenous ... 2. Cystophora. 
 Hyphse not vesiculose-inflated 
 
 Fertile hyphse erect 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 599 
 
 Branches circinate at apex; conidia 
 
 mesogcnous, muricate 3. Acrospeira. 
 
 Branches spirally twisted; conidia 
 
 exogenous 4. Streptothrix, p. 509. 
 
 Hypha; simple or with straight 
 
 branches 5. Virgaria. 
 
 All hyphce more or less creeping 
 
 Branches curved or lash-like. . . 6. Campsotrichum. 
 
 Branches not curved 
 
 Conidia spiny, rarely smooth 7. Zygodesmus, p. 599. 
 
 Conidia smooth 
 
 Conidia sessile 8. Trichosporiuin. 
 
 Conidia on stalks 
 
 Conidia on tooth-like sterig- 
 
 mata 9. Rhinocladium. 
 
 Conidia on jar-like stalks .... 10. Basisporium. 
 Hyphae forming a crust, parasitic 11. Glenospora. 
 
 Streptothrix Corda 
 
 Conidiophores erect, monopodially branched, 
 the branches spirally coiled; conidia apical or 
 lateral, single, sessile or with short sterigmata, 
 dark colored. 
 
 A small genus. S. dassonvillei Broc-Ros. is 
 
 noted as the cause of mold of grain and fod- 
 der.337 
 
 Zygodesmus Corda 
 
 Hyphie and conidiophores creeping, the lat- 
 ter branched, light or dark colored, here and 
 there irregularly inflated, septate at the swel- 
 lings; conidia globose or ovate, muricate, rarely 
 smooth, on short sterigmata or on basidia-like 
 branches of the sterigmata. 
 
 Some fifty species, chiefly non-parasitic. 
 
 Z. albidus E. & H.^^ 
 
 Halsted describes a disease characterized by a floury coating 
 on violet leaves and ascribes it to this species. 
 
 Fig. 401. — Periconia. 
 After Saccardo. 
 
600 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Monotosporeae (p. 595) 
 Conidia dark, solitary, acrogenous. 
 
 Key to Genera of Monotosporeae 
 
 Sterile hyphae lacking 
 
 Fertile hyphse short and fascicled at 
 
 base 1. Hadrotrichum, 
 
 Fertile hyphse longer, separate 2. Monotospora. 
 
 Sterile hyphse present 
 
 Conidia with a loose hyaline membrane . 3. Nigrospora. 
 Conidia without a membrane 
 
 Conidia with a large shining drop. . . 4. Sporoglena. 
 Conidia without a shining drop 5. Acremoniella, p. 600. 
 
 Acremoniella Saccardo 
 
 Hyph£e creeping, simple or ramose, hyaline or colored; conidio- 
 phores simple, short, subbulbous below; 
 conidia globose to ovoid, fuscous. 
 About a dozen species. 
 A. occulta Cav.-^'' forms brownish-yellow 
 flakes on the stems of cereals; 
 
 A. verrucosa Togn. on wheat in 
 A 't\\^ Al .y:^ Italy. 
 
 Fig. 402.-Acremoniella. Haplographicae (p. 595) 
 
 After Bonorden. /-, • i- i i 
 
 Conidia dark, catenulate. 
 Key to Genera of Haplographieae. 
 
 Sterile hyphse all creeping or obsolete 
 Fertile hyphse simple, not branched at tip 
 
 Chains of conidia lateral 1. Dematium. 
 
 Chains terminal 
 
 Conidia without isthmi 2. Catenularia. 
 
 Conidia connected by cylindric 
 
 isthmi 3. Prophytroma. 
 
 Fertile hyphse branched 
 
 Hyphse dendroid 4. Hormodendrum, p. 601. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 601 
 
 Hyphse capitate branched at tip. . . . 5. Haplographium. 
 Some sterile hyphse erect and mixed witli 
 
 the fertile 6. Hormiactella. 
 
 Hormodendrum Bonarden (p. 600) 
 
 Hyphse creeping; conidiophores erect, septate, brown, variously 
 dendritically branched; conidia catenulate on 
 the branches, globose, ovoid, olivaceous to 
 fuscous. 
 
 About a dozen species. 
 
 H. hordei Bruhne on barley stems and 
 leaves often reduceg the yield. 
 
 Spots brown, scattered over the entire leaf or 
 confluent, oblong; hyphse simple, septate; co- 
 
 ... . ,. 1 • 11 1 ij^ Fig. 403. — H. hordei 
 
 nidia various, cylmdric, rounded or su batten- After Bruhne. 
 uate, or ellipsoid to subglobose, verrucose. 
 
 Dematiaceae-Didymosporae (p. 594) 
 Conidial 1-celled, dark, rarely hyaline, ovoid or oblong. 
 
 Key to Genera of Dematiaceae-Didymosporae 
 
 Hyphse very short or scarcely different from 
 the conidia 
 Conidia not in chains 
 
 Hyphse lacking 1. Dicoccum, p. 602. 
 
 Hyphse present, circinate 2. Cycloconium, p. 602. 
 
 Conidia in chains 3. Bispora. 
 
 Hyphse distinctly different from the conidia 
 Conidia smooth, muticate 
 Conidia not capitate 
 Conidia more or less catenulate at 
 first 
 Hyphse and conidia biform, the 
 latter 1-celled or continuous, 
 
 dark or hyaline 4. Epochnium. 
 
 Hyphse and conidia uniform 
 
 Hyphse here and there inflated 5. Cladotrichum, 
 
602 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Hj'phse not inflated 
 
 Hyphse erect; conidia long- 
 
 catenulate 6. Diplococcium, p. 603. 
 
 Hyphse somewhat decumbent ; 
 conidia short-catenulate 
 
 or finally solitary 7. Cladosporium, p. 606, 
 
 Conidia not catenulate 
 
 Hyphse beautifully flexuose- 
 
 torulose 8. Polythrincium, p. 603. 
 
 Hyphse not torulose or flexuose 
 Hyphse inflated at tip, branched 9. Pseudobeltrania. 
 Hyphse not inflated, usually 
 short and little branched 
 Conidia merely acrogenous 
 Conidiophores short, 1 or 2- 
 
 septate 10. Fusicladium, p. 606. 
 
 Conidiophores rather long, 
 
 multiseptate 11. Passalora, p. 607. 
 
 Conidia acro-pleurogenous . . . 12. Scolecotrichum, p. 607. 
 
 Conidia capitate 13. Cordana. 
 
 Conidia muriculate or ciliate 
 
 Conidia muriculate 14. Trichocladium. 
 
 Conidia ciliate at apex; fertile and 
 
 sterile hyphse intermixed 15. Beltrania. 
 
 Dicoccum Corda (p. 601) 
 
 Hj'^phse creeping, chiefly very short, simple; conidia elongate 
 or short-clavate, dark. 
 About a dozen species. 
 D. rosae Bon. produces spots on rose leaves. 
 
 Cycloconium Castaigne (p. 601) 
 
 Hyphae in the walls of the epidermis, dichotomous branched, 
 very fugacious, black; conidia ovoid, solitary. 
 
 There is one species: 
 
 C. oleaginum Cast. Mycelium circinate, fugacious, black; 
 conidia sessile, ovoid, yellow-green. 
 
 It forms blotches on olive leaves and on peduncles of the fruit 
 in Italy and France and is somewhat injurious in California. ^^^ 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 603 
 
 Diplococcium Grove (p. 602) 
 
 Conidiophores erect, septate, branched, olivaceous; conidia 
 catenulate, 2-celled. 
 
 Fig. -104. — Cycloconium 
 oleaginum. After Boyer. 
 
 Fig. 405.— Clodosporium cu- 
 cumerinum, mycelium, a 
 hyphal knot, conidiophore 
 and spores. After Hum- 
 phrey. 
 
 D. conjunctum (Bon) Sacc. is reported as a parasite of the 
 
 geranium 
 
 Cladosporium Link (p. 602) 
 
 Hyphffi decumbent, intricately-branched, olivaceous; conidia 
 globose to ovoid, greenish. In part=Mycosphffirella. See p. 243. 
 
 Some one hundred seventy-five species, many of them of 
 economic importance. 
 
 C. fasciculare Fr. on hyacinth =Pleospora hyacinthi. See p. 260. 
 
 C. herbarum (Pers.) Lk. on many hosts = My cosphserella tu- 
 lasnei. See p. 247. 
 
604 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 C. herbarum (Pers.) Lk. var. citricolum.^^^- 22 
 Fawcett ^^^ recognizes this as the cause of scaly bark of Citrus. 
 The fungus was grown in pure culture and inoculations were made 
 resulting in from forty to sixty days in typical spots. From these 
 the fungus was re-isolated, 
 
 C. cucumerinum E. & kP' ^s^-ss? 
 
 Effused, maculose; in mass greyish-brown, changing to dark 
 olivaceous, forming spots on fruits; condiophores cespitose, 
 sparingly septate, simple, denticulate, pale; conidia ovoid, lemon- 
 shaped or fusoid; olivaceous, 10-13 x 3-4 ju. It causes watery 
 spots on cucumber leaves, also decayed spots in fruit. 
 
 C. elegans Penz. is the cause of disease on various Idnds of 
 oranges in Italy. This species is in the literature much confused 
 with the next. 
 
 C. citri Mas.^3' 288-291 
 
 Conidiophores tufted, erect, branched, septate, brown, 30-75 
 X 2-4 11; conidia fusiform, dusky, continuous, or 1 to 3-septate, 
 8-9 X 2.5-4 n. 
 
 The cause of scab on lemons, sour oranges, satsumas and pom- 
 elos. It was grown in artificial culture by Fawcett. 
 C. carpophilum Thum.^e- 292-294. 459 
 
 Spots orbicular, often confluent, blackish-green, forming circles; 
 conidiophores erect, simple, sinuous, septate; conidia 
 ovate, obtuse, continuous or 1-septate, 10-12 x 
 4-6 fi. 
 
 This is the cause of the widely distributed scab 
 
 of peach, plum, nectarine, apricot, cherry. The 
 
 deep olive-broAvn hyphse are found intermingled 
 
 with the hairs of the peach. The disease was first 
 
 noted in Austria in 1877. The fungus was cultured 
 
 carpophilum.' and inoculations were made by Chester.^^^ 
 
 After Cobb. jj^ ^j^g ^^jg ^j^g fungus breaks the cuticle from 
 
 the layers below and its hyphae project through cracks. Upon the 
 
 leaf it causes shot holes. 
 
 C. sicophilum Far. attacks fig fruits. 
 C. fulvum Cke.32 
 
 Conidiophores densely crowded rupturing the cuticle, sparingly 
 branched, septate, nodulose, bearing a few conidia near the apex; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 605 
 
 conidia elliptic-oblong, 1-septate, translucent, tawny, 10-20 x 4- 
 6 yL. 
 
 The hyphae are abundant on the lower sides of tomato leaves, 
 forming a mold, varying from whitish to purplish in color. 
 
 It causes serious disease in Europe and America. 
 
 C. condylonema Pass, is found on leaves of Prunus causing leaf 
 spot nnd curl. 
 
 C. bigarardia is on Citrus. 
 
 C. macrocarpum Preu.-° 
 
 Subeffuse, black; conidiophores subfasciculate, simple, some- 
 
 FiG. 407.— C. fulvum. After Southworth. 
 
 what flexuose, brown; conidia oblong, oblong-ovate, 2 to several 
 septate, obtuse, pale brown. 
 
 On spinach leaves in New Jersey, causing disease. 
 
 C. graminum Cda. 
 
 Clusters minute, irregular, scattered, greyish-brown; conidio- 
 phores distinct, erect, simple, nodulose-flexuose, brown; co- 
 nidia concolorous, continuous to several-celled, rounded or 
 oblong. 
 
 It is reported that this fungus was commonly present on sterile 
 wheat florets and that inoculation with it increased such sterility 
 slightly. 
 
 C. cryzae S. & Sy. is on rice; 
 
 C. orchidis C. & M. on Oncidium; 
 
 C. pisi Cu. & Ma. on Pisum. 
 
606 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 C. peoniae Pass. 
 
 Spots large, chestnut brown, hyphse short, simple; spores 
 various, long, 1 to 2-septate. On peony. 
 
 C. epiphyllum Mart, is on oak, sycamore, poplar, etc. ; 
 
 C. juglandis Cke. on walnut; 
 
 C. scribnerianum Cav. on beech; 
 
 C. hypophyllum Fcl. on elm; 
 
 C. tuberum Cke. on sweet potato tubers; 
 
 C. scabies Cke. on tomato and cucumber; 
 
 C. oxycocci Sh. on cranberry. 
 
 C. zeae Pk. 
 
 Sterile hyphse hyaline, sub-cutaneous, erumpent ; spores elliptic- 
 oblong, 4 X 20 jLi, continuous or 1 to 3-septate. 
 
 In immature corn grains. 
 
 C. brunneo-atrum McA. is on orange leaves and young shoots 
 in Australia; 
 
 C. javanicum Wak. on sugar cane in Java causing root molds. 
 
 Polythrincium Kunze & Schmidt (p. 602) 
 
 Conidiophores erect, fasciculate, regularly flexuose or toru- 
 lose, black, simple; conidia acrogenous, obo- 
 void. 
 
 Monotypic. In part =Phyllachara. See 
 p. 220. 
 
 P. trifolii Kze. on clover =Phyllachora tri- 
 folii. See p. 220. 
 
 Fusicladium Bonardin (p. 602) 
 
 Conidiophores short, erect, straight, spar- 
 FiG. 408.— P. trifolii. ingly Septate, subfasciculate, olivaceous; co- 
 ter or a. nidia ovoid or subclavate, continuous or 
 1-septate, acrogenous, solitary or paired. 
 
 In part=Venturia and Phyllachora. ' 
 
 Over forty species, several pathogenic. 
 
 F. fraxini Aderh. on Ash.=V. fraxini. See p. 255. 
 
 F. saliciperdum (All. & Pub.) Land, on Salix=V. chlorospora. 
 See p. 255. 
 
 F. cerasi (Rab.) Sacc. on cherry, peach, =V. cerasi. See p. 255. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 607 
 
 F. pirinum (Lib.) Fcl. on pear=V. pirinia. See p. 253. 
 
 F. dendriticum (Wal.) Fcl. on pomaceous fruits=V. inscqualis. 
 See p. 253. 
 
 F. orbiculatum Thiim on Sorbus=V. insequalis var. cinerascens. 
 See p. 255. 
 
 F. depressum (B. & Br.) Sacc. on Umbellifer2e=Phyllachora. 
 
 F. betulae Aderh. on birch =V. ditricha. See p. 255. 
 
 F. tremulae Fr. on aspen =V. tremulse. See p. 255. 
 
 F. fagopyri Oud. is found on buckwheat; 
 
 F. lini Sor. on Linum. 
 
 F. eriobotryae Cav. attacks leaves of Eriobotrys.^ 
 
 F. destruens Pk. 
 
 Conidiophores short, 20-50 /x, fasciculate, continuous or 1 
 to 2-septate, basally, colored, clusters slightly olive-green; conidia 
 acrogenous, continuous or 1-septate, subcatenulate, ellipsoid 
 to oblong, colored, 7-20 x 5-7 n. 
 
 On oats. 
 
 F. effusum Wint.^^s 
 
 Spots minute, rounded, rarely effused, confluent, smoky; coni- 
 diophores erect, simple or slightly branched, septate, torulose, 
 brownish, lighter above, 100-140 x 4 /i; conidia oblong fusoid to 
 rhomboid, continuous or uniseptate, light fuscous, subtruncate, 
 17-24 X 5.5-7 M- 
 
 It constitutes the pecan scab affecting the leaves, stems and nuts. 
 
 F. vanillae Zim. is on vanilla. 
 
 An undetermined species is the cause of a black canker of Hevea. 
 
 Passalora Fries & Montaigne (p. 602) 
 
 Conidiophores filiform, intricate multiseptate, olive; conidia 
 oblong to fusoid, acrogenous. 
 
 A small genus quite similar to Fusicladium except for the pluri- 
 septate conidiophores. 
 
 P. bacilligera M. & F. and P. microsperma Fcl. occur on Alnus. 
 
 Scolecotrichum Kunze & Schmidt (p. 602) 
 
 Conidiophores short, subfasciculate, olive; conidia oblong or 
 ovate, pleurogenous or acrogenous. 
 
 A genus of some thirty species very similar to Fusicladium. 
 
608 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 S. graminis Fcl. 
 
 Spots foliicolous, elongate, ochraceous; conidiophores densely 
 fasciculate, filiform, simple, sinuose, 90-100 x 
 6-8 n, subcontinuous; conidia fusoid-obclavate, 
 35-45 X 8-10 n, uniseptate, olive-brown. 
 
 It is common, causing leaf spots on grasses, 
 especially on Avena and Phleum. It is de- 
 scribed on the latter by Trelease.^^^ The my- 
 celium collects below the stomata and pushes 
 its tuft of hyphae through them. 
 
 S. melophthorum P. & D, parasitizes melons 
 and cucumbers in France; ^°° 
 S. fraxini Pass, is on ash. 
 S. iridis F. & R. is on Iris; 
 S. musae on banana. 
 S. avense Erik, is on oats. 
 
 Fig. 409. — S. grami 
 nis. After Sac 
 cardo. 
 
 Dematiaceae-Phragmosporae (p. 594) 
 
 Conidia 2 to many-celled, dark, rarely light or hyaline, ovoid to 
 cylindric or vermicular. 
 
 Key to Genera of Dematiaceae-Phragmosporae 
 
 Fertile hyphae very short or little different 
 from the conidia 
 Conidia not in chains 
 Conidia muticate 
 Conidia united at base, fasciculate, 
 
 cylindric 1. Cryptocoryneum. 
 
 Conidia separate 
 
 Conidia straight ovoid to cylindric 
 
 Conidia solitary 2. Clasterosporium, p. 609. 
 
 Conidia in bundles 3. Stigmina, p. 610. 
 
 Conidia fusoid-falcate 4. Fusariella. 
 
 Conidia cuspidate or setose 
 
 Hyphse dichotomous and broadened 
 
 at apex 5. Urosporium. 
 
 Hyphae not dichotomous or broad- 
 ened 6. Ceratophorum, p. 610. 
 
 Conidia in chains 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 609 
 
 Conidia not connected by isthmi 7. Septonema. 
 
 Conidia connected by isthmi 8. Polydesmus. 
 
 Fertile hyphse distinctly different from 
 the conidia 
 Conidia soUtary or nearly so, acrog- 
 enous for the most part 
 
 Conidia muticate 9. Helminthospora. 
 
 Conidia echinulate 10. Heterosporium, p. 610. 
 
 Conidia smooth 
 
 Hyphse creeping, radiate 11. Ophiotrichum. 
 
 Hyphae short, ascending or 
 erect, conidia ovoid to 
 
 oblong 12. Napicladium, p. 611. 
 
 Hyphse longer, rigid; conidia 
 ovoid to elongate 
 
 Conidia ovoid 13. Brachysporium. 
 
 Conidia elongate 14. Helminthosporium, p. 611. 
 
 Hyphae flexuous, pannose. ... 15. Drepanospora. 
 
 Conidia 1 to 3-ciliate at apex 16. Camposporium. 
 
 Conidia verticillate or capitate 
 Hyphse dark 
 Conidia acrogenous, forming a 
 head 
 
 Hyphse simple 17. Acrothecium. 
 
 Hyphae branched at the apex. 18. Atractina. 
 Conidia pleurogenous, some- 
 what verticillate 
 Hyphse rostrate and naked at 
 
 apex 19. Rhynchomyces. 
 
 Hyphffi not rostrate at apex. . 20. Spondylocladium, p. 614. 
 Hyphse hyaline or bright colored, 
 
 apex denticulate 21. Neomichelia. 
 
 Conidia catenulate as a rule 
 
 Conidia arising from the interior of 
 
 the hyphae IV. Sporoschismeae. 
 
 Conidia arising from the apex, 
 
 sometimes solitary V. Dendryphieae, p. 615. 
 
 Clasterosporium Schweinitz (p. 608) 
 
 Hyphse creeping, here and there swollen, erect, bearing 2 to 
 several-septate, solitary, apical conidia. 
 
610 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 A genus of some seventy-five species. 
 
 C. glomerulosum Sacc. on Juniperus leaves is often reported 
 as Sporodesmium glomerulosum. 
 
 C. carpophilum (Lev.) Aderh.^^' ^°^' ^°^' '^^ Aderhold by inocu- 
 lations, properly controlled, showed this fungus capable of causing 
 gummosis of prunaceous hosts though C. herbarium did not do so. 
 Effuse, hyphse simple or short-branched, densely aggregated, 
 septate, conidia elongate-fusoid, obtuse, 4 to 5-septate, slightly con- 
 stricted at the septa. It is commonly seen as 
 the cause of a brown spot on peaches. Spores 
 do not appear in the young spots but are found 
 sparingly in older bro^vn areas. 
 
 Pure* culture inoculations by Stewart ^^ on 
 peach twigs resulted in blackening and gum- 
 
 FiQ. 410.— Stigmina. mosis. 
 
 After Saccardo. ^ amygdalearum (Pass.) Sacc. is also de- 
 
 scribed on rosaceous hosts. It is perhaps identical with C. car- 
 pophilum and may be connected with Pleospora vulgaris.^^^ 
 
 C. putrefaciens (Fcl.) Sacc. causes spots on leaves of the sugar- 
 beet. 
 
 Stigmina Saccardo (p. 608) 
 
 Hyphse epiphyllous; conidiophores very short or obsolete; coni- 
 dia ovate or elongate, 3 or more-celled, aggregated. 
 S. briosiana Far. causes disease of apricots in Europe. 
 
 Ceratophorum Saccardo (p. 608) 
 
 Hyphae creeping, scant; conidiophores short, erect; conidia 
 fusoid or cylindric, 2 to many-septate, dark or reddish-brown. 
 
 A small genus. 
 
 C. setosum Kirch, is found on leaves and shoots of young plants 
 of Cytisus, etc., in greenhouses; ^°^ 
 
 C. ulmicolum E. & K. on Ulmus leaves. 
 
 Heterosporium Klotzsch (p. 609) 
 
 HyphsB subcespitose, smoothish, often branched; conidia oblong, 
 2 to several-septate, smoothish to granular or echinulate. 
 A genus of forty species or more. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 611 
 
 H. echinulatum (Berk.) Cke.-^- -°' 
 
 Spots gregarious, on fuscous areas; conidiophores fasciculate 
 from a stromatic base, 150-200 x 8 /x, rarely shorter, flexuose- 
 nodose, fuliginous; conidia at the nodes, oblong-cylindric, rounded 
 at the ends, 2 to 3-septate, 40-50 x 15-lG /i, slightly constricted, 
 roughened, brownish. 
 
 It causes a destructive mold on carnation leaves and stems. The 
 first epidemic was noted by Sorauer in Berlin in 1883. 
 
 H. gracile (Wal.) Sacc. was determined to be the cause of dis- 
 ease of Iris, Narcissus and other Monocotyledons. ^°^ 
 
 H. variable Cke.^oe 
 
 Conidiophores flexuose, slender, more or less nodulose at the 
 septa; conidia cylindric oblong, 2 to 4-septate, minutely warted, 
 20-25 X 7-10 ju, pale olive. On spinach. 
 
 Other parasitic species are: 
 
 H. ornithogali Klotz. on Liliaceae; 
 
 H. laricis C. & M. on larch leaves; 
 
 H. auriculi ]Mas. on cultivated Auricula; 
 
 H. syringae Oud. on lilac leaves.** 
 
 H. minutulum C. & M. causes disease of hops. 
 
 Napicladium von Thiimen (p. 609) 
 
 Conidiophores short, subfasciculate, smoothish; conidia acroge- 
 nous, solitary, large, oblong, 2 to many-septate, smoothish. 
 
 A small genus. 
 
 N. janseanum Rac. is on rice. 
 
 N. soraueri is a form of Venturia inaequalis with somewhat 
 atypical napiform spores. See p. 253. 
 
 Helminthosporium Link (p. 609) 
 
 Conidiophores erect, rigid, subsimple, fuscous; conidia fusoid 
 to elongate-clavate or cylindric, pluriseptate, fuscous, smooth. 
 
 In part=Pleospora. See p. 259. 
 
 About two hundred species; several are important pathogens, 
 others saprophytes. 
 
 The species show biologic differentiation into races similar to 
 
612 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 that exhibited in the Erysiphacese, though morphologically they 
 may be inseparable. 
 
 Fig. 411. — Helminthosporium gramineum. Conidio- 
 phoree and spores. After Eling. 
 
 H. gramineum (Rab.) Erik, on grasses =Peleospora gramineum. 
 See p. 261. 
 H. trichostoma=Pleospora trichostoma. See p. 260. 
 
 Fig. 412. — Helminthosporium teres. Conidiophores 
 and spores. After King. 
 
 H. teres Sacc. 
 
 Spots oblong, olive, amphigenous; conidiophores fasciculate, 
 often crooked and nodulose, septate, brown, 100-130 x 12 )u; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 613 
 
 conidia acrogenous, straight, cylindrical, ends rounded, 4 to 5- 
 septate, not constricted, dark olive-brown, 100-115 x 14- 
 18 ju. On oats and barley. 
 
 H. avenae Ei. 
 
 Similar to H. teres, but the conidiophores scattered, 150-200 x 
 9-12 fx, septate, brown; conidia cylindric, brownish, 4 to 6-septate, 
 80-100 X 15-16 M. On oats. 
 
 The conidia of the two last species infect grains and seedlings. 
 The conidia spread the disease from the early infection centers 
 to other parts of the plants but the mycelium remains local. 
 
 H. bromi Died, on Bromus=Pleospora bromi, see p. 261. 
 
 H. tritici-repentis Died.=Pleospora tritici-repentis, see p. 262. 
 
 H. sativum (P.) K. & B.^^^ 
 
 Mycelium branched, septate; conidiophores fasciculate, fuscous, 
 brown, septate, 8-10 /x wide, sometimes swollen between the 
 septa; conidia solitary, apical, dark brown, 6 to 11-septate, 105- 
 130 X 15-20 M. 
 
 The cause of a destructive late blight of barley from Iowa to 
 Saskatchewan. The disease manifests itself by dark colored, 
 elongate spots on the leaves. 
 It also occurs on the glumes 
 and spikelets, sometimes even 
 penetrating the grains. 
 
 H. sorokinianum Sacc. is re- 
 ported on wheat and rye in 
 Russia; 
 
 H. tritici Hen. on wheat in 
 Africa; H. sigmoideum Cav. 
 on rice in Italy; while several 
 species are recorded on bam- 
 boo. 
 
 H. turcinum Pass. 
 
 Spots, large, dry, brownish; conidiophores, gregarious to fascicu- 
 late, septate, 150-180 x 6-9 n, pale olive, apex almost hyaline, 
 often nodulose; conidia spindle-shaped, acute, 5 to 8-septate, 
 pale olive, 80-140 x 20-26 /x. 
 
 It produces spots on corn and sorghum in Europe and America. 
 
 H. inconspicuum C. & E.^^- 308-3io 
 
 Fig. 413. — Helminthosporium sativum 
 from barley, spores and conidiophores. 
 After King. 
 
614 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Conidiophores elongate, septate, nodose, pale brown; conidia 
 lanceolate, 3 to 5-septate, 80-120 x 20 ju, smooth. 
 
 It has been reported on sweet corn from Long Island by Stewart. 
 H. gramineum, H. turcinum and H. incon- 
 spicuum are closely related, possibly identical. 
 
 Johnson ^^° concludes that H. gramineum with 
 its ascosporic stage includes Piricularia grizea, 
 P. oryzse, Helminthsporium oryzae and H. tur- 
 cinum. 
 H. inaequalis Sh. 
 
 Sterile hyphse effuse, much branched, dark 
 brown; conidiophores erect, septate, variable 
 in length, 6-8 ju in diameter; conidia both ter- 
 FiG. 414.— Helmin- ^\^q\ and lateral, more or less curved, 3 to 
 
 thosporium in- ' ' 
 
 sequalis. After 5-celled, thick- walled, browTi, 23-32 x 11-14 fx. 
 
 Shear. ^ , 
 
 On cranberry. 
 
 H. heveae Fetch, is on Para rubber; 
 
 H. theae Bernard on tea in India; 
 
 H. iberidis Poll, on Iberis and H. lunariae Poll, on Lunaria, both 
 
 in Italy. 
 
 Spondylocladium Martius (p. 609) 
 
 Hyphse creeping, septate; conidiophores erect, simple, rigid; 
 conidia v^rticillate, fusoid, usually 3-celled, brownish. 
 A small genus. 
 
 22 
 
 S. atrovirens Harz. 
 
 Conidiophores solitary or clustered, cylindric, septate, dingy, 
 olive or brownish, up to 400 /x high; conidia elongate, ovate, apex 
 narrowed, 5 to 7-septate, concolorous with the conid- 
 iophores, 30-50 X 6-9 IX. 
 
 On potatoes this fungus causes blackish to olive 
 spots soon depressed, 2-3 cm. across, which are 
 beset with small black sclerotia and followed by dry 
 rot. According to Appel & Laubert ^^^ the sclerotia 
 develop whorls of conidiophores. The species is atrovirens! 
 said to occur in the British Isles, the Continent After Massee. 
 and in America.^^- Its sterile mycelium has been described under 
 the name Phellomyces.^^^ 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 615 
 
 Dendryphium Wallroth (p. 609) 
 
 Hyphse creeping or obsolete; conidiophores erect, with short 
 apical brandies; conidia cylindric, 2 to many-septate, catenulate, 
 brown. 
 
 Some thirty or more species. 
 
 D. comosumWal. is the cause of a cucumber leaf spot in England. 
 
 Dematiaceae-Dictyosporae (p. 594) 
 Conidia dark, rarely light, muriform, globose to oblong. 
 
 Key to Genera of Dematiaceae-Dictyosporae. 
 
 Hyphae very short or scarcely different from 
 
 the conidia I. Micronemeae. 
 
 Conidia not in chains 
 Conidia not appendaged 
 
 Conidia irregularly muriform or 
 sarciniform 
 Conidia with a conic point at each 
 
 side 1. Oncopodium. 
 
 Conidia without conic points 
 Conidia globose to oblong 
 Conidia ovoid to oblong, loose 2. Sporodesmium,p. 616. 
 Conidia globose to ovoid, ag- 
 gregated 3. Stigmella. 
 
 Conidia sarcinseform, often co- 
 
 alescent 4. Coniothecium, p. 617. 
 
 Conidia as if composed of parallel 
 chains of cells 
 Chains of conidia never separat- 
 ing 5. Dictyosporium. 
 
 Chains of conidia separating 6. Speira. 
 
 Conidia corniculate at apex 7. Tetraploa. 
 
 Conidia in chains, often asperate or with 
 
 isthmi 8. Sirodesmium. 
 
 Hyphse distinctly different from the conidia II. Macronemeae. 
 Conidia of the same form ' 
 
 Conidia not in chains or capitate 
 Conidia bearing little conidia on their 
 - surfaces 9. Xenosporium. 
 
616 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Conidia single 
 Hyphse alike 
 
 Conidia cruciate-divided, verm- 
 cose 10. Tetracoccosporium. 
 
 Conidia muriform, typically 
 smooth 
 
 Hyphse decumbent 11. Stemphylium, p. 617. 
 
 Hyphse erect or ascending 
 Conidia globose, pleuro- 
 gynous 
 Conidia around the apex 
 
 of the hyphse 12. Coccosporium. 
 
 Conidia conglobate 
 
 around the base 13. Trichaeguia. 
 
 Conidia ovoid to oblong, 
 mostly acrogenous 
 Conidiophores somewhat 
 
 lax, colored 14. Macrosporium, p. 618. 
 
 Conidiophores rigid, very 
 
 dark 15. Mystrosporium, p. 620. 
 
 Hyphse of two kinds, longer 
 
 sterile, shorter fertile 16. Septosporium, p. 620. 
 
 Conidia capitate 17. Dactylosporium. 
 
 Conidia catenulate 
 Hyphse velvety, erect, subsimple; 
 
 conidia caudate 18. Alternaria, p. 621. 
 
 Hyphse crustose, various; conidia 2- 
 celled; conidia-like ganglia sar- 
 
 cinseform 19. Fumago, p. 624. 
 
 Conidia of two forms, dark sarcinseform 
 
 and subhyaline falcate 20. Sarcinella, p. 625. 
 
 Sporodesmium Link.^^^ (p. 615) 
 
 Mycelium and conidiophores poorly developed; conidia ovoid 
 oblong, subsessile or short-stalked, rather large, clathrate-septate, 
 fuligineus. 
 
 Over eighty species. 
 
 S. piriforme Cda. on oranges =Pleospora hesperidearum, 
 p. 260. 
 
 S. exitiosum Ktihn on crucifers=Leptosphseria napi, p. 258. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 617 
 
 S. exitiosum var. solani Schenck is reported as the cause of a 
 potato disease. 
 
 S. solani-varians Vanha is the cause of 
 potato disease in Europe, the foliage bearing 
 brown spots and finally dying in a manner 
 resembling death caused l)y Phytophthora. 
 Cladosporium and pycnidial forms are said 
 to exist. 
 
 S. mucosum Sacc. was reported by Ader- 
 holt on cucumber fruit and leaves causing 
 disease. 
 
 S. scorzonerae Aderh. causes a salsify 
 stem and leaf disease. ^^'* 
 
 Other parasitic species are: 
 
 S. melongena Thiim. on egg plant; 
 
 S. dolichopus Pass, on potato leaves in 
 Italy; 
 
 S. ignobile Karst. on asparagus; 
 
 S. putrefaciens Fcl. on beet; 
 
 S. brassicae Mas. on Brassica in Bengal. 
 
 Fig. 416. — Sporodesmium 
 antiquum. After Sac- 
 cardo. 
 
 Coniothecium Corda (p. 615) 
 
 Hyphse obsolete or poorly developed; conidia 
 gemmiform in origin, variously septate. 
 
 Over fifty species of very simple parasitic or 
 saprophytic fungi. 
 
 C. chomatosporum Cda. resembling apple 
 scab in its effect is noted as common in Tas- 
 mania^^^ and Australia. "^^^ 
 
 Stemphylium Walroth (p. 616) 
 
 Conidiophores decumbent, intricately 
 branched, hyaline or smoky; conidia acrogenous, 
 ovoid to subglobose, 2 to many-muriform- 
 septate, fuligineus. 
 
 Over thirty species. 
 S. ericoctonum B. & deB. is parasitic on Erica in green-houses. 
 
 Fig. 417.— Stemphy. 
 lium. After Sac 
 cardo. 
 
618 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 S. citri Pa. & Ch.^^ 
 
 Vegetative mycelium long, hyaline, becoming dark, 4 ju in 
 diameter, septate; conidiophores short; conidia dark ])rown, sub- 
 globose to oblong, apiculate, irregularly muriform, 20-30 x 12- 
 15 n, usually in chains of three. 
 
 This was found associated with an end-rot of oranges from 
 Arizona. Inoculated in pure culture in oranges the fungus de- 
 veloped well. It is perhaps the cause of the disease. 
 
 S. tritici Pa. 
 
 Hyphse irregularly branched; conidiophores closely septate, 
 4-5 fjL in diameter; conidia catenulate, irregular, usually clavate, 
 constricted slightly at the septa, 24-35 x 12-15 n, vermiculate, 
 fuligineus, isthmus short, 3-4 n in diameter. It is described as 
 the cause of floret sterility of wheat. ' 
 
 Macrosporium Fries (p. 616) 
 
 Conidiophores fasciculate, erect or not, more or less branched* 
 colored; conidia usually apical, elongate or globose, dark-colored. 
 
 In part=Pleospora. See p. 259. 
 
 About one hundred eighty species, many of them saprophytes 
 while others are important pathogens. 
 
 M. commune Rab.=M. sarcinula parasiticum Thiim. on vari- 
 ous grasses =Pleospora herbarium. ^^^' ^^^ See p. 260. 
 
 This is reported by Thaxter ^^^ as the common black mold which 
 follows Peronospora on the onion and which occurs often also on 
 onions no^ so diseased, being especially common on the seed stalks. 
 It is usually associated with injured plants and may be important 
 only as a wound parasite. 
 
 M'. porri E.^^^ 
 
 Effuse, fuligineus; hyphse short, simple, subfasciculate; conidia 
 elongate-clavate, basally attenuate, multiseptate, 150-180 x 
 12-20 M- 
 
 It is common on seed onions, less common on market onions. 
 The dark mycelium penetrates the host in all directions and finally 
 produces stromata below the stomata and sends up short hyphis. 
 
 M. alliorum C. & M. is also on onion; ^^ 
 
 M. hurculeum E. & M. 
 
 Amphigenous on rounded, grey spots; conidiophores erect, ces- 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 619 
 
 pitose, flexuose, brown, few septate, 70-80 x 5 m; conidia brown, 
 multiseptate, clavate, 200-225 x 21-26 /x- 
 
 It causes leaf spots on turnips, horse radish and other crucifers. 
 
 M. brassicae Berk. 
 
 Mycelium inconspicuous, conidia clavate, antennaiform, 5 to 
 11-septate, 50-60 x 12-14 ju. 
 
 It is a common cause of black mold on cabbage, collards and 
 other crucifers. 
 
 M. ramulosum Sacc. is on celery. 
 
 M. catalpae E. & M. ^^ 
 
 On brownish spots; conidiophores brown, curved, nodose, 8 to 
 12-septate, erect, amphigenous, 90-135 x 6 m; conidia brown, 
 obovate to pyriform, submuriform, 27-51 x 15-27 fx. 
 
 Producing leaf spots on Catalpa in company with Phyllosticta 
 eatalpse. 
 
 M. nobile Vize. is on Dianthus. 
 
 M. iridis C. and E. and M. aductum Mas. are on iris; 
 
 M. cheiranthi (Lib.) Fr. on Cheiranthus. 
 
 M. tabacinum E. & E.^^® causes thin, white amphigenous spots, 
 2-3 mm. with a narrow dark border; conidiophores effused, 35-45 x 
 3-4 n, septate and torulose above; conidia obovate, 15-25 x 10- 
 12 n, sessile or short stipitate, usually 3-septate. 
 
 It is reported to cause white leaf spots on tobacco. 
 
 M. longipes E. & E. 
 
 On concentric, rusty brown, amphigenous spots, 3 to 5 mm. in 
 diameter; conidiophores effused, amphigenous, slender, 40-70 x 
 3-4 n, septate, often contracted at the septa, erect and more or 
 less torulose above; conidia clavate, 40-50 x 15-20 m, 3 to 
 7-septate, attenuate below into a distinct stipe. On tobacco. 
 
 M. sarciniforme Cav. is reported by Walkoff ^^^ on red clover 
 in Germany where it causes the leaves to dry and die. 
 
 M. nigricanthium Atk.^-^ 
 
 Amphigenous; condiophores subfasciculate or scattered nodose, 
 septate, olive-brown, 50-140 x 6-7 ju; conidia olive-brown, con- 
 stricted about the middle, rostrate at one side of the apex, 18- 
 22 x 36-50 fjL. On cotton. 
 
 M. cucumerinum E. & E.^-^'^-^ 
 
 Epiphyllous on orbicular, subconfluent, brownish spots, 3-4 
 
620 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Fig. 418. — Macio- 
 sporium cucumer- 
 inum on cante- 
 loupe. After 
 Chester. 
 
 mm. in diameter; conidiophores fasciculate or 
 solitary, subgeniculate, 1 to 3-septate, 35-50 x 
 5-6 /x; conidia clavate, slender-stipitate, 3 to 
 8-septate, somewhat constricted, submuriform, 
 30-75 X 15-25 fj.; pedicel 25-35 n long. 
 
 On leaves, stems and fruits of cantaloupes. 
 
 M. cladosporioides Desm. is on beet, lettuce, 
 onion and many other hosts. 
 
 M. verrucosum Lutz. occurs on cacao; 
 
 M. gramineum Cke.^-^ on sugar cane. 
 
 M. uvarum Thtim. is reported on Vitis; 
 
 M. violae Poll, on violets in Italy; 
 
 M. saponariae Pk. on Saponaria. 
 
 M. macalpinianum S. &. Sy. is injurious to 
 Pelargonium. 
 
 Mystrosporium Corda (p. 616) 
 
 Conidiophores simple or sparingly branched, short, septate, 
 fuscous, rigid; conidia elliptic, subglobose or oblong, pluriseptate, 
 muriform, dark, usually solitary, acrogenous. 
 
 Some twenty species. 
 
 M. abrodens Nebr. is described as the cause of a very serious 
 grain disease in France. 
 
 M. aductum Mas. injures Iris bulbs; 
 
 M. alliorum Berk, forms dark spots on onion. 
 
 Septosporium Cda. (p. 616) 
 
 Conidiophores short, intermixed with longer sterile hyphae; 
 conidia ovoid to pyriform, fuscous. 
 
 A small genus. 
 
 S. heterosporium E. & G. 
 
 Spots scattered, confluent or not, rusty brown, 0.5-1 cm. in 
 diameter, conidiophores hypophyllous, fasciculate from the sto- 
 mata; conidia variable, oblong cylindric, constricted at the 
 septa, 20-40 x 5-7 fx, separating into gemmse. 
 
 Reported in 1888 ^- on the wild grape in California. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 621 
 
 Alternaria Nees. (p. 616) 
 
 Conidiophores fasciculate, erect, sub-simple, short; conidia 
 clavate-lageniform, septate, muriform, catenulate. 
 
 In part=Pleospora. See p. 259. 
 
 Some thirty or more species, many of pronounced economic im- 
 portance. 
 
 A. sp. on Tropoeolum=Pleospora tropoeoli. See p. 260. 
 
 A. trichostoma Died, on barley =Pleospora trichostoma. See 
 p. 260. 
 
 A. forsythiae Harter.^^^ 
 
 Hyphae cespitose, amphigenous; spot concentric zonate: conidia 
 18-60 X 10 X 16.5 M- 
 
 It causes subcircular leaf spots on cultivated Forsythia. 
 
 A. brassicae (Berk.) Sacc. 
 
 Conidiophores short, continuous, short-branched, apically 
 equal, conidia elongate, fusoid, clavate, 60-80 x 14-18 n, 6 to 8- 
 muriform-septate, olivaceous. 
 On crucifers. 
 
 A. brassicae (Berk.) Sacc. 
 var. phaseoli Brun. occurs on 
 beans in Italy. 
 
 A. cucurbitae Let.^-^' ^-^ may 
 be identical with A. brassicae. 
 
 It was noted by Thax- 
 ter in Connecticut causing 
 
 blight of melons. The black Fig. 419. — A. violae, germinating spores. 
 , , . . • i 1 11 After Dorsett. 
 
 mold IS copious m the older 
 
 circular spots. Pure cultures were obtained and successful in- 
 oculations were made on normal uninjured melon leaves. 
 
 It is also reported by Selby^-^ as the probable cause of muskmelon 
 leaf spots in Ohio, and it is a common source of troubles on various 
 cruciferous hosts. 
 
 A. tenuis Nees.^^ is reported by Behrens on tobacco seedlings. 
 
 A. violae G. & D. '^' 
 
 Conidiophores erect, pale-olive, septate, simple, 25-30 x 4 ^t, 
 conidia in chains at or near the apex of the conidiophore, clavately 
 
622 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 flask-shaped, strongly constricted at the septa, olive, 40-60 x 
 10-17 M- 
 
 Circular leaf-spots are produced on violets. Spores are found on 
 the spots only when conditions are most favorable, i. e., in a humid 
 air. The parasitism of the fungus was demonstrated by inocula- 
 tion with spores on living leaves in distilled water. 
 
 A. panax Whet.-^^ 
 
 Spots amphigenous, circular, becoming dingy white with a 
 
 Fig. 42U.— Alter- 
 n a r i a. Spores 
 and spore-bear- 
 ing stalks. Af- 
 ter van Hook. 
 
 Fig. 421. — A. clianthi. 3, Mycelium showing 
 branching and septation. 4< Showing my- 
 celium below stoma and hyphse emerging 
 through the stoma. 5, Showing catenu- 
 late spores as borne upon hyphse. 6, Spores 
 showing shape, septation and catenulation. 
 7, A young cluster of hyphse. 5, An older 
 cluster of hyphse. After Stevens and Hall. 
 
 reddish-brown margin, covering half the leaflet or less; hyphse 
 -brown, septate, 5-7 (x in diameter; conidiophores erect, tufted, 
 somewhat irregular, especially at the tips, brown, septate, 100- 
 120 X 5-6 fj-; conidia brown, in chains of 5 or 6, elliptic to oblong, 
 45-65 X 15-20 /x- 
 
 On ginseng causing leaf blight. 
 
 A. dianthi S. & B..^^^ 
 
 Spots epiphyllous, ashen-white, definite, circular. Conidiophores 
 cespitose from stomata, amphigenous, dark-brown, 1 to 4-septate, 
 erect, 1-25 from a stoma; conidia 26-123 x 10-20 fx, clavate. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 623 
 
 tapering, obtuse, basally dark-brown, slightly constricted at the 
 
 septa, 5 to 9 times cross-septate and 0-5 times longitudinally 
 
 septate. 
 
 It causes injury on carnation leaves and stems. 
 
 A. solani (E. & M.) Jones & Grout. '''• '''• ^''-^" 
 
 Spots brown, circular to elliptic, concentrically zonate, amphige- 
 
 nous, irregularly scattered over the leaf surface; mycelium 
 
 Fig. 422. — A. solani, 2, spores germinating and penetrating the living 
 potato leaf; 5, showing catenulation of spores. After Jones. 
 
 light-brown; conidiophores erect, septate, 50-90 x 8-9 ix; conidia 
 obclavate, brown, 145-370 x 16-18 /x with 5 to 10 transverse 
 septa, longitudinal septa few, conidia terminating in a very long 
 hyaline, septate beak Y2 the length of the conidium or longer. 
 
 It causes early blight, a leaf spot disease of potatoes and toma- 
 toes,^^^ and is widely prevalent. It was first described in 1882 in 
 America but is now known to be widely destructive.^^'' On potatoes 
 it was first recorded by Galloway in 1891. In 1891 also Ches- 
 ter ^^^ and Galloway ^^^ proved its pathogenicity by inoculations on 
 
624 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 tomato and potato, the spots appeared in eight or ten days after 
 inoculation. Jones, using pure cultures, confirmed the conclu- 
 sions of Chester and Galloway, the disease spots appearing as early 
 as the third to fifth day after inoculation on vigorous uninjured 
 leaves. The mycelium grows luxuriantly within the leaf but spores 
 do not usually form until after the death of the supporting tissues 
 when the conidiophores emerge through the stomata or by ruptur- 
 ing the epidermis. Often no spores are formed and rarely are 
 many present. The mycelium may live a year or more and resume 
 sporulation the following season. 
 
 A. fasciculata (C. & E.) Jones & Grout.^^^' ^^^' ^^^' ^^^ 
 
 Conidiophores light or dark-brown, becoming almost black, 
 darker than the vegetative hyphae but like them echinulate, 
 30-40 X 4-5 n; conidia concolorous with the conidiophores, 35-66 
 X 16-20 M, obclavate, 3 to 6 times cross-septate, 1 to 2 longi- 
 tudinal septa, apical cell hyaline. 
 
 This fungus is associated as a saprophyte with the blossom- 
 end-rot of tomatoes and also causes a serious decay of the ripened 
 fruit. The literature of the disease is rather voluminous and con- 
 tains a number of synonyms, among them Macrosporium tomato. 
 M. lycopersici, M. rugosa, M. fasciculata. Alternaria solani has 
 also been credited with this disease and indeed the two species 
 may be identical. ^^^ 
 
 A. fici Far. is on figs; 
 
 A. tabacinum Hori on tobacco;" 
 
 A. vitis Cav. on Vitis. 
 
 An undetermined Alternaria accompanied by a Macrosporium 
 was constantly found in Nevadillo bianco olives which were 
 shrivelled, particularly at the apex. 
 
 These fungi were regarded as the cause of the disease.^*^ 
 
 Fumago Persoon (p. 616) 
 
 Hyphae decumbent, intricate, frequently pseudo-stromatic, 
 black; conidiophores, erect, branched; conidia ovoid, oblong or 
 sarcinseform, 1 to 2-septate. 
 
 A small genus, chiefly conidial forms of Capnodium and Meliola. 
 See pp. 192, 193. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 625 
 
 F. camelliae Cat. on various hosts =Meliola camellise. See 
 p. 193. 
 
 Sarcinella Saccardo (p. 616) 
 
 Hyphaj decumbent, septate, branched, dark; conidiophores 
 much reduced; conidia of two kinds: 1, dark packet-like; 2, sub- 
 hyaline falcate. Both are intermixed. 
 
 A small genus chiefly conidial forms of Dimerosporium. See 
 p. 190. 
 
 S. heterospora Sacc. on various hosts = Dimerosporium pul- 
 chrum. See p. 191. 
 
 Dematiaceae-Scolecosporae (p. 594) 
 
 Conidia dark or subhyaline, vermiform or filamentose, multi- 
 septate. 
 There is only one genus. 
 
 Cercospora Fries 
 
 Conidiophores variable, almost obsolete or well developed, 
 simple or branched; conidia vermiform or filiform, straight or 
 curved, multiseptate, subhyaline to dark. 
 
 In part =Mycosph8erella. See p. 243. 
 
 The genus is a very large one, some seven hundred species, and 
 contains very many aggressive, important parasites, chiefly causing 
 leaf spotting. The spots are often blanched and are rendered 
 ashen colored in the centers by the presence of the dark hyphse. 
 The hyphse are usually geniculate at the point of spore produc- 
 tion. Fig. 427, and thus old hyphse bear traces of spores previously 
 borne. 
 
 C. cerasella Sacc. on cherries =Mycosphserella cerasella. See 
 p. 245. 
 
 C. gossypina Cke. on cotton =Mycosphserella gossypina. See 
 p. 248. 
 
 C. circumscissa Sacc. 
 
 Spots amphigenous, circular, pallid, dry, deciduous; conidio- 
 phores fasciculate, nodulose, brownish, simple; conidia acicular, 
 narrowed apically, attenuate, tinged brown, 50 x 3.5-4 /x. 
 
626 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 On various species of Prunus this causes leaf holes. 
 It is reported as especially serious on the almond.^^^ 
 C. bolleana (Thum.) Sacc. 
 
 Hypophyllous, spots subfuscous to olivaceous; conidiophores 
 fasciculate, filiform, 50-80 x 5-6 n, non-septate, fuscous; conidia 
 terete, fusoid, 35-40 x 7-8 n, apically obtuse, somewhat con- 
 stricted, 1 to 5-septate, olive-green. 
 On figs causing leaf spotting.^*^ 
 C. viticola (Ces.) Sacc. 
 
 Spots amphigenous, subcircular to irregular, 2-10 mm. in 
 diameter, ochraceous, emarginate; conidiophores erect, densely 
 fasciculate, filiform, septate, 50-200 x 4-5 fx, 
 straight, somewhat denticulate, ochraceous; 
 conidia elongate-obclavate, somewhat at- 
 tenuate, 3 to 4-septate, 50-70 x 7-8 n, olive- 
 brown. ^^^ 
 
 It is apparently an unimportant parasite 
 on grape leaves. 
 
 C. rubi Sacc. is on Rubus; 
 C. fumosa Pass, on leaves of Citrus fruits. 
 C. moricola Cke. is common on mulberry; 
 C. musae Zimm. on banana leaves in 
 Java. 
 
 C. roesleri Sacc. occurs in Europe, causing 
 
 Fig. 423.— C. concors. , ^ • • ^ x, 
 
 6. Hyphce emerging ' late uijury to the grape. 
 
 through a stoma and p ancnilata Wini- 113 
 
 twining about hair. ^' anguiata vvmt. 
 
 After Jones and Spots roundish, angulats, whitish to cine- 
 
 Pomeroy. • i ^ o • t 
 
 reous, margined, 1-3 mm. m diameter, often 
 confluent; conidiophores hypophyllous, fasciculate, erect, straight 
 or only slightly flexuose, simple, brownish, few septate, 78-105 x 
 5 /i; conidia filiform-obclavate, long attenuate, hyaline, 7 to 16- 
 septate, 80-170 x 3.5 /i. 
 
 On the currant. 
 
 C. oryzae Miy.^^ is on rice in Japan. 
 
 C. concors (Casp.) Sacc.^^^' ^^^ 
 
 Spots amphigenous, pale above, whitish beneath, rounded, in- 
 definite; conidiophores fasciculate or single from the stomata, 
 erect, brown, septate, simple, 40-80 n high; conidia single, 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 627 
 
 apically variable in form, ovate to elongate, curved, 1 to 5-septate, 
 subhyaline, 15-90 x 4-6 jx. 
 
 In America this potato parasite was noted in Vermont in 1905 
 and study of herbarium material revealed two earlier collections. 
 In Germany it was known in 1854 and it has been seen in many 
 parts of Europe since, sometimes in epidemic form.^'*'^ 
 
 Conidia are abundant on the spots on stalks emerging from 
 the stomata. The superior and inferior hypha; differ considerably 
 in length and branching. Brown bead-like chlamydospores form 
 within the leaf. The mycelium is strictly intercellular. The fungus 
 
 Fig. 424.— C. nicoti- 
 anae. After Jones. 
 
 Fig. 425. — C. nicotianse, spores germinating and 
 entering stomata. After Jones. 
 
 was studied in artificial culture by Jones & Pomeroy^'^^ and inocu- 
 lations were made, diseased spots appearing about three weeks 
 after inoculation by spraying with suspensions of spores. 
 
 C. nicotianse E. & E. 
 
 Spots amphigenous, pale, becoming white, with a narrow and in- 
 conspicuous reddish border, 2-5 mm. in diameter, conidiophores 
 amphigenous, tufted, brown, septate, 2 or 3-times geniculate above, 
 simple or sparingly branched, septate, 75-100 x 4-5 n; conidia 
 slender, slightly curved, multiseptate, 40-75 x 3-3.5 n, hya- 
 line. 
 
 On tobacco it causes leaf spots. ^-^ The sporiferous hyphae are 
 abundant near the center of the disease spots. 
 
 C. raciborskii S. & Sy. on tobacco in Java and Austraha,^^^ is a 
 near relative of C. nicotianse. 
 
628 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 C. apii Fr. 
 
 Spots amphigenous, subcircular, pale-brown, 4-6 mm. in diame 
 ter, with a more or less definite elevated margin; conidiophores hy 
 pophylous, light-brown, fasciculate, con- 
 tinuous or 1 or 2-septate, subundulate, 
 40-60 X 4-5 ju; conidia hyaline obclavate, 
 or almost cylindric, 3 to 10-septate, slen- 
 der, 50-80 X 4 /x. 
 
 A serious leaf spot is produced on celery, 
 parsnips, etc.^^"'^^^ 
 C. beticola Sacc^^' ^52 
 Spots amphigenous, brownish, purple- 
 bordered, becoming ashy centered; co- 
 nidiophores fasciculate, short, simple, erect, 
 fiavous, 35-55 x 4-5 m; conidia elongate, 
 filiform obclavate, hyaline, multiseptate, 
 75-200 X 3.5-4 /x. 
 
 This fungus, described in 1873, causes 
 a very serious disease of beet producing 
 spots on the leaves. It is common and de- 
 structive in America and Europe. The 
 conidiophores usually, though not always, 
 emerge from the sto- 
 mata from a few-celled 
 stroma and are amphig- 
 enous. They vary in 
 length and septation 
 with age. If in humid Fig 
 atmosphere the spots 
 
 become hoary, due to the large number of 
 
 spores present. Each cell of the spore is 
 
 capable of germination. The germ tubes 
 
 infest the host through the stomata. Pure 
 
 Fig. 427.— Fertile hy- cultures of the fungus may readily be se- 
 
 c. ^beticoia.^^laer cured by the usual methods. Here the 
 
 ^^sga.r. mycelium produces dense matted colonies 
 
 of deep olive color and a greenish-grey aerial growth but no 
 
 conidia. Found also on Spinach in Texas. 
 
 . 426.— C. apii. After 
 Duggar and Bailey. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 629 
 
 C. flagelliformis E. & H. 
 
 Spots amphigcnous, indefinite, yellowish; conidia very long, 
 curved, tapering. 
 
 The cause of spinach leaf spots. 
 
 C. citrullina Cke. 
 
 Epiphyllous, spots orbicular, 2-4 mm. in diameter, white with a 
 purple margin; conidiophores elongate, terete, pale olivaceous, 
 conidia very long, attenuate above, few-septate, hyaline, 120-140 
 
 X 3 ;U. 
 
 The cause of leaf spots on watermelon.^^^ 
 
 C. cucurbitae E. & E.^^ 
 
 Spots amphigenous, rounded, subochraceous, becoming thin and 
 white, 1 to 4 mm. in diameter, border slightly raised; conidiophores 
 tufted, olive-brown, 70-80 x 4 ju, continuous, subgeniculate 
 above, apically obtuse; conidia linear clavate, 100-120 x 3-4 ju, 
 hyaline, septate. 
 
 On cucumbers in America, associated with Phyllosticta cu- 
 curbitacearum. 
 
 C. melonis Cke. grows on cucumbers and melons in England 
 and New Zealand. What is probably the same fungus has been 
 set up by Giissow ^'"'^ as a new genus Corynespora. 
 
 C. armoraciae Sacc. 
 
 Spots amphigenous, pale; conidiophores short, simple, 30-40 
 X 5 ju; conidia rod-shaped, cuspidate, 100-120 x 5 /x, hyaline, 
 multiseptate. 
 
 On horseradish. 
 
 C. bloxami B. & Br. occurs on Brassica. 
 
 C. personata (B. & C.) E. 
 
 Spots hypophyllous, small, brown, orbicular, 2-4 mm. or more 
 in diameter; conidiophores densely tufted, short, brown, con- 
 tinuous; conidia clavate, pale-brown, about 3 to 4-septate, 30- 
 50 X 5-6 fx. 
 
 On the peanut in the Southern United States and West Indies. ^^^ 
 
 C. cruenta Sacc. 
 
 Spots amphigenous, indefinite, reddish ; conidiophores, subfasci- 
 culate, simple, subdenticulate, light olivaceous; conidia obclavate, 
 curved, 60-80 x 4 /i, subacute, 6 to 7-septate, hyaline or oliva- 
 ceous. 
 
630 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 On cowpea and bean in America. Usually causing but slight 
 damage. 
 
 C. vignae Rac. (not E. & E.) is described as injurious to the 
 cowpea in Java.^'''* 
 
 C. medicaginis E. & E. 
 
 Spots amphigenous, smoky to black, 0.5-5 mm. in diameter, 
 orbicular, indefinite; conidiophores subhy aline, becoming brown- 
 ish, continuous, geniculate, 35-45 x 4-5 n; conidia cylindric- 
 fusoid, 3 to 6-septatc, 40-60 x3 fx. 
 
 On alfalfa and crimson clover.^''^ 
 
 C. ariminensis Br. & Cav. is found on sulla leaves; 
 
 C. saccharii Br. d. H. C. longipes Butler, C. acerosum D. 
 & H., C. vaginae and C. kopkei Krug. are on sugar-cane. 
 
 C. capparidis Sacc. is found on caper. 
 
 C. asparagi Sacc. & C. caulicola Wint. affect asparagus. 
 
 C. malkoffi Bubak causes an anise disease in Sadova. 
 
 C. these v. Br. d. H. occurs on tea in India; 
 
 C. violae Sacc. 
 
 Spots amphigenous, rounded, bleached; conidiophores short, 
 simple, greyish, 30-35 x 4 /x; conidia long and slender, rod- 
 shaped, multiseptate, hyaline, 150-200 x 3.5 m- 
 
 It produces a violet leaf spot.-^ 
 
 C. althaeina Sacc. occurs on hollyhock. 
 
 Spots amphigenous, brown, 2-4 mm. broad; conidiophores 
 fasciculate, slender, 40 x 5 ju, few-septate, olive brown; conidia 
 apical, cylindric, to obclava,te or broadly fu- 
 soid, straight, 40-60 x 5 ju, apically obtuse, 
 2 to 5-septate, hyaline. 
 C. kellermanii Bub. 
 
 Spots amphigenous, irregular, angular, olive- 
 brown, up to 1 cm. across; conidiophores fas- 
 MlflMlBJM ciculate, slender, few-septate, 150 n x 4-5 n, 
 
 Fig. 428.— C. rosfficola. olive-brown; conidia filiform, 50-150 x 4-5 n, 
 
 After Southworth. 5 ^^ I5_septate, straight or curved, hyaline. 
 
 It also occurs on hollyhock and is nearly related to C. malvarum 
 Sacc. 
 
 C. rosicola Pass.^^ 
 
 Spots ochraceous, fuscous-margined, 2-3 mm. in diameter; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE G31 
 
 conidiophores cespitose, small, densely gregarious, fuliginous, 
 subcontinuous, 20-40 x 3-5 /x, conidia cylindric, straight, short, 
 30-50 X 3.5-5 n, subfuscous, 2 to 4-septate. 
 
 On roses. 
 
 C. hypophylla Cav, on roses in Europe is very like the preceding 
 species. 
 
 C. omphacodes E. & H. and C. phlogina Peck, are the causes of 
 rather unimportant leaf spots of cultivated phlox. 
 
 C. neriella Sacc. is on oleander. 
 
 C. sordida Sacc. produces leaf spots and defoliates Tecoma. 
 
 C. angreci Roum. is on orchids; 
 
 C. cheiranthi Sacc. on Cheiranthus. 
 
 C. brunkii E. & G. is reported on the geranium (Pelargonium 
 zonale.) 
 
 C. resedae Fcl.^^^ 
 
 Spots punctiform, greyish; conidiophores fasciculate, simple, 
 continuous or few-septate, 50-70 x 4-5 /x, fuscous; conidia apical 
 to linear, obclavate, 4 to 5-septate, hyaline, 100-140 x 2.5-3 /x. 
 
 Spots are caused on the mignonette aTid the plants are blighted. 
 The hyphae appear through the stomata. 
 
 C. odontoglossi P. & D. occurs on cultivated Odontoglossum ; 
 
 C. unicolor S. & P. on lily. 
 
 C. richardiaecola Atk.^^ 
 
 Spots amphigenous, black, with small white centers, subcircular, 
 2-6 mm. broad; conidiophores fasciculate, light-brown with a 
 reddish tinge, becoming reddish-brown, erect or apically flexuose, 
 denticulate, 30-80 x 5 /x; conidia hyaline, obclavate, 4 to 10 
 or more septate, 50-100 x 3-4 /t. 
 
 On calla lily. 
 
 C. microsora Sacc.^^ 
 
 Spots amphigenous, minute, brown, gregarious; conidiophores 
 subfasciculate from a tubercular stroma, short, continuous, sub- 
 olivaceous, 20-30 X 3 ju; conidia filiform, 3 to 5-septate, con- 
 stricted at the septa, olivaceous, 35—15 x 3.5 fj.. 
 
 It causes spotting and defoliation of Tilia. 
 
 C. cercidicola E. 
 
 Spots amphigenous, dull grey above, rusty-brown beneath, 
 with a blackish-brown raised border; conidiophores amphigenous, 
 
632 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 fasciculate, brown, 90-114 x 3.5-4 fi, subgeniculate above; conidia 
 oblong, clavate, faintly 3-septate, 30-40 x 5-7 /x. 
 
 It seriously injures the Japanese red-bud and occurs also on the 
 American species.^^^ 
 
 C. acerina Hartig is on maple seedlings. 
 
 C. sequoiae E. & E. 
 
 Large compact olivaceous tufts are formed on languid leaves; 
 conidiophores ferruginous, brown, abruptly bent, subnodose, 
 toothed, sparingly septate, 50-70 x 4-5 fi; conidia oblong, becom- 
 ing clavate, 40-70 xQ n, concolorous with the hyphse, 3 to 5-septate, 
 constricted at the septa. 
 
 It is said to seriously interfere with the growth of Sequoia in 
 the eastern states. 
 
 C. halstedii E. & E. 
 
 Spots hypophyllous, indefinite, brownish to olivaceous, 2-4 mm. 
 across; conidiophores few-septate, 100-150 x 5-7 /x, undulate or 
 crisped; conidia obclavate, 65-80 x 5-7 n, 3-septate, somewhat 
 constricted. 
 
 It produces blotches on pecan leaves and causes partial de- 
 foliation. ^^^ 
 
 Stilbaceae (p. 565) 
 
 Sterile hyphae creeping, scanty; fertile hyphse collected into a 
 stalk-like or stroma-like fascicle, bearing conidia at the top, more 
 rarely along the sides, pale, bright-colored or dark. 
 
 Key to Sections of Stilbaceae 
 
 Hyphse and conidia hyaline or light 
 
 colored I. Hyalostilbeae. 
 
 Conidia globose, elliptic or oblong 
 
 1-celled 1. Amerosporae, p. 633. 
 
 2-celled 2. Didymosporae. 
 
 3 to several-celled 3. Phragmosporae. 
 
 Conidia filiform, coiled 4. Helicosporae. 
 
 Hyphse or conidia dark II. Phaeostilbeae. 
 
 Conidia globose, elliptic, or oblong, 
 With cross walls only 
 
 1-celled 5. Amerosporae, p. 635. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 633 
 
 2-celIed 6. Didymosporae. 
 
 3 or more-celled 7. Phragmosporae, G37. 
 
 Muriform 8. Dictyosporae. 
 
 Conidia of a stellately arranged group of 
 
 cells 9. Staurosporae. 
 
 Hyalostibeae-Amerosporae (p. 632) 
 
 Bright or light-colored, conidia globose, elliptic or oblong, 
 continuous. 
 
 Key to Genera of HyalostibeaB-Amerosporae 
 
 Conidial part distinctly capitate or at least 
 terminal 
 Conidia not in chains 
 Head of conidia not gaping or split- 
 ting above 
 Head not spiny 
 
 Conidiophores of head normal 
 Conidia covered with mucus 
 Synnema monocephalous 
 Conidiophores dendroid- 
 verticillate 
 Without distinct sterig- 
 
 mata 1. Dendrostilbella. 
 
 With obpiriform sterig- 
 
 mata 2. Pirobasidium. 
 
 Conidiophores not dendroid- 
 
 verticillate 3. Stilbella, p. 635. 
 
 Synnema polycephalous 
 Capitula on extremely 
 
 short branches 4. Polycephalum. 
 
 Capitula on spreading 
 
 subulate branches ... 5. Tilachlidium. 
 Capitula on erect 
 
 branches 6. Corallodendron. 
 
 Conidia without mucus 
 Synnema monocephalous 
 Conidiophores spirally 
 
 twisted 7. Martindalia. 
 
634 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Conicliophores more or less 
 straight 
 Conidia rhombic or 
 
 biconic 8. Rhombostilbella, p. 635 
 
 Conidia globose to fu- 
 
 soid 9. Ciliciopodium. 
 
 Synnema polycephalous 
 Terrestrial, large, 1-2 cm.; 
 
 conidia ovoid 10. Macrostilbum. 
 
 Not terrestrial, small; co- 
 nidia elongate-ovate. . 11. Chondromyces. 
 Conidiophores conidium-like, sep- 
 tate; monocephalous 12. Atractiella. 
 
 Head spiny with radiating spic- 
 ules 
 
 Spicules conic, granulate 13. Actiniceps. 
 
 Spicules with many . curved 
 
 branches at middle 14. Heterocephalum. 
 
 Head of conidia persistent below, 
 
 splitting above 15. Pilacre. 
 
 Conidia in chains 
 Synnema with conidia above; conidia 
 without mucus 
 
 Synnema not pubescent 16. Coremium, p. 635. 
 
 Synnema pubescent 17. Lasioderma. 
 
 Synnema with conidia below; conidia 
 
 with mucus 18. Microspatha. 
 
 Conidial part cylindric or long-clavate 
 Conidia more or less equally scat- 
 tered 
 Sterigmata denticulate, branched ... . 19. Cladosterigma. 
 
 Sterigmata none or simple 20. Isaria, p. 635. 
 
 Conidia in lateral heads or racemes 
 Conidia in racemes; synnema lo- 
 
 bate 21. Peribotryum. 
 
 Conidia in heads 
 Conidiophores with lateral nodes, 
 usually escaping through the 
 
 stomata 22. Helostroma. 
 
 Conidiophores without nodes, usu- 
 ally entomophilous 23. Gibellula. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 635 
 
 Stilbella Lindau (p. 633) 
 
 Hyphse forming a coremium which is capitate above; conidio- 
 phores borne on the cap; conidia small, often enclosed in slime. 
 
 Over one hundred species chiefly saprophj'^tes. (Commonly 
 known as Stilbum but the type of the genus being a hymenomycete 
 it was renamed.) 
 
 S. flavida (Cke.) Kohl, causes a serious coffee disease. 
 
 S. theae Bern, is on tea in India. 
 
 S. nanum Mas. causes the thread blight of tea. 
 
 S. populi on poplar =Mycosph8erella populi. See p. 250. 
 
 Rhombostilbella Zimmermann (p. 634) 
 
 Synnemata verticillate-stilbiform; conidia rhomboid to biconic, 
 acute, without mucus. Monotypic. 
 
 R. rosae Zimm. is found on Liberian coffee. ^^^ 
 
 Coremium Link (p. 634) 
 
 Coremium cylindric, apically enlarged and 
 fertile; conidia very small, catenulate. A 
 small genus. In part = Rosellinia and Penicil- 
 lium. See p. 230. 
 
 Isaria Persoon (p. 634) 
 
 Stromata erect, clavate or branched, fer- 
 tile throughout, hairy; conidia small, globose 
 to ellipsoid, hyaline. 
 
 Over one hundred species, chiefly entomog- 
 enous. 
 
 I. fuciformis Berk, is reported from Eng- 
 land and Australia forming its stromata 
 on the inflorescences of Festuca. 
 
 I. graminiperda B. & M. also causes con- 
 siderable injury to grasses in Australia. ^^^ 
 
 
 
 Fig. 429. — Coremium 
 glaucum. After 
 Corda. 
 
 Phaeostilbeae-Amerosporae (p. 632) 
 Dark conidia continuous, globose to elongate. 
 
636 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Key to Genera of Phaeostilbeae-Amerosporae 
 
 Conidia not in chains 
 
 Synnema setose 1. Saccardaea. 
 
 Synnema naked 
 
 Conidia asperate, on minute basidia. . . 2. Basidiella. 
 Conidia smootli 
 Synnema carnose, racemose-branclied 3. Stilbothamnium. 
 Synnema fibrous or corneous, not 
 racemose 
 
 Conidiophore lageniform 4. Ceratocladium. 
 
 Conidiophore lacking, at least not 
 lageniform 
 Synnema stalked, fibrous 
 
 Conidia dark, globose to ellip- 
 tic 5. Sporocybe. 
 
 Conidia hyaline 
 
 Conidia ovoid to oblong. . . 6. Graphium. 
 Conidia elongate or falcate. 7. Harpographium. 
 
 Synnema sessile, corneous 8. Glutinium. 
 
 Conidia in chains 
 
 Synnema setose 9. Trichurus. 
 
 Synnema not setose 
 
 Stalk branched above 10. Stemmaria. 
 
 Stalk simple or nearly so 
 Capitule loose 
 
 Base of synnema subequal; usually 
 
 on stems 11. Stysanus, p. 636. 
 
 Base of synnema perithecioid; 
 
 usually on leaves 12. Graphiothecium. 
 
 Capitule compact 
 Conidia globose 
 
 Conidia echinulate 13. Harpocephalum. 
 
 Conidia smooth 
 
 Conidia pleurogenous 14. Heydenia. 
 
 Conidia acrogenous 15. Briosia. 
 
 Conidia ovoid to oblong 16. Antromycopsis. 
 
 Stysanus Corda 
 Stromata erect, cylindro-clavate, dark, rigid ; conidia in an oblong 
 
THE FUNGI WHICH CAUSE PLANT DISEASE (,37 
 
 or subglobose panicle, ovoid, lemon-shaped or fusoid, subhya- 
 line. 
 
 Some twenty-five species. See Fig. 430. 
 
 S. veronicae Pers. occurs on cultivated Veronicas in Italy; 
 
 S. ulmariae M'W. on Spirea in Ireland. 
 
 S. stemonitis Cda. causes a brown rot of potatoes in storage. 
 
 Phaeostilbeae-Phragmosporae (p. G33) 
 
 Conidia 3 to several-celled, oblong to cylindric, dark or hya- 
 line. 
 
 Key to Genera of Phaeostilbeae-Phragmosporae 
 
 Conidia capitate 
 Synnema simple 
 
 Synnema black; conidia densely capi- 
 tate 1. Arthrobotryum. 
 
 Synnema fuscous or pale; conidia 
 
 loosely capitate 2. Isariopsis, p. 637. 
 
 Synnema dendroid-branched 3. Xylocladium. 
 
 Conidia not capitate 
 
 Conidia catenulate 4. Dendrographium. 
 
 Conidia not catenulate 
 Stalk fibrous 
 
 Synnema simple or branched ; conidia 
 
 acro-pleurogenous 5. Podosporium. 
 
 Synnema branched; conidia acro- 
 
 genous 6. Negeriella. 
 
 Stalk parenchyma-like 
 
 Conidia pleurogenous, on a disk. ... 7. Riccoa. 
 Conidia acrogenous 8. Podosporiella. 
 
 Isariopsis Fries 
 
 Slender, dark or subhyaline, cylindric hyphse laxly aggregated; 
 conidia in a lax panicle or head, cylindric or clavate. See Fig. 431. 
 
 I. griseola Sacc. 
 
 Spots hypophyllous, ochraceous; coremium stipitate, dense. 
 200 X 30-40 n, composed of filiform hyphse; conidia borne on 
 the reflexed ends of the hyphse, cylindric-fusoid, curved, 50-60 
 X 7-8 n, grey, 1 to 3-septate, constricted. 
 
 It causes disease of beans. 
 
638 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Tuberculariaceae (p. 565) 
 Hyphse compacted into a globose, discoid, or verruciform body, 
 
 Fig. 430. — Stysanus. 
 After Saccardo. 
 
 Fig. 431. — Isariopsis. 
 After Saccardo. 
 
 the sporodochium; sporodochia typically sessile, waxy or subge- 
 latinous, white, bright-colored or dark to black. 
 
 In part =Nectria, Claviceps and Hymenoscypha, etc. See 
 pp. 146, 201, 211. 
 
 Key to Sections of Tuberculariaceae 
 
 Hyphse and conidia hyaline or bright-colored 
 Conidia glol^ose to fusoid or falcate 
 
 Conidia continuous 
 
 Conidia 1-septate 
 
 Conidia 2 to many-septate 
 
 Conidia muriform ." 
 
 Conidia spirally coiled 
 
 Conidia forked or cruciate 
 
 Hyphse olive to brown or black; conidia 
 
 concolorous, rarely hyaline 
 
 Conidia globose to elongate 
 
 Conidia continuous 
 
 Conidia 1-septate 
 
 I. Mucedineae. 
 
 1. Amerosporeae, p. 639. 
 
 2. Didymosporae. 
 
 3. Phragmosporae, p. 645. 
 
 4. Dictyosporae. 
 
 5. Helicosporae. 
 
 6. Staurosporae. 
 
 II. Dematieae. 
 
 7. Amerosporae, p. 654. 
 
 8. Didymosporae. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 639 
 
 Conidia 2 to many-septate 9. Phragmosporae, p. 657. 
 
 Conidia muriform 10. Dictyosporae, p. 658. 
 
 Conidia filiform, hyaline 11. Scolecosporae. 
 
 Conidia spirally twisted 12. Helicosporae. 
 
 Conidia angulo^e-stellate 13. Staurosporae. 
 
 Tuberculariaceae-Mucedineae-Amerosporae (p. 638) 
 
 Conidia hyaline, or bright-colored, continuous, globose to fusoid; 
 hj'phce hyaline. 
 
 Key to Genera of Tuberculariaceae-Mucedineae-AmerosporeaB 
 
 Sporodochia smooth or nearly so 
 Conidiophores normal 
 Conidia muticate 
 Conidia not covered with mucus 
 Conidia not acrogenous-capitate 
 Sporodochium girt by a heterogenous 
 
 cup 1. Patellina. 
 
 Sporodochium without a heterogenous 
 cup 
 Conidia not catenulate or scarcely so 
 Conidia escaping from interior of 
 hyphai 
 
 Conidiophores branched 2. Endoconidium, p. 641. 
 
 Conidiophores simple 3. Trichotheca. 
 
 Conidia arising on outside of hyphjE 
 Conidiophores lacking 
 Conidia large, pellucid 
 
 Conidia globose 4. Sphaerosporium. 
 
 Conidia oval 5. Diaphanium. 
 
 Conidia small, not pellucid 6. Pactilia. 
 
 Conidiophores present 
 Conidia pleurogenous or acro- 
 pleurogenous 
 
 Conidia globose 7. Beniowskia. 
 
 Conidia ovoid to oblong 8. Tubercularia, p. 642. 
 
 Conidia fusoid to cylindric 9. Fusicolla. 
 
 Conidia acrogenous 
 
640 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Conidiophores vermcose 10. Dacrymycella. 
 
 Conidiophores not verrucose 
 
 Uredinicolous 11. Tuberculina. 
 
 Not uredinicolous 
 Sporodochia globose 
 Conidia globose ; conidio- 
 phores short 12. .ffigerita. 
 
 Conidia ovoid ; conidiophores 
 
 branched 13. Granularia. 
 
 Sporodochia pulvinate 
 
 Conidia acicular 14. Kmetia. 
 
 Conidia terete-oblong 15. Bactridiopsis. 
 
 Sporodochia disk-shaped 16. Hymenula. 
 
 Sporodochia cupulate 17. Hyphostereum. 
 
 Sporodochia verruciform or 
 effuse 
 Conidiophores simple 
 Conidiophores radiate, 
 
 united at base 
 Conidiophores not arising 
 
 from a cellular mass. . 18. Clinoconidium. 
 Conidiophores arising from 
 
 a cellular mass 19. Ustilaginoidea, p. 643. 
 
 Conidiophores not united or 
 
 radiate 20. Sphacelia, p. 643. 
 
 Conidiophores dendroid 
 
 branched 21. Dendrodochium, p. 643. 
 
 Conidia in chains 
 
 Conidia covered with mucus. ... 22. CoUodochium. 
 Conidia without mucus 
 Conidia globose 
 
 Conidia hyaline 23. SphaerocoUa. 
 
 Conidia blue 24. Sporoderma. 
 
 Conidia elliptic to oblong 
 Sporodochium disk-shaped, 
 
 orange-red 25. Necator, p. 643. 
 
 Sporodochium subglobose, 
 
 whitish 26. Patouillardia. 
 
 Conidia cylindric 
 Sporodochium dilated above, 
 
 stalked 27. Bizzozeriella. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 641 
 
 Sporodochia globose to verruci- 
 form 
 Sporodochia gelatinous, sessile 28. Cylindrocolla. 
 Sporodochia not gelatinous, 
 
 short-stalked 29. Sphaeridium. 
 
 Conidia acrogenous-capitate; sporo- 
 dochia turbinate 30. Cephalodochium. 
 
 Conidia covered with mucus 
 
 Sporodochium globose, hardened 31. Thecospora. 
 
 Sporodochia verruciform or subeffuse. . 32. Illosporium, p. 643. 
 
 Sporodochia discoid 33. Epidochiopsis. 
 
 Conidia ciliate 
 
 Conidia 1-ciliate at base only 34. Stigmatella. 
 
 Conidia 1-ciliate at each end 35. Thozetia. 
 
 Conidia 7 to 8-ciliate at each end 36. Chaetospertaum. 
 
 Conidiophores with internal conidia- 
 
 bearing areoles 37. Scoriomyces. 
 
 Sporodochia setulose, ciliate or uniformly 
 woolly 
 Sporodochia woolly or setulose 
 Sporodochia setulose; conidia catenu- 
 
 late 38. Periola. 
 
 Sporodochia woolly or velvety; conidia 
 capitate 
 
 Conidia globose 39. Dacryodochium. 
 
 Conidia oblong 40. Lachnodochiuin. 
 
 Sporodochia ciliate at the margin 
 
 Sporophores none; conidia coacervate . . . . 41. Volutellaria. 
 Sporophores distinct 
 
 Conidia in chains 42. Volutina. 
 
 Conidia not in chains 
 Conidiophores 6-ciliate above, united 
 
 below 43. Guelichia. 
 
 Conidiophores not ciliate or united. ... 44. Volutella, p. 644. 
 
 Endoconidium Prillieux & Delacroix (p. 639) 
 
 Sporodochia pulvinate, white; conidiophores hyaline, racemose; 
 conidia hyaline, rounded, formed within the conidiophore and 
 escaping apically. 
 
 A small genus, chiefly saprophytes. 
 
642 
 
 THE FUxNGI WHICH CAUSE PLANT DISEASE 
 
 E. temulentum P. & D. = Hymenoscypha temulenta. See 
 p. 146. 
 
 Tubercularia Tode (p. 639) 
 
 Sporodochium tubercular or wart-like, sessile or subsessile, 
 smooth, rarely with bristles, usually reddish; conidiophores very 
 
 Fig. 432.— Hyphas 
 of Tubercularia, 
 bearing conidia. 
 After Durand. 
 
 Fig. 433. — T. fici, sporodochium, showing setse 
 and conidial formation. After Edgerton. 
 
 In 
 
 slender, usually branched; conidia apical, ovate to elongate 
 part=Nectria. See p. 201. 
 
 Over one hundred species, chiefly saprophytes. 
 
 T. vulgaris Tode=Nectria cinnabarina. See p. 202. 
 
 T. fici Edg.^'^' 361 
 
 Sporodochia scattered or gregarious, superficial or subcuticular, 
 light pink, variable in size up to 3-4 x 1-1.5 mm., smooth, irregular 
 in outline; conidiophores crowded, hyaline, 20-27 x 1-2 n; 
 conidia small, clear, elliptic to oval, regular in size, 5-7 x 2.5-5 /x; 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 643 
 
 setsB scattered or abundant, variously placed, straight or curved, 
 hyaline or subhyaline, septate, papillose, 60-90 x 4-6 ai. 
 It is the cause of a fig canker. 
 
 Tuberculina Saccardo 
 
 Several species occur in sori of the Uredinales. 
 
 Ustilaginoidea Brefeld, a small genus of Ascomycetes, one species 
 of which, U. virens, on rice is known only in the conidial stage. 
 See p. 214. 
 
 Sphacelia L^vielle (p. 640) 
 
 Sporodochia planose, effuse, stromate or sclerotioid; conidio- 
 phores short, simple, filiform; conidia apical, ovate, 
 
 A small genus, chiefly conidia of Claviceps and related genera. 
 S. segetum Lev. = Claviceps purpurea. See p. 212. 
 S. typhina (Pers.) Sacc. =Epichloe typhina. See p. 210. 
 
 Dendrodochium Bonardin (p. 640) 
 
 Sporodochium pulvinate or verruciform, white or light-colored; 
 conidiophores verticillate, branched; conidia acrogenous, ovoid to 
 oblong. 
 
 A genus of about forty species. 
 
 D. lycopersici March is found on tomatoes in Belgium.^^^ 
 
 Necator Massee (p. 640) 
 
 Sporodochium erumpent, small, slightly convex, becoming 
 orange-red; conidia oblong or elliptic, catenulate, contents orange. 
 Monotypic. 
 
 N. decretus Mas. is a dangerous parasite of coffee, tea, etc.^^^' ^^^ 
 
 Illosporium Martius (p. 641) 
 
 Sporodochia wart-like, pulvinate or subeffuse, white or light- 
 colored, subgelatinous or waxy; conidiophores variable; conidia 
 globose, sigmoid, variable, embedded in mucous. There are some 
 forty species. 
 
 I. malifoliorum Shel. 
 
 Spots suborbicular or coalescing and becoming irregular, brown 
 
644 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Fig. 434.— lUospo- 
 rium maculicola 
 After Saccardo. 
 
 or mottled with gray and with a small gray spot near the center, 
 5-15 mm. in diameter; sporodochia hypophyllous, minute, gelat- 
 inous, yellow-amber, becoming black, spherical, becoming discoid 
 or irregular, 150-160 /x in diameter; conidio- 
 phores branched; conidia oblong, 1-3.5 x 4 /x. 
 
 It is said by Sheldon ^^^ to be one of the most 
 common and destructive causes of leaf spots of 
 the apple often resulting in nearly complete de- 
 foliation. In the centers of the leaf spots other 
 spots bearing other species of fungi are often 
 found, leading to the thought that perhaps the 
 Illosporium in such cases results from secondary infection in the 
 wounds made by the earlier fungus. The sporodochia are hypo- 
 phyllous, often hidden by the normal pubescence of the leaf. 
 
 Volutella Tode (p. 641) 
 
 Sporodochia discoid, regular, margin ciliate, sessile or stipitate; 
 conidiophores usually simple; conidia ovoid to oblong. 
 
 Some seventy species. 
 
 V. leucotricha Atk. 
 
 Sporodochia convex-discoid, white to pale flesh-color; setse few, 
 filiform, few-septate, subhyaline ; conidiophores densely fasciculate, 
 filiform; conidia oblong. 
 
 On cuttings in greenhouses. 
 
 V. fructi S. & H. 
 
 Spots on the fruit, circular; sporodochia, numerous in concentric 
 circles, subcu ti c ul ar, 
 erumpent, elevated 200- 
 250 n, 150-400 /x in 
 diameter; mycelium 
 black; seta? distributed 
 throughout the sporodo- 
 chium, black, to 3- 
 septate, acute, smooth, 
 100-400 X 5-8 fJL] co- 
 nidiophores elongate, hyaline, simple, 25-35 x S /i; conidia 
 smooth, oblong-fusoid to falcate-fusoid, hyaline or sub-olivaceous, 
 17-23 X 2.5-3.5 fi. 
 
 Fig. 435. — V. fructi. Sporodochia in section. 
 After Stevens and Hall. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 645 
 
 It is the cause of a dry rot of apples.^^' ^^^ 
 V. dianthi (Hal.) Atk.-^ 
 It is the cause of anthracnose of carnation. 
 The acervuH are conspicuous with black seta?. 
 V. concentrica Hals, is reported by Halsted as the cause of leaf 
 spots of Bletia.^^ 
 
 Tuberculariaceae-Mucedineae-Phragmosporae (p. 638) 
 
 Hypha3 hyaline; conidia 2 to several-septate, hyaline or bright- 
 colored, fusoid to falcate, rarely short and simple in some species 
 of Fusarium. 
 
 Key to Genera of Tuberculariaceae-Mucedineae-Phragmosporae 
 
 Conidia somewhat catenulate, cylindric. .. . 1. Discocolla. 
 Conidia rarely catenulate 
 
 Conidia cruciately 4-celled; sporodochium 
 
 gelatinous 2. Sarcinodochium. 
 
 Conidia not cruciate 
 
 Conidiophores short, simple 
 
 Conidia very large, terete-oblong. . . 3. Bactridium. 
 
 Conidia doliform 4. Pithomyces. 
 
 Conidiophores more or less branched 
 Conidiophores dichotomous; conidia 
 
 key-like 5. Heliscus. 
 
 Conidiophores usually verticillately 
 branched, conidia usually fal- 
 cate, sometimes oblong 
 
 Sporodochium gelatinous 6. Pionnotes, p. 645. 
 
 Sporodochium waxy or byssoid ... 7. Fusarium, p. 646. 
 
 Pionnotes Fries 
 
 Sporodochium gelatinous, then firm, orange, pulvinate or lobed; 
 conidiophores fasciculate, simple or branched; conidia rather large, 
 fusoid to cylindric, curved. 
 
 Only twelve or fifteen species, chiefly saprophytes. 
 
 P. betae Mas. occurs on mangels and beets and according to 
 Massee is probably identical with P. rhizophila which attacks 
 stored Dahlia roots and potatoes. 
 
646 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Fusarium Link (p. 645) 
 
 Sporodochiiim pulvinate, or subeff used ; conidiophores branched ; 
 conidia terminal, solitary, fusiform or falcate, more or less curved, 
 pluriseptate. 
 
 In part=Nectria, Neocosmospora, Gibberella. See pp. 201, 
 205, 206. 
 
 This is a large genus, (some four hundred species have been de- 
 scribed) though future study will undoubtedly relegate many 
 names to synonymy. 
 
 Many of the species are destructive parasites, invading the ducts 
 of plants and by stoppage of the water-supply causing the class of 
 diseases known as "wilts." Others induce rot, spotting, cankers, 
 etc. Taken as a whole the genus is one of the most injurious with 
 which plant pathology has to do. 
 
 It seems probable that some of the forms that live normally as 
 saprophytes in soil may encroach upon living roots of susceptible 
 plants when these are available. 
 
 In nature the spores typical of this form-genus are borne in 
 sporodochia, coremia or acervuli and are crescent-shaped or fusoid. 
 The same mycelium that produces these structures often, indeed 
 usually, produces also similar and smaller conidia scattered 
 on single hyphce (=Cephalosporium). These two forms are called 
 macroconidia and microconidia respectively. Tlie microconidia 
 are regarded by Appel & Wollenweber ^^^ as depauperate mac- 
 roconidia. Frequently chlamydospores form in the mycelium; 
 either terminal or intercalary. Sclerotia are also not uncom- 
 mon. 
 
 Undoubted species of Fusarium have been shown to belong to 
 several different Hypocrealous ascomycetes, while still more have 
 as yet revealed no ascomycete connection. 
 
 Biologic specialization has been found, in that forms morpho- 
 logically indistinguishable are frequently incapable of cross in- 
 oculation onto other than their usual hosts. 
 
 Fusarium grows well in culture and the species often show 
 marked differences in growth on various media, particularly in 
 the colors that are developed. 
 
 As with the anthracnoses much study is here needed to throw 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 647 
 
 • 
 
 / 
 \ 
 
 
 ,-'-'" 
 
 - 
 
 — -.,^ 
 
 ^^ 
 
 \ 
 
 / 
 
 
 
 
 \ 
 
 \ 
 
 \ 
 
 : 
 
 
 
 
 \/ 
 
 
 \ 
 
 ^^ 
 
 
 
 ^4 
 
 
 j^ ^^^^fe 
 
 sS 
 
 ^^^^tT" 
 
 >ls^ 
 
 
 _,_- 
 
 
 — 
 
 ~- — .^^ 
 
 , **" 
 
 
 
 
 "^.^^ 
 
 
 
 
 
 
 • '^ 
 
 
 
 
 ^^ 
 
 
 
 
 
 
 
 
 
 
 
 / 
 
 
 
 
 ^, 
 
 \ 
 
 
 
 
 / 
 
 
 
 - -- ' 
 
 
 — ~^ ^ 
 
 
 ^ ■ 
 
 
 
 ^ ^ ^^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 ^ 
 
 ^s 
 
 ^ 
 
 ^^^^ 
 
 
 !^ 
 
 
 T3 
 
 <u 
 
 c5 
 
 is 
 
 oj 
 
 
 
 TS 
 
 % 
 
 a 
 
 0. 
 
 o. 
 
 <i> 
 
 <5 
 
 
 u, 
 
 3 
 
 <u 
 
 ><1 
 
 .y o 
 
 ^3 
 
 O <;< 
 
 CO i^ 
 
 
 
 sa 
 
 00 3 
 
 
 fM a 
 
 >> 
 
 •??:2 
 
 •fl 
 
 
 iiife 
 
 
 p. 
 
 w^ 
 
648 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 light on the inter-relation of the various species and their hosts. 
 Apple & Wollenweber ^'^^ have made an extensive study of several 
 species to lay the ground for a monograph. They conclude that 
 in delimiting species important characters are the forms of the 
 conidia, especially their bases, apices, and degree of curvature and 
 septation (see Fig. 436); the color of the mycelium and spores; 
 the presence or absence of chlamydospores. They cast aside as 
 valueless many earlier descriptions substituting new diagnoses 
 and new names. According to their conception, the following 
 names should stand. 
 
 F. solani (Mart.) Sacc. =Fusisporium solani Mart. =Fusarium 
 commutatum Sacc. 
 
 F. martii A. & W. =Fusisporium solani Mart. 
 
 F. coeruleum Lib. =Fusarium solani. 
 
 F. discolor A. & W. =Fusarium solani. 
 
 F. rubiginosum A. & W. =Fusarium solani. 
 
 F. discolor var. sulphureum (Schl.) A. & W. =Fusarium sul- 
 phureum Schlecht. 
 
 F. subulatum A. & W. 
 
 F. metachroum A. & W. 
 
 F. orthoceras A. & W. =F. oxysporum Sm. & Sw. not Schl. 
 
 F. theobromae A. & Struk. 
 
 F. wilkommii Lin. =F. bacilligerum B. & Br. 
 
 F. falcatum A. & W. =F. vasinfectum pisi Schk. 
 
 F. gibbosum A. & W. 
 
 It will be noted that several of the species mentioned below 
 are here involved. 
 
 F. platani Mont. =Calonectria pyrochroa. See p. 205. 
 F. rubi Wint. 
 
 Mycelium white, becoming pink, especially 
 
 abundant on the flowers; conidia elongate, 1 
 
 to 8-septate, variable in size and form, 
 
 „ ,. ^ straight or curved, 14-30 x 3-3.5 ju, not con- 
 
 FiG. 437. — Section of . ' 
 
 ovary showing my- stncted. 
 
 pei^aml ovuie.^^After Cook ^^^' ^^^ found this fungus in diseased 
 ^°°^' buds of dewberries and by inoculation dem- 
 
 onstrated that it is responsible for witches-broom, double- 
 blossom, and similar abnormal growths of this plant. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 649 
 
 F. gemmiperda Aderh. is described by Aderhold ^™ as fatal to 
 flower buds of cherry before they open, a conclusion supported by 
 inoculation experiments. The disease in general appearance re- 
 sembles sclerotiniose. 
 
 F. rhizogenum P. & C. 
 
 Sporodochia superficial, 1 to 2 mm. wide, dense, convex, white 
 or whitish, hyphae densely interwoven, septate, subramose; conidia 
 oblong, roundish, 1-septate, 70 x 4 ;u. 
 
 It was originally described as a parasite on apple roots in Ne- 
 braska ^^^ and is mentioned by Aderhold ^° as the cause of death of 
 roots of apple and cherry trees in Europe. The mycelium grows 
 within the roots and gummosis of the wood occurs. A Cephalo- 
 sporium form is known, also chlamydospores. 
 
 F. putrefaciens Osterw.^^^'^^'' is said by Osterwalder ^''^ to cause 
 decay of pomaceous fruits. 
 
 F. cubense E. F. Sm. was isolated from bananas affected with 
 blight. Inoculation showed the fungus capable of growing through 
 the bundles for long distances.^''^ 
 
 F. limonis Bri.i^O' ^'^' '^'^ 
 
 Sporodochia gregarious, confluent, white; hyphse spreading, 
 branched, septate; conidiophores erect, with alternate or opposite 
 branches; conidia variable, acrogenous, continuous to 3-septate, 
 oblong to fusiform, curved, pointed, slightly constricted, 26-27 x 
 2.4-2.8 II. 
 
 This fungus is held to be contril^utory to, if not responsible for, 
 the Mal-di-gomma or foot-rot of citrous 
 fruits which is known practically wherever 
 these fruits are cultivated. 
 
 F. culmorum (W. Sm.) Sacc.^^^' ^^^ 
 
 Reddish-yellow, gelatinous, effuse; hyphae 
 few-septate, tortuous; fertile, short, con- 
 tinuous; conidia fusoid-falcate, 3 to 5-sep- 
 
 tate, 28-32 X 6-8 /x on wheat. Fig. 438.— F. culmorum. 
 
 The fungus affects chaff and seed, first After Chester, 
 
 appearing as a whitening of the upper halves of the glumes fol- 
 lowed later by a pink color. The glumes become cemented to- 
 gether and the whole head may be involved. The grains are of 
 light weight and are often covered with the fungus. Chester 
 
650 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 showed that the mycelium penetrates the seed and may even 
 consume it entirely. 
 
 F. sp. occurs on raspberry.^^* 
 
 F. moniliforme Shel. 
 
 Sporodochium subeffuse, salmon-pink; conidiophores simple 
 or with opposite branches; microconidia continuous, oblong-ovoid, 
 
 Fig. 439. — Fu^^arium 
 on corn. After 
 Burrill and Bar- 
 rett. 
 
 Fig. 440. — F. vasinfectum. A. Macro- 
 conidia. B. Portion of a hypha. 
 C. A germinating macroeonidium. 
 After Reed. 
 
 380-383 
 
 moniliform, 6-10 ju long; macroconidia falcate, acute, usually 
 3-septate, 25-40 /x long. 
 It causes molding of corn.^"^ 
 
 Several other undetermined species have been isolated from 
 corn on which they occur as the cause of dry rot of the grain. ^"^ 
 
 A fusarium on banana is by Essed referred to Ustilaginoidella. 
 See p. 214. 
 F. vasinfectum Atk.' 
 Hyphse at maturity yellowish, 2-4 ju in diameter; conidia borne 
 
 singly; microconidia oval, con- 
 tinuous; macroconidia falcate, 2 to 
 3-septate, 1-2 x 2-4 /i. 
 
 Atkinson ^^^ first described this 
 on cotton and okra in which 
 plants it was found plugging the 
 ducts with its mycelium. The 
 m3''celium here was 2-4 fj. in diameter and microconidia were 
 seen within the ducts. Pure cultures were obtained and inocula- 
 tions with these on plants already injured by Pythium resulted in 
 
 Fig. 441. — F. v^asinfectuni. D. Mi- 
 croconidia. E. Chlamydo.spores 
 After Reed. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 651 
 
 infection. The ascigerous stage was said by Smith ^^° to be a 
 Neocosmospora and the many wilts caused by Fusarium have by 
 various authors who follow 
 Smith been reported as 
 Neocosmospora though 
 without real evidence that 
 they are such. See 
 page 205. 
 
 Recent studies of Hig- 
 gins ^^^ and Butler ^^^ in- 
 dicate that the Fusarium 
 of the Neocosmospora is 
 a saprophyte and that the 
 Fusariums parasitic in the 
 wilt diseases are as yet 
 unknown in ascigerous 
 form. 
 
 The Fusarium parasitic 
 on cotton is believed 
 be identical with that on 
 okra but distinct biologically if not morphologically from that 
 of watermelon. 
 
 F. vasinfectum var. tracheiphila E. F. Sm.^^^ 
 
 This form on cowpea, which appears to be morphologically 
 identical with F. vasinfectum is not capable of infecting cot- 
 ton. 
 
 F. niveum E. F. Sm.^^*'" ^^-"^^* is the cause of the watermelon 
 wilt. Morphologically it is Hke F. vasinfectum. 
 
 A fungus regarded by Reed ^^' ^^^ as identical with this was also 
 described as causing wilt of ginseng. 
 
 F. vasinfectum var. pisi v. Hall has been described as a variety 
 affecting the pea.^^^' ^^^ 
 
 F. udum Butler on pigeon pea in India is closely related to 
 this last fungus. 
 
 F. aurantiacum (Lk.) Sacc. is recorded for cucurbs occurring 
 on stems, leaves and fruits. 
 
 F. oxysporum Schl.^^^' ^^^ 
 
 Sporodochia convex, subverrucose, rose, erumpent,. confluent; 
 
 to Fig. 442. — F. vasinfectum, showing thrombosis 
 of veins. After Atkinson. 
 
652 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 conidia on short conidiophores; microconidia continuous, elliptic; 
 macroconidia falcate-fusoid, 3 to 4-septate, 40-60 x 7-8 n. 
 
 Smith and Swingle ^^^ mention 1 1 described species of Fusarium 
 recorded by Saccardo for the Irish potato, viz. ; 
 
 Fusarium oxysporum Schl., F. (Fusisporium) solani (Mart.) 
 Sacc, F. (Fusisporium) solani-tuberosa Mart., F. didymum 
 Harting, F, solani Schl., F. (Fusisporium) roseolum (B. &. B.) 
 Sacc, F. violaceum Fcl., F. caruleum (Lib.) Sacc, F. diplosporum 
 C. & E,, F. commutatum Sacc, F. pestis Sorauer, F. aeruginosum 
 Delacroix, F. acuminatum E. & E., F. affine Fautr. & Lamb, all 
 of which they tentatively regard as synonyms, attributing such 
 differences as have been noted in descriptions to variations in the 
 environment under which the fungus was growing when described. 
 The potato disease caused is common over a considerable portion 
 of the United States and is variously known as "bundle blacken- 
 ing," "stem rot," "dry end rot," and "dry rot." 
 
 The fungus grows readily on many culture media, showing large 
 variation with the environment. It is aerobic and tolerates large 
 amounts of malic, citric and tartaric acids. 
 
 F. acuminatum E. & E. Sporodochia gregarious, minute, whitish 
 or flesh-colored; conidia falcate, attenate, 3 to 5 or 6-septate, 
 not constricted. 
 
 Described by Stewart ^^^ as causing a girdling of potato stems in 
 New York. 
 
 F. roseum-lupini-alba Sacc 
 
 Sporodochia pulvinate, minute, confluent, cinnabarine; co- 
 nidiophores variable, long, slender, branched, branches nodulose, 
 fusoid; conidia fusoid falcate, 45-55 x 4 /z, 4 to 6-septate. It 
 causes spots on leaves and pods of lupines and attacks the seeds, 
 inducing rot. 
 
 F. cucurbitariae Sacc. is on cucumbers in Queensland. 
 
 F. solani (Mart.) Sacc. 
 
 Sporodochia globose, irregular, white; conidiophores branched; 
 conidia fusoid-falcate, 3 to 5-septate, 40-60 x 7-8 fx, subhyaline. 
 
 Clinton, ^^^ also Wehmer ^^^ and others, have shown this to be 
 the cause of "dry end rot " of stored potatoes. It may be iden- 
 tical with F. oxysporum. 
 
 F. pestis Sor. is given by Sorauer as the cause of "black-leg" 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 653 
 
 Fig. 443. 
 
 After Bolley. 
 
 (see p. 46) of potatoes; it is perhaps identical with F. oxy- 
 sporum. 
 
 F. erubescens A. & v. Ov. produces small black sunken spots 
 on green and ripe toma- 
 toes in German}^ '^^ re- 
 sulting finally in mummi- 
 fication. Parasitism by 
 means of enzymes was 
 demonstrated. 
 
 F. lycopersici Sacc.'"'^"^°'' 
 
 Sporodochia as in F. oxy- 
 sporum; conidia falcate, 
 acute, 25-30 x 3.5-4 /z, 
 hyaline to yellowish. 
 
 It is the cause of a to- 
 mato wilt or "sleeping 
 disease" resulting from in- 
 vasion of the ducts. Conidia of two kinds are produced, Fusa- 
 rium and Diplocladium. Infection is subterranean. 
 
 A nearly related disease differing chiefly in the fact that the 
 fungus does not reach far above ground has been described by 
 Smith.'"'- The fungus in both cases is perhaps identical with 
 
 F. oxysporum. 
 F. lini Boll. 403 
 
 Sporodochia erum- 
 pent, compact, cream 
 to flesh-colored; co- 
 nidiophores short, 
 much-branched ; co- 
 nidia 3-septate, fusi- 
 form, slightly curved 
 to falcate, 27-38 x 
 3-3.5 ^. 
 
 A serious widespread flax wilt is caused. The mycelium develops 
 luxuriantly from bits of diseased stem laid in sterile Petri dishes 
 and grows well in culture media. Normally a soil saprophyte, it 
 invades the roots, grows through the veins, plugs the ducts and 
 causes death. The sporodochia are found abundantly on the bases 
 
 Fig. 444. — F. lini, sketch, showing the mode of attack 
 upon a young root tip of a seedling flax plant. 
 After Bolley. 
 
654 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 of diseased plants. The spores abound on all diseased parts, 
 particularly on the seeds. Infection experiments have demon- 
 strated its pathogenicity. 
 
 F. tabacivorum Del. is said to cause a rot of tobacco in 
 France. 
 
 F. brassicae Thiim. is of economic importance on cabbage. '^°^ 
 
 Inoculations of an undetermined species of Fusarium in pure 
 culture into soil also resulted in infection of 83% of the cabbage 
 plants grown therein. 
 
 F. decemcellulare Brick and F. theobromae Lutz. occur on 
 cacao. 
 
 F. ricini (Ber.) Bizz. is injurious to the castor oil plant. 
 
 F. incarnatum (Desm.) Sacc. is reported as the probable 
 cause of an aster wilt or blight in Europe. ''"^ An undetermined 
 species is also reported on China aster by Galloway '^°^' **°^ and 
 others. 
 
 A species of Fusarium on carnation leaves following in rust 
 sori was reported by Stewart '"'^ and a wilt disease or stem rot of 
 carnation was studied by Sturgis.^°^ He found the Fusarium in 
 the affected plants, it was isolated and inoculated into the soil 
 around the roots of carnations producing disease in several in- 
 stances. 
 
 F. pelargonii Crou. is described from geraniums. ^^° 
 
 F. dianthi P. & D.^^^ on Dianthus cuttings, is a wound parasite, 
 following insect injury. 
 
 F. violae Wolf. 
 
 Infected areas dark, sunken; sporodochia within the host; 
 conidia fusiform-falcate, 28-38 x 4-6 fx, 3 to 5 times septate; 
 hyphse hyaline, 4-7 /x in diameter, irregularly branched. It causes 
 a disease of roots and stems of pansy. 
 
 F. pini is believed to be the species responsible for a disease of 
 pine seedhngs.*^^ 
 
 F. blasticola Rost. causes death of conifer seedhngs in Europe. 
 
 Tuberculariaceae-Dematiae-Amerosporae (p. 638) 
 
 Hyphse olive to brown or black; conidia continuous, rarely 
 hyaline globose to elongate, sometimes unequal. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 655 
 
 Key to Genera of Tuberculariaceae-Dematiae-AmerosporaB 
 
 Conidia not in chains 
 Sporodochia not setose 
 Conidiophores lacking 
 
 Lichenicolous 1. Spilomium. 
 
 Not lichenicolous 
 Sporodochia gelatinous; conidia 
 
 globose, vesiculose 2. Myriophysa. 
 
 Sporodochia not gelatinous 
 
 Sporodochia hemispheric, with a 
 
 stratum of conidia 3. Spermodermia. 
 
 Sporodochia disk-like, applan- 
 
 ate 4. Sclerodiscus. 
 
 Conidiophores present 
 
 Sporodochia thick, tremelloid 5. Epidochium, p. 656. 
 
 Sporodochia not tremelloid 
 
 Conidiophores with a slender 
 apical appendage; conidia glo- 
 bose 6. Bonplandiella. 
 
 Conidiophores not appendaged 
 Conidia globose 
 Sporodochia cellular, uniform 7. Epicoccum, p. 656. 
 Sporodochia of three hyphal 
 
 layers 8. Triplicaria. 
 
 Conidia ovoid to bacillar 
 
 Conidiophores bacillar; sporo- 
 dochia subdiscoid 9. Hymenopsis. 
 
 Conidiophores branched 
 No brown radiate hypha? at 
 
 base 10. Strumella, p. 656. 
 
 Brown radiate hyphse at 
 
 base 11. Astrodochilum. 
 
 Sporodochia ciliate or with exserted hj'^phse 
 Sporodochia with loose exserted co- 
 nidiophores, verruciform 12. Trichostroma. 
 
 Sporodochia margins with hairs or 
 setae 
 
 Setae dark. 13. Chaetostroma, p. 656. 
 
 Setae or hairs white 14. Myrothecium. 
 
656 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Conidia in chains 
 
 Conidiophores lacking 15. Exosporina, p. 656. 
 
 Conidiophores present 
 
 Sporodochia globose 16. Sphaeromyces. 
 
 Sporodochia stellate 17. Actinomma. 
 
 Epidochium Fries (p. 655) 
 
 Sporodochiiim thick, tremelloid, subglobose or wart-form, black 
 or pallid, erumpent; sporophores filiform, equal or apicall}^ swollen; 
 conidia ovoid, oblong or pyriform, solitary or catenulate. 
 
 Some fifteen species. 
 
 E. oryzae Miy. is found ^^ on rice. 
 
 Epicoccum Link (p. 655) 
 
 Sporodochia globose or convex, cellular, 
 dark; conidiophores very short; conidia glo- 
 bose. Some fifty species. 
 
 E. hyolopes Miy. is on rice. 
 
 Strumella Saccardo (p. 655) 
 
 Sporodochia wart-shaped; conidiophores 
 „ . . r ^ . branched ; conidia ovate, often somewhat bent. 
 
 1<IG. 445. — Epicoccum. ' , ' 
 
 After Saccardo. Some fifteen species. 
 
 S. sacchari Cke. is found on sugar cane.^^^ 
 
 Chaetostroma Corda (p. 655) 
 
 Sori dark or cushion-form black bordered Avith black hairs; 
 spores elliptical, fusiform or rarely almost spherical. 
 
 C. buxi Corda on Box=Nectria rousseliana. See p. 204. 
 C. cliviae Oud. causes blotches on Clivia. 
 
 Exosporina Oudemaus 
 
 Sporodochia erumpent; conidia catenulate, homomorphic, 
 continuous, greenish. Monotypic. 
 
 E. laricis Oud. is parasitic on larch leaves in Europe. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 657 
 
 Tuberculariaciae-Dematieae-Phragmosporae (p. G39) 
 
 Hyphffi dark; conidia usually colored, 2 to several-septate, ob- 
 long to cylindric. 
 
 Key to Genera of Tuberculariacese-Dematiae-Phragmosporae. 
 
 Conidia in chains; sporodochium discoid. 1. Trimmatostroma, p. 657. 
 Conidia not in chains 
 
 Conidia 1-ciliate at each end.. 2. Ciliofusarium. 
 
 Conidia muticate 
 
 Sporodochium hairy 3. Excipularia. 
 
 Sporodochium smooth 
 
 Conidia laterally proliferate and 
 
 joined in bundles 4. Amallospora. 
 
 Conidia not proliferate and 
 united 
 Sporodochia convex-pulvinate . . 5. Exosporium, p. 658. 
 Sporodochia vertically cylindric 
 
 or clavate 6. Listeromyces. 
 
 Trimmotostroma Corda 
 
 Sporodochia pulvinate, compact, bearing a layer of conidio- 
 phores; conidia oblong, often curved, 2 to 8-septate, catenulate 
 brown. 
 
 A genus of a half dozen species. 
 
 T. abietina Doh.^i^ 
 
 Mycelium perennial; sporodochia foliicolus or caulicolus, 
 diffuse; conidiophores subhyaline, or tinged with olive-brown, 
 4.5 X 20-30 ju, septate, sparsely branched, bearing the conidia 
 terminally; conidia catenulate, very variable, dark olivaceous- 
 brown, slightly roughened, usually oblong, spherical, straight or 
 inequilateral, continuous, spherical, 5 fi, or 2 to 5-celled and 5-6 
 X 8-16 fi, not constricted, rarely muriform, 5 x 10 ju. 
 
 On white and balsam firs in Canada. The perennial habit of 
 the mycelium makes the pest a persistent one and as no conidia 
 are produced till the second year after infection its presence is 
 the more readil}^ overlooked. 
 
658 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 Exposorium Link (p. 657) 
 
 Sporodochia convex, compact; conidiophores dark, simple, 
 densely compacted; conidia single, oblong to cylindric, plurisep- 
 tate. 
 
 Some twenty-five species. 
 
 In part=Coleroa and Coryneum. See pp. 227, 236. 
 
 E. juniperinum (E.) Jacz. = Coryneum juniperinum. See p. 236. 
 
 E. laricinum Mas. is found on living larch twigs. . 
 
 E. tiliae Lk. grows on young shoots of Tilia. 
 
 E. palmivorum Sacc."*^^ 
 
 Fig. 446. — E. palmivorum. 3, a sporodochium, 
 5, spores. After Trelease. 
 
 Spots amphigenous, minute, suborbicular, 1-3 mm. in diameter, 
 brown, scattered; sporodochia superficial, densely gregarious, 
 punctiform, black; 30 x 60-80 ix; conidiophores oblong, con- 
 tinuous, reddish olive, 5-6 x 14-16 n, conidia borne singly, 
 fusoid, straight or curved, apically obtuse or acute, basally obtuse, 
 8 to 10-septate, not constricted, olive-brown, ends paler, 8-9 x 
 80-90 At. 
 
 On palms, especially species of Phcenix in America. 
 
 E. presii Bub. on species of Phcenix in Europe is very similar 
 to the preceding species. 
 
 In the Tuberculariacese-Dematiese-Dictyosporse Thjrrococcum 
 sirakofii Bubak forms black tubercles under bark of mulberry 
 and kills the twigs.^^^ 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 659 
 
 Mycelia-Sterilia (p. 479) 
 
 Numerous forms are known moroly as sterile mycelia. They 
 may or may not make sclerotia. In several instances these sterile 
 forms are so aggressive as to warrant classing them among the 
 worst of plant pathogens. Until more is known of them it becomes 
 necessary to arrange and name them, for convenience of reference, 
 in a purely artificial manner. 
 
 Key to form Genera of Mycelia-Sterilia. 
 
 Tubercle-like 
 
 Tubercles connected with fibrils 1. Rhizoctonia, p. 659. 
 
 Tubercles without fibrils 
 
 Cortex discrete 2. Acinula. 
 
 Cortex not discrete 3. Sclerotium, p. 660. 
 
 Maculiform 
 
 Black stromata in leaves and stems 4. Ectostroma. 
 
 Pseudo stromata in cortex 5. Phellomyces. 
 
 Root-like 
 Filaments rigid, broad, terete or depressed, 
 
 dark, wliite within 6. Rhizomorpha. 
 
 Filaments rigid, capilliform, dark, closely 
 
 adhering 7. Capillaria. 
 
 Cla variform; filaments terete, vertical, sim- 
 ple or branched 8. Anthina. 
 
 Cobwebby or byssoid 
 
 Cespitose interwoven, primary hyphse 
 
 joined in bundles 9. Ozonium, p. 661. 
 
 Cespitose interwoven, hyphse not fascicu- 
 late, black 10. Rhacodium. 
 
 Cobwebby, soft, evanescent, white or pale 11. Hypha. 
 Adpressed, creeping, dendritic, white to 
 brownish, not forming a continuous 
 
 membrane 12. Himantia. 
 
 Membrane-like; densely interwoven, form- 
 ing a continuous suberose or coriaceous 
 membrane 13. Xylostroma, p. 663. 
 
 Rhizoctonia De Candolle 
 Sclerotia variable in form, horn3^-fleshy; cortex thin, mem- 
 
660 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 branous, persistent, inseparable; formed among and connected by 
 the mycelial threads. 
 
 There are about a dozen so-called species, some of them very 
 important plant pathogens. See pp. 407, 408. 
 
 R. betae Klihn and R. solani Klihn = Corticium vagum solani, 
 as does also part of what has been referred to as R. violaceai. 
 
 R. medicaginis D. C. (Tul.); ^^ (see also ^^^^ ^i^-'^O- 
 
 Hyphse subtomentose, on the cambium of the host, forming a 
 membrane or fasciculate strands, covering the host in time with a 
 violet coating; sclerotia reddish-violet. 
 
 On alfalfa in Europe and America.*^^^ 
 
 Duggar who has studied this form and the form allied to Corti- 
 cium (pp. 407, 408) regards the two as distinct though Giissow ^^^ 
 who has also studied both pronounces them the same. Duggar says, 
 "The fungus appears upon the root as a close weft of violet-colored 
 hyphae composed of cells more or less uniform in diameter. Mor- 
 phologically it bears no resemblance to the sterile stage of Cor- 
 ticium." This form is found on alfalfa, asparagus, beet, and pos- 
 sibly other plants. 
 
 Leptosphseria has been reported as its ascigerous stage though 
 the evidence of such connection is not conclusive. 
 
 R. crocorum D. C. is a form which kills the corms of saffron. 
 
 R. strobi Scholz is the name given to a form described as seriously 
 injuring young pine trees in Austria. ^^^ 
 
 R. subepigea Ber. is destructive on the roots of coffee.^^^ 
 
 A Rhizoctonia of undetermined species has been found on buck- 
 wheat in the United States.^"^ 
 
 Sclerotium Tode (p. 659) 
 
 Sclerotia roundish or irregular in form, cartilaginous-fleshy, not 
 connected by mycelial threads; cortex thin, membranous, in- 
 separable. 
 
 Over 200 species have been described. 
 
 S. rolfsii Sacc.2i' ''^s- 438 
 
 Sclerotia small, brown, about the size of a mustard seed. 
 
 This sterile fungus possesses a very aggressive mycelium which 
 under favorable conditions of moisture grows on almost anything 
 living or dead, producing a dense white cotton-like mass of threads. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 661 
 
 Soon the sclerotia form as mustard-seed-like bodies. They are 
 produced in great abundance on all media l)ut neither these struc- 
 tures nor the mj^celium have yet been seen to bear spores of any 
 kind. The fungus was first studied by Halsted -^ and later by 
 many others. It was described and named by Saccardo from speci- 
 mens communicated by Stevens. 
 
 S. cepivorum Berk. 
 
 Minute, spherical, gregarious, black. It is found on various 
 species of Allium, causing rot. 
 
 Fia. 447. — S. rolfsii, sclerotia. After Halsted. 
 
 S. rhizoides Auer.^-® 
 
 Subglobose, at first white-villose, then smooth, black, rugose. 
 
 On Calamagrostis and other grasses. It causes considerable 
 injury to the hay crop in Europe. 
 
 S. tuliparum Klebahn,^-^ S. tulipae Lib. and S. bulborum Wak. 
 are found on tulips, and other l)ulbs. A relation to Sclerotinia is 
 usually assumed but has not been dem.onstrated. See p. 136. 
 
 S. oryzae Catt. is found on rice in Japan and Italy. 
 
 Ozonium Link. (p. 659) 
 
 Col:)webby or byssoid, cespitose, hyphae densely interwoven, 
 primary hyphoe fasciculate. 
 Some twelve species. 
 
662 
 
 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 O. omnivorum Sh.*'"' ^-^'^^^ 
 
 Mycelium dirty yellow; sometimes whitish when young, grow- 
 ing in the vascular bundles of the host; hyphse forming strands 
 and spreading from them, producing a rather dense arachnoid 
 layer on the surface of the host and l^earing 1 to 4 branches arising 
 
 l-'iG. 448. — S. rolfsii, sterile mycelium growing on carrot. After Stevens and Hall. 
 
 and growing at right angles from the same point near the ends, 
 3 to 5 /x in diameter, tapering toward the ends. 
 
 It causes root rot on almost any kind of plant including among 
 its hosts a large variety of trees. The first description was by 
 Pammel in a Texas Bulletin; a later one was by Shear. The fungus 
 destroys the smaller rootlets, cortex of older roots and invades the 
 vascular system and medullary rays, resulting in wilt and death. 
 It may he seen as dirty yellowish strands or as a thin weft 
 superficially. Sclerotia-like bodies appear on the roots often at 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 663 
 
 lenticels. Inside of the host tissue the mycelium is not typically 
 associated to form strands and its cells are hyaline. 
 
 The fungus was in early studies difficult to isolate but Atkinson 
 in 1893 **~^ obtained pure cultures by rinsing the diseased roots in 
 distilled water, cutting in small pieces and placing on sterile filter 
 paper lying on sterile sand in a moist chamber. In a few days the 
 strands grew over the paper onto sterilized slides. Bits of sterilized 
 cotton-root were then placed in contact with the advancing hyphse. 
 Soon the new culture thus secured could be transferred at will. 
 A slight acidity retards bacterial growth and renders isolation of 
 the Ozonium less difficult. In culture sclerotia about 3 mm. in 
 diameter, whitish and woolly, later brown, appear. 
 
 Xylostroma Tode (p. 659) 
 
 This occurs, forming thick, felt-like layers, in cracks of timber. 
 It is regarded as the mycelium of various Hjinenomycetes, es- 
 pecially Fomes. 
 
 Fungi of Unknown Affinity 
 
 The following imperfectly known genera do not fit readily into 
 the scheme of classification and are all in need of careful study. 
 
 Acrocystis Ellis & Halsted 
 
 Monotypic ; though technically a nomen nudem, the illustrations 
 are recognizable. Examination of the original material shows 
 Saccardo's reference to the Mucorales to be untenable. 
 
 A. batatae E. & H.^^ 
 
 Hyphse intercellular, branched, producing enlarged cysts at the 
 ends of branches, the nature of these unknown; enlarged, intra- 
 mycelial swellings contain numerous rounded conidia. 
 
 It is described as the cause of soil rot of sweet potatoes. 
 
 Graphiola Poit 
 
 Mycelium within the host; fruiting body rotund, carbonous 
 duplex, the outer layer of interwoven branched hyphse, firm, in- 
 
664 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 terior softer, of fertile and sterile fasciculate hyphse; fertile hyphae 
 with short branches bearing the spore-mother-cells which divide 
 into two globose or angular spores; germination by a filiform 
 conidia-bearing mycelium. 
 
 A genus of seven species, chiefly on palms. 
 
 G. phoenicis (Moug.) Poit/^^' "'^ 
 
 Sprodochium 1-1.5 x 500 n; exoperidium horny, black, inner 
 peridium membranous, hyaline; spore-mass yellow; spores globose 
 or elliptic, 3-6 ju, with a thick, smooth, hyaline wall. 
 
 On the date and other palms throughout the world. 
 
THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 665 
 
 Fig. 449. — G. phoonicis. II, sporiferous organ. 
 Ill, section of the same. After Stone and Smith. 
 
BIBLIOGRAPHY OF FUNGI IMPERFECTI* 
 
 1 Stevens, F. L. and Hall, J. G., Bot. Gaz. 4S: 1, 1909. 
 
 ^Leininger, H., C. Bak. 29: 4, 1911. 
 
 ' Cobb, N. A., D. Agr. New So. Wales, Miss. Pub. 666: 21. 
 
 * Hedgcock, G., Myc. 10: 2, 1904. 
 
 ^ Kirk, T. W., N. Z. R. 348, 1906. 
 
 8 Potebnia, A., Ann. Myc. 8: 58, 1910. 
 
 ' Scott, W. M. and Rorer, J. B., B. P. I. B. lU: 1909. 
 
 8 Scott, W. M. and Quaintance, A. C, F. B. 283: 14, 1907. 
 
 9 Clinton, G. P., 111. B. 69: 1902. 
 
 Stewart, F. C, N. Y. (Geneva) R. H: 545, 1895. 
 
 1 Scott, W. M. and Rorer, J. B., B. P. I. B. 121: 1908. 
 
 2 Stevens, F. L., N. C. B. 196: 54, 1907. 
 
 3 Ann. Inst. Cent. Amp. Roy. Hong. 3: 167, 1905. 
 ' Selby, A. D., 0. B. 2U: 445, 1910. 
 
 5 Briesig, Bui. Min. Ag. Ind. & Cen. Rome, 1910. 
 
 6 Miyaki, Bot. Mag. Tokyo 23: 1909. 
 
 ' Stewart, F. C, N. Y. (Geneva) B. 328: 1911. 
 
 8 Halsted, B. D., N. J. R. 12: 279, 1891. 
 
 9 7rfem. 19, iL-355, 1890. 
 
 20 Halsted, B. D., N. J. B. 70: 9, 1890. 
 " Halsted, B. D., N. J. R. 1^: 355, 1893. 
 
 22 Selby, A. D., 0. B. 105: 222, 1899. 
 
 23 Patterson and Charles, B. P. I. B. 171. 
 2^ Diedicke, H., C. Bak. 19: 168, 1907. 
 
 25 Halsted, B. D., N. J. R. 13: 297, 1892; R. 12: 1891. 
 28 N. J. R. 15: 331, 1894. 
 
 27 Humphrey, J. E., Mass. R. 10: 231, 1892. 
 
 28 Humphrey, J.E., Zeit. 3: 360, 1893. 
 2«Gueguin, B., S. M. Fr. 18: 312, 1902. 
 3» Aderhold. R., C. Bak. 6: 620, 1900. 
 
 " Trinchieri, R., Bui. Ort. Bot. R. Univ. Napoli 2: 409, 1909. 
 
 '2 U. S. D. Agr. R. 88. 
 
 " Stewart, F. C, (Geneva) R. 15: 456, 1896. 
 
 * See footnote, page 53. 
 666 
 
BIBLIOGRAPHY OF FUNGI IMPERFECTI 667 
 
 3" U. S. Dept. Agr. R. 87. 
 " Chester, F. D., Del. R. 5: 75, 1892. 
 3« Selby, A. D., 0. B. 92: 233, 1898. 
 " Lewis, C. E., Sc. 31: 752, 1910. 
 
 38 Lewis, C. E., Me. B. 170: 1909. 
 
 39 Hiilsted, B. D., N. J. B. 91: 1892. 
 
 « McAlpine, Dept. Agric. Melbourne, 132, 1899. 
 
 ^' McAlpine : Fungi of the Vine in Australia. 
 
 *2 Frank, Zeit. 3: 28, 1893. 
 
 " Prillieux and Delacroix, B. S. My. Fr. G: 178, 1890. 
 
 '* Rostrup, E., Zeit. I^: 195, 1894. 
 
 « Manns, T. F., Sc. 32: 726, 1910. 
 
 « Manns, T. F., Mycologia 1: 28, 1911. 
 
 « Bos. Zeit. 16: 257, 1906. 
 
 « Quanjer, Zeit. 17: 259, 1907. 
 
 « Rostrup, E., Zeit. 4: 322, 1894. 
 
 ^a Rostrup, E., Tid. f. Landok. R. 5: 11, 330, 1891. 
 
 " Kirk, T. W., New Zealand, D. Ag. R. 13: 410, 1905. 
 
 ^2 Klebahn, H., Zeit. 20: 1, 1910. 
 
 " Fron, G., Bull. Trim. Soc. Myc. France 25: 66. 
 
 ^^ Halsted, B. D., N. J. B. 76: 25, 1890. 
 
 " Stewart, F. C, N. Y. (Geneva) B. 179, 1900. 
 
 6« Arthur, J. C., N. Y., (Geneva) R. 3: 383, 1884. 
 
 " Deidicke, H., Ann. Myc. 9: 8, 1911. 
 
 ^« Steward, F. C., Rolfs, F. M., and Hall, F. H., N. Y. B. 191: 298, 1900. 
 
 59 Cordlcy, A. B., Ore. Bui. 60: 1900. 
 
 6« Paddock, W., N. Y. (Geneva) B. 163: 203, 1899. 
 
 81 Eriksson, Zeit. 1: 29, 1891. 
 
 82 Halsted, B. D. and Fairchild, D. G., J. Myc. 7: 1891. 
 
 83 AUescher, A., Zeit. 5: 276, 1895. 
 8" Reed, H. S., Mo. B. 69: 1905. 
 
 8s Linhart, Zeit. 5: 92, 1895. 
 
 88 Stoneman, B., Bot. Gaz. 26: 1898. 
 
 8^ Thaxter, R., Ct. R. 13: 163, 1889. 
 
 88 Ducomet, Ann. I'ecole Nat. d'Agr, d. Rennes 24, 1909. 
 
 89 Agr. Soc. 8: 292, 1894. 
 
 '" Williams, T. A., S. Dak. B. 29: 1891. 
 
 '1 Miyake, I., Phytopath. Inst. Agrikult. Abt. der Univ. Tokyo, 1909. 
 
 " Bubak, F., Zeit. Land. Ver. Oe. 18: 502, 1910. 
 
 " Chester, F. D., Del. R. 40, 1902. 
 
 '' Edgerton, C. W. La. B. 126: 194. 
 
668 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 '5 Scott, W. M. and Rorer, J. B., B. P. I. B. 121: Dt. 5, 1908. 
 ^9 Chester, F. D., B. Torr. Bot. Club, IS: 373. 
 " Paddock, W., N. Y. (Geneva) B. 185: 1900. 
 '8 Peck, C. H., R. N. Y. Mus. Nat. Hist. 1881. 
 " Atwood, Proc. A. A. A. S. 47; 413, 1898. 
 «" Clinton, G. P., lU. B. 69: 192, 1902. 
 " Paddock, W., Science 8: 596. 
 «'^ Shear, C. L., Sc. 31: 748, 1910. 
 ^^ Mangin, L., Jour. d'Agric. Pratique, 1901. 
 «^ Griffon and Maublanc, B. S. Myc. Fr. 26: 3. 
 
 «5 GUssow, H. T., Zeit. 20: 406; 1909 also Jour. Roy. Hort. Soc. (Lon- 
 don) 222, 1908. 
 86 B. S. My. Fr. ^L-75, 1895. 
 
 8' Stewart, F. C. and Eustace, H. J., N. Y. (Geneva) B. 226: 1902. 
 88 Stevens, F. L. and Hall, J. G., N. C. B. 196: 1907. 
 8» O'Gara, P. J., Phyto. 1: 100, 1911. 
 '0 Viali and Ravez, Rev. d. Vit. 197, 1895. 
 " Van Hook, J. M., 0. B. 173: 1906. 
 
 92 Kruger, F., C. Bak. 1: 620, 1895. 
 
 93 Bolthauser-Aurisweil, H., Zeit. 1: 135, 1891. 
 9^ Porto Rico, R. 397, 1904. 
 
 95 Clinton, G. P., Ct. R. 326, 1903. 
 
 99 Bolthauser, H., Zeit. 8: 263, 1898. 
 
 9' Dudley, W. R., N. Y. (Cornell) B. U: 182, 1889. 
 
 98 Stevens, F. L., Bot. Gaz. U: 241, 1907. 
 
 99 Stewart, F. C, French, G. T. and Wilson, J. K., N. Y. (Geneva) B. 
 305: 395, 1908. 
 
 'o" Laubert, R., Arb. K. Gesund. Biol. Abt. 3: 441. 
 '01 McAlpine D., Melbourne Dept. of Agric. 132, 1899. 
 i«2 Prillieux and Delacroix, B. S. My. Fr. 9: 275, 1893. 
 '«3 Burrill, T. J. and Barrett, J. T., 111. B. 133: 1909. 
 '"4 Barrett, J. T., Sc. 27: 212, 1908. 
 •05 Stevens, F. L. and Hall. J. G., N. C. R. 31: 38, 1909. 
 10" Smith, E. F. and Hedges, F., Sc. 30: 60, 1909. 
 
 107 Howard, A., Ann. Bot. 15: 683, 1901. 
 
 108 Pole, J. B. Evans, Trans. D. Agr. Soc. B. 4: 1910. 
 
 109 Butler, E. J., Pusa Agr. Reas. B. 9: 1908. 
 "0 Clendenin, I., Bot. Gaz. 21: 92, 1896. 
 
 111 Munch E. and Tubeuf, C, Nat. Zeit. f. For. u. Land. 8: 39, 1910. 
 
 112 Cavara, F., Zeit. 4.- 109, 1894. 
 
 1" Pammel, L. H., la. B. 13: 67, 1891. 
 
BIBLIOGRAPHY OF FUNGI IMPERFECTI 669 
 
 * Agr. Jour. 9: 135, 1896. 
 
 s Taft, L. R., Mich. Bui. 83: 1892. 
 
 8 Cavara, F., Zeit. 3: 23, 1893. 
 
 ' Mangin, L., E. S. R. 10: 452, 1898. 
 
 8 B. Soc. Myc. Fr. 15: 108. 
 i« Humphrey, J. E., Mass. R. 7: 1889. 
 20 Patouillard and Lagerheim, B. S. My. Fr. 136, 1892. 
 " McCarthy, G., N. C. B. 98: 151, 1894. 
 •" Chester, F. D., Bull. Torr. Bot. CI. 372, 1891. 
 '' N. Y. (Geneva) B. 51: 137, 1893. 
 2" Duggar, B. M., N. Y. (Cornell) B. 132: 256, 1897. 
 " Humphrey, J. E., Mass. R. 231, 1891. 
 26 Rogers, S. S., Cal. B. 208: 1911. 
 " Halsted, B. D. N. J. R. 95, 294. 
 2« Selby, A. D., 0. B. 73: 1896. 
 
 -3 Chittenden, F. J., Jour. Hort. Soc. London 35: 216. 
 3" Beach, S. A., N. Y. (Geneva) R. 11: 557, 1893. 
 31 Salmon, R., Econ. Myc. 1908. 
 3= Stewart, F. C, N. Y. (Geneva) R. 455, 1896. 
 S3 Spaulding, P., B. P. L Cir. 35: 1909. 
 
 34 Jaczewski, A., Zeit. 10: 340, 1900. 
 
 35 Hall, C. J. J. von, Ann. Myc. 1: 503, 1903. 
 
 36 Sturgis, W. C, Conn. State R. 21. 
 
 37 Selby, A. D., Ohio B. 79: 1897. 
 
 38 Kirk, T. W., N. Z. D. Agr. 157, 1907. 
 
 39 Stone, G. E., and Smith, R. E., Mass. R. 67, 1897. 
 
 40 Delacroix, G., B. S. My. Fr. 19: 353, 1903. 
 " Scribner, F. L., Tenn. B. 4- 1891. 
 
 « Pierce, N. B., V. P. P. B. 2: 170, 1892. 
 " Viala & Pacottet, Rev. de Vit. 1904. 
 
 44 Grossenbacher, J. G., N. Y. (Geneva) T. B. 9: 1909. 
 
 45 Brizi, U., Zeit. 6: 65, 1896. 
 
 46 Paddock, W., N. Y. (Geneva) B. 124, 1897. 
 
 47 Burrill, T. J., Agr. Rev. Wash. 97: 1882. 
 
 48 Lawrence, W. H., Wash. Bui. 97: 1910. 
 
 49 Rorer, J. B., Rep. of the Mycologist, Trinidad, 1910. 
 60 Cardin, P. P., Cuba Rev. 8: 28. 
 
 6iWehmer, B., Zeit. 11: 193, 1901. 
 
 62 Kirchner, 0., Zeit. 12: 10, 1902. 
 
 63 Linhart, G., Zeit. 12: 281, 1902. 
 
 64 Fulton, H.. R., Sc. 752, 1910. 
 
670 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 i«5 Chester, F. D., Del. R. I^: 60, 1891. 
 
 158 Edgerton, C. W., Bot. Gaz. J^5: 403, 1908. 
 1" Sorauer, Zeit. 1: 255, 1897. 
 
 168 Laubert, R., Zeit. IJ^: 257, 1904. 
 
 159 Stone, G. E. and Smith, R. E., Mass. R. 10: 69, 1898. 
 
 160 Stewart, F. C., N. Y. (Geneva) R. IJ^: 531, 1895. 
 1" Edgerton, C. W., Ann. Myc. 6: 1908. 
 
 i«2 Massee, G., Kew. Bull. 269, 1908. 
 
 163 Commes, Mit d. Kais. Welt. Inst. f. Land., Bramberg, 2: 1910. 
 
 1" Whetzel, H. H., N. Y. (Cornell) B. 239: 1906. 
 
 "5 Whetzel, H. H., N. Y. (Cornell) B. 255: 1908. 
 
 166 Bull. Torr. Bot. CI. 20: 246, 1893. 
 
 16' Harvey, F. L., Me. R. 152, 1893. 
 
 168 Bull. Soc. Myc. D. Fr. 10: 162, 1894. 
 
 169 Stevens, F. L. and Hall, J. G., Zeit. 19: 65, 1907. 
 i™Hume, H. H., Fla. B. 53: 171, 1900. 
 
 1" Rolfs, P. H., B. P. I. B. 52: 1904. 
 
 1" Hume, H. H., Fla. B., 7J^: 1904. 
 
 1" Smith, R. E., Cal. Cult. 1911. 
 
 1'" Edgerton, C. W., Sc. 31: lYJ, 1910. 
 
 1" Lewton-Brain, L., Hawaii Sugar Planters Assn. Bui. 8: 1908. 
 
 1^6 Stevens, F. L., N. C. R. 33: 71, 1911. 
 
 1" Selby, A. D. and Manns, T. F., 0. B. 203: 187, 1909. 
 
 1^8 Bain, S. M. and Essay, S. H., Tenn. B. 75: 1906. 
 
 179 Bain, S. M. and Essay, S. H., J. Myc. 12: 192, 1906. ' 
 
 180 Bain, S. M. & Essay, S. H. Sc. 22: 503, 1905. 
 
 181 Barre, H. W., S. C. B. 153: 1910. 
 
 182 Southworth, E. A., J. Myc. 6: 46, 1890. 
 
 18' Hedgcock, G. G., Mo. Bot. Card. R. 153, 1905. 
 
 18* Stone, G. E. and Smith, R. E., Mass. R. 11: 152, 1898. 
 
 185 Smith, R. E., Bot. Gaz. 27: 203, 1899. 
 
 186 Stewart, F. C, N. Y. (Geneva) B. 179: 105, 1900. 
 
 187 Noack, F., Zeit. 11: 202, 1901. 
 
 188 Halsted, B. D., N. J. R. 17: 410, 1896. 
 
 189 Noack, F., Zeit. 9: 4, 1899. 
 
 190 Atkinson, G. F., N. Y. (Cornell) B. 61: 302, 1893. 
 
 191 Southworth, E. G., J. Myc. 6: 171, 1891. 
 
 192 Edgerton, C. W., La. B. 120: 1910. 
 
 193 Jones, L. R., and Giddings, N. J., Vt. R. 19: 235, 1907. 
 19* Raciborski, Zeit. 8: 66, 1899. 
 
 196 Vuillemin, P., B. Sc. M. Fr. 12: 33, 1896. 
 
BIBLIOGRAPHY OF FUNGI IMPERFECTl 671 
 
 "6 Reed and Cooley, A., Va. 115, 1909-10. 
 
 '" Shear, C. L., B. P. I. B. 110: 1907. 
 
 "8 Wolf, F. A., Neb. R. 21: 69, 1908. 
 
 193 Pierce, N. B., V. P. P. B. 20: 1900. 
 
 ^oo Wagner, F. and Sorauer, P., Zeit. 8: 256, 1898. 
 
 =01 Jaczewski A., Zeit. 11: 203, 1901. 
 
 202 Smith, R. E., et al, Cal. B. 191: 73, 1906. 
 
 203 Lewis, C. E., So. 31: 752, 1910. 
 
 204 Butler, E. J., India D. Agr. 2: 8, 1909. 
 
 205 Stewart, F. C. and Eustace, H. J., N. Y. (Geneva) R. 20: 146, 1902. 
 208 Pammel, L. H., la. B. 13: 61, 1891. 
 
 207 Fairchild, D. G., J. Myc. 7: 249, 1893. 
 
 208 Arthur, J. C., N. Y. (Geneva) R. 6: 347, 1887. 
 
 209 Geneva R. 8: 293. 
 
 210 Pammel, L. H., la. B. 15: 62, 1891. 
 
 211 Brooks, C., Bull. Torr. Bot. CI. 35: 423, 1908. 
 
 212 Brooks, C., N. H. B. lU: 116, 1909. 
 
 213 Constantin, Rev. Gen. d. Bot. 6: 289, 1894. 
 
 214 Massee, G., Gard. Chron. July 23, 1898. 
 
 215 Oudemans, C. R. Acad. Roy. Sc. d. Pays.-Bas. Jan. 1897. 
 21" Sturgis, W. C., Ct. (New Haven) R. 20: 263, 1896. 
 
 21' Thaxter, R., Ct. R. 81, 1890. 
 
 218 Frank, Ber. d. Bot. Ges. 16: 280. 
 
 219 Sturgis, W. C, Ct. State. Sta R. 20: 266, 1896. 
 
 220 Arthur, J. C, Ind. B. 65: 1897. 
 
 221 Arthur, J. C, Ind. B. 39, 1892. 
 
 222 Sturgis, W. C, R., Ct. R. 15: 153, 1891. 
 
 223 W. Va. B. 2: 1897. 
 
 224 Duggar, B. M., N. Y. Cornell B. 163: 359, 1899. 
 
 225 Griffon and Maublanc, B., S. M. d. Fr. 26: 132, 1910. 
 22« Magnus, P., Ver. d. Gas. lux Natur freunde. 
 
 227 Brizi, U., Ric. Lab. Chem. Agr. Sc. Milano 3: 169. 
 
 228 Thom, C, B. B. Animal Industry. 
 
 229 Heald, F. D., Neb. D. 103: 1907. 
 
 230 Stewart, F. C. and Hodgkiss, H. E., N. Y. (Geneva) T. B. 7: 1908. 
 
 231 Smith, R. E., Bot. Gaz. 29: 395, 1900. 
 
 232 Brizi, U., C. Bak. 3: 141, 1897. 
 
 233 Ward, H. M., Ann. Bot. 2: 319, 1888. 
 
 234 Istvanffi, G., Ann. L'Inst. Cent. Amp. Roy. Hong. 1905. 
 
 235 Kean, A. L., Bot. Gaz. 15: 8, 1890. 
 238 Wehmer, C, Zeit. J^: 204, 1894. 
 
672 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 23' Humphrey, J. E., Mass. R. 1892: 219. 
 
 "8 Jones, L. R., Vt. R. 5: 141, 1892. 
 
 "9 Bailey, L. H., N. Y. (Cornell) B. 96: 387, 1895. 
 
 2« Stone, G. E. and Smith, R. E., Mass. B. 69: 1900. 
 
 2" Brooks, F. T., Ann. Bot. 22: 479, 1908. 
 
 2^2 Kisshng, Hedwegia 28: 227, 1889. 
 
 2" Reidemeister, Ann. Myc. 7: 19, 1909. 
 
 24" Wulff, T., Ark. Bot. 8: 18, 1909. 
 
 2« Bos. J. R., Zeit. 8: 263, 1898. 
 
 2« Bureau Plant Industry, B. 171. 
 
 24' Fawcett, H. S. and Burger, 0. F., Mycologia 3: 151, 1911. 
 
 2« Behrens, J., Zeit. 3: 89, 1893. 
 
 2« C. Bak. 6: 625, 1900. 
 
 25" Clinton, G. P., Ct. R. 1905: 274. 
 
 2" Salmon, Econ. Mycol. 1909: 98. 
 
 252 Briosi, G. and Farneti, R., Atti. Inst. Bot. Univ. Pavia 8: 4. 
 
 2" McAlpine, Fungus Diseases Citrus, Austral, 77. 
 
 2" Delacroix, G., B. S. M. Fr. 19: 128. 
 
 2" Fawcett, G. L., P. Rico R. 1909: 35, 1910. 
 
 256 Van Hook, J. M., N. Y. (Cornell) B. 219: 1904. 
 
 2" Rankin, W. H., Spec. Crops, N. S. 9: 349, 1910. 
 
 258 Gueguen, F., Bui. Tri. Soc. Myc. France, 22: 254. 
 
 2M Gueguen, F., C. R. Soc. Biol. Paris 68: 221. 
 
 26" Craig, J. and v. Hook, J. M., N. Y. (Cornell) B. 207: 199, 1902. 
 
 2" Eustace, H. J., N. Y. (Geneva) B. 227: 367, 1902. 
 
 2" Aderhold, R., C. Bak. 5: 552, 1899. 
 
 2«3 Twaroff, K. S., Zeit. IJ^: 36, 1904. 
 
 2"'' Patterson, F. W., Sc. 31: 756, 1910. 
 
 2«'5 Constantine, J. A. Dufour, L., Zeit. 3: 310, 1893. 
 
 2«6 Atkinson, G. F., Bot. Gaz. 15: 166, 1890. 
 
 2" Atkinson, G. F., 0. E. S. B. 33: 309, 1896. 
 
 268Thaxter, R., Ct. R. U: 98, 1890. 
 
 2«9 Porto Rico R. 1903: 449. 
 
 2"> Chittenden, F. J., Card. Chron. 3: 277. 
 
 2'i Metcalf, H., S. C. B. 121: 1906. 
 
 2" Fulton, H. R., La. B. 105: 1908. 
 
 2" Metcalf, H., Sci. 25: 264, 1907. 
 
 27< Smith, E. F., J. Myc. 7: 91, 1892. 
 
 2" Magnus, P., Ber. d. deut. Bot. Ges. 28: 26, 1910. 
 
 2« Zeit. 5: 335. 
 
 2" Fetch, T., Circ. Roy. Bot. Card. Ceylon, Nov. 1909. 
 
BIBLIOGRAPHY OF FUNGI IMPERFECTI 673 
 
 "« Petri, L., Mo. Gior, Bot. Ital. 582, 1803. 
 
 "» Porto Rico R. 398, 1904. 
 
 =»« Cavara, F., Zeit. 3: 24, 1893. 
 
 =8' Smith, R. E. and Butler, 0., Cal. B. 200: 1908. 
 
 »" Fawcett, H. S., Fla. R. 46: 1909. 
 
 2" Swingle, W. T. and Webber, H. J., V. P. P. B. 8: 1896. 
 
 2" Cal. R. 297, 1892-3. 
 
 2«5 Aderhold, R., Zeit. 6: 72, 1896. 
 
 2«« Arthur, J. C, Ind. B. 19: 8, 1889. 
 
 2" Penzig, Studi Bot. Lugli Agrunii, 1887. 
 
 =«8 Scribner, F. L., Torr. Bull. 13: 181, 1886. 
 
 2«9 Fawcett, Fla. R. 42, 1909. 
 
 =»« Fawcett, Fla. R. 46, 1907. 
 
 291 Fawcett, Mycologia, 2: 245, 1910. 
 
 292 Chester, F. D., Del. R. 8: 60, 1895. 
 
 293 Pammel, L. H., la. B. 23: 919, 1893. 
 29" Sturgis, W. C, Ct. R. 20: 269, 1896. 
 295 Johnson, E. C, Sc. 31: 792, 1910. 
 
 299 Johnson, E. C, Phytopy. 1: 1911. 
 
 297 Farraris, T., Ann. Myc. 7: 283, 1909. 
 
 298 Orton, W. A., Sc. 21: 503, 1905. 
 
 299 Trelease,"W., D. Agr. R. 129, 1886. 
 
 300 Prillieux and Delacroix, B. S. M. Fr. 7; 218. 
 
 301 Butler, 0., Ann. Bot. 25: 130, 1911. 
 
 3«2 Aderhold, R., Arb. d. biol. Abt. f. land, u for. Gesund II, 519, 1902. 
 3«3 Karchner, 0., Zeit. 2: 324, 1892. 
 ^"^ Sorauer, P., Zeit. 8: 283, 1898. 
 
 305 Bos. J. R., Zeit. 13: 87, 1903. 
 
 306 Reed, H. S. and Cooley, J. S., Va. R. 78, 1911. 
 
 307 Pammel, L. H., King, C. M. and Bakke, A. L., la. B. 116: 1910. 
 
 308 Harvey, F. L., Me. R. 95, 1894. 
 
 309 Thaxter, R., Ct. R. 1889. 
 
 310 Johnson, T., Econ. Proc. Roy. Dublin Soc. 1: 345, 1907. 
 
 311 Appel and Laubert, Ber. d. deut. Bot Ges. 23: 218, 1905. 
 
 312 Chnton, G. P., Ct. State R. 357, 1907. 
 
 313 Aderhold, Zeit. 6: 72, 1896. 
 
 3" Aderhold, R., Arb. K. Ges. Biol. Ab. 3: 439. 
 
 315 Jensen, C. N. and Stewart, V. B., Phyto. 1: 120, 1911. 
 
 318 Patterson, F. W., Torrey Bull. 37: 205, 1910. 
 
 317 Thaxter, R., Ct. R. 13: 158, 1889. 
 
 318 Miyake, Ann. Bot. 3: 1889. 
 
674 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 3" Sturgis, W. C, Ct. R. 20: 276, 1896. 
 
 320 Collinge, W. E., R. I. Econ. Biol. Birmingham. • 
 
 '21 Walkoff, K., Zeit. 12: 283, 1902. 
 
 '" Atkinson, G. F., Bot. Gaz. 16: 62, 1891. 
 
 '23 Griffin, H. H., Col. B. 62: 1901. 
 
 "" Ga. R., 351, 1900. 
 
 '" New South Wales Dept. Agric. Rept. 1893. 
 
 328 Harter, L. L., Mycologia 3: 154. 
 
 '" Sturgis, W. C., Ct. R. 19: 186, 1895. 
 
 328 Behrens, J., Zeit. 2: 327, 1892. 
 
 329 Dorsett, P. H., V. P. P. B. 23: 1900. 
 "« Halsted, B. D., N. J. B. 76: 1890. 
 
 331 Stevens, F. L. and Hall, J. G., Bot. Gaz. 47: 409, 1909. 
 
 332 Rolfs, P. H., Fla. B. 47: 124, 1898. 
 
 333 Jones, L. R., Vt. B. 72: 16, 1899. 
 
 334 Jones, L. R. Vt. R. 10: 45, 1896. 
 
 335 Jones, L. R. Vt. R. 9: 79. 
 
 336 Galloway, B. T., Agric. Science 7: 377, 1893. 
 
 337 Brocq-Rousseau, D., B. Soc. Nat. Agr. France, 67: 271. 
 
 338 Jones, L. R., and Grant, Bull. Tor. Bot. Club, 24: 257, 1897. 
 33^ Barre, H. W., S. C. B. 153: 1910. 
 
 '"o Fawcett, H. S., Fla. B. 106: 1911. 
 
 3" Beach, S. A., N. Y. (Geneva) B. 125: 1897. 
 
 342 Bioletti, F. T., Cal. R. 235, 1895. 
 
 3" Pierce, N. B., Myc. 7: 66, 232, 1892. 
 
 344 Earle, F. S., Div. Pom. B. 5: 27, 1897. 
 
 3« Jones, L. R. and Morse, W. T., Vt. R. 18: 271, 1905. 
 
 346 Bubak, F., Ber. d. deut. Bot. Gez. 28: 533, 1910. 
 
 347 Lagerheim, G. and Wagner, G., Handloch Tid. 426, 1903. 
 
 348 Sturgis, W. C, Ct. R. 20: 273, 1896. 
 
 349 Tyron, H., Rept. Dept. Agric. and Stock. Queensland 89: 1907. 
 
 350 Atkinson, G. F., N. Y. (Cornell) B. 49: 314, 1892. 
 3" Scribner, F. L., U. S. D. Agr. R. 117, 1886. 
 
 3" Duggar, B. M., N. Y. (Cornell) B. 163: 352, 1899. 
 
 3" Selby, A. D., 0. B. 105: 232, 1899. 
 
 354 Raciborski, M., Zeit. 8: 66, 1898. 
 
 3" Chester, F. D., Del. R. 95, 1889. 
 
 35^ Fairchild, D. G., U. S. D. Ag. R. 429, 1889. 
 
 3" Halsted, B. D., N. J. R. 397, 1896. 
 
 358 Atkinson, G. F., Am. Flor. 8: 723, 1893. 
 
 359 Zimmermann, A., C. Bak. 8: 221, 1902. 
 
BIBLIOGRAPHY OF FUNGI IMPERFECTI 675 
 
 MO McAlpine, D., J. Dept. Agr. Victoria, 801, 1902. 
 "1 Edgerton, C. W., Phytop. 1: 12, 1911. 
 "2 Marchal, E., Bui. Agr. Brussels 17: 4. 
 303 Zimmerman, A., C. Bak. 7: 145, 1901. 
 3" Massee, G., Kew Bui. 19, 1898. 
 3«5 Sheldon, J. L., Torreya 8: 141, 1908. 
 '«« South, F. W., W. Ind. B. 11: 83, 1911. 
 =>" Stevens, F. L., and Hall, J. G., J. Myc. 13: 94, 1907. 
 '*^ Appel and Wallenweber, Arb. d. Kais. Biol. Ans. f. Land. u. Frst. 8: 
 Heft 1. 
 
 ="'3 Cook, M. T., Sc. 31: 751, 1910. 
 
 ^'^ Aderhold, Zeit. 11: 65, 1901. 
 
 "1 Aderhold, R., C. Bak. 5: 523, 1899. 
 
 3" Pound and Clements, Neb. Bot. Sur. 3: 12, 1893. 
 
 ='' Cook, M. T., Del. Bull. 93: 1911. 
 
 "^ Osterwalder, A., C. Bak. 13: 207, 1904. 
 
 "5 Morse, W. T. and Lewis, C. E., Maine B. 185: 1910. 
 
 3™ Smith, E. F., Sc. 31: 755, 1910. 
 
 "^ Briosi, Att. d. R. Acad. d. Lincei Roma Ser. 2: 3. 
 
 "8 Proc. W. N. Y. Hort. Soc. 43: 9, 1898. 
 
 "9 Sheldon, J. L., Neb. R. 23, 1904. 
 
 '80 Smith, E. F., V. P. P. B. 17: 1899. 
 
 '81 Atkinson, G. F., Ala. B. 4I: 19, 1892. 
 
 '82 Orton, W. A., V. P. P. B. 27: 1900. 
 
 '8' Higgins, B. B., N. C. R. 32: 100, 1909. 
 
 '84 Chester, F. D., Del. R. 5.- 89, 1890. 
 
 '85 Detmers, F., Ohio B. 44: 147, 1892. 
 
 '89 von Hall, Ber. deut. Bot. Gez. 21: 2. 
 
 '87 Schikorra, G., Diss. 1906. 
 
 '88 Butler, Mem. Dept. Agr. India,^Bot. Ser. 2: 9, 1910. 
 
 '89 Smith, E. F., Proc. A. A. A. S. 190, 1895. 
 
 '«» Smith, E. F., Proc. A. A. A. S. 43: 289, 1894. 
 
 '91 Bubak, Fr., Ber. d. deut. Bot. Ges. 29: 73. 
 
 '" Smith, R. E., Mass, B. 79, and Mass. R. 57, 1902. 
 
 '" Reed, H. S., Sc. 23: 751, 1906. 
 
 »94 Stone, G. E., and Smith, R. E., Mas. B. 69: 1900. 
 
 '« Manns, T. F., 0. B. 229: 1911. 
 
 89« Smith, E. F. and Swingle, D. B., B. P. I. B. 55: 1904. 
 
 '" Stewart, F. C, N. Y. (Geneva) B. 101: 85, 1896. 
 
 '=8 Wehmer, C, C. Bak. 3: 727, 1897. 
 
 '5^ Clinton, G. P., 111. B. 4O: 139, 1895. 
 
676 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 «o Oven., Lanchv. Jahr. 3J^: 489, 1905. 
 
 401 Massee, Gard. Chron. Ser. 3: 17, 707. 
 
 «2 Smith, R. E., Cal. B. 175: 8, 1906. 
 
 «3 Bolley, H. L., N. D. B. 50: 1901. 
 
 «4 Harter, L. L., Sc. 30: 934, 1910. 
 
 «5 Ostervvalder, A., Land. Jahr. Schw. 2 4: 247. 
 
 «« Galloway, B. T., Amer. Gard. 17: 518, 1896. 
 
 4«' Smith, R. E., Mass. B. 79: 1902. 
 
 «8 Stewart, F. C., N. Y. (Geneva) B. m: 219, 1899. 
 
 ^"^Sturgis, W. C, Ct. R. 21: lib, 1897. 
 
 41" Chifflat, J., Jour. Soc. Nat. Hort. France, 4: Ser. 8, 348. 
 
 411 Pollock, J. B., Sc. 31: 638, 1910. 
 
 412 Prillieux and Delacroix, C. R. 131: 961, 1900. 
 
 413 N. S. R. Wales, 93. 
 
 414 Doherty, M. W., Bot. Gaz. 30: 400, 1900. 
 
 415 Rept. Mo. Bot. Gard. 9: 159, 1898. 
 4iSSci. ;4.-899, 1901. 
 
 4'^ Duggar, B. M., N. Y. (Cornell) B. 163, 1899. 
 418 Stone and Smith, Mass. R. 67: 1897. 
 413 Heald, F. D., Phytop. 1: 103, 1911. 
 
 420 Gussow, H. T., Zeit. 16: 135, 1906. 
 
 421 Stevens, F. L. and Wilson, W. G., Sc. 33: 943, 1911. 
 
 422 Scholz, E., Verh. K. K. Zool. Bot. Ges. Wien, 47: 541. 
 
 423 Selby, A. D., 0. B. 92. 
 
 424 Bertoni, W. S., Rev. Agr. Cien. Apt. Paraguay 1: 211. 
 
 425 Earle, F. S., Ala. B. 108: 1900. 
 420 Stout, A. B., Sc. 33: 156, 1911. 
 
 427 Klebahn, H., Jahr. d. Hamb. Wiss. Ans. 22. 
 
 428 Shear, C. L., Bull. Tor. Bot. Club 3^: 305, 1907. 
 
 429 Atkinson, G. F., Bot. Gaz. 18: 16, 1893. 
 43oPammel, L. H., Tex. R. 2: 61, 1889. 
 
 431 Pammel, L. H., B. Tex. 4: 1888. 
 
 432 Shear, C. L. and Miles, G. F., B. P. I. B. 102: 39, 1907. 
 
 433 Galloway, B. T., and Woods, A. F., Y. B. 248, 1896. 
 
 434 Stewart, F. C. and Blodgett, F. H., N. Y. (Geneva) B. 167: 283. 
 
 435 Johnston, T. H., Agr. Gaz. N. S. Wales 21: 563. 
 
 436 Stevens, F. L. and Hall, J. G., N. C. R. 31: 72, 1909. 
 
 437 Swingle, W. T., and Webber, H. J., V. P. P. B. 8: 32, 1896. 
 "8 Fulton, H. R., La. B. 101: 1908. 
 
 «» Porto Rico R. U9: 1903. 
 
 440 Arthur, J. C, N. Y. (Geneva) R. 4: 250, 1885. 
 
BIBLIOGRAPHY OF FUNGI IMPERFECTl 677 
 
 "> Laubert, R., Gartenflora 59: 409, 1910. 
 ^^2 Chester, F. D. Del, 6:111, 1893. 
 ^" Peck, N. Y. St. Mus. Nat. Hist. B. 137: 21. 
 "^ Bot. Gaz. 54: 231. 
 ^^5 Sc. 37: 638. 
 
 ^« Cordley, Ore. Sta. Bienn. Crop. Kept. & Hort. R. 1911-12, 187: 
 1913. 
 
 ^" Stone, Ann. Myc. 10: 564, also Melhus, Phytop. 3: 56. 
 
 ^^8 Stewart, F. C. N. Y. (Geneva) B. 328, 387. 
 
 ^" Ann. Myc. 10: 491. 
 
 «« Gussow, Canada Exp. Farms. R. 1912, 202. 
 
 "1 Ann. Myc. 6: 112. 
 
 4^2 Peck, N. Y. Mus. R. S^; 41. 
 
 «3 Chester, F. D., Del. B. 70: 13. 
 
 «4 Gussow, Zeit. 16: 10. 
 
 <" Heald, F. D., Mycol. 1: 215, 1909. 
 
 «« Wehmer, C, C. Bak. 5; 646, 1897. 
 
 "^ Percival, J., Jour. Southeast Agr. Col. Wye, 81: 1902. 
 
 «8 Chifflat, J., Jour. Soc. Nat. Hort. France, Ser. 4, 8, 348. 
 
 «« Arthur, J. C, Ind. B. 19: 5, 1889. 
 
SOME OF THE MOST USEFUL BOOKS 
 
 1. Buller Researches on Fungi. 
 
 2. A. De Bary: Comparative Morphology & Biology of the Fungi Myce- 
 
 tozoa & Bacteria. Clarendon Press, 1887. 
 
 3. G. Delacroix and A. Maublanc: Maladies des Plantes Cultiv^es. 
 
 J. B. BailUere & Fils, 1909. 
 
 4. Ducomet: Pathologie Veg^tale, Chas. Amat, 1908. 
 
 5. B. M. Duggar, Fungous Diseases of Plants. Ginn & Co., 1909. 
 
 6. A. Engler: Syllabus der Pflanzcnfamilicn, Gebriider Borntrseger, 
 
 1907. 
 
 7. Engler and Prant: Natlirliche Pflanzenfamihen, Wm. Engelmann, 
 
 1897. 
 
 8. W. G. Farlow: BibUographical Index to N, American Fungi, Car- 
 
 negie Inst, of Washington, 1905. 
 
 9. Farlow & Seymour: Host Index of the Fungi of the U. S., Cambridge, 
 
 1888. 
 
 10. A. B. Frank: Die Pilzparasitaren Krankheiten der Pflanzen. Ed. 
 
 Trewendt, 1896. 
 
 11. E. M. Freeman: Minnesota Plant Diseases, Pioneer Press, 1905. 
 
 12. K. Goebel: Outlines of Classification & Special Morphology of Plants, 
 
 Clarendon Press, 1887. 
 
 13. R. Hartig: The Diseases of Trees. 
 
 14. R. Hartig: Lehrbuch d. Pflanzenkrankheiten, JuHus Springer, 1900. 
 
 15. Ideta: Text-book of Plant Diseases, Japanese. 
 
 16. 0. Kirchner: Die Krankheiten und Beschadigungen unserer land- 
 
 wirtschaftUchen Kulturpflanzen. Eugen Ulmer, 1906. 
 
 17. Ernst Kuster: Pathologische Pflanzenanatomie, Gustav Fischer, 
 
 1903. 
 
 18. Franz Lafar: Handbuch d. Technischen Mykologie, Gustav Fischer, 
 
 1904-1907. 
 
 19. Lindau in P. Sorauer: Handbuch d. Pflanzenkrankheiten. Paul 
 
 Parey, 1908. 
 
 20. Lindau and Sydow, Thesaurus Literaturse Mycologicse. 
 
 21. Lotsy: Vortrage tiber botanische Stammesgeschichte, Gustav Fischer, 
 
 1907. 
 
 678 
 
SOME OF THE MOST USEFUL BOOKS G79 
 
 22. Geo. Massee: Diseases of Cultivated Plants and Trees. Duckworth & 
 
 Co., 1910. 
 
 23. Geo. Massee: Text-book of Fungi, Duckworth & Co., 1906. 
 
 24. E. Prillieux: Maladies des plantes agricoles. 
 
 25. P. A. Saccardo: Sylloge Fungorum, Pa via; R. Friedlander & Sohn 
 
 1882. 
 
 26. Stevens and Hall: Diseases of Economic Plants, Macmillan Co., 1910. 
 
 27. Tubeuf and Smith: Diseases of Plants Induced by Cryptogamic 
 
 Parasites, Longmans, Green & Co., 1897. 
 
 28. L. M. Underwood: Moulds, Mildews and Mushrooms. Henry Holt & 
 
 Co., 1899. 
 
 29. H. Marshall Ward: Disease in Plants. Macmillan & Co., 1901. 
 
 30. Strasburger, Noll, Schenck and Karsten: Text-book of Botany, 1908. 
 
 31. F. D. Chester: Manual of Determinative Bacteriology. Macmillan & 
 
 Co., 1901. 
 
 32. H. W. Conn: Agricultural Bacteriology. P. Blakiston's Son & Co., 
 
 1909. 
 
 33. A. Fischer: Vorlesungen ueber Bakterien, Gustav Fischer, 1903. 
 
 34. C. Flugge: Die Mikroorganismen. F. C. W. Vogel, 1896. 
 
 35. E. 0. Jordan: General Bacteriology. W. B. Saunders Co., 1908. 
 
 36. J. G. Lipman: Bacteria in Relation to Country Life. Macmillan & 
 
 Co., 1908. 
 
 37. W. Migula: System der Bakterien. Gustav Fischer, 1897. 
 
 38. Miquel et Cambier: Traits de Bacteriologie Pure et Appliqu6e. 
 
 Masson et Cie, 1902. 
 
 39. E. F, Smith: Bacteria in Relation to Plant Diseases. Carnegie In- 
 
 stitution, Sept., 1905. 
 
 40. A. Lister: The Mycetozoa, 1895. 
 
 41. Geo. Massee: Monograph of the Myxogastres, 1892. 
 
 42. H. Macbride: North American Slime-Moulds. Macmillan, 1899. 
 
 43. Rostafinski: Sluzowce Monografia, 1875. 
 
 44. Torrend: Les Myxomyc6tes. Brotevia 7: 5, 177; pi. 1-9, also sepa- 
 
 rate, 1908. 
 
 45. Plowright, British Uredinese & Ustilaginese. 
 
 46. Salmon, Monograph of the Erysiphacese. 
 
 47. Clinton, G. P., North American Flora, Ustilaginales. 
 
 48. Murrill, W. A., North American Flora, Polyporacese, etc. 
 
 49. Arthur, J. C, North American Flora, Urediniales. 
 
 50. Atkinson, G. F., Mushrooms. 
 
 51. Clements, The Genera of Fungi. 
 
 52. Ellis and Everhart, North American Pyrenomycetes. 
 
680 THE FUNGI WHICH CAUSE PLANT DISEASE 
 
 '53. Rabenhorst, Kryptogamen Flora von Deutschland. 
 64. Bancroft, K., Handbook of the Fungous Diseases of West Indian 
 Plants, 1910. 
 
 55. Hartig, The Diseases of Trees, Trans, by Sommerville. 
 
 56. McAlpine, Rusts of AustraUa. 
 
 57. Jaczewski, A. A., Phytopathology (Russian). 
 
 58. Noel Deer: Sugar Cane. Norman Rodger, Manchester, 1911. 
 
 59. Klebahn, H., Die Wirtwechselnden Rostpilze, 1894 
 
 60. Sydow, Monographia Uredinearum, 1904. 
 
 61. Holway, E. W. D., North American Uredineee, 1905. 
 
 62. Seaver, North American Flora, 3: Pt 1. 
 
 63. Viala, R., Les Maladies de la Vigne. 
 
 64. P. Harlot, Les Uredin^es, Paris, 1908. 
 
 Periodicals of use to the Phytopathologist 
 
 Phjiiopathology. 
 
 Annales Mycologici. 
 
 Centralblatt fur Bakteriologie U. Paristenkunde II. Abt. 
 
 HoUrung's Jahresbericht u. d. Gebeit der Pflanzenkrankheiten. 
 
 ■Experiment Station Record. 
 
 Zeitschrift fiir Pflanzenkrankheiten. 
 
 Rivista di Patologia vegetale. 
 
 Hedwigia. ' 
 
 Mycologia, formerly Journal of Mycology. 
 
 Practische Blatter fiir Pflanzenschutz. 
 
 Just's Botanischer Jahresbericht. 
 
 Bulletin Trimestriel de la Societie Mycologique de France. 
 
 For Bibhographies of special articles, see pages 53, 109, 288, 466, 666. 
 
GLOSSARY 
 
 A, privative. Signifying without. 
 
 Acervulus (i). A small cluster, tuft of mycelium bearing spores. 
 
 Acicular. Slender or needle-shaped. 
 
 Acrogenous. Growing at the apex. 
 
 Acropetal. Produced in a succession towards the apex. 
 
 Adnata. Attached the whole length. 
 
 ^ciospore. .fficidiospore. A spore formed in an secium. 
 
 JEciuta (a), .fficidum (a). A special form of sorus in the Uridinales. 
 
 Aerial. Living above the surface of the ground or water. 
 
 Aerobic. ASrobiotic. Requiring oxygen. 
 
 .ZEthalioid. Like an sethalium. 
 
 .^thalium (a). A compound sporiferous body formed from a large 
 combination of plasmodia. 
 
 Agglutinated. Agglutinate. Glued together. 
 
 Aggregated. Aggregate. Collected together. 
 
 AUantoid. Sausage-shaped, crescent-shaped with rounded ends. 
 
 Alveola (ae). Cavities or pits on the surface. Alveolate. Pitted like 
 a honeycomb. Alveolar. Pertaining to or resembling Alveolae. 
 
 Amoeboid. Like an amoeba, exhibiting creeping movement by pseudo- 
 podia. 
 
 Amorphous. Shapeless. 
 
 Amphigenous. Growing all round an object, not restricted to any par- 
 ticular surface. 
 
 AmpuUiform. Swollen out. Flask-shape. 
 
 Anastomosing. Uniting and forming a network. 
 
 Angiocarpous. Invested by some covering. 
 
 Annulate. Ring-shaped or with a ring. 
 
 Annulus. A ring-like portion of the ruptured marginal veil, after the 
 expansion of the pileus. 
 
 Anoderm. Without a skin. 
 
 Antheridium (a). In fungi the male sexual organ. 
 
 Apical. At the point of any structure. 
 
 Apicula. A sharp and short, but not stiff point. 
 
 681 
 
682 GLOSSARY 
 
 Apogamous. Showing apogamy. 
 
 Apothecium (a). An ascocarp in which the hymenium lies exposed 
 while the asci are maturing. 
 
 Appendages. Processes of any kind. 
 
 Appendiculate. Furnished with appendages. 
 
 Appiculate. Furnished with an appicula. 
 
 Appressed. Lying flat for the whole length. 
 
 Appresoria. Organs of attachment of germinating parasites. 
 
 Approximate. Close together, but not united. 
 
 Arachnoid. Like a cobweb. 
 
 Arcuate. Curved. 
 
 Areola (ae). A space marked out on a surface. 
 
 Aristate. Awned. 
 
 Armilla. A bracelet-like frill. 
 
 Armilla-form. Armilla-like. 
 
 Ascigerous. Bearing asci. 
 
 Ascocarp. A sporocarp producing asci. 
 
 Ascogenous. Producing asci. 
 
 Ascogonium. In ascomycetous fungi, the cell or group of cells fer- 
 tilized by a sexual act. 
 
 Ascoma. Receptacle and hymenium of the larger fungi. 
 
 Ascopla§m. Protoplasm of the ascus. 
 
 Ascus (i). A large cell in the ascocarp in which spores are developed, 
 usually eight. 
 
 Aseptate. Without cross-divisions. 
 
 Asexual. Destitute of male and female organs. 
 
 Asperate. Rough with hairs or points 
 
 Attenuate. Tapered. 
 
 Auriform. Ear-shaped. 
 
 Autoecious. A parasite which runs its whole course on a single host. 
 
 Avellaneous. Drab, hazel, hazel-nut-brown. 
 
 B 
 
 Bacillar. Bacilliform. Rod- or club-shaped. 
 
 Basal. At the base of. 
 
 Basidiospore. A spore acrogenously abjointed upon a basidium. 
 
 Basidium. The mother-cell from which spores are acrogenously 
 
 abjointed. 
 Basipetal. Growth in the direction of the base. 
 Bay. Reddish brown or chestnut color. 
 Biogenous. Growing on living organisms. 
 
GLOSSARY 683 
 
 Botryose. Racemose. 
 BuUate. Blistered or puckered. 
 Byssoid. Flax-like or cottony. 
 
 Calcareous. Chalk-white, chalky. 
 
 Campanulate. Bell-shaped. 
 
 Cancellate. Latticed, as in Clathrus. 
 
 Capillitium. Sterile thread-like tubes or fibers, mixed with the spores 
 
 within a sporangium. 
 Capitate. Having a head. 
 Carbonous. Carbonaceous. Dark colored. Consisting chiefly of sul> 
 
 stances in which carbon predominates. 
 Carpogonium (a). Part of a procarp resulting in a sporocarp after 
 
 fertilization. 
 Cartilagenous. Hard and tough. 
 Castaneous. Chestnut-colored. 
 Catenulate. Concatenate. Formed of parts united or linked as in 
 
 a chain. 
 Caulicolous. Living on stems. 
 Cespitose. Growing in tufts. 
 
 Chlamydospore. A spore having a very thick membrance. 
 Chromogenesis. Color production. 
 Chromogenic. Chromogenous. Color-producing. 
 Ciliate. Fringed with hairs. 
 Cilium (a). Vibratile whip-like processes of protoplasm by which 
 
 zoospores and similar bodies move. 
 Cinereous. Cineraceous. Ashy. 
 
 Circinate. Circinnate. Coiled into a ring or partially so. 
 Circumscissile. Dehiscing as if cut circularly around. 
 Cirrhose. Cirrose. Cirrhous. Having a cirrhus or tendril. 
 Clathrate. Latticed. 
 
 Clavate. Club-shaped, thickened towards the apex. 
 Clypeate. Buckler or shield-shaped, having a clypeus. 
 Clypeus. A buckler or shield-shaped tissue around the mouth of a 
 
 perithecium. 
 Ccenocyte. A multinucleate cell. 
 Collabent. Collapsing. 
 CoUiculose. With little round elevations. 
 Columella. Sterile axile body within a sporangium. 
 
684 GLOSSARY 
 
 Columnar. Having the form of a column. 
 
 Compound. Similar parts aggregated into a common whole. 
 
 Con or Com. In Latin compounds signifying with. 
 
 Conchate. Shell-shaped. 
 
 Concolorous. Of one color. 
 
 Confluent. Blended into one. 
 
 Conglobate. Collected into a ball. 
 
 Conidiophore. A sporophore bearmg a conidium. 
 
 Conidiospore. Same as conidium. 
 
 Conidium (a). Dust-like spores usually produced directly from the 
 
 hypha3. 
 Conjugation. Union of two like gametes to form a zygote. 
 Connate. United. 
 
 Constricted. Drawn together; contracted. 
 Context. The flesh of a mushroom and the corresponding substance in 
 
 other pileate fungi. 
 Continuous. The reverse of interrupted. 
 Convoluted. Convolute. Rolled round. 
 Coremium. The name of a genus of fungi, derived from a Greek word 
 
 meaning broom. 
 Coriaceous. Leathery. 
 Corneous. Of horny texture. 
 Cortex. The bark or rind. The peridium of Fungi. 
 Cortical. Relating to the cortex. 
 Costate. Ribbed. 
 
 Crateriform. Globet or cup-shaped. 
 Cristate. Crested. 
 Cruciate. Cross-shaped. 
 Crustose. Crust-like. 
 Cuboid. Resembling a cube. 
 Cupulate. With a cupule. 
 Cupuliform. Shaped like a small cup. 
 Cuticle. The outermost skin. 
 Cuticulate. Having a cuticle. 
 
 Cylindric. Cylindrical. Elongated, with a circular cross-section. 
 Cyme. Cluster of determinate or centrifugal type, especially a broad 
 
 and flattened one. 
 Cyst. A sac or cavity. 
 Cystidium (a). Large, one-celled, sometimes inflated bodies, projecting 
 
 beyond the basidia and paraphyses of the hymenium of Agarics. 
 Cytolitic. A ferment which dissolves the cell-wall. 
 
GLOSSARY 685 
 
 Deciduous. Falling in season. 
 
 Decumbent. Reclining with the summit ascending. 
 
 Decurrent. Running down. 
 
 Definite. Precise; of a certain number. 
 
 Dehiscence. The mode of opening. 
 
 Deliquescent. Dissolving or melting away. 
 
 Dendritic. Having a branched apiDearance. 
 
 Dendroid. Tree-like in form, or branching. 
 
 Denticulate. Minutely toothed. 
 
 Depressed. Sunk down, flattened. 
 
 Determinate. Definite. 
 
 Di. Two or double. 
 
 Dichotomous. Forked. 
 
 Dichotomy. Forking in pairs. 
 
 Difiform. Of double form, irregular. 
 
 Diffuse. Widely or loosely spreading. 
 
 Digitate. Fingered: compound. As in the Horse Chestnut leaf. 
 
 Dimidiate. Halved, as when half an organ is so much smaller than the 
 
 other as to seem wanting. 
 Disciform. Flat and circular. 
 Discoid. Resembling a disk. 
 Disculate. Having a disk. 
 
 Dis junctors. Spindle-shaped cellulose connections between conidia. 
 Dissepiment. A partition. 
 Doliform. Barrel-shaped. 
 
 E, Ex. Privative in Latin compounds. 
 
 Echinulate. Having small prickles. 
 
 Efifuse. Expanded. 
 
 Ellipsoid. ElUpsoidal. Elliptic. Like an ellipse. 
 
 Embedded. Surrounded in. 
 
 Endogenous. Produced within. 
 
 Endophyte. Growing inside another plant. 
 
 Endophytic. As an endophyte. 
 
 Endospores. Spores formed endogenously. 
 
 Endozoic. Living inside an animal. 
 
 Entire. With even margin. 
 
686 GLOSSARY 
 
 Entomogenous. On insects. 
 
 Enzyme. An unorganized or soluble ferment. 
 
 Epi. In Greek compoimds to mean " upon ". 
 
 Epiphyllous. Growing on leaves. 
 
 Epispore. Outer coat of a spore. 
 
 Epithecium. The surface of the fructifying disk. 
 
 Epixylous. Growing on wood. 
 
 Erumpent. Breaking through. 
 
 Evanescent. Soon disappearing. 
 
 Excipuliform. Wart-like. 
 
 Exospore. The outer covering of the spore. 
 
 Explanate. Spread out flat. 
 
 Exserted. Protruding beyond. 
 
 F 
 
 Facultative. Occasional, incidental as opposed to obligate. 
 
 Falcate. Sickle-shaped. 
 
 Fascicle. A little bimdle. 
 
 Fasciculate. In clusters or bundles. 
 
 Favoid. Like a honeycomb. 
 
 Ferruginous. Ferrugenous. Ferrugineous. Rust-colored. 
 
 Fibrinous. Fibrillose. Furnished with fibers. 
 
 Filamentous. Of free hyphse which are at most loosely interwoven 
 
 but without forming bodies of definite shape and outline. 
 Filiform. Thread-shaped. 
 
 Fimbriate. With the margin bordered by long slender processes. 
 Fission. Splitting. 
 Flabellifonn. Shaped as a fan. 
 Flaccid. Limp, flabby. 
 
 Flagellate. Provided with whip-like processes. 
 Flagellum (a). Whip-like process of protoplasm of a swarmspore. 
 Flavous. Nearly pure yellow. 
 Fleshy. Succulent. 
 
 Flexuose. Flexuous. Bent alternately in opposite directions, zigzag. 
 Flocci. Locks Uke soft hair or wool. 
 Floccose. Bearing flocci. 
 Flocculent. Diminutive of Floccose. 
 Fluorescence. The property of diminishing refrangibility. 
 Fluorescent. Exhibiting fluorescence. 
 Foetid. Fetid, stinking. 
 
GLOSSARY 687 
 
 Foliar. Leafy or leaf-like. On a leaf. 
 
 Foliicolous. On leaves. 
 
 Free. Not adhering. 
 
 Fructicolous. Living on fruit. 
 
 Fruticolous. Living on shrubs. 
 
 Fruticose. Shrubby. 
 
 Fugacious. Soon perishing. 
 
 Fuligineus. Fuliginous. Sooty, or soot-colored. 
 
 Fulvous. Yellow, tawny. 
 
 Fumaginous. Smoky; sooty. 
 
 Furcate. Forked. 
 
 Fuscous. Dusky, too brown for a gray. 
 
 Fusiform. Thick but tapering towards each end. 
 
 Fusoid. Somewhat fusiform. 
 
 Gametangium (a). A differentiated cavity, which produces gametes. 
 
 Gamete. A sexual protoplasmic body. 
 
 Gemma (ae). A young bud. 
 
 Gemmation. Budding. 
 
 Gemmiform. Bud-shaped. 
 
 Gill. The plates or lamella? of an Agaric. 
 
 Glabrous. Without hair. 
 
 Gleba. The gelatinous spore mass in the Phallales. 
 
 Globoid. Rounded. 
 
 Globose. Nearly spherical. 
 
 Glomerate. Agglomerate, collected into heads. 
 
 Granular. Composed of grains. 
 
 Gregarious. Growing in company. Associated but not matted. 
 
 Guttulate. Resembling drops, with drops. 
 
 Gymnocarpous. Naked fruited. 
 
 Gyrose. Curved backward and forward in turn. 
 
 Hamate. Hooked at the tip. 
 
 Haustorium (a). Special branch of a filamentous mycelium serving 
 
 as an organ of attachment and suction. 
 Hetercecism. Condition of a heteroecious parasite. 
 Hetercecious. Passing its stages on more than one host. 
 Heterogamy. With gametes not uniform. 
 
688 GLOSSARY 
 
 Heteromorphic. Heteromorphous. Variation from normal structure, 
 as liaving organs differing in length; dimorphic, 
 
 Hirtose. Hirtus. Hairy; hirsute. 
 
 Hispid. Bristly. 
 
 Hoary. Gray from fine pubescence. 
 
 Host. A plant which nourishes a parasite. 
 
 Hyaline. Colorless or translucent. 
 
 Hyaloplasm. The hyaline matrix or clear non-granular portion of pro- 
 toplasm. 
 
 Hymenium (a). An aggregation of spore mother-cells in a continuous 
 layer on a sporophore. 
 
 Hymenophore. That part which bears the hymenium. 
 
 Hypha (ae). The thread-like vegetative part of a fungus. 
 
 Hyphoid. Resembling hyphae. 
 
 Hypertrophy. An abnormal enlargement of an organ. 
 
 Hypophyllous. Situated under a leaf. 
 
 Hypopodium (a). The stalk or support. 
 
 Hypothallus. The marginal outgrowth of hyphae often strand-like, 
 from the thallus. 
 
 Hypothecium. A layer of hyphal tissue immediately beneath the 
 hymenium. 
 
 Hysterioid. Elongated boat-shaped, resembling the genus Hysterium. 
 
 I, n, HI. Symbols for the stages of the rusts, see p. 324, 326. 
 
 Imbricate. Overlapping as the tiles on a roof. 
 
 Immersed. Below the surface. 
 
 Imperforate. Without an opening. 
 
 Incrassation. Thickened growth. 
 
 Indehiscent. Not opening along regular lines. 
 
 Indeterminate. Not terminated definitely. 
 
 Indurate. Hardened. 
 
 Infundibuliform. Shaped like a funnel. 
 
 Innate. Born on the apex of the support. Imbedded. 
 
 Intercalary. Growth which is not apical but between the apex and the 
 
 base. 
 Intercellular. Between cells. 
 Intracellular. Inside a cell. 
 Intramycelial. Within the mycelium. 
 
 Involute. Enwrapped, having the edges of the leaves rolled inwards. 
 Irpiciform. Having teeth resembling those in Irpex. 
 
GLOSSARY G89 
 
 Isabelline. A dirty tawny tint. 
 
 Isogamous. Used for those plants which produce like gametes. 
 
 Isogamy. Conjugation of two gametes of similar form. 
 
 Keeled. Carinate. 
 
 Labyrinthiform. Marked by sinuous lines. 
 Lacerate. Torn, or irregularly cleft. 
 Lactiferous. Latex bearing. 
 Lamella (ae). The gills of Agaricales. 
 Lamellate. Made up of thin plates. 
 Lamelliform. In the shape of a plate or scale. 
 Lamelloid. Resembling lamellse. 
 Lageniform. Shaped like a Florence flask. 
 Lanceolate. Narrow, tapering to each end. 
 Latericious. Lateritious. Brick-red. 
 Latticed. Cross-barred. 
 Lax. Loose, distant. 
 
 Lenticular. Shaped like a double convex lens. 
 Lichenoid. Irregularly lobed as lichens. 
 Lignicole. Growing on wood. 
 Limonifonn. Lemon-shaped. 
 Linear. Narrow, several times longer than wide. 
 Lipochrome. A yellow pigment. 
 Lobate. Lobed. Divided into or bearing lobes. 
 Locule. Loculus. A cell or cavity. 
 
 Lumen. The space which is bounded by the walls of an organ, as the 
 central cavity of a cell. 
 
 M 
 
 Macro. Mega. In Greek compounds to signify large. 
 Maculicole. On spots. 
 Mammiform. Breast-shaped. 
 
 Marginate. Broad-brimmed, furnished with a margin of distinct char- 
 acter. 
 Matrix. The body on which a Fungus or Lichen grows. 
 Malleus. Melleous. Like honey. 
 
690 GLOSSARY 
 
 Membranous. Membranaceous. Thin and semi-transparent, like a 
 fine membrance. 
 
 Medullary. Relating to the pith, pithy. 
 
 Micro. To signify small, little. 
 
 Microsporangium (a). A sporangium which produces microspores. 
 
 Mon. In Greek compounds to signify one. 
 
 Monopodium (a). An axis which continues to grow at the apex in 
 the direction of previous growth, while lateral structures of like 
 kind are produced beneath it in acropetal succession. 
 
 Monosporic. Bearing one spore. 
 
 Monostichous. In a single vertical row. 
 
 Mucose. Slimy. 
 
 Multi. A Latin element signifying many or much. 
 
 Muricate. Rough with short hard excrescences. 
 
 Muriculate. Diminutive of Muricate. 
 
 Muriform. With cells resembling bricks in a wall, with both longitudi- 
 nal and transverse septa. 
 
 Muticous. Muticate. Pointless, blunt. 
 
 Mycelium. Vegetative portion of thallus of fungi composed of one or 
 more hyphse. 
 
 Myxamoeba (ae). Swarm-cells with purely amoeboid creeping motion. 
 
 N 
 
 Nodose. Knotty or knobby. 
 Nodule. A small knot or rounded body. 
 
 O. A symbol for the pycnial stage of the rusts. 
 
 Ob. As a prefix meaning inversely or oppositely. 
 
 Obese. Excessively fat; fleshy. 
 
 Obligate. Necessary, essential. Comp. Facultative. 
 
 Obsolete. Wanting or rudimentary. 
 
 Ochraceous. Ocher-colored, yellow with a tinge of red. 
 
 Olivaceous. The color of a ripe olive. 
 
 Oogonium. Female sexual organ, containing one or more oospheres. 
 
 Oosphere. Naked mass of protoplasm which, after fertilization, develops 
 
 into the oospore. 
 Oospore. Immediate product of fertilization of oosphere. 
 Opalescent. Reflecting an iridescent light. 
 Operculate. Furnished with a lid. 
 
GLOSSARY 691 
 
 Operculum. A lid or cover which separates by a transverse hne of 
 
 division. 
 Opt. Abbreviation for Optimum. 
 Ostiolate. Bearing an ostiole. 
 Ostiole. An o])ening or mouth. 
 Oval. Broadly elliptic. 
 
 Ovate. Shaped like a longitudinal section of a hen's egg. 
 Ovoid. Resembling an egg. 
 
 Pannose. Felt-like. 
 
 Papilla (ae). Soft superficial protuberances. 
 
 Papillate. Having papilte. 
 
 Papilliform. Shaped like a papilla. 
 
 Papilloid. Resembling a small nipple. 
 
 Paraphysate. With paraphyscs. 
 
 Paraphyses. Sterile filaments occurring in the fructification of crypto- 
 gams. 
 
 Parasite. An organism living on or in and at the expense of another 
 living organism (the host). 
 
 Patellate. Shaped like a patella. 
 
 Patelliform. Like a small dish, circular and rimmed. 
 
 Pedicel. The support. 
 
 Pedicellate. Borne on a pedicel. 
 
 Pellicle. A small skin; a delicate superficial membrane. 
 
 Pellucid. Wholly or partially transparent. 
 
 Penicillate. Like a little brush. Pencil-shaped. 
 
 Perforate. Pierced through. 
 
 Peridium. The outer enveloping coat of a sporangium. 
 
 Periplasm. The protoplasm in the oogonium and the antheridium 
 which does not share in conjugation. 
 
 Perithecium. A rounded, oval, pyriform or beaked structure in which 
 asci are borne. 
 
 Peritrichiate. With hairs from all of surface. 
 
 Persistent. Remaining till the part which bears it is wholly matured. 
 
 Phycochrome. The coloring matter of brown Algae. 
 
 Phyllogenous. Growing upon leaves. 
 
 Phytogenous. Growing on plants. 
 
 Pileate. Having the form of a cap. 
 
 Pileiform. Pileus-shaped. 
 
 Pileus. Cap. The dome-shaped part of a sporophore. 
 
692 GLOSSARY 
 
 Pilose. Pilous. Hairy, having soft and distinct hairs. 
 
 Planose. Plane. 
 
 Plasmodiocarp. An asymmetrical sporangium of the Myxogastres. 
 
 Plasmodium. Body of naked plurinucleated protoplasm exhibiting 
 
 amoeboid motion. 
 Pleurogenous. Growing from the sides. 
 Plexus. A network. 
 
 Plicate. Folded into plaits usually lengthwise. 
 Polar. Relating to the poles of an organ. 
 Polymorphic. Polymorphous. With several or various forms, variable 
 
 as to habit. 
 Polysporic. Many spored. 
 Porcelaneous. Like porcelain. 
 Poroid. Resembling pores. 
 Porose. Containing pores. 
 Proliferous. Bearing offshoots. 
 Promycelium. Short and short-lived product of tube-germination of 
 
 a spore which adjoins acrogenously a small number of spores 
 
 (sporidia) unlike the mother-spore and then dies off. 
 Pseudo. In prefix signifying false, counterfeit, spurious. 
 Pulverulent. Powdered, as if dusted over. 
 Pulvinate. Cushion-shaped. 
 Punctiform. In the form of a point or dot. 
 Punctulate. Marked with small points. 
 Pustular. Blister-like, bearing blisters. 
 Pustule. A pimple or blister. 
 
 Pustuliform. Having slight blister-like elevations. 
 Putrescent. Becoming rotten. 
 Pycnidium (a). A variously shaped cavity resembling a pyrenocarp 
 
 and containing conidia. 
 Pycniospore. Spores borne in pycnia. 
 Pycnium. A structure of the Uridinales; see pp. 324-326. 
 Pycnosclerotia. Sclerotia bearing pyenidia. 
 Pycnospores. Spores from pyenidia. 
 Pyriform. Piriform. Resembling a pear in shape. 
 
 R 
 
 Radiate. Spreading from or arranged around a common center. 
 
 Ramicole. Growing on branches. 
 
 Ramose. Branched. 
 
 Receptacle. That part which bears one or more organs. 
 
GLOSSARY 693 
 
 Reniform. Kidney-shaped. 
 
 Resupinate. Without a pileus. 
 
 Reticulate. Netted, like network. 
 
 Revolute. Rolled back from the margin or apex. 
 
 Rhizoid. A root-like structure. 
 
 Rhizomorph. A root-like branched strand of mycelial hyphse. 
 
 Rhomboidal. Approaching a rhombic outline. 
 
 Rimose. Rimous. Cracked. 
 
 Rostrate. With a beak. 
 
 Rostrum. Any beak-like extension. 
 
 Rufous. Reddish. 
 
 Rugose. Rugous. Covered with wrinkles. 
 
 Saccate. Bag-shaped. 
 
 Saprophyte. A plant living on dead organic substance. 
 Sarcinaef orm. Having the form of the genus Sarcina. 
 Scabrous. Rough to the touch. 
 Sclerotioid. Like a sclerotium. 
 
 Sclerotium. A compact mass of hyphse in dormant state. 
 Scopulate. Broom-like or brush-like. 
 
 Scorpioid. With the main axis coiled like the tail of a scorpion. 
 Scrupose. Jagged, rough. 
 Scutiform. Buckler-shaped. 
 Septate. Divided by a partition. 
 Septum (a). Any kind of partition. 
 Seriate. In a series. 
 Sessile. Destitute of a stalk. 
 Seta(ae). A bristle or bristle-shaped body. 
 Setaceous. Bristle-like. 
 Setose, Bristly, beset with bristles. 
 Setulose. Resembling a fine bristle. 
 
 Shield-shaped. In the form of a buckler; clypeate, peltate, or scutate. 
 Sigmoid. Doubly curved in opposite directions, like the Greek sigma. 
 Simple. Of one piece or series, opposed to compound. 
 Sinuous. Sinuose. Sinuate. With a deep wavy margin. 
 Sorus (i). Heap, or aggregation; a heap of spores. 
 Spatulate. Like a druggist's spatula. 
 Sperm. A male reproductive cell. 
 
 Spermatum (a). Male non-motile gamete, sometimes erronously used 
 for various conidia. 
 
694 GLOSSARY 
 
 Sphaeroidal. Somewhat spherical. 
 
 Spindleform. Spindle-shaped, fusiform. 
 
 Sporangiophore. A sporophore bearing a sporangium. 
 
 Sporangium. Sac producing spores endogenously. 
 
 Spore. A single cell which becomes free and is capable of developing 
 
 directly into a new plant. 
 Sporidium. Diminutive of spore, especially applied to the spores pro- 
 duced on promycelia. 
 Sporocarp. A many-celled body serving for the formation of spores. 
 Sporodochium. The sporiferous apparatus in fungi belonging to 
 
 the Tuberculariales. 
 Sporogenous. Producing spores. 
 
 Stellate. Star-shaped or radiating like the points of a star. 
 Sterigma (ta) . A stalk-like branch of a basidium bearing a spore. 
 Stipe. A general term for stalk. 
 Stipitate. Having a stipe. 
 Stolon. A sucker or runner. 
 Stoloniferous. Bearing stolons. 
 Stratose. In distinct layers. 
 
 Striate. Marked with fine longitudinal parallel lines. 
 Strigose. With sharp-pointed appressed straight and stiff hairs or 
 
 bristles. 
 Stroma (ta). A cushion-like body, on or in which the perithecia are 
 
 immersed. 
 Stromatic. Pertaining to or resembling a stroma. 
 Stuffed. Solid, farctate. 
 Stylospore. A spore borne on a filament. 
 Sub. Under or below; in compounds usually implies an approach to the 
 
 condition designated; somewhat or slightly. 
 Subiculum. Subicle. A felted or byssoid basal stratum of hyphse. 
 Subulate. Awl-shaped. 
 Sulcate. Grooved or furrowed. 
 Superj&cial. On the surface. 
 Suspensor. A club-shaped or conical portion of hypha adjoining a 
 
 gamete-cell. 
 Sympodium. An axis made up of the bases of a number of successive 
 
 axes arising as branches in succession one from the other. 
 Syn. Signifies adhesion or growing together. 
 Synema. A column of combined filaments. 
 
GLOSSARY 695 
 
 T. D. P. Abbreviation for Thcrmal-death-point. 
 
 Teleutospore. A resting spore of Uridinales on germination producing 
 
 a promycelium. 
 Teleuto-stage. Stage producing a teleutospore. 
 Telium. A sorus of the Uredinales; see pp. 324-326. 
 Terete. Circular in transverse section. 
 Ternate. In threes. 
 
 Thalloid. Having the nature or form of a thallus. 
 
 Thallus. A vegetative body without differentiation into stem and leaf. 
 Tomentose. Densely pubescent with matted wool, or short hairs. 
 Tortuous. Bent or twisted in different directions. 
 Torulose. Irregularly bending. Somewhat moniliform with swollen 
 
 portions. 
 Tremelliform. Gelatinous in texture. 
 Tremelloid. Jelly-like in substance or appearance. 
 Trichogyne. The receptive filament of the female organ. 
 Trident. Having three teeth. 
 
 Triquetrous. Three-edged, with three salient angles. 
 Truncate. As though cut off at the end. 
 Tubercular. Having tubercles, or like a tubercle. 
 Tuberculate. Beset with knobby projections or excrescences. 
 Tubular. Cylindrical and hollow. 
 Tumid. Inflated, swollen. 
 
 U 
 
 Umbellate. Having the inflorescence in umbels. 
 
 Umbilicate. Navel-like. 
 
 Umbo. A boss. 
 
 Umbrinaceous. Umbrinous. Umbrinus. Umbrinose. The color of 
 
 raw umber. 
 Uncinate. Hooked. 
 Ungulate. Having claws or hoofs. 
 Unguliform. Hoof-shaped. 
 Uni. In composition, one, or single. 
 Urceolate. Urceolar. Pitcher-like, hollow and contracted at the mouth 
 
 like an urn. 
 Uredinium. A sorus in the Uredinales, see pp. 324-326. 
 
696 GLOSSARY 
 
 Vacuolate. Possessing vacuoles. 
 
 Valsoid. Resembling Valsa. 
 
 Valvate. Opening by valves. 
 
 Vegetative. Growing. 
 
 Veil. A special envelope in Agaricales within which the growth of the 
 
 sporophore takes place. 
 Velutinous. Velvety, due to a coating of fine soft hairs. 
 Vermicular. Vermiculate. Worm-shaped, thickened and bent in places. 
 Verruciform. Wart-shaped. 
 
 Verrucose. Verrucous. Verruculose. Full of warts. Warty. 
 Verticillate. Whorled. 
 Vesicular. Composed of vessels. 
 Villi. Long weak hairs. 
 Villous. Bearing villi. 
 Vinose. Vinous. Wine colored. 
 Viscid. Sticky from a tenacious coating or secretion. 
 Volva. A covering, the sac enclosing the Agaric sporophore. 
 
 Zonate. Marked circularly. 
 
 Zoogloeae. A colony embedded in a gelatinous substance. 
 Zoosporangia. Sporangia which produce zoospores. 
 Zoospore. A motile spore. 
 
INDEX 
 
 (Boldface figures refer to headings, italic figures to illustrations) 
 
 Abies, 229, 230, 347, 391, 41G, 
 
 580 
 Absidia, 104 
 Acacia, 436, 457 
 Acanthorhynchus, 224 
 
 Vaccinii, 224, 225 
 
 Acanthostigma, 226, 229 
 
 Parasiticum, 229, 229 
 
 Acer, 188, 202, 499, 507, 529 
 
 Pseudoplatanus, 152, 159 
 
 Aciculosporium, 199 
 Acinula, 659 
 Acladium, 575 
 Acolium, 153 
 Aconitum, 93 
 Acontium, 571 
 Acorus, 73, 320 
 Acrasiales, 5 
 Acremoniella, 600, 600 
 
 Occulta, 600 
 
 Verrucosa, 600 
 
 Acremonium, 575, 577, 577 
 Acrocylindriura, 583 
 Acrocystis, 663 
 
 Batata;, 663 
 
 Acrospeira, 599 
 Acrospermacese, 160 
 Acrostalagmus, 583, 584, 581). 
 
 Albus, 584, 585 
 
 Panax, 585 
 
 Vilmorinii, 585 
 
 Acrotheca, 598 
 Acrothecium, 609 
 Actidium, 164 
 
 Actiniceps, 634 
 Actinida, 181 
 558, Actinomma, 656 
 
 Actinonema, 505, 508 
 
 Fagicola, 509 
 
 Fraxani, 509 
 
 Rosffi, 508, 508 
 
 Tilia;, 509 
 
 Actinothecium, 528 
 
 Actinothyrium, 532 
 
 Adonis, 178 
 
 iEcidium, 324, 334, 335, 389, 390 
 
 Abietinum, 349 
 
 Asperifolium, 381 
 
 Berberidis, 334, 378 
 
 Brassica;, 378, 390 
 
 Cinnamomi, 390 
 
 Columnare, 347 
 
 Cyparissise, 372 
 
 Euphorbise-gerardianse, 375 
 
 Grossularise, 376 
 
 Leucospermum, 336 
 
 Mespili, 371 
 
 Otogense, 390 
 
 Oxalidis, 384 
 
 Pelargonii, 390 
 
 Rhamni, 382 
 
 Rubellum, 377 
 
 ■ Strobilinum, 347 
 
 Tuberculatum, 390 
 
 iEgerita, 640 
 
 iEsculus, 182, 202, 489, 507, 579 
 
 Agaric, 394 
 
 Agaricacese, 402, 442 
 
 Key to, 442 
 
 Agaricale^, 395, 397 
 697 
 
698 
 
 INDEX 
 
 Agaricales, Key to, 402 
 Agaricese, 443, 448 
 Agaricus, 448, 455 
 Agave, 89, 248, 552 
 Agropyron, 306, 320, 389 
 
 Repens, 262 
 
 Agrostis, 321, 380 
 Agyriella, 538 
 Agyriellopsis, 534 
 Albuginaceffi, 78, 82 
 Albugo, 78, 79, 82 
 
 Bliti, 79, 81, 82, 102-116 
 
 Candida, 81, 95 
 
 Ipomoese-panduranae, 81 
 
 Occidentalis, 82 
 
 Portulaceae, 82 
 
 Tragopogonis, 82 
 
 Alder, 130, 203, 243, 264, 274, 419, 
 
 428, 545 
 Aldridgea, 405 
 Aleurodiscus, 404, 405 
 Aleyrodes, 194 
 Alfalfa, 29, 36, 97, 132, 148, 208, 250, 
 
 258, 315, 408, 486, 508, 514, 521, 
 
 543, 551, 556, 582, 630, 660 
 Alfilaria, 71, 101 
 Alga-Uke Fungi, 3, 65 
 Allantospora, 589 
 Allium, 97, 318, 344, 661 
 Almond, 36, 357, 498, 542, 626 
 Alnus, 186, 188, 278, 408, 541, 582, 
 
 607 
 Aloe, 493, 560 
 Alternaria, 260, 261, 616, 621 
 
 Brassicse, 621 
 
 Cucurbits, 621 
 
 Dianthii, 622, 622 
 
 Fasciculata, 624 
 
 Fici, 624 
 
 Forsythia;, 621 
 
 Panax, 622 
 
 • Phaseoli, 621 
 
 Solani, 623, 623, 624 
 
 Tabacinum, 624 
 
 Tenuis, 621 
 
 Trichostoma, 262, 621 
 
 Alternaria, Viola;, 621, 621 
 
 Vitis, 624 
 
 Althea, 386 
 
 Alyssum, 178 
 
 Alveolaria, 341 
 
 Amallospora, 657 
 
 Amanita, 398, 450 
 
 Amantiopsis, 450 
 
 Amarantacea;, 303 
 
 Amaranthus, 82 
 
 Amaryllidacea;, 405 
 
 Amblyosporium, 572 
 
 Amelanchier, 183, 366, 368, 369, 370, 
 
 371 
 Amentacese, 127 
 Amerosporae, 633, 635 
 
 Key to, 636 
 
 Amerosporium, 534 
 
 fficonomicum, 534 
 
 Amoebochytrium, 72 
 
 Ampelopsis, 181, 238, 484 
 
 Amphicarpa, 71 
 
 Amphisphseriacese, 222 
 
 Amphispore, 327 
 
 Anacardiacea;, 127 
 
 Ancylistidiales, 66 
 
 Andromeda, 398 
 
 Anemone, 72, 143, 178, 318, 336, 357, 
 
 389 
 Angelinia, 160 
 Angiopoma, 515 
 Anise, 630 
 Anixia, 189 
 Annularia, 450 
 Antennaria, 190, 192 
 
 Elffiophila, 192 
 
 Footi, 192 
 
 Piniphilum, 192 
 
 Pityophila, 192 
 
 Setosa, 192 
 
 Anthina, 657 
 Anthostoma, 277 
 Anthostomella, 208, 276 
 
 ■ Bohiensis, 277 
 
 Coffea;, 277 
 
 Destruens, 277, 277 
 
INDEX 
 
 693 
 
 Anthostomella, Sullce, 277 
 
 Anthracoderma, 483 
 
 Anthracophyllum, 445 
 
 Anthrinieai, 594 
 
 Anthurium, 270, 489, 511, 544, 552 
 
 Anthurus, 463 
 
 Antromycopsis, 630 
 
 Aphanoascus, 167 
 
 Aphis, 194 
 
 Apiospora, 251 
 
 Apiosporium, 190, 191, 192 
 
 Brasiliense, 192 
 
 Salicinum, 191, 192 
 
 Aposphseria, 481, 494 
 
 Apple, 36, 38, 52, 88, 105, 122, 123, 
 139, 184, 203, 220, 231, 246, 248, 
 249, 255, 265, 267, 268, 271, 278, 
 285, 329, 365, 367, 368, 371, 404, 
 405, 408, 412, 415, 419, 421, 428, 
 452, 485, 486, 490, 492, 502, 503, 
 504, 515, 519, 539, 540, 542, 546, 
 547, 561, 563, 574, 586, 617, 644, 
 645, 649 
 
 Rot, 266 
 
 Twig Canker, 266 
 
 Appressoria, 266 
 
 Apricot, 139, 357, 486, 491, 560, 569, 
 604, 610 
 
 Aquilegia, 178, 544 
 
 Arachnopeziza, 135 
 
 Aralia, 168 
 
 Arbor Vitae, 424, 431 
 
 Arbutus, 36 
 
 Archangelia, 251 
 
 Armillaria, 123, 450, 455 
 
 Fuscipes, 457 
 
 Mellea, 230, 410, 411, 455, 4S7, 
 
 458 
 
 Mucida, 457 
 
 Arnica, 176 
 
 Aronia, 366, 368 
 
 Arrhenatherum, 180 
 
 Arrhenia, 443 
 
 Arrowroot, 207 
 
 Arthrobotrys, 586 
 
 Arthrobotryum, 637 
 
 Artichoke, 41, 591 
 Arundinaria, 211 
 Aschcrsonia, 195, 527 
 Asciculosporium Take, 211 
 Asclepias, 188 
 AscobolacesB, 133, 134 
 Ascochyta, 243, 409, 505, 506 
 
 iEsculi, 507 
 
 Aquilegia;, 507 
 
 Armoraciffi, 506 
 
 Aspidistra?, 507 
 
 Beticola, 507 
 
 Boltshauseri, 506 
 
 Brassicaj, 506 
 
 Caulicola, 508 
 
 Chrysanthemi, 507 
 
 Cookei, 508 
 
 Corticola, 508 
 
 Digitalis, 507 
 
 Dianthi, 507 
 
 Ellisii, 506 
 
 Fragaria;, 507 
 
 Graminicola, 508 
 
 Imperfecta, 508 
 
 Iridis, 507 
 
 Juglandis, 507 
 
 Lactuca;, 507 
 
 Lycopersici, 508 
 
 Manihotes, 508 
 
 Medicaginis, 507 
 
 Melutispora, 508 
 
 Nicotiana;, 506 
 
 Orobi, 507 
 
 Pallida, 507 
 
 Parasitica, 506 
 
 Piniperda, 507 
 
 Pisi, 506 
 
 Polemonii, 507 
 
 ■ Populicola, 507 
 
 Primulse, 507 
 
 Pruni, 507 
 
 Rhei, 506 
 
 Tremula;, 508 
 
 Vicise, 503 
 
 Viola;, 507 
 
 AscocorticiaceiB, 125 
 
700 
 
 INDEX 
 
 Ascoideaceae, 118 
 Ascomycetes, 64, 113 
 
 Key to, 117 
 
 Ascospora, 235, 236 
 
 Beijerinckii, 236, 560 
 
 Geographicum, 237 
 
 — ^— Himantia, 236 
 
 Padi, 237 
 
 Aseroe, 463 
 
 Ash, 52, 164, 203, 232, 255, 284, 419, 
 421, 433, 509, 524, 530, 557, 564, 
 603, 608 
 Asparagus, 41, 328, 376, 553, 617, 
 
 630, 660 
 Aspedistra, 507, 552 
 Aspen, 255, 428, 446, 607 
 Aspergillaccaj, 165, 166 
 
 Key to, 166 
 
 Aspergillales, 114, 124, 164, 167 
 
 Key to, 165 
 
 Aspergillea;, 566, 572, 572 
 
 Key to, 572 
 
 AspergiUus, 166, 167, 168, 169, 572, 
 573 
 
 Ficuum, 169, 572 
 
 Fumigatus, 572 
 
 Phocnicis, 169, 572 
 
 Aster, 89, 179, 289, 328, 585, 654 
 Asterocystis, 68, 69 
 
 Radicis, 69 
 
 Asterodon, 413 
 Asteroma, 274, 482, 496 
 
 Codiaji, 496 
 
 Geographicum, 496 
 
 Padi, 275, 496 
 
 Punctiforme, 496 
 
 Stuhlmanni, 496 
 
 Asterophora, 577 
 Asterosporium, 558 
 Asterostomella, 481, 531 
 Asterostomidium, 514 
 Asterostroma, 406 
 Asterothyrium, 531 
 Astragalus, 187 
 Astrodochilum, 655 
 Atractiella, 634 
 
 Atractina, 609 
 Atractium, 207 
 Atriplex, 74 
 Atrocarpus, 273, 541 
 Attachment organs, 141, 142 
 Auerswaldia, 216 
 Aulographum, 163 
 Aureobasidium, 403, 405 
 
 Vitis, 405 
 
 Auricula, 611 
 Auricularia, 393 
 
 Auricula judia3, 393 
 
 Auriculariacea;, 392 
 
 Key to, 392 
 
 Auriculariales, 323, 326, 392 
 
 Key to, 392 
 
 Auriculariese, 393 
 Auta^cious, 329 
 Avena, 608 
 Avocado, 512 
 Azalea, 523 
 
 B 
 
 Bacillus, 18, 21, 37 
 
 Ampelopsorse, 51, 37 
 
 Amylovorus, 3S, 38 
 
 Anthracis, 37 
 
 Apii, 39 
 
 Araliavonis, 39 
 
 Aroidea;, 39, 39, 42 
 
 Atrosepticus, 40, 47 
 
 Avena?, 24, 40, 40 
 
 Beta;, 41 
 
 Brassicsevorus, 27, 41 
 
 Caratovorus, 39, 40, 41, 42, 46 
 
 Caulivorus, 27, 43 
 
 Cepivorus, 43 
 
 CoU, 43 
 
 Cubonianus, 31, 43 
 
 Cypripedii, 43 
 
 • Dahlia;, 43 
 
 Delphini, 43 
 
 Elegans, 43 
 
 Glanga3, 52 
 
INDEX 
 
 701 
 
 Bacillus, Gossyj)ini, 43 
 
 Gum mis, 43 
 
 Haria, 44 
 
 Hyacinthi Septicus, 39, 44 
 
 Inflatus, 15 
 
 Koraiensis, 39 
 
 Lactuca?, 44 
 
 Lycopersici, 44 
 
 Maculicola, 44 
 
 Megatherium, 13, 15 
 
 Melangenus, 44 
 
 Melonis, 44, 44, 4-5 
 
 Mori, 21 
 
 Mycoides, 45 
 
 Nicotianse, 45 
 
 Olea;, 45 
 
 Oleracea;, 39, 42, 46 
 
 Omnivorus, 42, 46 
 
 Oncidii, 46 
 
 Oryzse, 46 
 
 Pestis, 37 
 
 Phytophthorus, 46 
 
 Populi, 47 
 
 Prodigiosus, 21 
 
 Pseudarabinus, 47 
 
 Rosarum, 47 
 
 Sacchari, 52 
 
 Sesami, 47 
 
 Solanacearam, 30, 45, 47, 49 
 
 Solanicola, 48 
 
 ■ Solaniperda, 48 
 
 Solanisaprus, 47, 48, 48, 49 
 
 Sorghi, 49 
 
 Spongiosus, 49 
 
 Subtilis, 15, 49 
 
 Tabacivonis, 50 
 
 Tabificans, 50 
 
 • Tracheiphilus, 50, oO, 57 
 
 Typhosus, 19, 37 
 
 Uva;, 37, 51 
 
 Vulgatus, 51 
 
 Zea^, 51 
 
 Zinzgiberi, 52 
 
 Bacteria, 1, 3, 13, 18 
 
 • Cell structure, 14 
 
 Classification, 17 
 
 Bacteria, Constancy of species, 17 
 
 Entrance to the host plant, 
 
 17 
 
 Group numbers, 20 
 
 Involution forms, 16 
 
 Migula, system of, 18 
 
 Mode of increase, 14 
 
 Modes of spore germination, 16 
 
 Numerical system of recording, 
 
 19 
 
 Specific characters, 19 
 
 Spores, 15 
 
 Three type forms, 13 
 
 Bacteriacese, 18, 21 
 Bacterium, 18, 21 
 
 Briosianum, 21 
 
 Fici, 22 
 
 Montemartinii, 21 
 
 Pini, 22 
 
 Scabigenum, 22 
 
 Teutlium, 22 
 
 Tuberculosis, 19 
 
 Bactridiopsis, 640 
 Bactridium, 645 
 Bseodromus, 341 
 Bagnisiella, 216 
 Bahamia, 11 
 Balansia, 199, 209, 209, 537 
 
 Claviceps, 209 
 
 Hypoxylon, 209 
 
 Balsam, 423, 436 
 
 Bamboo, 209, 211, 215, 310 
 
 Banana, 52, 214, 253, 448, 496, 540, 
 
 542, 608, 626, 649, 650 
 Barberry, 333, 380, 385, 546 
 Barclay ella, 341 
 
 Bariey, 24, 105, 180, 206, 249, 260, 
 261, 304, 305, 306, 307, 315, 333, 
 380, 383, 550, 567, 587, 601, 613, 
 621 
 BartaHnia, 513 
 Barya, 198 
 Basiascum, 553 
 Basidiella, 636 
 Basidiobolacese, 107 
 Key to, 107 
 
702 
 
 INDEX 
 
 Basidiobolus, 107 
 Basidiomycetes, 64, 298, 475 
 
 Key to, 299 
 
 Basidiophora, 83, 89 
 
 Entospora, 89 
 
 Basisporium, 599 
 
 Baumanniella, 411, 412 
 
 Bean, 12, 31, 37, 86, 267, 373, 408, 
 
 487, 491, 506, 540, 548, 621, 630, 637 
 Beccariella, 406 
 Beech, 106, 134, 152, 162, 203, 249, 
 
 415, 421, 427, 429, 430, 433, 436, 
 
 440, 444, 445, 509, 544, 545, 547, 
 
 608 
 Beet, 8, 22, 26, 36, 37, 41, 44, 45, 50, 
 
 52, 73, 82, 100, 187, 247, 258, 321, 
 
 412, 486, 490, 507, 526, 568, 590, 
 
 610, 617, 620, 628, 645, 660 
 Begonia, 43, 168, 544 
 Belanioscypha, 136 
 Belonidium, 147 
 Beloniella, 147 
 Belonium, 136 
 Belonopsis, 147 
 Beltrania, 602 
 Beniowskia, 639 
 Berberis, 185, 188, 235, 256, 329, 379, 
 
 384 
 Berlesiella, 283 
 Bertia, 226 
 Beta, 374 
 Betula, 130, 157, 186, 188, 202, 220, 
 
 221, 255, 348 
 Betulaceae, 143 
 Bibliography of introduction, Myxo- 
 
 mycetes and Bacteria, 53 
 
 Ascomycetes, 288 
 
 Books, 678 
 
 Basidiomycetes, 466 
 
 Fungi Imperfecti, 667 
 
 Periodicals, 680 
 
 Phycomycetes, 109 
 
 Biologic species and specialization, 
 
 174, 260, 262, 332, 380, 611, 640 
 Birch, 418, 421, 426, 428, 430, 433, 
 
 436, 444, 446, 545, 607 
 
 Bird nest fungi, 395 
 Bispora, 601 
 Bizzozeria, 234 
 Bizzozeriella, 640 
 Blackberry, 276, 360, 525 
 Black-leg, 652 
 Blastomyces, 575 
 Blastotrichum, 200, 588 
 Blennoria, 538 
 Bletia, 552, 645 
 Blossoms, 107, 108 
 Bloxamia, 538 
 
 Blue grass, 213, 385, 497, 550 
 Blue-green Algse, 3 
 Boletacese, 402, 440 
 
 Key to, 440 
 
 Boletinese, 440 
 Bolinia, 285 
 Bombardia, 226 
 Bombardiastrum, 227 
 Bonia, 406 
 Bonplandiella, 655 
 Boraginacese, 329, 382 
 Borago, 178 
 Bornetina, 323 
 Bostrichonema, 586 
 Botryodiplodia, 510, 513 
 Botryospha;ria, 283, 2S3, 503 
 
 Dothidffi, 284 
 
 Gregaria, 284 
 
 Ribis, 283 
 
 Botryosporium, 571 
 
 Diffusum, 571 
 
 Longibrachiatum, 571 
 
 Pulchrum, 571 
 
 Botrytidea;, 566, 574, 575 
 
 Key to, 575 
 
 Botrytis, 86, 91, 96, 137, 142, 570, 578 
 
 Cinerea, 140, 578, 578, 581 
 
 Citricola, 581 
 
 Deprsedens, 580 
 
 Diospyri, 581 
 
 Douglasii, 141, 581 
 
 Fascicularis, 580 
 
 Galanthina, 141, 581 
 
 Infestans, 681 
 
INDEX 
 
 703 
 
 Eotrytis, Longibrachiata, 581 
 
 Pajoniae, 580 
 
 Parasitica, 580 
 
 Patula, 581 
 
 Vulgaris, 140 
 
 Boudiera, 115, 116 
 
 Bovilla, 224 
 
 Bovista, 465 
 
 Bovistella, 465 
 
 Box, Buxus, 204, 220, 221, 243, 529, 
 
 656 
 Box elder, 545 
 Brachysporium, 609 
 Brachy-type, 328 
 Brassica, 69, 178, 390, 617, 629 
 Bread fruit, 411 
 Brefeldiacca;, 10 
 Bremia, 84, 90, 95 
 
 Lactucae, 95, 95 
 
 Briarea, 572 
 Briosia, 636 
 Bromus, 260, 261, 613 
 Broomella, 199 
 Brown alga;, 3 
 Brunchorstia, 532 
 
 Destruens, 151, 532 
 
 Bubakia, 340 
 
 Buckwheat, 378, 589, 607, 660 
 
 Bulb, 141, 661 
 
 Bulgaria, 151, 152 
 
 ■ Polymorpha, 152 
 
 Bulgariea;, 151 
 
 Bulgariella, 151 
 
 BuUaria, 556 
 
 Burillia, 315 
 
 Buseella, 570 
 
 Butomus, 323 
 
 Butternut, 275, 419, 428, 545 
 
 Byssocystis, 482 
 
 Cabbage, 7, 24, 25, 26, 29, 41, 42, 46, 
 52, 69, 73, 81, 95, 231, 249, 378, 
 408, 484, 491, 492, 530, 544, 619, 
 503, 654 
 
 Cacao, 130, 204, 205, 206, 232, 277, 
 
 278, 409, 411, 448, 4-93, 509, 512, 
 
 525, 536, 552, 553, 573, 584, 585, 
 
 590, 592, 620 
 Cacospha>ria, 281 
 Cactus, 36, 488, 512, 544 
 Ca;oma, 334, 335, 342, 358, 361, 389, 
 
 390 
 
 Nitens, 360 
 
 Orchidis, 344 
 
 Pinitorquum, 344 
 
 Calamagrostis, 661 
 Calcarisporium, 583 
 Calceolaria, 52 
 Calendula, 176, 178, 321 
 Caliciacese, 134, 163 
 
 Key to, 153 
 
 Calicium, 153 
 Calistephenis, 338 
 Calla, 39, 488, 560, 631 
 Calloriea;, 147 
 Calocasia, 89 
 Calonectria, 198, 205 
 
 Bahiensis, 206 
 
 Cremea, 205, 585 
 
 Flavida, 205 
 
 Gigaspora, 206 
 
 Platani, 205 
 
 Pyrochroa, 205, 648 
 
 Calospha;ria, 281, 282 
 
 Princeps, 282, 282 
 
 Calosphariese, 281 
 Calospora, 280, 539 
 
 Vanilla;, 280, 541 
 
 Calyptromyces, 104 
 Camarops, 285 
 Camarosporium, 516, 517, 617 
 
 Fissum, 517 
 
 Mori, 517 
 
 Viticola, 617 
 
 Camellia, 497, 559, 561 
 Campanella, 443 
 Campanula, 101, 333, 340 
 Camphor, 411 
 Camposporium, 609 
 Campsotrichum, 599 
 Camptosphaeria, 263 
 
704 
 
 INDEX 
 
 Camptoum, 598 
 Canker, 266, 349 
 Canna, 389 
 Canteloupe, 620 
 Cantharelleffi, 442, 443 
 
 Key to, 443 
 
 Cantharellus, 443 
 Caper, 81, 630 
 Capillaria, 659 
 Capnodiastrum, 501 
 Capnodium, 190, 192, 624 
 
 Citri, 193 
 
 Citricolum, 193 
 
 Coffea;, 192 
 
 Foedum, 192 
 
 GuajaviB, 192 
 
 Javanicum, 193 
 
 Meridionale, 193 
 
 Olea, 193 
 
 Quercinum, 192 
 
 Stellatum, 193 
 
 Taxi, 192 
 
 Tilia;, 192 
 
 Capparis, 179 
 Capronia, 252 
 Capsule, 14 
 Caragana, 524, 525 
 Caravonica, 411 
 CarduaceiE, 303 
 Carex, 303, 376 
 
 Carnation, 27, 52, 375, 408, 497, 523, 
 544, 553, 578, 580, 581, 611, 623, 
 645, 654 
 Carpinus, 130, 188, 191, 492, 545 
 Carrinia, 504 
 Carrot, 27, 41, 42, 44, 91, 119, 141, 
 
 142, 260, 408, 491 
 Carya, 186, 202, 546 
 Caryophyllaceaj, 310, 405 
 Cassava, 493, 543 
 Castanea, 140, 186, 188, 558, 562 
 Castilloa, 411 
 Castor plant, 89, 654 
 Casuarina, 571 
 
 Catalpa, 168, 178, 18G, 188, 256, 426, 
 489, 619 
 
 Catastoma, 465 
 Catenularia, 600 
 Catinula, 534 
 
 Cattleya, 253, 273, 541, 544 
 
 Caudospora, 277 
 
 Cauliflower, 25, 26, 28, 46, 95, 
 544 
 
 Caulocassia, 100 
 
 Cedar, 234 
 
 incense, 424 
 
 Celastrus, 188 
 
 Celery, 27, 39, 41, 42, 52, 377, 487, 
 492, 521, 619, 628 
 
 Celidiaceai, 134 
 
 Cenangella, 150 
 
 Cenangiacese, 134, 150 
 
 Key to, 150 
 
 Cenangium, 150, 151, 152 
 
 Abietis, 151, 532 
 
 Vitesia, 500 
 
 Centaurea, 178, 377 
 
 Cephaliophora, 588 
 
 Cephalodochium, 641 
 
 Cephalosporiea}, 566, 570 
 
 Key to, 570 
 
 Cephalosporium, 201, 571, 646, 649 
 
 Cephalotheca, 166 
 Cephalothecium, 586 
 
 Roseum, 586, 5S6 
 
 Cephalotrichum, 598 
 Ceraplastes, 194 
 Ceratiomyxaceae, 9 
 Coratocarpia, 190 
 Ceratocladium, 630 
 Ceratophorum, 608, 610 
 
 Setosum, 610 
 
 Ulmicolum, 610 
 
 Ceratosphseria, 232 
 Ceratostoma, 232 
 Ceratostomatacese, 222, 232 
 
 Key to, 232 
 
 Ceratostomella, 232 
 
 Pilifera, 233, 233 
 
 Cercis, 5t)6, 524 
 
 Cercospora, 243, 257, 478, 625 
 
 Acerina, 632 
 
INDEX 
 
 705 
 
 Corcosponi, Acerosum, 630 
 
 Altha^ina, 630 
 
 Angreci, 631 
 
 Angulata, 245, 626 
 
 Apii, 628, l!2S 
 
 Arimincnsis, 630 
 
 Armoraciae, 629 
 
 Asparagi, 630 
 
 Beticola, 628, 628 
 
 Bloxami, 629 
 
 Bolleana, 626 
 
 Brunkii, 631 
 
 Capparidis, 630 
 
 Cerasella, 245, 625 
 
 Cercidicola, 631 
 
 Cheiranthi, 631 
 
 Circumscissa, 625 
 
 Citrullina, 629 
 
 Concors, 626, 626 
 
 Cruenta, 629 
 
 Cucurbitaj, 629 
 
 Flagelliformis, 629 
 
 Fumosa, 626 
 
 Gossypina, 248, 625 
 
 Halstedii, 632 
 
 Hypophylla, 631 
 
 • Kellermanii, 630 
 
 Kopkei, 630 
 
 Longipes, 630 
 
 -. Malkoffi, 630 
 
 Malvarum, 630 
 
 Medicaginis, 630 
 
 Melonis, 629 
 
 Microsora, 631 
 
 Moricola, 626 
 
 Miisa;, 626 
 
 Neriella, 631 
 
 Nicotianaj, 627, 627 
 
 Odontoglossi, 631 
 
 Omphacodes, 631 
 
 Oryzse, 626 
 
 Personata, 629 
 
 Phlogina, 631 
 
 Raciborskii, 627 
 
 Resedse, 631 
 
 Richardiaecola, 631 
 
 Ceroospora, Roesleri, 626 
 
 Rosicola, 630, 630 
 
 Rubi, 626 
 
 Sacchari, 630 
 
 Sequoia?, 632 
 
 Sordida, 631 
 
 Theaj, 630 
 
 Unicolor, 631 
 
 Vagina;, 630 
 
 Vigna;, 630 
 
 Violaj, 630 
 
 Viticola, 626 
 
 Cercosporelki, 592 
 
 Albo-maculans, 592 
 
 Inconspicuus, 592 
 
 Narcissi, 592 
 
 Pastinacffi, 592 
 
 Persies;, 592 
 
 Cereal, 248, 250, 385, 491, 600 
 
 Cereus, 499, 529 
 
 Cerocorticium, 405 
 
 Cerotelium, 341 
 
 Cesatiella, 198 
 
 Ceuthospora, 483, 500 
 
 Cattleya, 500, 500 
 
 Coffeicola, 500 
 
 Chaenotheca, 153 
 Chsetocladiaceae, 103 
 Chsetoconidium, 577 
 Chffitodiplodia, 510 
 
 VaniUae, 510 
 
 Chaetomella, 501 
 ChBetomiaceae, 222 
 Chffitopeltis, 532 
 Chaetophoma, 191, 482, 495 
 
 Glumarum, 495 
 
 Chsetospermum, 641 
 Chaetosphaeria, 226 
 Chffitostroma, 201, 655, 666 
 
 Buxi, 656 
 
 Cliviae, 656 
 
 Chsetozythia, 527 
 Chalara paradoxa, 596 
 Chalarieae, 595 
 Chamaecyparis, 370, 416 
 Characese, 3 
 
706 
 
 INDEX 
 
 Charrinia, 262, 263 
 Cheiranthus, 619, 631 
 Chenopodiaceae, 96 
 Chenopodium, 74 
 
 Cherry, 49, 129, 138, 184, 219, 237, 
 245, 255, 268, 275, 282, 357, 376, 
 
 419, 507, 512, 520, 560, 562, 604, 
 606, 625, 649 
 
 Cherry laurel, 410 
 
 Chess, 550 
 
 Chestnut, 36, 101, 209, 281, 321, 419, 
 
 420, 439, 442, 445, 489, 498, 499, 
 509, 524, 560, 597 
 
 Chicory, 490 
 China berry, 202 
 Chitonia, 448 
 Chitonospora, 251 
 Chlamydobacteriacese, 19 
 Chlamydospores, 60 
 Chlorophycea?, 3 
 Chlorosplenium, 135, 144 
 
 iEruginosum, 143, 144 
 
 Choanephora, 107 
 
 Americana, 107 
 
 Cucurbitarum, 107 
 
 Infundibulifera, 107 
 
 Choanephoracese, 103, 106, 107 
 Chondromyces, 634 
 Chromosporium, 566 
 Chrysanthemum, 36, 105, 386, 389, 
 
 392, 409, 488, 492, 507, 522, 563, 
 
 569 
 Chrysomyxa, 341, 350 
 
 Abietis, 350 
 
 Chrysophlyctis Endobiotica, 70, 71 
 Chrysopsora, 336 
 Chytridiales, 60, 65, 66, 101 
 
 Key to, 67 
 
 Ciboria, 135 
 Cicer, 179 
 
 Cichorlum, 178, 378 
 Cicinnobella, 501 
 Cicinnobolus, 174, 482, 494 
 Cienkowskia, 11 
 Ciliciopodium, 634 
 Ciliofusarium, 657 
 
 Ciliospora, 527 
 
 Cineraria, 339 
 
 Cinnamon, 390, 398, 487 
 
 Cintractia, 302, 310 
 
 Cionothrix, 342 
 
 Circinella, 105 
 
 Cissis, 303 
 
 Citron, Citrus Fruits, 44, 45, 193, 
 
 194, 249, 490, 491, 504, 512, 520, 
 
 540, 541, 548, 559, 574, 581, 604, 
 
 605, 626, 649 
 Citysus, 100 
 Cladobotyrum, 583 
 Cladochytriacese, 67, 72 
 
 Key to, 72 
 
 Cladochytrium, 72 
 
 Brassicse, 73 
 
 Csespitus, 73 
 
 Graminis, 73 
 
 Mori, 73 
 
 Tenue, 73 
 
 Viola?, 73 
 
 Viticolunj, 73 
 
 Cladoderris, 406 
 
 Cladosphseria, 283 
 
 Cladosporium, 217, 219, 257, 602, 
 
 603, 617 
 
 Bigarardia, 605 
 
 Brunneo-atrum, 606 
 
 Carpophilum, 604, 60^ 
 
 Citri, 604 " 
 
 Condylonema, 605 
 
 Cucumerinum, 603, 604 
 
 Elegans, 604 
 
 Epiphyllum, 606 
 
 Fasciculare, 260, 603 
 
 Fulvum, 604, 605 
 
 Graminum, 605 
 
 Herbarum, 248, 603 
 
 Citricolum, 604 
 
 Hypophyllum, 606 
 
 Javanicum, 606 
 
 Juglandis, 606 
 
 Macrocarpum, 605 
 
 Orchidis, 605 
 
 Oryzae, 605 
 
INDEX 
 
 707 
 
 Cladosporium, Oxycocci, 606 
 
 Pconiae, 600 
 
 Pisi, 605 
 
 Scabies, 606 
 
 Scribnerianum, 606 
 
 Sicophilum, 604 
 
 Tuberum, 606 
 
 Zeai, 606 
 
 Cladosterigma, 634 
 Cladotrichum, 601 
 Clanostachys theobromse, 206 
 Clasterosporium, 60S, 609 
 
 Amygdalearum, 610 
 
 Carpophilum, 500, 610 
 
 Glomerulosum, 610 
 
 Putrefaciens, 610 
 
 Clathracese, 462, 463 
 
 Key to, 463 
 
 Clathrus, 464 
 Claudopus, 449 
 Clautriavia, 462 
 Clavaria, 412 
 Clavariacete, 402, 412 
 
 Key to, 412 
 
 Claviceps, 199, 211, 211, 213, 215, 643 
 
 Microcephala, 213 
 
 Paspali, 213 
 
 Purpurea, 212, 643 
 
 Rolfsii, 213 
 
 ClavicipitejE, 196, 197 
 — Key to, 199 
 Cleistotheca, 190 
 .Clematis, 43, 178, 179, 390, 492, 544, 
 
 563 
 Clinoconidium, 640 
 Clithris, 156, 157, 157 
 
 Aureus, 157 
 
 Juniperus, 157 
 
 — — - Quercina, 157 
 Clitocybe, 450, 457, 459, 569 
 
 Parasitica, 458 
 
 Clitopilus, 450 
 Clivia, 656 
 Clonostachys, 584 
 Clostridium Butyricum, 13 
 Persicae tuberculosis, 63 
 
 Clove, 415 
 
 Clover, 71, 74, 97, 143, 187, 206, 220, 
 221, 258, 373, 374, 494, 543, 551, 
 569, 582, 593, 606, 619, 630 
 
 Clusia, 560 
 
 Clypeosphajria, 276 
 
 Clypeospha?riacea\ 223, 276 
 
 Key to, 276 
 
 Coccaceaj, 18, 21 
 
 Cocci, 13 
 
 Coccomyces, 156, 563 
 
 Cocconia, 156 
 
 Coccophacidium, 156 
 
 C'occospora, 566 
 
 Coccosporella, 566 
 
 Coccosporium, 616 
 
 Cocoa, 88 
 
 Cocoanut, 43, 191, 193, 433, 512, 
 513 
 
 Codiaeum, 496, 544 
 
 Coemansia, 583 
 
 Coemansiella, 571 
 
 Coffee, 168, 170, 192, 193, 195, 205, 
 207, 249, 250, 277, 356, 409, 415, 
 486, 500, 504, 512, 515, 525, 543, 
 553, 583, 591, 597, 635, 643, 660 
 
 Colchicum, 375, 563 
 
 Coleosporiacea?, 335 
 
 Key to, 336 
 
 Coleosporium, 326, 333, 336, 390, 391 
 
 Campanula", 339 
 
 Ipomoeae, 337 
 
 Pini, 339 
 
 Senecionis, 338, 338 
 
 Solidaginis, 337, 337 
 
 Coleroa, 226, 227, C58 
 
 Chsetomium, 227, 227 
 
 Sacchari, 227 
 
 Collacystis, 527 
 
 Collard, 25, 95, 619 
 
 CoUetotrichum, 147, 264, 267, 268, 
 538, 539, 540, 547 
 
 • Agaves, 552 
 
 Altha;ae, 552 
 
 Ampelinum, 549 
 
 Anthurii, 662 
 
708 
 
 INDEX 
 
 CoIIetotrichum, Antirrhini, 553 
 
 Bletise, 552 
 
 Brachytrichum, 553 
 
 Camellia?, 553 
 
 Carica, 549, oJ^O 
 
 Cereale, 550, noO 
 
 Cincta, 269, 547 
 
 Coffeanum, 553 
 
 Cradwickii, 553 
 
 Cyclamena', 553 
 
 Dracsenae, 553 
 
 Elasticse, 552 
 
 Falcatum, 549 
 
 Gloeosporioides, 549 
 
 Gossypii, 267, 272, 547 
 
 Hedericola, 553 
 
 Hevese, 553 
 
 Incarnatum, 553 
 
 Kentise, 552 
 
 Lagenarium, 548 
 
 Lineola, 550 
 
 Lindemuthianum, 267, 543, 547, 
 
 Luxificum, 552 
 
 Macrosporum, 553 
 
 Malvarum, 552 
 
 Nigrum, 551 
 
 Oligochffitum, 548 
 
 Omnivorum, 552 
 
 — ^ Phomoides, 551 
 
 Piperitum, 551 
 
 PoUaccii, 553 
 
 Primulse, 552 
 
 Rubicolum, 270, 5^7 
 
 Schizanthi, 552 
 
 Spinaciaj, 551 
 
 Theobroma;, 553 
 
 Theobromicolum, 553 
 
 Trifolii, 551 
 
 Violse-tricoloris, 552 
 
 cGollodochium, 640 
 CoUonema, 517 
 Collybia, 450, 458 
 
 Velutipes, 458, ^60 
 
 Columbine, 507 
 Colus, 464 
 
 Colutea, 187 
 
 Completoria, 107 
 
 Complens, 108 
 
 Composite, 82, 92, 95, 178, 386 
 
 Comptonia, 352 
 
 Conidiobolus, 107 
 
 Conifers, 132, 145, 159, 161, 162, 203, 
 229, 235, 350, 390, 417, 418, 423, 
 431, 436, 452, 512, 547, 559, 579, 
 654 
 
 Coniocybe, 153 
 
 Pallida, 153 
 
 Coniophora, 405 
 
 ConiosporieEe, 594, 595 
 
 Key to, 595 
 
 Coniosporium, 595, 595 
 
 Filicinum, 595 
 
 Onobrychidis, 595 
 
 Coniothecium, 615 
 
 Chomatosporum, 617 
 
 Coniothyrium, 245, 257, 501, 503 
 
 Anomale, 504 
 
 Brevisporum, 504 
 
 Coffea;, 504 
 
 Concentricum, 503 
 
 Diplodiella, 263, 504, 604 
 
 Fuckelii, 257, 258, 503 
 
 Hellebori, 505 
 
 Japonicum, 504 
 
 Megalospora, 228 
 
 Melastorum, 503 
 
 Pyriana, 503 
 
 Scabrum, 504 
 
 Tumefaciens, 503 
 
 Vagabundum, 504 
 
 Wernsdorffiaj, 505 
 
 Conjugate, 3 
 
 Conjugate division, 321, 331, 332 
 
 Convallaria, 494 
 
 Convolvulacese, 82 
 
 Coprinese, 442 
 
 Corallodendron, 633 
 
 Corallomyces, 199 
 
 Cordana, 602 
 
 Cordieritidacese, 134 
 
 Cordyceps, 199 
 
INDEX 
 
 709 
 
 Coremium, 230, G34, 635, 635 
 
 Coreopsis, 176 
 
 Corethropsis, 571 
 
 Coronella, 570 
 
 Corn, 34, 52, 90, 101, 308, 310, 312, 
 
 329, 408, 511, 512, 606, 613, 614, 
 
 650 
 Cornularia, 517 
 Cornus, 188, 191, 279, 524 
 Coronophora, 281 
 Corpyha, 560 
 Corticium, 403, 405, 406, 409 
 
 ■ Chrysanthemi, 409 
 
 Comedens, 409 
 
 Dendriticum, 409 
 
 Javanicum, 409 
 
 La;tum, 408 
 
 Lilacino-fuscum, 409 
 
 Vagum-solani, 404, J^06, 407, 
 
 660 
 
 Zimmermannii, 409 
 
 Cortinarius, 449 
 
 Corydalis, 344 
 
 Corylus, 188, 408, 530, 545, 557 
 
 Corymbomyces, 583, 584, 584 
 
 Albus, 205, 584 
 
 Coryneliacese, 222 
 Corynespora, 629 
 Corynetes, 131 
 Coryneum, 558, 560, 564, 658 
 
 Beijerinckii, 236, 237, 560, 561 
 
 Camellise, 561 
 
 Folliicolum, 561 
 
 Juniperinum, 560, 658 
 
 Modonia, 560 
 
 Mori, 561 
 
 Cosmonectria, 201 
 
 Cosmos, 493 
 
 Costinellus, 450 
 
 Cotton, 29, 36, 43, 249, 267, 272, 303, 
 
 361, 408, 411, 486, 492, 547, 589, 
 
 619, 625, 650, 651 
 Cotton-wood, 437 
 Cotoneaster, 366 
 Couturea, 515 
 Cowpea, 187, 487. 521, 535, 651 
 
 Cranberry, 71, 140, 225, 231, 267, 277, 
 397, 486, 495, 500, 520, 525, 529, 
 536, 543, 559, 606, 614 
 Crandallia, 532 
 Crataegus, 130, 183, 188, 255, 366, 
 
 367, 368, 569 
 Craterellus, 406 
 Craterium, 12 
 Creonectrieaj, 196 
 Cribrariaceae, 9 
 Crocicreas, 481 
 Crocus, 121, 143 
 Cronartium, 341, 350, 351, 390, 391 
 
 Asclepiadeum, 352 
 
 Comptoniae, 352, 352 
 
 Quercus, 352, 390 
 
 Ribicola, 350 
 
 Crotalaria, 408 
 
 Crotonocarpia, 226 
 
 Crown gall, 12 
 
 Crucifer, 6, 25, 41, 43, 69, 81, 95, 616, 
 
 619, 621 
 Crumenula, 150 
 Cryptocoryncum, 608 
 Crjqjtodcris, 263 
 Cryptomela, 553 
 Cryptomyces, 156, 158 
 
 Maximus, 158 
 
 Cryptospora, 279 
 Cryptosporella, 279, 280 
 
 Anomala, 280 
 
 Viticola, 280, 282, 498 
 
 Cryptosporiuni, 562, 564 
 
 Leptostromiforme, 564 
 
 Minimum, 564 
 
 Cryptostictis, 515, 516, 516 
 
 Caudata, 516 
 
 Cynosbati, 516 
 
 Cucumber, 44, 45, 46, 51, 52, 76, 95, 
 
 141, 247, 404, 487, 543, 548, 569, 
 
 604, 606, 608, 615, 617, 629, 
 
 652 
 Cucumis, 178 
 Cucurb, 6, 51, 94, 95, 107, 178, 179, 
 
 487, 509, 521, 539, 548, 651 
 Cucurbita, 178 
 
710 
 
 INDEX 
 
 Cucurbitaria, 234 
 
 Berberdis, 235, 235 
 
 Elongata, 235 
 
 Laburni, 235 
 
 Picese, 235 
 
 Pityophila, 235 
 
 ■ Sorbi, 235 
 
 Cucurbitariaceaj, 222, 234 
 
 Key to, 234 
 
 Cudoniese, 131 
 
 Cuphea, 187 
 
 Cupressus, 369 
 
 Currant, 92, 148, 155, 203, 207, 284, 
 
 351, 433, 499, 500, 519, 542, 626 
 Curry a, 216 
 Curryella, 216 
 Cuttings, 644 
 Cyanocephalium, 198 
 CyanophyceEe, 3 
 Cyanospora, 232, 233 
 
 Albicedra;, 233, 283 
 
 Cyathicula, 136 
 Cycad, 248, 516 
 Cyclamen, 52, 168, 268, 488, 492, 522, 
 
 553 579 
 Cycloconium, 601, 602, 603 
 
 Oleaginum, 603 
 
 Cyclomyces, 417 
 Cyclostomella, 163 
 Cydonia, 366, 368 
 Cylindrium, 568 
 Cylindrocephalum, 571 
 Cylindrocladium, 586 
 Cylindrocolla, 641 
 Cylindrodendrum, 577 
 Cylindrophora, 576 
 Cylindrosporium, 243, 562, 662 
 
 Castanicolum, 249, 562 
 
 Cercosporoides, 564 
 
 Chrysanthemi, 563 
 
 Clematidis, 563 
 
 Jackmani, 563 
 
 Colchici, 563 
 
 Humuli, 563 
 
 Inconspicuum, 563 
 
 Mori, 249, 525, 562 
 
 Cylindrosporium, Orni, 564 
 
 Padi, 562, 562, 563 
 
 Pomi, 563, 563 
 
 Quercus, 564 
 
 Saccharinum, 563 
 
 Tubeufianum, 563 
 
 Viridis, 564 
 
 Cylindrotrichum, 575 
 
 Cymbridium, 547 
 
 Cynachum, 352 
 
 Cynodon, 221 
 
 CyperaceaJ, 303 
 
 Cyperus, 89, 303, 408 
 
 Cyphella, 406 
 
 Cystophora, 598 
 
 Cytisus, 235, 253, 375, 610 
 
 Cytodiplospora, 505 
 
 Cytoplea, 501 
 
 Cytospora, 209, 279, 483, 499, 499 
 
 Acerina, 499 
 
 — — Ceratophora, 499 
 
 Palmarum, 499 
 
 Rubescens, 278 
 
 • Sacchari, 499 
 
 Cytosporella, 483, 498 
 
 Cerei, 499 
 
 Citri, 499 
 
 Damnosa, 499 
 
 Persicse, 499 
 
 Cytosporina, 518, 526, 526 
 
 Ribis, 526 
 
 Cytosporium, 516 
 Cystothyrium, 531 
 Cystotricha, 505 
 Cyttariacese, 134 
 
 D 
 
 Dacromycetales, 395, 396 
 Dacryodochium, 641 
 Dacrymycella, 640 
 Dactylaria, 588 
 Dactylella, 588 
 Dactylium, 588 
 Dactylopias, 194 
 Dactylosporium, 616 
 
INDEX 
 
 711 
 
 Dadap, 411 
 Daedalea, 417, 439 
 
 Quercina, 439, UO 
 
 Dahlia, 43, 178, 492, 645 
 Daisy, 36 
 Daldinia, 285 
 Dammara, 489 
 Damping Off, 77 
 Dandelion, 71, 119, 378, 590 
 Daphne, 544 
 Darluca, 335, 505 
 Darwinella, 216 
 Dasyscypha, 135, 144, /44 
 
 Abietis, 145 
 
 Calyciforniis, 145 
 
 Resinaria, 145 
 
 Subtilissima, 145 
 
 Willkommii, /44, 145 
 
 Date, 169, 310 
 Datura, 48 
 Daucus, 178 
 Deconica, 449 
 Delacourea, 252 
 Delitschia, 224 
 Delphinium, 178, 321 
 Dematiacese, 565, 594 
 
 Key to, 594 
 
 AmerosporiE, 594, 599 
 
 Key to, 599 
 
 Dictyosporse, 594, 615 
 
 Key to, 615 
 
 Didymospora;, 599, 601 
 
 Key to, 601 
 
 Heliocosporse, 594 
 
 Phragmosporse, 594, 608 
 
 Key to, 608 
 
 Saturosporse, 594 
 
 Scolecosporse, 594, 625 
 
 Key to, 625 
 
 Dematium, 217, 600 
 
 Prunastri, 495 
 
 Dematophora, 230 
 
 Glomerata, 201 
 
 Necatrix, 230, 2S1 
 
 Dendrodochium, 640, 643 
 Lycopersici, 643 
 
 Dendrographium, 637 
 Dcndrophagus Globosus, 12 
 Dendrophoma, 481, 494, J^9l^ 
 
 Convallaria', 494 
 
 Marconii, 494 
 
 Valsispora, 494 
 
 Dendrostilbella, 633 
 Dendryphieai, 609, 615 
 Dendryphium, 615 
 
 Cornosum, 615 
 
 Dermatea, 151, 152, 152 
 
 Acerina, 152 
 
 Carpinea, 152 
 
 Cinnamomea, 162 
 
 Prunastri, 152 
 
 Dermateaj, 150 
 Dcsmazierella, 135 
 Desmodium, 187, 188 
 Dewberry, 648 
 Diachnai, 11 
 Diachora, 216, 217 
 
 Onobrychidis, 217 
 
 Dialonectria, 201, 205 
 
 Dianthus, 101, 312, 328, 375, 387, 
 
 488, 507, 619, 654 
 Diaphanium, 639 
 Diaporthe, 277, 278, 279, 490, 498 
 
 Albocarnis, 279 
 
 Ambigua, 279, 490 
 
 Parasitica, 209 
 
 Sarmentella, 279, 490 
 
 Strumella, 279, 499 
 
 Taleola, 279 
 
 Diatomese, 3 
 Diatrypaceaj, 223, 281 
 
 Key to, 281 
 
 Diatrypea;, 281 
 DichsenacejE, 160, 162 
 Dichea, 162 
 
 Faginea, 162 
 
 Quercina, 162, 16S 
 
 Dicheirinia, 353 
 Dichlsena, 527 
 Dichomera, 516 
 Dicoccum, 601, 602 
 Rosae, 602 
 
712 
 
 INDEX 
 
 Dicotyledones, 203 
 Dictyophora, 462, 463 
 Dictyosporse, 633 
 Dictyosporium, 615 
 Dictyuchus, 75 
 
 Monosporus, 75 
 
 Dicyma, 598 
 Di derma, 10 
 
 Didymaria, 586, 587, 587 
 Didymella, 251, 255, 256 
 
 Citri, 256 
 
 Didymiacese, 10 
 
 Key to, 10 
 
 Didymium, 9, 10 
 
 Daedalium, 10 
 
 Didymochseta, 505 
 Didymocladium, 586 
 Didymopsis, 586 
 Didymopsora, 342 
 Didymosphseria, 251, 25f>, 256 
 
 Catalpa;, 256 
 
 Epidermidis, 256 
 
 Populina, 256 
 
 Spheroides, 256 
 
 Didymosporse, 633 
 Didymosporium, 556, 556 
 
 Salicinum, 556 
 
 Dieback, 278 
 
 Diervilla, 178 
 
 Dietelia, 342 
 
 Digitalis, 100, 488, 507 
 
 Digitaria, 591 
 
 Dill, 377 
 
 Dilophia, 251, 257, 525, 590 
 
 Graminis, 256, 257, 525 
 
 Dilophospora, 518, 525, 525 
 
 Graminis, 257, 525 
 
 Dimargaris, 572 
 Dimerosporium, 189, 191 
 
 CoIIinsii, 191 
 
 Mangiferum, 191 
 
 Pulchrum, 191, ir,'l, 625 
 
 Dinemasporium, 534, 535, 535 
 
 Oryzae, 535 
 
 Dinoflagellates, 3 
 Diospyrus, 183 
 
 Diplocladium, 200, 586, 653 
 Diplococcium, 602, 603 
 
 Conjunctum, 603 
 
 Diplodia, 243, 510, 511, 511, 
 513 
 
 Aurantii, 512 
 
 Cacaoicola, 512 
 
 Cerasorum, 512 
 
 Citricola, 512 
 
 Coffeicola, 512 
 
 Destruens, 512 
 
 Epicocos, 512 
 
 Gongrogena, 512 
 
 Heteroclita, 512 
 
 Macrospora, 511 
 
 Mori, 512 
 
 Natalensis, 512 
 
 Opuntise, 612 
 
 Oryzeaj, 512 
 
 Perseana, 512 
 
 Pinea, 512 
 
 Rapax, 512 
 
 Sapinea, 512 
 
 Zea;, 511 
 
 Diplodiella, 510, 512, 512 
 
 Oryzae, 512 
 
 Diplodina, 247, 505, 509, 509 
 
 Castanese, 509, 509 
 
 Citrullina, 247, 509 
 
 Corticola, 509 
 
 Parasitica, 509 
 
 Salicina, 509 
 
 Diplodiopsis, 510 
 Diplophysa, 73 
 Diplorhinotrichum, 585 
 Diplosporium, 586 
 Dipsacus, 176, 178 
 Discella, 536, 536 
 
 Cacaoicola, 536 
 
 Discocyphella, 406 
 Discomycetes, 116, 117, 123, 159 
 Discomycopsella, 531 
 Discomycopsis, 501 
 Discosia, 531 
 
 Pini, 531 
 
 Discula, 534, 535, 535 
 
 511, 
 
INDEX 
 
 713 
 
 Discula, Platani, 274, 535 
 Dispira, 572 
 Ditopella, 263, 264 
 
 Ditopa, 264 
 
 Fusispora, 264 
 
 Doassansia, 301, 315, 322, 322 
 
 Gossypii, 323 
 
 NiessUi, 322 
 
 Dogwood, 158, 203 
 Dolichos, 373 
 Doratomyces, 571 
 Doscocolla, 645 
 Dothichiza, 534, 535, 535 
 
 Ferruginosa, 152 
 
 Populea, 535 
 
 Dothidiaceae, 215 
 
 Key to, 216 
 
 DothichlcE, 210 
 
 Aristida), 210 
 
 Atramentosa, 210 
 
 Dothidea, 216, 218, 220 
 Noxia, 220 
 
 Rosa;, 220 
 
 Dothidella, 219, 221 
 
 Betulina, 221 
 
 Thoracella, 221 
 
 Ulmi, 221 
 
 Dothidiacese, 215 
 
 Key to, 216 
 
 Dothidiales, 124, 195, 215 
 
 Dothiochloe, 199 
 
 Dothiopsis, 483 
 
 Dothiora, 155, 156 
 
 Virgultorum, 157 
 
 Dothiorella, 284, 483, 499 
 
 Mori, 499, 499 
 
 Populi, 499 
 
 Ribis, 499 
 
 Dothiorellina, 483, 499 
 
 Tankoffii, 499 
 
 Double Blossom, 648 
 
 Downy Mildew, 82 
 
 Dracsna, 270, 487, 489, 497, 503, 
 553 
 
 Dracaenacea;, 303 
 
 Drepanospora, 609 
 
 Drupe, 139, 236, 237, 410, 486 
 Durio, 221 
 Dusiella, 211 
 Dyctilium, 200 
 
 E 
 
 Earlea spiciosum, 359 
 Eccilia, 450 
 Echinobotryeae, 594 
 Echinodontium, 414, 415 
 
 Tinctorium, 415 
 
 Echinodorus, 315 
 Echinodothis, 199, 211 
 
 Tuberiformis, 211 
 
 Ectostroma, 657 
 
 Ectrogella, 68 
 
 Egg plant, 37, 42, 47, 204, 268, 408, 
 
 487, 491, 508, 539, 540, 580, 617 
 Elaphomycetacese, 165 
 Elder, 185, 393 
 Eleutheromyces, 197 
 Elm, 71, 127, 130, 182, 221, 249, 260, 
 393, 421, 430, 437, 455, 484, 489, 
 503, 530, 544, 557, 608 
 Emericella, 167 
 Emmer, 206, 550 
 Enchnoa, 262 
 Endive, 377 
 
 Endobotrya, 516 
 
 Endoconidium, 146, 639, 641, 641 
 
 Temulentum, 642 
 
 Endogone, 118 
 
 Endomyces, 122 
 
 Decipiens, 123 
 
 Mali, 122, 123, 123 
 
 Parasitica, 123 
 
 Endomycetacese, 120, 122, 165 
 
 Key to, 122 
 
 Endophyllum, 342, 353 
 
 Sempervivi, 353 
 
 Endothia, 283 
 
 Entoloma, 450 
 
 Entomogenous fungi, 194 
 
 Entomophthoraceae, 107 
 
714 
 
 INDEX 
 
 Entomophthorales, 66, 102, 107 
 
 Key to, 107 
 
 Entomosporium, 243, 531, 532, 532 
 
 Maculatum, 149, 532 
 
 Mespili, 150, 532 
 
 Thumenii, 632 
 
 Entyloma, 314, 320 
 
 Australe, 322 
 
 Betiphilum, 321 
 
 Calendulse, 321 
 
 Crastophilum, 321 
 
 Ellisii, 321, 321 
 
 Fuscum, 322 
 
 Irregulare, 321 
 
 Lephroideum, 321 
 
 Polysporum, 321 
 
 Enzymes, 2 
 Ephelis, 209, 537 
 Epichloe, 199, 210, 210, 211 
 
 Typhina, 210, 643 
 
 Epicoccum, 655, 656, 656 
 
 Hyolopes, 656 
 
 Epidochiopsis, 641 
 Epidochium, 655, 656 
 
 Oryzse, 656 
 
 Epilobium, 347 
 
 Epochnium, 601 
 
 Eremascus, 122 
 
 Ergot, 213 
 
 Erica, 617 
 
 EricaceiB, 143, 159, 186, 397 
 
 Erigeron, 89 
 
 Erinella, 136 
 
 Eriobotrys, 607 
 
 Eriocaulacea), 303 
 
 Eriopeziza, 135 
 
 Eriospora, 518 
 
 Eriosporangium, 355 
 
 Eriosporina, 515 
 
 Eriothyrium, 528 
 
 Erysiphaceai, 117, 166, 170, 171, 176, 
 
 192 
 
 Key to, 174 
 
 Erysiphales, 332, 475, 494, 569 
 Erysiphe, 117, 143, 166, 172, 173, 
 
 175, 177 
 
 Erysiphe, Cichoracearum, 174, 178, 
 178, 569 
 
 Graminis, 171, 179, 179, 569 
 
 Liriodendri, 178 
 
 Martii, 178 
 
 Polygoni, 177, 177, 178, 187 
 
 Taurica, 179 
 
 Umbelliferarum, 178 
 
 Erysiphea, 260 
 Euascomycetes, 117, 123 
 
 Key to, 123 
 
 Eubacteriales, 18 
 Eubasidii, 299 
 Eubasidiomycetes, 394 
 
 Key to, 394 
 
 Eucalyptus, 310, 560 
 Eumycetes, 1, 3, 59 
 
 Key to, 64 
 
 Eunectria, 201, 202 
 
 Euphorbia, 187, 329, 330, 372, 374, 
 
 375 
 Eurotiopsis, 167, 527 
 Eusclerotinia, 137 
 Eutaphrina, 127 
 Eutypa, 278 
 Eu-type, 328 
 Excipula, 534 
 Excipulacese, 479, 533 
 
 Key to, 533 
 
 Hyalodidyma;, 533, 537 
 
 Key to, 536 
 
 Hyalophragmiae, 533, 536 
 
 Hyalosporae, 533 
 
 Key to, 534 
 
 Phseophragmiae, 533, 536 
 
 Phseospora;, 533 
 
 Scolecospora?, 533, 536 
 
 Key to, 536 
 
 Excipularia, 657 
 Exoascacese, 125 
 
 Key to, 126 
 
 Exoascales, 396 
 Exoascus, 125, 127 
 Exobasidiales, 125, 395, 396 
 
 Key to, 396 
 
 Exobasidium, 396 
 
INDEX 
 
 715 
 
 Exobasidium, Andromedse, 396, 397 
 
 Azalese, 398 
 
 Cinnamomi, 398 
 
 Japonicum, 398 
 
 Lauri, 398 
 
 Oxycocci, 397 
 
 Peckii, 398 
 
 Rhododendri, 398 
 
 Vaccinii, 397 
 
 Vexans, 397 
 
 Vitis, 398 
 
 Exosporina, 656, 656 
 
 Laricis, 656 
 
 Exosporium, 227, 657, 658 
 
 Juniperinum, 560, 658 
 
 Laricinum, 658 
 
 Palmivorum, 658, 658 
 
 Preslii, 658 
 
 Rubinus, 227 
 
 Tiliai, 658 
 
 Fabacese, 303 
 Fabrsa, 147, 243 
 
 Malculata, 149, 149, 532 
 
 Mespili, 150, 532 
 
 Fagopyrum, 178 
 Fagus, 188, 545 
 Farlowiella, 160 
 Favolus, 417, 439 
 
 Australis, 438 
 
 Europa^us, 43S, 439 
 
 Fenestrella, 278 
 
 Ferments, organic, 2 
 
 Fern, 77, 108, 126, 250, 581, 595 
 
 Festuca, 180, 310, 383, 635 
 
 Ficaria, 375 
 
 Ficus, 205, 249, 267, 278, 533, 544, 
 
 552 
 Fig, 22, 169, 310, 346, 408, 549, 564, 
 
 572, 573, 604, 624, 626, 643 
 Filbert, 280 
 Fimbrystylis, 303 
 Fir, 132, 145, 162, 192, 203, 276, 
 
 320, 347, 349, 418, 424, 431, 434, 
 
 438, 440, 465, 490, 492, 493, 507, 
 
 568, 581, 657 
 Fission, 14 
 Fistulina, 440, 441 
 
 Hepatica, 441, 442 
 
 Fistulinea;, 440 
 Flagella, 14 
 Flammula, 449, 452 
 
 Alnicola, 452 
 
 Penetrans, 452 
 
 Spumosa, 452 
 
 Flax, 69, 343, 653 
 Floccomutinus, 462 
 Fodder, 599 
 Fomes, 417, 418, 663 
 
 Annosus, 431 
 
 Applanatus, 433, 436 
 
 Australis, 437 
 
 Carneus, 430 
 
 Everhartii, 430 
 
 Fomentarius, 426, 429, 429 
 
 Fraxinophilus, 433 
 
 Fulvus, 433 
 
 Fulvus olesc, 433 
 
 Hartigii, 434 
 
 Igniarius, 401, 428, 428, 429, 433, 
 
 434 
 
 Juniperinus, 431 
 
 Laricis, 432 
 
 Lucidus, 433 
 
 Marmoratus, 434 
 
 Nigricans, 433 
 
 Pinicola, 435, 436 
 
 Ribis, 432 
 
 Robiniae, 434 
 
 Semitosus, 437 
 
 Sessilis, 435 
 
 Ulmarius, 437 
 
 Forget-me-not, 101 
 Form Genera, 476 
 Forsythia, 621 
 Fox Tail, 90 
 Fracchia?a, 234 
 Fragaria, 176, 244 
 Fraxinus, 188 
 Fruits, 106 
 
716 
 
 INDEX 
 
 Fuckelia, 152, 155, 483, 500 
 
 Ribis, 500 
 
 Fuligo, 11, 12, 200 
 
 Fumago, 191, 616, 624 
 
 Camellia;, 194, 625 
 
 Fungi, 1, 3 
 
 Classification, 64 
 
 Imperfecti, 64, 475 
 
 Key to, 479 
 
 Slime. See Mycomycetes. 
 
 True, 1, 2, 59 
 
 Funkia, 489 
 
 Fusariella, 608 
 
 Fusarium, 201, 204, 203, 475, 571, 
 645, 646 
 
 Acuminatum, 652 
 
 iEruginosum, 652 
 
 Affine, 652 
 
 Aurantiacum, 651 
 
 ■ Avenaceum, 206 
 
 Blasticola, 654 
 
 Brassica?, 654 
 
 Cocruleum, 647, 648, 652 
 
 Commutatum, 648, 652 
 
 Cubense, 649 
 
 Cucurbitariae, 652 
 
 Culmorum, 206, 649, 6^9 
 
 Decemcellulare, 654 
 
 Dianthi, 654 
 
 Didymium, 647, 652 
 
 Diplosporum, 652 
 
 Discolor, 648 
 
 Sulphureum, 648 
 
 Erubescens, 653 
 
 — — Falcatum, 648 
 
 Gemmiperda, 649 
 
 Gibbosum, 648 
 
 Heterosporum, 206 
 
 — Hordei, 206 
 
 Incarnatum, 654 
 
 Limonis, 649 
 
 Lini, 653, 653 
 
 Lycopersici, 653 
 
 Martii, 648 
 
 Metachroum, 648 
 
 Moniliforme, 650 
 
 Fusarium, Nivale, 205 
 
 Niveum, 651 
 
 Oxysporum, 648, 651, 652, 653 
 
 Pelargonii, 654 
 
 Pestis, 652 
 
 Pini, 654 
 
 Platani, 205, 648 
 
 Putrefaciens, 649 
 
 Rhizogenum, 649 
 
 Ricini, 654 
 
 Roseolum, 652 
 
 Roseum-lupini-alba, 652 
 
 Rubi, 648 
 
 Rubiginosum, 647, 648 
 
 Solani, 204, 585, 648, 652 
 
 Subulatum, 648 
 
 Tabacivorum, 654 
 
 Theobromse, 648, 654 
 
 ITdum, 651 
 
 Vasinfectum, 205, 650, 650, 651 
 
 Pisi, 648, 651 
 
 Tracheiphila, 651 
 
 Violaceum, 652 
 
 Violae, 654 
 
 Wilkommii, 648 
 
 Fusella, 595 
 Fusicladium, 253, 602, 606 
 
 Betula?, 255, 607 
 
 Cerasi, 255, 606 
 
 Dendriticum, 253, 255, 607 
 
 Depressum, 607 
 
 Destruens, 607 
 
 Effusum, 607 
 
 Eriobotryse, 607 
 
 Fagopyri, 607 
 
 Fraxini, 255, 606 
 
 Lini, 607 
 
 Orbiculatum, 255, 607 
 
 Pirinum, 253, 607 
 
 Saliciperdum, 606 
 
 Tremulse, 255, 607 
 
 Vanilla;, 607 
 
 Fusicoccum, 274, 280, 483, 498 
 
 Amygdali, 498 
 
 Bulgarium, 498 
 
 Perniciosum, 281, 498 
 
INDEX 
 
 717 
 
 Fusicoccum, Veronense, 275, 498 
 
 Viticolum, 498, 498 
 
 Fusicolla, 639 
 
 Fusidium, 201, 203, 5G7, 568 
 
 Candidum, 568 
 
 Fusisporium solani, 648 
 Fusoma, 588, 590 
 Parasiticum, 590 
 
 G 
 
 Galera, 449 
 Gallowaya, 339 
 Gamospora, 517 
 Gamosporclla, 483 
 Gaphiothecium, 630 
 Garden-pea, 408 
 Garlic, 97 
 
 Gasteromycetes, 395 
 Gaylussacia, 397 
 Geaster, 465 
 Gelatinosporium, 518 
 Geminispora, 263 
 Gemmae, 60 
 Gentiana, 352, 389 
 Geoglossacese, 131, 154 
 
 Key to, 131 
 
 Geoglosseaj, 131 
 Geoglossum, 131 
 Geotrichum, 568 
 Geranium, 52, 315, 390, 591, 603, 631, 
 
 654 
 Gherkin, 247 
 Gibbellina, 251, 256 
 
 Cerealis, 256 
 
 Gibellula, 634 
 Gibbera, 234 
 — Vaccinii, 234, 235 
 Gibberella, 198, 206, 646 
 
 Cerealis, 207 
 
 Moricola, 207 
 
 Saubineitii, 206, 206 
 
 Gibberidea, 234 
 Gibelia, 283 
 Ginger, 77 
 
 Ginkgo, 267 
 
 Ginseng, 39, 88, 141, 496, 559, 585, 
 
 622, 651 
 Giulia, 532 
 
 Gladiolus, 250, 318, 320, 389 
 Gleditschia, 2G7 
 Glenospora, 599 
 Gliobotrys, 570 
 Gliocephalus, 570 
 Gliocladium, 574 
 
 Agaricinum, 574 
 
 Gliodcladium, 572, 574 
 
 Globaria, 465 
 
 Gla^ocephala, 412 
 
 Gloeoporus, 417 
 
 Gloeosphajra, 583 
 
 Gloeosporium, 147, 252, 264, 266, 267, 
 
 269, 274, 475, 478, 538, 539, 547 
 
 Affine, 544 
 
 Alborubrum, 544 
 
 Allescheri, 545 
 
 Alneum, 545 i 
 
 Ampelophagum, 541 
 
 Amygdalinum, 542 
 
 Anthuriophilum, 544 
 
 Apocryptum, 545 
 
 Aquiligise, 544 
 
 Atrocarpi, 273, 541 
 
 Begonise, 544 
 
 Berberidis, 546 
 
 Betularum, 545 
 
 Betulinum, 545 
 
 Beyrodtii, 544 
 
 Bicolor, 541 
 
 Bidgoodii, 544 
 
 Bruneum, 544 
 
 Cactorum, 544 
 
 Canadense, 546 
 
 Carpini, 545 
 
 Caryae, 545 
 
 Cattleya;, 544 
 
 Caulivorum, 543 
 
 Cinctum, 541 
 
 Cingulatum, 268, 541 
 
 Citri, 541 
 
 Clematidis, 544 
 
718 
 
 INDEX 
 
 Gloeosporium, Coffeanum, 543 
 
 Concentricum, 544 
 
 Coryli, 545 
 
 Crotonis, 544 
 
 Curvatum, 542 
 
 Cydonise, 542 
 
 Cylindrospermum, 541 
 
 Cytisi, 544 
 
 Depressum, 541 
 
 Dianthi, 544 
 
 Diospyri, 542 
 
 Elastica;, 267, 544 
 
 Euphobiae, 544 
 
 Fagi, 545 
 
 Fagicolum, 544 
 
 — — Fragaria", 542 
 
 Fructigenum, 267, 539 
 
 Helicis, 544 
 
 Hendersonii, 541 
 
 Inconspicuum, 544 
 
 Intermedium, 541 
 
 Juglandis, 545 
 
 Kawakami, 546 
 
 Laeliae, 544 
 
 Laeticolor, 267, 539 
 
 Lagenarium, 543 
 
 Macropus, 253, 541 
 
 Malicorticis, 493, 542, 5Jt2 
 
 Mangiferse, 543 
 
 Manihotis, 543 
 
 Medicaginis, 543 
 
 Melengonea, 539 
 
 Mezerei, 544 
 
 — Minus, 543 
 
 Morianum, 543 
 
 Musarum, 542 
 
 Importatum, 542 
 
 Myrtilli, 543 
 
 Nanoti, 546 
 
 Nervicolum, 545 
 
 Nervisequum, 274, 541 
 
 Olivarum, 543 
 
 OpuntiiE, 544 
 
 Pallidum, 544 
 
 Paradoxicum, 157, 541 
 
 Pelargonii, 544 
 
 Gloeosporium, Pestis, 643 
 
 Piperatum, 269, 541 
 
 Platani, 274 
 
 Psidii, 271, 541 
 
 Quercinum, 545 
 
 Rhododendri, 544 
 
 Ribis, 148, 541 
 
 Rosae, 544 
 
 Rufomaculans, 265, 235, 267, 
 
 539 
 
 Saccharini, 545 
 
 Salicis, 148, 541 
 
 Soraurianum, 544 
 
 Spegazzinii, 541 
 
 Stanhopeicola, 544 
 
 Tamarindi, 546 
 
 Thea, 544 
 
 Sinensis, 544 
 
 Tiliaceum, 545 
 
 Tilia;, 545 
 
 Tremulse, 545 
 
 Trifolii, 543 
 
 Umbrinellum, 544 
 
 VanilliE, 280, 541 
 
 Variabile, 542 
 
 Venetum, 542 
 
 Versicolor, 267, 539 
 
 Violse, 544 
 
 Gloesporiella, 555 
 
 Glomerella, 263, 264, 475, 539, 547 
 
 Atrocarpi, 273, 541 
 
 Cactorum, 265 
 
 Cincta, 269, 270, 541, 547 
 
 Cingulata, 268, 541 
 
 Gossypii, 267, 271, 272, 273, 
 
 547 
 
 Piperata, 269, 270, 271, 541 
 
 Psidii, 270, 541 
 
 Rubicolor, 270, 547 
 
 Rufomaculans, 264, 265, 266, 
 
 267, 268, 269, 270, 271, 272, 539, 
 
 541, 548 
 
 Cyclaminis, 268 
 
 Glomerularia, 566 
 Gloniella, 161 
 Glonium, 163 
 
INDEX 
 
 719 
 
 Clumaceae, 199 
 
 Glutinium, 481, 630 
 
 Glyceria, 383 
 
 Glycophila, 567 
 
 Glycyrrhiza, 187 
 
 Gnomonia, 264, 274, 529, 539 
 
 Carya;, 545 
 
 Erythrostoma, 275 
 
 Leptostyla, 275, 555 
 
 Oryza;, 276 
 
 Padicola, 275, 496 
 
 Quercus lUicis, 275 
 
 Rubi, 276 
 
 Veneta, 274, 274, 275, 498, 
 
 535, 541, 546 
 
 Gnomoniaceai, 223, 263 
 
 Key to, 263 
 
 Gnomoniella, 283, 273, 539 
 
 Coryli, 274 
 
 Fimbriata, 274 
 
 Tubiformis, 274, 274, 529, 
 
 541 
 
 Gnomoniopsis, 264, 265 
 
 Godroniella, 534 
 
 Golden Rod, 179 
 
 GonatobotrytidiEe, 566 
 
 Gongromeriza, 596 
 
 Gooseberry, 141, 148, 155, 185, 245, 
 351, 433, 504, 519, 526 
 
 Gordonia, 150 
 
 Gorgonicepes, 136 
 
 Gossypium, 168 
 
 Gourd, 95, 247 
 
 Grain, 257, 260, 333, 384, 451, 508, 
 599, 620 
 
 Grallardia, 176, 178 
 
 Gramineae, 143, 179 
 
 Grandinia, 413 
 
 Granularia, 640 
 
 Grape, 36, 37, 43, 51, 52, 73, 141, 148, 
 153, 192, 201, 231, 242, 249, 250, 
 253, 258, 267, 268, 281, 345, 398, 
 405, 463, 484, 486, 490, 491, 494, 
 498, 504, 506, 517, 520, 540, 541, 
 549, 554, 560, 579, 580, 620, 
 626 
 
 Graphiola, 323, 663 
 
 Phoenicis, 664, 665 
 
 Graphiothecium, 243 
 
 Graphium, 630 
 
 Grass, 8, 11, 24, 69, 73, 209, 210, 
 
 211, 213, 220, 259, 260, 303, 
 
 310, 312, 320, 321, 329, 333, 379, 
 
 383, 385, 405, 508, 520, 612, 635, 
 
 661 
 Green Algae, 3 
 Grossulariae, 493 
 Guava, 271, 541 
 Guelichia, 641 
 Guignardia, 236, 237, 484 
 
 Ampelicida, 238 
 
 Baccaj, 242 
 
 Bidwellii, 238, 238, 239, 241, 
 
 484, 490 
 
 Buxi, 243 
 
 Thea;, 243 
 
 Vaccinii, 242, 242 
 
 Gymnoascacese, 165 
 Gymnoascus, 164 
 Gymnoconia, 355, 359, 390 
 
 Interstitialis, 360, 360 
 
 Gymnosporangium, 330, 355, 361, 
 
 362, 391 
 
 Biseptatum, 370 
 
 Clavariseforme, 331, 363, 365, 
 
 366 
 
 Clavipes, 363, 368 
 
 Cornutum, 368, 371 
 
 Ellisii, 369 
 
 Germinale, 368 
 
 Globosum, 363, 366 
 
 Japonicum, 371 
 
 Juniperinum, 367 
 
 Juniperi-virginianae, 329, 363, 
 
 364 
 
 Nelsoni, 363, 370 
 
 Nidus-avis, 363, 369 
 
 Sabinse, 369 
 
 Terminali-juniperinum, 371 
 
 Transformans, 369 
 
 Yamada?, 371 
 
 Gyroceras, 596 
 
720 
 
 INDEX 
 
 H 
 
 Hackberry, 93 
 Hadrotrichum, 600 
 Haematomyces, 151 
 Hsematomyxa, 151 
 Hainesia, 538 
 Halobyssus, 567 
 Hamamelis, 188 
 Haplaria, 575 
 Haplariopsis, 586 
 Haplobasidium, 597 
 Haplographiese, 595, 600 
 
 Key to, 6l)0 
 
 Haplographium, 601 
 Haplosporella, 501 
 Haplotrichum, 571 
 Hariotia, 163 
 Harknessia, 501 
 Harpocephalum, 630 
 Harpographium, 630 
 Hartigiella, 570, 575 
 
 Laricis, 570 
 
 Hartigielleai, 566, 570 
 
 Hawthorn, 38, 39, 130, 502, 525 
 
 Hazel, 122, 203, 249, 274, 280, 444 
 
 Hebeloma, 449 
 
 Hedera, 249, 487, 522, 541, 553 
 
 Helianthus, 92, 178, 179, 388 
 
 Helicobasidium, 403 
 
 Heliomyccs, 445 
 
 Heliscus, 645 
 
 Hellebore, 505 
 
 Helminthospora, 609 
 
 Helminthosporium, 260, 584. 609, 611 
 
 Avenai, 613 
 
 Bromi, 261, 613 
 
 Gramineum, 261, 612, 612, 614 
 
 Hevea;, 614 
 
 Iberidis, 614 
 
 Inaequalis, 614, 614 
 
 Inconspicuum, 613, 614 
 
 Lunaria^, 614 
 
 Oryza>, 614 
 
 Sativum, 613, 613 
 
 Sigmoideum, 613 
 
 Helminthosporium, Sorokinianum, 
 613 
 
 Teres, 612, 613 
 
 Theaj, 614 
 
 Trichostoma, 612 
 
 Tritici, 613 
 
 Tritici Repentis, 262, 613 
 
 Turcicum, 613, 614 
 
 Vaccinii, 234 
 
 Helostroma, 634 
 Helotiacea), 133, 134 
 
 Key to, 135 
 
 Helotieae, 136 
 Helotium, 136 
 Helvellaceae, 131 
 Helvellales, 123, 130 
 
 Key to, 131 
 
 Hemiascomycetes, 114, 117, 118 
 Hemibasidii, 298, 299 
 Hemiglossum, 131 
 Hemileia, 354, 355 
 
 Oncidii, 356 
 
 Vastatrix, 355, 355 
 
 Woodii, 356 
 
 Hemi-parasites, 2 
 
 Hemi-saprophytes, 2 
 
 Hemi-type, 328 
 
 Hemlock, 418, 419, 423, 435, 436, 438 
 
 Hemp, 52, 101, 141, 486, 494, 521, 581 
 
 Hendersonia, 257, 264, 516, 615 
 
 Acicola, 515 
 
 Coffeaj, 516 
 
 CydoniE, 516 
 
 Foliicola, 516 
 
 Mali, 515 
 
 Notha, 516 
 
 Oryzae, 516 
 
 Piricola, 515 
 
 Togniniana, 515, 516 
 
 Hendersonula, 515, 516 
 
 Morbosa, 219 
 
 Henriquesia, 160 
 Hepatica, 93, 357 
 Heptameria, 252 
 Heracleum, 591 
 Hericiura, 413 
 
INDEX 
 
 721 
 
 Herpotrichia, 226, 229, 230 
 
 Nigra, 229 
 
 Heterobotrys, 595 
 Heterocephalum, 634 
 Heterocontse, 3 
 Hetercecism, 64, 329 
 Heteropatella, 534 
 Heterosphffiria, 155 
 Heterosporium, 609, 610 
 
 Auriculi, 611 
 
 Echinulatum, 611 
 
 Gracile, 611 
 
 Laricis, 611 
 
 Minutulum, 611 
 
 Ornithogali, 611 
 
 Syringa;, 611 
 
 Variabile, 611 
 
 Heterotheca, 408 
 
 Heuchera, 188 
 
 Hevea, 207, 278, 287, 411, 418, 437, 
 
 513, 544, 553, 607 
 Hexagonia, 417 
 Heydenia, 630 
 Hiatula, 450 
 Hibiscus, 488 
 Hickory, 428 
 Hicoria, 396 
 Himantia, 657 
 Holchus, 383 
 Hollyhock, 328, 38G, 487, 492, 523, 
 
 552, 630 
 HolstieUa, 280 
 Holwaya, 151 
 Homostegia, 216 
 Honey dew, 190 
 Honeysuckle, 36, 191 
 Hop, 8, 36, 93, 175, 279, 486, 490, 
 
 5G3, 569,590,611 
 Hordeum, 180, 317, 379 
 Hormiactella, 601 
 Hormiactis, 586 
 Hormiscium, 596 
 Hormodendrum, 600, 601 
 
 Cladosporioides, 248 
 
 Hordei, 601, 601 
 
 Hornbeam, 152, 274 
 
 Horse Chestnut, 445, 460, 524 
 Horse Radish, 95, 96, 506, 522, 582, 
 
 590, 619, 629 
 Hoya, 544 
 Humulus, 176, 178 
 Hyacinth, 27, 42, 44, 75, 143, 231, 
 
 260, 603 
 Hyaloceras, 558 
 Hyalodema, 593 
 Hyaloderma, ICO 
 Hyalodothis, 217 
 Hyalopus, 570 
 Hyalospora, 341 
 Hydnacea?, 402, 413 
 
 Key to, 413 
 
 Hydnocha^te, 414 
 Hydnum, 414, 414 
 
 Diversidens, 415 
 
 Erinaceus, 414, 414 
 
 Schiedermayeri, 415 
 
 Septentrionale, 414 
 
 Hydrangea, 347, 488, 493, 522 
 Hygrophorese, 442 
 Hymenium, 113 
 Hymenocha;t£E, 406 
 
 Noxia, 411 
 
 Hymenogast rales, 396 
 Hymenomycetes, 394 
 Hymenopsis, 655 
 Hymenoscypha, 136, 146, 146 
 
 Temulenta, 146, 642 
 
 Hymenula, 640 
 Hypha, 657 
 Hyphaene, 193 
 Hyphoderma, 575 
 Hypholoma, 449, 450 
 
 Appendiculatum, 451, 4^1 
 
 Fasciculare, 451 
 
 Lateritium, 451 
 
 Hyphomycete, 321, 402, 663 
 Hyphostereum, 640 
 Hypocenia, 501 
 HypochnacejE, 402 
 
 Key to, 403 
 
 Hypochnus, 403, 406 
 Cucumeris, 404 
 
722 
 
 INDEX 
 
 Hypochnus, Filamintosus, 404 
 
 Fuciformis, 404 
 
 Ochroleucus, 403 
 
 Solani, 404 
 
 These, 404 
 
 Hypochytriacese, 67 
 Hypocopra, 224 
 Hypocrea, 209, 199 
 
 Ceretiformis, 209 
 
 Sacchari, 209 
 
 Hypocreaceae, 196 
 
 Key to, 196 
 
 Hypocreales, 124, 195, 584 
 Hypocreeaj, 197 
 
 Key to, 198 
 
 Ilypocrella, 199 
 Hypocreodendron, 527 
 Hypocreopsis, 199 
 Ilypoderma, 161 
 
 Desmazieri, 161 
 
 Laricis, 161 
 
 ■ Pinicola, 161 
 
 Strobicola, 161 
 
 Hypodermatacea;, 160 
 
 Key to, 160 
 
 Hypodermella, 160, 161 
 
 Laricis, 161 
 
 Sulicigena, 161 
 
 Hypodermium, 538, 547 
 
 Orchidearum, 547 
 
 Hypolyssus, 405 
 
 Hypomyces,, 197, 200, 200 
 
 Hyacinthi, 200 
 
 Solani, 200 
 
 Hypomycetese, 196, 197 
 
 Hyponectria, 201 
 
 Hyponectriese, 196 
 
 Hypospila, 276 
 
 Hypoxylea;, 285 
 
 Hypoxylon, 285 
 
 Hysteriacese, 160, 163, 530 
 
 Key to, 163 
 
 Hysteriales, 124, 159 
 
 Key to, 160 
 
 Hysteriopsis, 161 
 
 Brasiliensis, 161 
 
 Hysterium, 164 
 Hysteroglonium, 163 
 Hysterographium, 164 
 
 Fraxini, 164, 164 
 
 Hysterostomella, 163 
 
 Iberis, 614 
 Ilex, 188 
 Illosporium, 641, 643 
 
 Maculicola, 644, 6^ 
 
 Malifoliorum, 643 
 
 Impatiens, 93, 176 
 
 Inocybe, 449 
 
 Ipomese, 337 
 
 Iris, 27, 41, 46, 73, 389, 507, 514, 522, 
 
 608, 611, 619, 620 
 Irish Potato, 105, 106 
 Irpex, 414, 415 
 
 Destruens, 415 
 
 Flavus, 415, U5 
 
 Fusco-violaceus, 415 
 
 Paradoxus, 415 
 
 Isaria, 196, 634, 635 
 
 Fuciformis, 635 
 
 Graminiperda, 635 
 
 Isariopsis, 637, 638 
 
 Griseola, 637 
 
 Isothea, 276 
 
 Itajahya, 462 
 
 Ivy, 152, 493, 497, 544 
 
 Jansia, 462 
 
 Johnson Grass, 311 
 
 Juglans, 186, 275, 396, 507 
 
 Juncus, 303 
 
 Juneberry, 38 
 
 June Grass, 578 
 
 Juniper, 52, 157, 162, 220, 230, 243, 
 
 330, 560 
 Juniperus, 362, 365, 366, 367, 368, 
 
 369, 370, 371, 516, 610 
 
INDEX 
 
 723 
 
 K 
 
 Kalmusia, 277 
 Kawakamia, 83, 89 
 
 Cyperi, 89 
 
 Keithia, 156 
 Kellermania, 513 
 Klachbrennera, 464 
 Kmetia, 640 
 Kneiffiella, 413 
 Kuehneola, 355, 361 
 
 Gossypii, 361 
 
 Uredinis, 361 
 
 Laboulbeniales, 124 
 Labrella, 529, 530 
 
 Coryli, 529, 530 
 
 Piricola, 530 
 
 Laburnum, 544 
 Lachnella, 135, 145, 145 
 
 Pini, 145 
 
 Lachnellula, 135 
 Lachnocladium, 412 
 Lachnodochium, 641 
 Lachnum, 136 
 Lactariea?, 423, 443 
 Lsestadia, 238 
 
 Buxi, 243 
 
 Lamyella, 483 
 
 Langloisula, 576 
 
 Larch, 145, 161, 162, 249, 348, 419, 
 
 424, 432, 436, 438, 530, 570, 611, 
 
 656, 658 
 Larix, 230, 344 
 Larkspur, 43 
 Laschia, 417 
 Lasiobotrys, 189, 191 
 
 Lonicera?, 191 
 
 Lasioderma, 634 
 Lasiodiplodia, 510, 613 
 
 Thoobroma;, 513 
 
 Tubericola, 513 
 
 Lasionectria, 201 
 
 Lasiosphaeria, 226 
 Lasmenia, 531 
 Laternea, 463, 464 
 
 Columnata, 464, 464 
 
 Lathyrus, 217, 313, 372 
 
 Laurel, 492 
 
 Laurel, Cherry, 409 
 
 Laurus, 398, 489 
 
 Lecythium, 198 
 
 Legume, 28, 31, 32, 313, 373 
 
 Lemalis, 521, 534 
 
 Lembosia, 163 
 
 Lemon, 77, 494, 508, 510, 512, 518, 
 
 540, 549, 574, 582, 604 
 Lemonniera, 593 
 Lentinus, 445 
 
 Conchatus, 446 
 
 Lepideus, 446, 446 
 
 Variegata, 446 
 
 Lentomita, 232 
 Lenzites, 417, 439 
 
 Abietina, 440 
 
 Betulina, 440, 44I 
 
 Corrugata, 440 
 
 Sepiaria, 440 
 
 Variegata, 440 
 
 Vialis, 440 
 
 Leocarpus, 11 
 
 Lepiderma, 10 
 
 Lepidonectria, 201 
 
 Lepotia, 450 
 
 Leptoglossum, 443 
 
 Leptomitaceae, 75 
 
 Leptonia, 450 
 
 Leptopus, 443 
 
 Leptospha?ria, 252, 257, 519, 660 
 
 Circinans, 258 
 
 Coniothyrium, 257, 258, 504 
 
 Ilerpotrichoides, 258 
 
 Iwamotoi, 258 
 
 Napi, 258, 616 
 
 Phlogis, 258, 519 
 
 Rhododendri, 258 
 
 Sacchari, 258 
 
 Stictoides, 258 
 
 Taxicola, 259 
 
724 
 
 INDEX 
 
 Leptosphseria, Tritici, 258, 520 
 
 Vagabunda, 259 
 
 Vitigena, 258 
 
 Leptospora, 226 
 Leptostroma, 529, 530 
 
 Larcinum, 249, 530 
 
 Piricola, 530 
 
 Punctiforme, 530 
 
 Leptostromatacea;, 479, 528 
 
 Key to, 528 
 
 HyalodydimfE, 528 
 
 Hyalosporse, 528 
 
 Key to, 528 
 
 Hyalophragmiffi, 528, 531 
 
 Key to, 531 
 
 Phaeodidymse, 528 
 
 Phseopharagmise, 528 
 
 Phseosporae, 528, 531 
 
 Key to, 531 
 
 Scolecosporaj, 528, 532 
 
 Key to, 532 
 
 Leptostromella, 532, 533 
 
 Elastics, 533, 533 
 
 Leptothyrium, 274, 528, 529 
 
 Acerinum, 529 
 
 Alneum, 274, 529 
 
 Buxi, 529 
 
 Macrothecium, 529 
 
 Oxycocci, 529, 529 
 
 Parasiticum, 529 
 
 Peonse, 529 
 
 Periclymeni, 529 
 
 Pomi, 529 
 
 Lepto-type, 328 
 
 Lespedeza, 187 
 
 Lettuce, 36, 37, 44, 52, 95, 141, 142, 
 
 408, 507, 522, 555, 556, 579, 620 
 Levieuxia, 501 
 Levisticum, 28 
 Libertella, 562, 564 
 
 Rubra, 208, 564 
 
 Ulcerata, 564 
 
 Libertiella, 527 
 Liceacea?, 9 
 Lichenopsis, 515 
 Lichens, 134 
 
 Lilac, 88, 404, 488, 581, 582, 611 
 
 LiliaceiB, 310, 318, 320 
 
 Lilium, 375 
 
 Lily, 106, 141, 250, 488, 563, 579, 580, 
 
 592, 631 
 Lily-of-the-valley, 523, 581 
 Limacinia, 190 
 
 Tangensis, 193 
 
 Lime, 203, 249 
 
 Limnanthemum, 315 
 
 Linaria, 168 
 
 Linden, 259, 421, 545, 560 
 
 Linospora, 276 
 
 Linum, 667 
 
 Liriodendron, 188, 258, 547 
 
 Lisea, 197 
 
 Lisiella, 197 
 
 Listeromyces, 657 
 
 Lizonia, 226 
 
 Lobelia, 492 
 
 Locellina, 449 
 
 Loculistroma, 199, 215 
 
 Bambusaj, 215 
 
 Locust, 419, 434 
 Locust Black, 438 
 Lolium, 73, 383 
 Lonicera, 186, 191, 529 
 Lopharia, 413 
 Lophiostomatacese, 223 
 Lophium, 164 
 Lophodermium, 161 
 
 Abietis, 162 
 
 Brachysporum, 162 
 
 Gilvum, 162 
 
 Juniperinum, 162 
 
 Laricinum, 162 
 
 Macrosporum, 162, 162 
 
 Nervisequum, 162 
 
 Pinastri, 161, 162 
 
 Loquot, 553 
 Lunaria, 614 
 Lupine, 560, 564, 652 
 Lupinus, 43, 178, 313 
 
 Albus, 168 
 
 Augustifolius, 168 
 
 Luteus, 168 
 
INDEX 
 
 725 
 
 Lupinus, Thermis, 168 
 Luzula, 303 
 Lycoperdaceae, 464 
 
 Key to, 464 
 
 Lycoperdales, 395, 464 
 Lycoperdon, 465 
 
 Gemmatum, 465, 46'5 
 
 Lycopersicum, 178 
 Lysurus, 463 
 
 M 
 
 Macrodendrophoma Salicicola, 253, 
 
 494 
 Macrobatis, 514 
 Macrodiplodia, 510 
 Macrophoma, 284, 481, 493 
 
 Abietis, 493 
 
 Curvispora, 493, 4S5 
 
 Dalmatica, 493 
 
 Helicinia, 493 
 
 Hennebergii, 493 
 
 Ligustica, 493 
 
 Malorum, 493 
 
 Manihotis, 493 
 
 Reniformis, 494 
 
 Taxi, 493 
 
 Vestita, 493 
 
 Macrosporium, 616, 618 
 
 Aductum, 619 
 
 Alliorum, 618 
 
 Brassies, 619 
 
 Catalpae, 619 
 
 Cheiranthi, 619 
 
 Cladosporioides, 620 
 
 Commune, 260, 618 
 
 Cucumerinum, 619, 620 
 
 Faseiculata, 624 
 
 Gramineum, 620 
 
 Herculeum, 618 
 
 Iridis, 619 
 
 Longipes, 619 
 
 Lycopersici, 624 
 
 Macalpinianum, 620 
 
 Nigricanthium, 619 
 
 Macrosporium, Nobile, 619 
 
 Porri, 618 
 
 Ramulosum, 619 
 
 Rugosa, 624 
 
 Saponaria;, 620 
 
 Sarciniforme, 619 
 
 Sarcinula-parasitieum, 618 
 
 Tabacinum, 619 
 
 Tomato, 624 
 
 Uvarum, 620 
 
 Verrucosum, 620 
 
 Viola", 620 
 
 Macrostilbum, 634 
 
 Madia, 92 
 
 Magnolia, 188, 503, 559 
 
 Magnusia, 166 
 
 Magnusiella, 126 
 
 Maguey, 220 
 
 Mahonia, 379 
 
 Malbranchea, 567 
 
 Mal-di-gomma, 649 
 
 Malope, 386 
 
 Malus, 371 
 
 Malva, 386 
 
 Malvaceaj, 507 
 
 Mamiania, 263 
 
 Mandarin, 520 
 
 Mangel, 41, 645 
 
 Mango, 191, 193, 543 
 
 Mangold, 491, 581 
 
 Manihot, 557 
 
 Maple, 72, 130, 152, 159, 182, 203, 
 419, 421, 428, 430, 436, 455, 489, 
 524, 525, 545, 557, 563, 632 
 
 Marasmiese, 443, 445 
 
 Key to, 445 
 
 Marasmius, 445, 446 
 
 Equicrinus, 448 
 
 Ilawiiensis, 448 
 
 Plicatus, 447, 448 
 
 Sacchari, 448 
 
 Sarmentosus, 448 
 
 Semiustus, 448 
 
 Marchalia, 156 ' 
 
 Marchaliella, 189 
 
 Marssonia, 147, 274, 556 
 
726 
 
 INDEX 
 
 Marssonia, Castagnei, 157, 555 
 
 Juglandis, 275, 555 
 
 Martini, 555 
 
 Medicaginis, 556 
 
 Panattoniana, 555 
 
 Perforans, 555 
 
 Populi, 555 
 
 Potent ilia;, 555 
 
 Rosa?, 555 
 
 Secalis, 555 
 
 Violaj, 556, 556 
 
 Martensella, 576 
 Martindalia, 633 
 Massalongiella, 236 
 Massaria, 263 
 
 Theicola, 263 
 
 Massariaceaj, 223, 262 
 
 Key to, 2G2 
 
 Massarina, 263 
 Massariovalsa, 263 
 Massospora, 566 
 Mastigosporium, 588, 590 
 Mastomyces, 155, 514 
 
 Friesii, 514 
 
 Matrouchotia, 403 
 Mattirolia, 198 
 Mazzantia, 216 
 Medicago, 178 
 Medick, 148 
 Medlar, 140, 150, 569 
 Megalonectria, 198 
 Melanconiales, 479, 527 
 Melampsora, 340, 342, 390 
 
 Allii-fragilis, 344 
 
 AUii-populina, 344 
 
 Allii-salicis albae, 344 
 
 Bigelowii, 344 
 
 Klebahni, 344 
 
 Larici-pentandrse, 344 
 
 Larici-populina, 344 
 
 Lini, 342 
 
 Medusae, 343 
 
 Pinitorqua, 344 
 
 Repentis, 344 
 
 Ribesii-viminalis, 344 
 
 Rostrupii, 344 
 
 Melampsora, Saxifragarum, 345 
 Melampsoraceae, 335, 340 
 
 Key to, 340 
 
 Melampsorella, 341, 348, 390, 391 
 
 Elatina, 348 
 
 Melampsoridium, 341, 347, 3^7, 391 
 
 Betula;, 348 
 
 Melampsoropsis, 341, 349, 350, 391 
 
 Rhododendri, 349 
 
 Melanconiacese, 537 
 
 Key to, 537 
 
 Hyalodidymse, 538, 555 
 
 Key to, 555 
 
 Hyalophragmiaj, 538, 556 
 
 Key to, 556 
 
 Hyalosporse, 538 
 
 Key to, 538 
 
 Phseodictyffi, 537, 561 
 
 Phajodidyma;, 537, 556 
 
 Key to, 556 
 
 Phseophragmise, 537, 557 
 
 Key to, 557 
 
 Phaeospora;, 537, 553 
 
 Key to, 553 
 
 Scolecosporse, 537, 561 
 
 Key to, 562 
 
 Staurosporse, 537 
 
 Melanconiales, 265, 525, 537, 564 
 Melanconidacese, 223, 279 
 
 Key to, 279 
 
 Melanconiella, 279 
 Melanconiopsis, 501 
 Melanconis, 279, 281 
 
 Modonia, 281, 498, 560 
 
 Melanconium, 553, 554 
 
 Fuligineum, 554, 554 
 
 Pandani, 554 
 
 Sacchari, 554 
 
 Melanomma, 227, 232 
 
 Cdumarum, 232 
 
 Henriquesianum, 231 
 
 Melanops, 283, 284, 503 
 Melanopsamma, 227 
 Melanopsichium, 302 
 Melanospora, 196, 197, 200, 201 
 Damnosa, 200 
 
INDEX 
 
 727 
 
 Melanospora, Stysanophora, 201 
 Melanosporea?, 196, 197 
 Melanostroma, 538 
 Melanotacnium, 314 
 Melasmia, 158, 529, E30 
 
 Acerina, 159, 530 
 
 Punctata, 530 
 
 Salicina, 530 
 
 Melica, 497 
 
 Melilotus, 508 
 
 Aleliola, 189, 190, 191, 193, 193, 624 
 
 Camellia^, 193, 193, 625 
 
 Niesslcanea, 194 
 
 Penzigi, 194 
 
 Melogramma, 283 
 
 Henriquetii, 284 
 
 Melogrammatacese, 223, 282 
 
 Key to, 283 
 
 Melon, 10, 27, 487, 608, 621, 629 
 Melophia, 532 
 Mentha, 178 
 Merasmiese, 443, 445 
 
 Key to, 445 
 
 Merasmiopsis, 445 
 Mercurialis, 344 
 Merulieai, 416, 418 
 Merulius Lacrymans, 418 
 Mesospore, 327, 375, 384 
 Mespilus, 570 
 Metanectria, 198 
 Metasphffiria, 252, 257 
 
 Albescens, 257 
 
 Michenera, 405 
 Micothyriaceae, 170 
 Microascus, 166 
 Microcera, 207 
 Micrococcus, 18, 21 
 
 Albidus, 21 
 
 Delacourianus, 21 
 
 Flavidus, 21 
 
 Imperatoris, 21 
 
 ■ Nuclei, 21 
 
 Pellucidus, 21 
 
 Phytophthorus, 21 
 
 Populi, 21 
 
 Tritici, 21 
 
 Microdiplodia, 510 
 
 Anthurii, 511 
 
 Microglossum, 131 
 Micropera, 518 
 Microspatha, 634 
 Microspha'ra, 175, 185 
 Alni, 185, 186, 570 
 
 Calocladophora, 106 
 
 Extensa, 186 
 
 Lonicera;, 186 
 
 Vaccinii, 186 
 
 Berberidis, 185 
 
 Beta>, 187 
 
 Diffusa, 186 
 
 Elevata, 186 
 
 Euphorbia;, 187 
 
 Ferruginea, 187 
 
 Grossularia?, 185, 185 
 
 Microstroma, 396 
 
 Album, 396 
 
 Juglandis, 396 
 
 Microthyriacea;, 170, 195 
 Microthyrium Coffa;, 195 
 Micro-type, 328 
 Micula, 518 
 Mignonette, 81, 631 
 Mikronegeria, 336 
 Millet, 90 
 Milowia, 588 
 Mitrula, 131, 132 
 
 Sclcrotiorum, 132 
 
 Mohonia, 379 
 
 Molds, Slime. See Myxomycetes. 
 
 Mollisia, 146 
 
 Mollisiacese, 134, 146 
 
 Key to, 146 
 
 Mollisiella, 146 
 Monacrosporium, 588 
 Monascacea;, 118 
 Monilia, 137, 138, 140, 567, 568 
 
 Cinerea, 139, 569 
 
 Crategi, 569 
 
 Fimicola, 569 
 
 Fructigena, 139, 569 
 
 Laxa, 569 
 
 Linhartiana, 569 
 
728 
 
 INDEX 
 
 Monilia, Seaveri, 140, 569 
 Moniliaceaj Scolecosporsc, 592 
 Moniliacese, 565 
 
 Key to, 565 
 
 Amerosporae, 565 
 
 Key to, 565 
 
 Chromosporiea^ 565 
 
 Key to, 566 
 
 Dictyosporaj, 565, 592 
 
 Key to, 592 
 
 — — - Didymospora;, 565, 585 
 
 Key to, 585 
 
 Helicospora;, 565, 593 
 
 Oosoporeaj, 565, 567 
 
 Key to, 567 
 
 Phragmosporse, 565, 588 
 
 Key to, 588 
 
 Staurosporaj, 565, 593 
 
 Key to, 593 
 
 Moniliales, 464, 479, 554 
 
 Key to, 465 
 
 Monilochajtes, 596, 597 
 
 Infuscans, 597 
 
 Monoblepharidiales, 66 
 Monochaetia, 558 
 
 Pachyspora, 558 
 
 Monocotyledones, 611 
 Monographus, 217 
 Monopodium, 576 
 Monospore, 121 
 Monosporium, 576 
 Monotospora, 600 
 Monotosporese, 595, 600 
 
 Key to, 600 
 
 Montagnella, 216 
 Montagnites, 442 
 Moon Flower, 82 
 Morel, 114 
 
 Morning Glory, 82, 337 
 Mortierellacea;, 103 
 Morus, 182, 202, 207, 231, 249, 
 491, 499, 503, 512, 517, 525, 
 562 
 Mountain Ash, 39, 367, 368, 427 
 Mucor, 90, 101, 104, 105, 106 
 • Mucedo, 106 
 
 Mucor, Pyriformis, 106 
 
 Racemosus, 106 
 
 Mucoraceae, 103, 107 
 
 Key to, 104 
 
 Mucorales, 66, 102 
 
 Key to, 103 
 
 Mucorese, 104 
 
 Mucronella, 413 
 
 Mucrosporium, 589 
 
 Mulberry, 21, 31, 43, 52, 73, 393, 
 
 445, 454, 499, 557, 561, 582, 626, 
 
 658 
 Mullerella, 236 
 Munkia, 527 
 Munkiella, 217 
 Muricularia, 482, 527 
 Muscari, 375 
 Mushroom, 200, 398, 567, 569, 574, 
 
 584, 587 
 Muskmelon, 44, 51, 95, 247, 487 
 Mutinus, 462 
 Mycelia Sterilia, 479, 659 
 
 Key to, 659 
 
 Myceliophthora, 566, 567 
 
 Lutea, 567 
 
 Mycelophagus Castanese, 101 
 Mycena, 450, 460, 461 
 
 Epipterygia, 460 
 
 Mycenastrum, 465 
 
 Mycogala, 481 
 
 Mycogone, 200, 586, 587, 587 
 
 Perniciosa, 200, 587 
 
 Rosea, 200, 587 
 
 Mycoplasm Theory, 333 
 Mycosphffirella, 236, 243, 484, 490, 
 
 519, 525 
 
 Abietis, 249 
 
 Brassicsecola, 249, 484 
 
 Cerasella, 245, 625 
 
 ■ Cinxia, 250 
 
 CitruUina, 246, 2^8, 509 
 
 CofTcEe, 249 
 
 Coffeicola, 250 
 
 Comedens, 249 
 
 Convexula, 250 
 
 Cydonise, 249 
 
INDEX 
 
 729 
 
 Mycosphserella, Elasticse, 249 
 
 Fagi, 249 
 
 Fragaria;, 244, 2^, 519, 590 
 
 Fusca, 250 
 
 Gibelliana, 249 
 
 Gossypina, 248, 625 
 
 Grossularise, 245 
 
 Hedericola, 249 
 
 Hondai, 250 
 
 Laricina, 249, 530 
 
 Loefgreni, 249 
 
 Maculiformis, 249, 485, 562 
 
 Mori, 557 
 
 Morifolia, 249, 562 
 
 Pinifolia, 249 
 
 Pinodes, 250, 506 
 
 Populi, 249, 519, 035 
 
 Primulffi, 250 
 
 Punctiformis, 249 
 
 Rosigena, 249 
 
 Rubina, 245 
 
 Sentina, 246, 2Jt6, 247, 249, 519 
 
 Shiraina, 250 
 
 Stratiformans, 248 
 
 Tabifica, 247, 485, 490 
 
 Tamarindi, 250 
 
 Taxi, 249 
 
 Tulasnei, 247, 603 
 
 Ulmi, 249, 484 
 
 Vitis, 249 
 
 MycosphserellacesE, 223, 235 
 
 Key to, 235 
 
 Mykosyrinx, 302 
 Myrangiella, 170 
 
 Orbicularis, 170 
 
 Myrangium, 170 
 Myriangiaceae, 165, 170 
 
 Key to, 170 
 
 Myriogenospora, 216 
 Myriostoma, 465 
 Myrmaiciella, 283 
 Myrmfficiiim, 283 
 Myroiphysa, 655 
 Mystrosporium, 616, 620 
 
 Abrodens, 620 
 
 Aductxim, 620 
 
 Mystrosporium, Alliorium, 620 
 Myrothecium, 655 
 Mytilidium, 164 
 Myxobacteriales, 11 
 Myxogastrales, 5, 9 
 
 Key to, 9 
 
 Myxomycetes, 1, 3, 5 
 
 Key to, 5 
 
 Myxormia, 538 
 Myxosporella, 538 
 Myxosporium, 274, 538, 546 
 
 Abietinum, 547 
 
 Carneum, 547 
 
 Corticolum, 493, 5Jt6, 546 
 
 Devastans, 647 
 
 Lanceola, 547 
 
 Longisporum, 547 
 
 Mali, 547 
 
 Piri, 547 
 
 Valsoideum, 274, 646 
 
 Myxotrichellese, 595 
 
 N 
 
 Naemosphsera, 501 
 Najmospora, 122, 538, 647, 562 
 
 Ampelicida, 238 
 
 Coryli, 122 
 
 Crocea, 547 
 
 Napicladium, 609, 611 
 
 Janseanum, 611 
 
 Soraueri, 255, 611 
 
 Narcissus, 389, 489, 523, 591, 592, 611 
 Nasturtium, 37, 168, 260 
 Naucoria, 449 
 Necator, 640, 643 
 
 Decretus, 643 
 
 Necrosis, 281 
 
 Nectarine, 604 
 
 Nectria, 197, 201, 475, 646 
 
 Amerunensis, 204 
 
 Bainii, 204 
 
 Bogoriensis, 205 
 
 Bulbicola, 205 
 
 Cinnabarina, 202, 202, 642 
 
730 
 
 INDEX 
 
 Nectria, Coffeicola, 204 
 
 Cucurbitula, 203 
 
 Ditissima, 203, 568 
 
 Diversispora, 204 
 
 — — Fruticola, 205 
 
 Gigantispora, 205 
 
 Goroshankianna, 205 
 
 Graminicola, 205 
 
 Ipomoeaj, 204, 20Jt, 205 
 
 Jungeri, 205 
 
 Luteopilosa, 205 
 
 Pandani, 204 
 
 Ribis, 204 
 
 Rousselliana, 204, 656 
 
 Solani, 204 
 
 Striatospora, 205 
 
 Theobromse, 205 
 
 Theobromicola, 206 
 
 — Vandse, 205 
 
 Vanillse, 206 
 
 Nectriaceae, 196 
 Nectriese, 196 
 
 Key to, 197 
 
 Nectriella, 197 
 Nectrioidacese, 479, 526 
 Key to, 526 
 
 Hyalodidymise, 526 
 
 Hyalophragmiae, 526 
 
 Hyalosporse, 526 
 
 Key to, 526 
 
 Ollulea;, 526 
 
 — Phaeosporae, 526 
 
 Scolecosporse, 526 
 
 Zythieaj, 526 
 
 Negeriella, 637 
 
 Negundo, 260, 489 
 
 Nematospora, 121 
 
 Nematosporangium, 75 
 
 Nemophila Auriculata, 168 
 
 Neobarclaya, 556 
 
 Neocosmospora, 197, 205, 475, 646, 
 
 651 
 Neolecta, 131 
 Neomichelia, 609 
 Neopeckia, 226 
 Neottiospora, 482 
 
 Neovossia, 314, 315 
 Nephlyctis, 354 
 Nicotinia, 101, 168, 178, 486 
 Nidulariales, 396 
 Niesslia, 225 
 Nigrospora, 600 
 Niptera, 147 
 Nitschkia, 234 
 Nolanea, 450 
 Nothopatella, 501 
 Nowakowskiella, 72 
 Nummularia, 285 
 
 Discreta, 285, 286 
 
 Nyctaginacese, 303 
 
 O 
 
 Oak, 130, 152, 157, 162, 177, 186, 192, 
 193, 203, 220, 231, 249, 264, 275, 
 279, 281, 352, 396, 409, 410, 411, 
 414, 415, 419, 421, 422, 424, 428, 
 430, 434, 436, 439, 440, 442, 452, 
 489, 498, 545, 546, 547, 555, 564, 
 570, 603 
 
 Oat, 23, 206, 213, 260, 301, 304, 305, 
 306, 380, 383, 490, 520, 550, 607, 
 608 
 
 Oat Grass, 307 
 
 Ochropsora, 336 
 
 Sorbi, 336 
 
 Odontia, 413 
 
 Odontoglossum, 631 
 
 CEdemansiella, 444 
 
 (Edemium, 598 
 
 (Edocephalum, 570 
 
 ffinothera, 71 
 
 Oidiopsis, 567 
 
 Oidium, 60, 172, 567, 569 
 
 Alphitoides, 570 
 
 Ambrosia?, 178, 569 
 
 Balsamii, 177, 669 
 
 Chrysanthemi, 569 
 
 Crsetsegi, 183, 569 
 
 — — - Erysiphoides, 569 
 
 Farinosum, 184, 569 
 
INDEX 
 
 731 
 
 Oidium, Fragariae, 175, 569 
 
 Leucoconium, 170, 569 
 
 Mespilinum, 570 
 
 Monilioidcs, 179, 569 
 
 Qucrcinum, 570 
 
 Tabaci, 570 
 
 Tuckeri, 181, 569 
 
 Vcrbenae, 570 
 
 Okra, 650, 651 
 
 Olcacese, 164 
 
 Oleander, 36, 45, 192, 193, 422, 524, 
 
 631 
 Oleina, 122 
 Olive, 34, 45, 155, 192, 193, 433, 486, 
 
 493, 543, 602, 624 
 Olopecurus, 383 
 Olpidiaceaj, 67, 69 
 
 Key to, 68 
 
 Olpidiopsis, 68 
 Olpidium, 68, 69, 72 
 
 Brassica;, 68, 69 
 
 Olpitrichum, 575 
 
 Ombrophileae, 136 
 
 Omphalia, 450 
 
 Oncidium, 356, 392, 544, 605 
 
 Oncopodium, 615 
 
 Oncospora, 537 
 
 Onion, 41, 42, 43, 52, 97, 200, 377, 
 
 491, 497, 499, 512, 520, 541, 549, 
 
 574, 581, 604, 603, 616, 618, 
 
 620 
 Onobrychis, 168 
 Onygenacese, 165 
 Oochytriacea), 67, 75 
 
 Key to, 73 
 
 Oomyces, 199 
 Oomycetes, 62, 65, 66, 101 
 Oospora, 475, 567, 568, 568 
 
 Abietum, 568 
 
 Scabies, 568 
 
 Ophiobolus, 252, 259, 259 
 
 Graminis, 259 
 
 Herpotrichus, 259 
 
 Oryzeae, 259 
 
 Ophioceras, 232 
 Ophiochaeta, 252 
 
 Ophiocladium, 566, 567 
 
 Ilordii, 567, 567 
 
 Ophiodothis, 216 
 OphiomaK.saria, 262 
 Ophionectria, 198, 207 
 
 Coccicola, 207 
 
 Foliicola, 207 
 
 Ophiotrichum, 609 
 
 Opsis-type, 328 
 
 Opuntia, 544 
 
 Orange, 207, 249, 256, 260, 409, 422, 
 
 435, 445 
 Orbicula, 189 
 Orcadellaceae, 9 
 Orchard Grass, 52, 550 
 Orchid, 46, 52, 205, 270, 392, 500, 
 
 541, 544, 547, 631 
 Orchis, 344 
 
 Ornithogalum, 71, 320 
 Osage Orange, 346 
 Ostreion, 164 
 Ostropacese, 160 
 Ostrya, 188 
 Otthia, 234 
 Ovularia, 243, 577, 582, 582 
 
 Alnicola, 582 
 
 Armoracia;, 582 
 
 Canaigricola, 582 
 
 Citri, 582 
 
 Corcellensis, 582 
 
 Exigua, 582 
 
 Interstitialis, 582 
 
 Medicaginis, 582 
 
 Necans, 582 
 
 Primulana, 582 
 
 Rosea, 582 
 
 Syringae, 582 
 
 Vicise, 582 
 
 Villiana, 582 
 
 Ovulariopsis, 188, 577, 582 
 
 Ulmorica, 582 
 
 Oxalis, 168, 329, 384 
 Ozier, 253 
 Ozonium, 657, 661 
 Omnivorum, 662 
 
732 
 
 INDEX 
 
 Pachybasium, 583 
 
 Pachysterigma, 403 
 
 Pactilia, 639 
 
 Pajonia, 176, 178, 352 
 
 Psepalopsis, 567 
 
 Palm, 77, 88, 191, 323, 499, 545, 552, 
 
 560, 658, 664 
 Palmetto, 412 
 Pandanus, 204, 531, 554 
 Panicum, 305, 307, 310, 312, 314 
 Pansy, 99, 320, 488, 552, 654 
 Panus, 445, 446 
 
 Stipicus, 446 
 
 Papaver, 321, 322 
 
 Papulospora, 570 
 
 Paranectria, 198 
 
 Para Rubber, 101, 415, 487, 512, 
 
 614 
 Paraspora, 588 
 Parmularia, 163 
 Parodiella, 189 
 Parsley, 141, 377, 521 
 Parsnip, 36, 41, 42, 91, 592, 628 
 Paryphedria, 151 
 Paspalum, 213 
 Passalora, 602, 607 
 
 Bacilligera, 607 
 
 Microsperma, 607 
 
 Patellariacese, 134 
 
 Patellina, 639 
 
 Patouillardia, 640 
 
 Patzschkeella, 505 
 
 Paulownia, 545 
 
 Paxillea;, 442 
 
 Pea, 28, 99, 177, 248, 250, 260, 329, 
 
 373, 506, 519, 651 
 Peach, 36, 53, 106, 128, 137, 138, 
 
 176, 231, 268, 282, 357, 428, 485, 
 
 490, 499, 512, 539, 540, 541, 547, 
 
 560, 592, 604, 606 
 Peanut, 392, 557, 629 
 Pear, 38, 105, 130, 149, 202, 231, 246, 
 
 249, 253, 255, 268, 367, 369, 371, 
 
 404, 419, 421, 246. 279, 485, 490, 
 
 502, 515, 519, 530, 540, 546, 547, 
 
 553, 607 
 Pearl Millet, 90 
 Pecan, 250, 607, 632 
 Pecia, 482 
 Pedilospora, 593 
 Pelargonium, 36, 43, 389, 544, 620, 
 
 631 
 Pellicularia, 382, 577, 582 
 
 Koleroga, 583 
 
 Pellioniella, 510 
 
 Peltospha'ria, 276 
 
 Peltostroma, 531 
 
 Penicilliopsis, 167 
 
 Penicillium, 166, 167, 169, 169, 572, 
 
 573, 635 
 
 Digitatum, 574 
 
 Glaucum, 574 
 
 Italicum, 574 
 
 Luteum, 574 
 
 Olivaceum, 574 
 
 Peniophora, 406 
 
 Pennisetum, 209 
 
 Peony, 178, 529, 581, 606 
 
 Pepper, 37, 42, 268, 269, 5^0, 541 
 
 Peraphyllum, 371 
 
 Peribotryum, 634 
 
 Periconia, 598 
 
 Periconiese, 594, 597 
 
 Key to, 597 
 
 Pcriconiella, 597 
 
 Peridermium, 330, 333, 335, 336, 350, 
 
 389, 390 
 
 Acicolum, 337, 337 
 
 Cerebrum, 352 
 
 Cornui, 352 
 
 Elatinum, 349 
 
 Oblongisporium, 338 
 
 Pyriforme, 352 
 
 Rostrupi, 339 
 
 — Strobi, 351 
 Peridinese, 3 
 Peridium, 325 
 Periola, 641 
 Perisporiacese, 170, 189 
 Key to, 189 
 
INDEX 
 
 733 
 
 Perisporiales, IIG, 124, 165, 1G7, 
 
 170 
 
 Key to, 170 
 
 Pcrisporium, 189 
 Perithecium, 62, 63 
 Peronoplasmopara, 83, 90, 93 
 
 Celtidis, 93 
 
 Cubensis, 93, 94 
 
 Humuli, 93 
 
 Peronospora, 78, 82, 84, 90, 93, 95, 
 
 618 
 
 Antirrhini, 101 
 
 Arborescens, 100 
 
 Candida, 101 
 
 Cannabina, 101 
 
 Conglomerata, 101 
 
 Corolla}, 101 
 
 Cytisi, 100 
 
 Dianthi, 101 
 
 Dipsaci, 100 
 
 Effusa, 96, 96 
 
 Ficaria;, 101 
 
 Fragarise, 100 
 
 Jaapiana, 101 
 
 LifiarisB, 100 
 
 Maydis, 101 
 
 Myosotidis, 101 
 
 Nicotianse, 101 
 
 Parasitica, 95, 97 
 
 Phoenixse, 101 
 
 Potentillaj, 100 
 
 Rubi, 100 
 
 Schachtii, 100 
 
 Schleideni, 96, 98 
 
 Schleideniana, 96 
 
 Sparsa, 97 
 
 Trichomata, 100 
 
 Trifoliorum, 97 
 
 Valeriana;, 101 
 
 Valerianella, 101 
 
 Vicise, 97 
 
 Vincae, 101 
 
 Violacea, 100 
 
 Violae, 99 
 
 Peronosporacese, 78, 82 
 Key to, 83 
 
 Peronosporales, 66, 74, 75, 77, 
 475 
 
 Key to, 78 
 
 Persimmon, 540, 581 
 Pcstalozzia, 558 
 
 Aloea, 560 
 
 Clusise, 560 
 
 Discosioides, 560 
 
 Funerca, 559, S59 
 
 Fuscescens, 560 
 
 Sacchari, 560 
 
 Gongrogena, 560 
 
 Guepini, 559, 559 
 
 Hartigii, 558 
 
 Inquinans, 560 
 
 Lupini, 560 
 
 Palmarum, 560 
 
 Palmicola, 560 
 
 Pha^nicis, 560 
 
 Richardiaj, 560 
 
 Stictica, 560 
 
 Suffocata, 560 
 
 Tumefaciens, 560 
 
 Uvicola, 559 
 
 Pcstalozziella, 538 
 Pestalozzina, 557 
 Petunia, 48, 141 
 Pezizaceae, 133, 134 
 Pezizales, 123, 133 
 
 Key to, 133 
 
 Phacidiaceae, 154, 155 
 
 Key to, 155 
 
 Phacidiales, 124, 154 
 
 Key to, 154 
 
 Phacidiese, 156 
 Phacidium, 156, 157 
 
 Infestans, 157 
 
 Phaconectria, 201 
 Phseodon, 414 
 Phajonectria, 201 
 Phaeopeltosphaeria, 276 
 Phseophyceae, 3 
 Phseoseptoria, 517, 525 
 
 Oryzae, 525 
 
 Phaeosphseriella, 236 
 Phallacese, 462 
 
734 
 
 INDEX 
 
 Phallales, 395, 462 
 
 Key to, 462 
 
 Phallus, 462, 463 
 
 Impudicus, 463 
 
 Rubicundus, 463 
 
 Pharcidia, 236, 250 
 
 Oryz£E, 250 
 
 Phaseolus, 178, 187, 372 
 
 Multiflorus, 168 
 
 Vulgaris, 168 
 
 Phellomyces, 614, 657 
 Phlebia, 413 
 Phlebophora, 406 
 
 Phleospora, 243, 249, 518, 519, 
 625 
 
 Aceris, 525 
 
 Caraganaj, 525 
 
 Mori, 525 
 
 Moricola, 525 
 
 Oxycantha?, 525 
 
 Phleum, 180, 321, 374, 608 
 
 Phlox, 176, 178, 258, 497, 519, 523, 
 631 
 
 Phlycta?na, 493, 518 
 
 Phoenix, 101, 658 
 
 Pholiota, 449, 452 
 
 Adiposa, 452, 453 
 
 Aurivella, 452 
 
 Cervinus, 452 
 
 Destruens, 452 
 
 Mutabilis, 452 
 
 Spectabilis, 452 
 
 Squarrosa, 452 
 
 Phoma, 238, 243, 245, 247, 257, 279, 
 325, 478, 481, 484, 490, 493, 519, 
 532 
 
 Albicans, 260, 490 
 
 Aleracea, 491, 492 
 
 Ambigua, 490 
 
 Apiicola, 492 
 
 Batata;, 492 
 
 Betffi, 247, 490 
 
 Bohemica, 276, 490 
 
 Brassicse, 492 
 
 Phoma, Chrysanthemi, 492 
 
 Phoma, Citricarpa, 491 
 
 Cyclamenae, 492 
 
 Cydona;, 490 
 
 DahUffi, 492 
 
 Devastatrix, 492 
 
 Hennebergii, 491 
 
 Limonis, 490 
 
 Lophiostomoides, 491 
 
 Mah, 490 
 
 Malvacearum, 492 
 
 Mororum, 491 
 
 Myxiae, 491 
 
 Napobrassica;, 491 
 
 Oleandrina, 492 
 
 Oleracea, 491, 492 
 
 Persicse, 490 
 
 Pithya, 492 
 
 Pomarum, 491 
 
 Ileniformis, 242, 490 
 
 Ribesia, 492 
 
 Roumii, 492 
 
 Sanguinolenta, 491 
 
 ■ Sarmentella, 490 
 
 Solani, 491 
 
 Solanicola, 491 
 
 Sordida, 492 
 
 Sphserosperma, 247 
 
 Strobi, 492 
 
 Strobilinum, 492 
 
 Subcircinata, 491 
 
 Tiliaj, 259 
 
 Tuberculata, 491 
 
 Uvicola, 238 
 
 Phomatospora, 263 
 Phomopsis, 482, 493 
 
 Aloeapercrassse, 493 
 
 Stewartii, 493 
 
 Phorcys, 263 
 Phragmidium, 354, 358, 390 
 
 Americanum, 359, 359 
 
 Bulbosum, 358 
 
 Disciflorum, 359, 359 
 
 Montivagum, 359, 359 
 
 Rosaj-acicularis, 359 
 
 RosEe-arkansana;, 359, 359 
 
 Rosse-caUfornicse, 359, 359 
 
INDEX 
 
 735 
 
 Phragmidium, Rosae-setigerae, 359, 
 
 359 
 
 Rubi-idaei, 359 
 
 Speciosum, 359 
 
 Subcorticium, 359 
 
 Violacoum, 359 
 
 Phragmites, 315, 377, 378 
 Phragmopyxis, 354 
 Phragraosporse, 633, G37 
 
 Key to, 637 
 
 Phycomyces, 105 
 
 Phycomycetes, 1, 3, 59, 64, 65, 101, 
 
 113, 116, 118 
 
 Key to, 65 
 
 Phyllachora, 157, 217, 220, 221, 606, 
 
 607 
 
 Cynodontis, 221 
 
 Dapazioides, 221 
 
 Graminis, 220, 220 
 
 Makrospora, 221 
 
 Poffi, 221 
 
 Pomigena, 220 
 
 Sorghi, 221 
 
 Trifolii, 220, 606 
 
 Ulmi, 557 
 
 Phyllactinia, 171, 173, 175, 187, 
 
 582 
 
 Corylea, 174, 187, 188 
 
 Phyllostachys, 215 
 
 Phyllosticta, 148, 238, 242, 243, 325, 
 
 476, 481, 483, 490, 519 
 
 Acericola, 489 
 
 Aceris, 489 
 
 Altha?ina, 487 
 
 Ampelopsidis, 484 
 
 — Apii, 487 
 
 Argillacea, 487 
 
 Armenicola, 486 
 
 — — - Bataticola, 486 
 
 Bellunensis, 249, 484 
 
 Beta;, 486 
 
 Bizzozeriana, 486 
 
 Brassicse, 484 
 
 Brassica?cola, 249 
 
 Cannabinis, 486 
 
 Catalpae, 489 
 
 Phyllosticta, Cavara;, 489 
 
 Chenopodii, 487 
 
 Chrysanthcrni, 488 
 
 Cinnanioni, 487 
 
 Circum.scissa, 486 
 
 Citrullina, 487 
 
 Coffeicola, 486 
 
 Comoensis, 486 
 
 Cruenta, 488 
 
 Cucurbitacearum, 487, 629 
 
 Cyclaminis, 488 
 
 Dammara;, 489 
 
 Dianthi, 488 
 
 Digitalis, 488 
 
 Dracffinae, 489 
 
 Fragaricola, 486 
 
 Funckia, 489 
 
 Grossularia;, 486 
 
 Halstedii, 488 
 
 Hederacea, 487 
 
 Hedericola, 487 
 
 Hevea, 487 
 
 Hortorum, 487 
 
 Humuli, 486 
 
 Hydrangea?, 488 
 
 Ida?cola, 488 
 
 Ilicina, 489 
 
 Insulata, 486 
 
 Japonica, 486 
 
 Labrusca;, 238, 484 
 
 Leucanthemi, 488 
 
 Liliicola, 488 
 
 Limitata, 485 
 
 Maculicola, 487 
 
 Maculiformis, 2^9, 485 
 
 Magnolia;, 489 
 
 Malkcffi, 486 
 
 Medicaginis, 486 
 
 Minima, 489 
 
 Miuria, 486 
 
 Narcissi, 489 
 
 Nicotiana, 486 
 
 Nobilis, 489 
 
 Olea;, 486 
 
 Opuntia;, 488 
 
 Paviae, 489 
 
736 
 
 INDEX 
 
 Phyllosticta, Persicse, 486 
 
 Phaseolina, 487 
 
 Piricola, 485 
 
 Pirina, 485 
 
 Primulicola, 488 
 
 Prunicola, 486 
 
 Pteridis, 489 
 
 Putrefaciens, 486 
 
 Richardiae, 488 
 
 Rosae, 487 
 
 Rosarum, 487 
 
 Solitaria, 484, 485, 485 
 
 Sphaeropsidea, 489 
 
 Succedanea, 486 
 
 Syringae, 488 
 
 Tabaci, 486 
 
 Tabifica, 247, 485 
 
 Tilia;, 489 
 
 Ulmicola, 489 
 
 Vialae, 486 
 
 ■ Vincse-minoris, 488 
 
 Viola}, 488 
 
 Viridis, 489 
 
 Vitis, 486 
 
 Phymatotrichum, 576 
 Physalacria, 412 
 Physalis, 48, 322 
 Physalospora, 238, 251, 252, i 
 539 
 
 Abietina, 253 
 
 Cattleyae, 253, 541 
 
 Fallaciosa, 253 
 
 : Gregaria, 252, 494 
 
 Laburni, 253 
 
 Vanilte, 253 
 
 Woronini, 253 
 
 Physaraceae, 10, 11 
 
 Key to, 11 
 
 Physarella, 12 
 Physarum, 12, 12 
 
 Bivalve, 12 
 
 — - Cinereum, 12 
 Physoderma, 72 
 Physopella, 340, 345 
 
 Fici, 345 
 
 Vitis, 345 
 
 ?, 273, 
 
 Physospora, 575 
 
 Phytolacca, 408 
 
 Phytomyxa Leguminosarum, 8 
 
 Phytophthora, 78, 83, 84, 88, 90, 617 
 
 Agaves, 89 
 
 Cactorum, 88 
 
 Calocasise, 89 
 
 Faberi, 88 
 
 Fagi, 88 
 
 Infestans, 84, 85, 86, 87 
 
 Nicotianae, 89 
 
 Omnivora, 88, 89 
 
 Arecae, 88 
 
 Phaseoli, 84, 84, 86 
 
 Sempervivi, 88 
 
 Syringae, 88 
 
 Picea, 145, 235, 253, 349, 391, 408 
 Pichia, 121 
 Piggotia, 528, 530 
 
 Astroidea, 221, 530 
 
 Fraxini, 530 
 
 Pigweed, 408 
 Pilacre, 634 
 Pilaira, 104 
 Pileotaria, 354 
 Piloboleae, 104 
 Pilobolus, 104 
 
 Crystallinus, 105 
 
 Pilocratera, 135 
 Pilosace, 449 
 Pinaceae, 88 
 
 Pine, 22, 52, 141, 145, 151, 157, 161, 
 162, 203, 230, 233, 249, 330, 333, 
 
 351, 352, 391, 401, 415, 418, 419, 
 423, 424, 432, 431, 436, 438, 440, 
 446, 454, 460, 492, 499, 512, 515, 
 516, 524, 531, 532, 654, 660 
 
 Pineapple, 496, 512, 596 
 
 Pink, 349, 507 
 
 Pinus, 161, 337, 338, 339, 340, 351, 
 
 352, 390, 408 
 Pionnotes, 645 
 
 Betae, 645 
 
 Rhizophila, 645 
 
 Piptocephalidacese, 103 
 Piptostomum, 481 
 
INDEX 
 
 737 
 
 Pirella, 105 
 Piricularia, 589, 591 
 
 Caudata, 592 
 
 Grisea, 591, 591, 614 
 
 Oryzff, 592, G14 
 
 Pirobasidium, 033 
 Pirostoma, 531 
 
 Farnctianum, 531 
 
 Pirotta;a, 147 
 Pistillaria, 412 
 Pisum, 168, 178, 372, 605 
 Pithomyces, 645 
 Pitya, 136 
 PlacosphaM'ia, 483 
 Placospharella, 505 
 Plagiorhabdus, 483, 500 
 
 Oxycocci, 500, 500 
 
 Planococcus, 18 
 Planosarcina, 18 
 Plantago, 69, 96, 179 
 Plasmodiophora, 6 
 
 Brassica;, 6, 7 
 
 . Californica, 8 
 
 Humili, 8 
 
 Orchidis, 8 
 
 . Tomati, 8 
 
 _— Vitis, 8 
 Plasmodiophorales, 5 
 
 — — Key to, 6 
 
 Plasmopara, 82, 83, 90, 93, 95 
 
 ■ Halstedii, 91 
 
 . Nivea, 91 
 
 . Obducens, 93 
 
 Pygmsea, 93 
 
 Ribicola, 92 
 
 Viticola, 91, 92 
 
 Platanus, 186, 205, 535 
 
 Platygloiea, 392 
 
 Plectothrix, 576 
 
 Plenodomus, 482 
 
 Pleococcum, 534 
 
 Pleogibberella, 198 
 
 Pleolpidium, 68 
 
 Pleomassaria, 263 
 
 Pleomeliola, 190 
 
 Hyphsenes, 193 
 
 Pleonectria, 198, 207 
 
 Berolinensis, 207 
 
 Coffcicola, 207 
 
 Pleophragmia, 224 
 Pleosphserulina, 236, 250 
 
 Briosiana, 250 
 
 Pleospora, 252,259,^.79,611,618 
 
 Albicans, 260, 269, 490 
 
 Avense, 262 
 
 Bromi, 261, 613 
 
 Gramineum, 261, 612 
 
 Herbarum, 260, 618 
 
 . Hesperidearum, 260, 616 
 
 Hyacinthi, 260, 603 
 
 Infectoria, 260 
 
 Negundinis, 260 
 
 Oryza;, 260 
 
 Pisi, 260 
 
 Putrefaciens, 260 
 
 Teres, 262 
 
 Trichostoma, 260, 262, 612, 621 
 
 Tritici, 258 
 
 - Tritici-repentis, 262, 613 
 
 . Tropoeoli, 260, 621 
 
 Ulmi, 260 
 
 Vulgaris, 610 
 
 Pleosporaceje, 223, 250 
 
 Key to, 251 
 
 Plcotrachelus, 68 
 Pleurotus, 450, 454, 569 
 
 - Atrocoeruleus, 455 
 
 Corticatus, 455 
 
 . Mitis, 455 
 
 Nidulans, 455 
 
 Ostreatus, 454, J^56 
 
 Salignus, 454 
 
 Ulmarius, 454 
 
 Plowrightia, 216, 217 
 
 Agav.es, 220 
 
 Morbosa, 218, 218, 219, 516 
 
 . Ribesia, 220 
 
 Virgultorum, 220 
 
 Plum, 32, 38, 129, 138, 184, 219, 271, 
 278, 282, 357, 433, 516, 520, 562, 
 586, 604 
 Pockets, 129 
 
738 
 
 INDEX 
 
 Pluteolus, 449 
 Pluteus, 450, 454 
 
 Cervinus, 454, 1^55 
 
 Poa, 8, 119, 180, 221, 310, 321, 375 
 
 Pocillum, 136 
 
 Pocosphaeria, 252 
 
 Podocapsa, 122 
 
 Podocarpus, 597 
 
 Podocrea, 199 
 
 Podosphsera, 175, 182 
 
 Leucotricha, 184, 569 
 
 Myrtillina, 183 
 
 Oxyacantha;, 183, 183, ISA, 569 
 
 Tridactyla, 183, 184 
 
 Podosporiella, 637 
 Podosporium, 637 
 Polemonium, 507 
 Polycephalum, 633 
 Polyscytalum, 568 
 Polydesmus, 609 
 Polygonum, 96, 303 
 Polymorphism, 64 
 Polynema, 534 
 Polyphagus, 73 
 Polyporacese, 402, 416 
 
 Key to, 416 
 
 PolyporeEe, 416 
 Polyporus, 417, 418, 426 
 
 Adustus, 426 
 
 Amarus, 422 
 
 Betulinus, 425, 425 
 
 Borealis, m, 423, 4^3 
 
 Dryadeus, 423 
 
 Dryophillus, 421 
 
 Fruticum, 422 
 
 Giganteus, 421 
 
 Glivus, 421 
 
 Hispidus, 421 
 
 — — Obtusus, 418 
 
 Schweinitzii, 400, 401, 424 
 
 Squamosus, 419, J,20 
 
 Sulphureus, 419, 419 
 
 Polystictus, 417, 418, 426 
 
 Cinnabarinus, 425 
 
 — — Hirsutus, 426 
 Occidentalis, 425 
 
 Polystictus, Pergamenus, 426, 4^6 
 
 Sanguineus, 425 
 
 Velutinus, 425 
 
 Versicolor, 425, 427 
 
 Polystigma, 198, 207 
 
 Ochraceum, 208 
 
 Rubra, 208, 208, 564 
 
 Polythelis, 354 
 Polythrincium, 602, 606 
 
 Trifolii, 220, 606, 606 
 
 Pomelo, 549, 604 
 
 Pomes, 139, 237, 255, 278, 282, 362, 
 
 410, 491, 496, 502, 529, 569, 607, 
 
 649 
 Poplar, 21, 36, 47, 130, 182, 256, 340, 
 
 342, 419, 433, 440, 446, 454, 507, 
 
 535, 556, 606 
 Poppy, 100 
 
 Mallow, 390 
 
 Populus, 127, 130, 249, 344, 499, 512, 
 
 519, 545, 555 
 Poria, 418 
 
 Hypolaterita, 418 
 
 Laevigata, 418 
 
 Subacida, 418 
 
 Vaporaria, 418 
 
 Vineta, 418 
 
 PoropeUis, 531 
 
 Porothelium, 440 
 
 Potato, 8, 21, 40, 41, 43, 44, 46, 47, 
 
 48, 49, 69, 70, 86, 141, 200, 231, 
 
 258, 404, 408, 456, 491, 497, 568, 
 
 583, 584, 591, 614, 616, 617, 623, 
 
 624, 627, 637, 645, 652, 653 
 
 Beetle, 48 
 
 Potentilla, 175 
 Powdery Mildew, 171 
 Primrose, 101, 250, 320, 552, 582 
 Primula, 315, 318, 488, 507, 579, 582, 
 
 591 
 Primulaceae, 101 
 Prismaria, 593 
 Privet, 191, 269, 541 
 Promycelium, 63, 300 
 Prophytroma, 600 
 Prospodium, 354 
 
INDEX 
 
 739 
 
 Prosthemiella, 557 
 Prosthemium, 515 
 Protoascomycetes, 114, 117, 119 
 Protobasidii, 299, 323 
 
 Key to, 323 
 
 Protocoronospora, 405, 409 
 
 Nigricans, 409 
 
 Protodiscales, 114, 123, 125 
 
 Key to, 125 
 
 Protomyces, 118, 119 
 
 Macrosporus, 119 
 
 Pachydermus, 119 
 
 Rhizobius, 119 
 
 Protomycetacea?, 118 
 
 Key to, 118 
 
 Protomycetales, 118 
 
 Key to, 118 
 
 Protostegia, 536 
 
 Prunus, 129, 130, 140, 152, 182, 183, 
 
 184, 202, 208, 275, 347, 357, 486, 
 
 495, 496, 563, 564, 569, 579, 605, 
 
 610, 626 
 Psathyra, 449 
 Pseudobeltrania, 602 
 Pseudocenangium, 537 
 Pseudocolus, 463 
 Pseudodematophora, 231 
 Pseudographis, 156 
 Pseudographium, 515 
 Pseudomassaria, 262 
 Pseudomeliola, 189 
 Pseudomonas, 18, 21, 22 
 
 .^ruginosus, 23, 27 
 
 Amaranti, 22 
 
 Aralise, 39 
 
 Avens, 23, 23, 40 
 
 Campestris, 22, 24, 24, 25, 26, 
 
 28, 29, 31, 32, 43 
 
 Destructans, 26, 39, 42 
 
 Dianthi, 22, 27 
 
 Fluorescens, 27, 41 
 
 Exitiosus, 27 
 
 Liquefaciens, 27 
 
 Putrida, 27 
 
 Hyacinthi, 22, 25, 27, 28, 31 
 
 ■ Indigofera, 13 
 
 Pseudomonas, Iridis, 27 
 
 Juglandis, 27 
 
 Legurninipordus, 28 
 
 Levistici, 28 
 
 Maculicolum, 28 
 
 Malvacearum, 22, 29, 29 
 
 Medicaginis, 29, 30, 31 
 
 Michiganense, 30 
 
 Mori, 30, 43 
 
 Oleae-tuberculosis, 34 
 
 Phaseoli, 22, 27, 28, 31, 31 
 
 Pruni, 32, 32 
 
 Putridus, 23 
 
 Putrifaciens Liquefaciens, 43 
 
 Iladicicola, 8, 32 
 
 Savastanoi, 33, 46 
 
 Sesami, 34 
 
 Sps. Indet, 37 
 
 Stewarti, 22, 33, 34, 34 
 
 Syringae, 35 
 
 Tumefaciens, 35, 35 
 
 Vascularum, 37 
 
 Pseudopatella, 536 
 Pseudopeziza, 147, 149, 475, 539, 
 547, 555 
 
 Medicaginis, 147 
 
 Ribis, 148, 541 
 
 Salicis, 148, 541 
 
 Tracheiphila, 148 
 
 Trifolii, 148, 148, 494, 535 
 
 Pscudophacidea?, 155 
 Pseudophacidium, 155 
 Pseudoplasmopara, 93 
 Pseudorhytisma, 156 
 Pseudotryblidium, 150 
 Pseudotsuga, 408, 416 
 Pseudovalsa, 280, 281 
 
 Longipes, 281 
 
 Pseudozythia, 527 
 Psilocary, 303 
 Psilocybe, 449, 451 
 
 Henningsii, 451 
 
 Pennata, 4'52 
 
 Spadicea, 451 
 
 Psilopezia, 132 
 Psilospora, 534 
 
740 
 
 INDEX 
 
 Pteris, 489, 595 
 
 Pterocarpus Indicus, 426 
 
 Pterophyllus, 444 
 
 Pterula, 411 
 
 Puccinia, 355, 359, 361, 375, 390 
 
 AUii, 377 
 
 Anemones-virginianse, 389 
 
 Apii, 377 
 
 Arenarise, 387 
 
 Asparagi, 326, 328, 329, 330, 
 
 376, 376 
 
 Asteris, 389 
 
 BuUata, 377 
 
 Canna;, 389 
 
 Castagnei, 377 
 
 Cerasi, 376 
 
 Chrysanthemi, 386 
 
 Cichorii, 378 
 
 Convallarise-digraphidis, 388 
 
 Coronata, 382, 383 
 
 Coronifera, 383 
 
 Cyani, 377 
 
 Dianthi, 389 
 
 Dispersa, 382 
 
 Endiviaj, 377 
 
 Fagopyri, 378 
 
 Gentianaj, 389 
 
 Gladioli, 389 
 
 Glumarum, 383 
 
 Graminis, 329, 334, 378, 379, 
 
 385 
 
 Airse, 379 
 
 Avense, 379 
 
 Phlei-pratensis, 379 
 
 Poaj, 379 
 
 Secalis, 379 
 
 Tritici, 379 
 
 Granulans, 389 
 
 Helianthi, 386, 387 
 
 Heterogena, 386 
 
 Horiana, 389 
 
 Iridis, 389 
 
 IsiaciB, 378, 390 
 
 Magnusii, 376 
 
 Malvacearum, 328, 385, 386 
 
 Menthai, 378 
 
 Puccinia, Pazschkei, 389 
 
 Persistens, 389 
 
 Phlei-pratensis, 384 
 
 Phragmitis, 377 
 
 Poarum, 386 
 
 PodophyUi, 332 
 
 Porri, 377 
 
 Pringsheimiana, 376 
 
 Purpurea, 384 
 
 Ribis, 328 
 
 caricis, 376 
 
 Nigri-acuta?, 376 
 
 paniculatse, 376 
 
 Pseudocyperi, 376 
 
 Rubigovera, 329, 381, 383 
 
 Secalis, 382 
 
 Tritici, 382 
 
 Schroeteri, 389 
 
 Scilla;, 389 
 
 Simplex, 383 
 
 Sorghi, 329, 384, 384 
 
 Suaveolens, 328 
 
 Taraxici, 378 
 
 Tragopogonis, 328, 377 
 
 Triticina, 382 
 
 Tulips, 389 
 
 Vexans, 327 
 
 Viote, 388 
 
 Pucciniacese, 335, 353 
 
 Key to, 353 
 
 Pucciniastrum, 341, 346, 390, 391 
 
 Abieti-chamsenerii, 347 
 
 Epilobii, 347 
 
 Goeppertianum, 342, 347 
 
 Hydrangeae, 346 
 
 Myrtelli, 347 
 
 Padi, 347 
 
 Pustulatum, 347 
 
 Pucciniosita, 342 
 Pucciniospora, 505 
 Puff-balls, 395 
 Pulparia, 151 
 Pulsatilla, 333 
 
 Pumpkin, 95, 107, 247, 408, 548 
 Purslane, 82, 408 
 Pycnidium, 61 
 
INDEX 
 
 741 
 
 Pycnochytrium, 70, 72 
 — — Anemones, 72 
 — — Globosum, 72 
 Pyrenochaeta, 482, 497 
 
 Ferox, 497 
 
 Oryzse, 497 
 
 Phlogis, 497 
 
 Pyrenomycetes, 159, 165, 170, 195, 
 
 217 
 Pyrenopeziza, 147 
 Pyrenophora, 252, 262 
 
 Trichostoma, 262 
 
 Pyrenotrichum, 481 
 Pyroctonum, 72 
 
 Sphairicum, 73 
 
 Pyronema, 116 
 Pyronemaccae, 133, 134 
 Pyropolyporous Praerimosa, 430 
 Pyrus, 176, 183, 366, 590 
 
 Arbutifolia, 369 
 
 Pythiacea;, 75 
 Pythiacystis, 75, 77, Tl 
 
 Citrophthora, 77 
 
 Pythium, 75, 76, 76, 650 
 
 de Baryanum, 77 
 
 Gracile, 77 
 
 Intermedium, 77 
 
 Palmivorum, 77 
 
 Q 
 
 Quercus. 127, 186, 188, 202, 220, 544 
 Quince, 36, 38, 130, 140, 149, 249, 
 267, 268, 367, 369, 371, 404, 490, 
 502, 515, 540, 542, 557, 569, 582 
 
 R 
 
 Rabenhorstia, 483 
 
 Rabentischia, 251 
 
 Radish, 36, 42, 81, 95, 408, 571 
 
 Radulum, 413 
 
 Ramularia, 243, 245, 589, 590 
 
 Armoracise, 590, 590 
 
 Ramularia, Betae, 690 
 
 Coleosporii, 591 
 
 Cynarae, 591 
 
 Geranii, 591 
 
 Goeldiana, 591 
 
 Heraclci, 591 
 
 Lactea, 591 
 
 Modesta, 591 
 
 Narcissi, 591 
 
 Necator, 590 
 
 Onobrychidis, 591 
 
 Primula?, 591 
 
 Spinaciae, 690 
 
 Taraxaci, 590 
 
 Tulasnei, 244, 690 
 
 Vallambrosae, 591 
 
 Ramulaspera, 577 
 
 Ranunculacese, 93, 320 
 
 Ranunculus, 101, 321, 375 
 
 Rape, 141, 258 
 
 Raspberry, 38, 245, 248, 257, 258, 
 
 270, 359, 360, 451, 503, 543, 544, 
 
 547, 581, 650 
 Ravenelia, 353 
 Red Algse, 3 
 Red Bud, 632 
 Red Cedar, 329, 431 
 Redtop, 310 
 Reessia, 68 
 Rehmiella, 264 276 
 Rehmiellopsis, 264, 276, 490 
 
 Bohemica, 276 
 
 Reticulariacese, 10 
 Rhabdospora, 518, 519, 625 
 
 Coffea;, 519, 525 
 
 Coffeicola, 519, 525 
 
 Oxycocci, 519, 525 
 
 Rubi, 519, 525 
 
 Theobromae, 519, 525 
 
 Rhacodium, 657 
 Rhacophyllus, 444 
 Rhagadolobium, 155 
 Rhamphoria, 232 
 Rhamus, 383 
 Rhinocladium, 599 
 Rhinotrichum, 575 
 
742 
 
 INDEX 
 
 Rhizidiacese, 67 
 Rhizina, 132 
 
 Inflata, 132, 133 
 
 Undulata, 132 
 
 Rhizinacese, 131, 132 
 
 Key to, 132 
 
 Rhizoctonia, 230, 231, 407, 408, 657, 
 
 659 
 
 Betse, 660 
 
 Crocorum, 660 
 
 Medicaginis, 660 
 
 Solani, 407, 660 
 
 Strobi, 660 
 
 Subepigea, 660 
 
 Violacea, 407, 6G0 
 
 Rhizogaster, 462 
 Rhizomorpha, 659 
 Rhizopus, 104, 105, 105 
 
 Necans, 106 
 
 Nigricans, 105 
 
 Schizans, 106 
 
 Riiododendron, 141, 194, 221, 258, 
 
 349, 398, 544, 559 
 Rhodophycea?, 3 
 Rhombostilbella, 634, 635 
 
 Rosa?, 635 
 
 Rhopalidium, 557 
 Rhopographus, 217 
 Rhopalomyces, 570 
 Rhubarb, 41, 101, 377, 497, 506 
 Rhynchodiplodia, 510 
 
 Citri, 510 
 
 Rhynchomeliola, 232 
 Rhynchomyces, 609 
 Rhynchophoma, 505 
 Rhynchosporium, 586, 587 
 
 Graminicola, 587 
 
 Rhynchostoma, 232, 277 
 Rhytidhysterium, 161 
 Rhytidopeziza, 150 
 Rhytisma, 156, 158 
 
 Acerinum, 158, 159, 530 
 
 Punctatum, 159, 530 
 
 Salicinum, 159, 530 
 
 Symmetricum, 159 
 
 Ribes, 152, 176, 185, 188, 202, 220, 
 
 328, 344, 351, 376, 486, 541, 
 
 580, 581 
 Riccia, 251 
 Rice, 46, 213, 214, 232, 250, 257, 
 
 259, 260, 276, 317, 486, 495, 
 
 503, 504, 507, 512, 516, 520, 
 
 535, 591, 605, 611, 613, 626, 
 
 656, 661 
 Richardia, 408 
 Richonia, 189 
 Riccoa, 637 
 Rimbachia, 443 
 Robillarda, 505 
 Robinia, 235, 524 
 Roesleria Hypogsea, 154 
 Roostelia, 335, 361, 363, 389, 391 
 
 Aurantica, 368 
 
 Botryapites, 370 
 
 Cancellata, 369 
 
 Cornuta, 368 
 
 Cydoniaj, 371 
 
 Koreaensis, 371 
 
 Penicillata, 367 
 
 Pyrata, 364, S91 
 
 Transformans, 369 
 
 Rosa, 33, 47, 97, 105, 176, 220, 
 
 284, 359, 433, 487, 492, 503, 
 
 505, 509, 516, 517, 522, 544, 
 
 560, 564, 602, 631 
 Rosacea, 127, 143, 330, 359, 
 
 610 
 Rosellc, 187 
 Rosellinia, 226, 230, 635 
 
 Aquila, 230, 231 
 
 Bothrina, 231 
 
 Echinata, 232 
 
 Ligniaria, 232 
 
 Massinkii, 231 
 
 Necatrix, 230, 231 
 
 Quercina, 231 
 
 Radiciperda, 231 
 
 Rosenscheldia, 216 
 Rostrella, 166 
 
 Coffcffi, 168 
 
 Rotaea, 588 
 Rozites, 449 
 
 542, 
 
 258, 
 497, 
 525, 
 643, 
 
 249, 
 504, 
 555, 
 
 391, 
 
INDEX 
 
 743 
 
 Roumegueriella, 527 
 
 Roussoella, 216 
 
 Rozella, 70 
 
 Rubber plant, 270 
 
 Rubus, 39, 72, 100, 176, 227, 333, 359, 
 361, 626 
 
 Rumex, 74, 377, 582 
 
 Ruppia, 8 
 
 Rush, 329 
 
 Rust Fungi, 64, 298, 324 
 
 Rutabaga, 27 
 
 Rutstroemia, 135 
 
 Rye, 146, 180, 200, 206, 213, 257, 
 258, 262, 305, 310, 317, 319, 333, 
 380, 382, 520, 550, 555, 587, 613 
 
 Rynchospora, 303 
 
 Sabina, 234 
 Saccardsea, 630 
 Saccardia, 190 
 Saccardoella, 252 
 Saccharomycetacea', 120 
 
 Key to, 121 
 
 Saccharomyccs, 121 
 
 Croci, 121 
 
 Saccharomycetales, 119 
 
 Key to, 120 
 
 Saccharomycodes, 121 
 
 Saccharomycopsis, 121 
 
 Saccharum, 180 
 
 Saccoblastia, 393 
 
 Saffron, 660 
 
 Sagittaria, 315 
 
 Sainfoin, 217, 507, 591, 595 
 
 Salix, 148, 256, 344, 494, 541, 606 
 
 Salsify, 36, 42, 52, 82, 301, 328, 
 
 617 
 Sambucus, 185, 220, 256 
 Sanguisorba, 361 
 Santiella, 515 
 Sapindacese, 127 
 Saponaria, 620 
 Saprolegniaceae, 75 
 
 Saprolegniales, 66, 74, 75 
 
 Key to, 75 
 
 Sarcapodiese, 595 
 Sarcina, 18 
 
 Sarcinella, 191, 61(), 625 
 Sarcinodochium, 645 
 Sarcomyces, 151 
 Sarcoscypha, 135 
 Sarcoscypheaj, 135 
 Sarcosoma, 151 
 Sarracenia, 270 
 Sassafras, 433 
 Satsuma, 604 
 Saxifrage, 345, 389 
 Scabiosa, 100, 176, 178 
 Scaphidium, 536 
 Sceptromyces, 584 
 Schenckiella, 189 
 Schinzia, 323 
 Schizanthus, 552 
 Schizomycetes, 1, 3, 13, 18 
 
 Key to, 18 
 
 Schizonella, 302 
 Schizophyllese, 443, 444 
 
 Key to, 444 
 
 Schizophyllum, 444 
 
 Alneum, 444, 44-5 
 
 Schizosaccharomyces, 121 
 Schizothyrella, 536 
 Schizothyrium, 156 
 Schweinitzia, 150 
 Schweinitziella, 217 
 Scilla, 143, 375, 389 
 Scirrhia, 217 
 Scirrhiella, 217 
 Sclerodermatales, 398 
 Scleroderris, 155 
 Sclerodiscus, 655 
 Sclcrophoma, 482 
 Sclerospora, 82, 83, 89 
 
 Graminicola, 90, 90, 101 
 
 Macrospora, 89 
 
 Sclerotinia, 135, 136, 138, 568 
 
 Alni, 143 
 
 Aucuparia;, 143 
 
 Betulaj, 143 
 
744 
 
 INDEX 
 
 Sclerotinia, Bulborum, 143 
 
 Cinerea, 137, 139, 569 
 
 Crata?gi, 143, 569 
 
 Fructigena, 137, 139, 569 
 
 Fuckeliana, 139, 140, 141, 579, 
 
 581 
 
 Galanthi, 141, 581 
 
 Laxa, 137, 139, 569 
 
 Ledi, 137, 329 
 
 Libertiana, 140, 141, 141, 11^2, 
 
 581 
 
 Linhartiana, 140, 569 
 
 Mespili, 140 
 
 Nicotiana;, 142 
 
 Oxycocci, 140, 569 
 
 Padi, 140, 569 
 
 Rhododendri, 141 
 
 Seaveri, 140, 569 
 
 Trifoliorum, 143 
 
 Tuberosa, 143 
 
 Urnula, 1S7 
 
 Sclerotiopsis, 482 
 Sclerotium, 659, 660 
 
 Bulborum, 661 
 
 Cepivorum, 661 
 
 Oryzffi, 661 
 
 Rhizodes, 661 
 
 Rolfsii, 660, 661, 662 
 
 Tulipse, 661 
 
 Tuliparum, 143, 661 
 
 Scolecopeltis Jiruginea, 195 
 Scolecosporium, 557 
 Scolecotrichum, 602, 607 
 
 Avenae, 608 
 
 Fraxini, 608 
 
 Graminis, 608, 608 
 
 Iridis, 608 
 
 Melophthorum, 608 
 
 Musse, 608 
 
 Scorias, 190 
 Scoriomyces, 641 
 Scorzonera, 305 
 Secale, 180, 379 
 Sedge, 89, 220, 329 
 Sedum, 221, 497, 522 
 Seiridiella, 558 
 
 Seiridium, 558 
 
 Selenotila, 566 
 
 Selinia, 198 
 
 Sempervivum, 353 
 
 Senecio, 168, 333, 339 
 
 Sepedonium, 200, 577 
 
 Septobasidium, 405, 411 
 
 Pedicellata, 412 
 
 Septocylindrium, 588, 589 
 
 Areola, 589, 589 
 
 Radicicolum, 590 
 
 Rufomaculans, 589 
 
 Septodothideopsis, 518 
 
 Septogloeum, 243, 556, 557 
 
 Arachidis, 557 
 
 Cydonise, 557 
 
 Fraxini, 557 
 
 Hartigianum, 557 
 
 Manihotis, 557 
 
 Mori, 249, 557 
 
 Profusum, 557 
 
 Ulmi, 557 
 
 Septomyxa, 555 
 
 Septonema, 609 
 
 Septorella, 517 
 
 Septoria, 243, 257, 265, 478, 517, 518 
 
 Aciculosa, 519 
 
 ^sculi, 524 
 
 Ampelina, 520 
 
 Antirrhini, 522 
 
 Armoracise, 522 
 
 Avena?, 520 
 
 Azalese, 523 
 
 Beta;, 520 
 
 Canabina, 521 
 
 Caragana;, 524 
 
 Castanese, 524 
 
 Castanicola, 524 
 
 Cerasina, 520 
 
 Cercidis, 524 
 
 Chrysanthemella, 522 
 
 Citrulli, 520 
 
 Consimilis, 522 
 
 Cornicola, 524 
 
 Cucurbit acearum, 521 
 
 Curvata, 524 
 
INDEX 
 
 745 
 
 Septoria, Curvula, 520 
 
 Cyclaminis, 522 
 
 Dianthi, 522 
 
 Divaricata, 523 
 
 Dolichi, 521 
 
 Exotica, 523 
 
 Fairmanii, 523 
 
 Fragaria;, 519 
 
 Fraxani, 524 
 
 Glaucescens, 520 
 
 Glumarum, 520 
 
 Graminum, 520 
 
 Hedera;, 522 
 
 Helianthi, 523 
 
 Hippocastani, 524 
 
 Hydrangese, 622 
 
 Iridis, 522 
 
 Lactucae, 522 
 
 Limonum, 520 
 
 Locfgreni, 520 
 
 Longispora, 520 
 
 Lycopersici, 521, 5122 
 
 Majalis, 523 
 
 Medicaginis, 621 
 
 Narcissi, 523 
 
 Nicotians?, 521 
 
 Nigro-maculans, 524 
 
 Nodorum, 520 
 
 Ochroleuca, 524 
 
 Oleandrina, 524 
 
 Parasitica, 523, 524 
 
 Petroselini, 521 
 
 Apii, 621, 521 
 
 Phlogis, 258, 519 
 
 Pini, 162 
 
 Piricola, 246, 519 
 
 Pisi, 250, 519 
 
 Populi, 249, 619 
 
 Pruni, 620 
 
 Pseudoplatani, 524 
 
 Ribis, 245, 519, 519 
 
 Rosa;, 522 
 
 Rostrupii, 522 
 
 Secalina, 520 
 
 Sedi, 522 
 
 Spadicea, 524 
 
 Septoria, Tilise, 524 
 
 Tritici, 520 
 
 Ulmaria;, 524 
 
 Ulmi, 221 
 
 Varians, 522 
 
 Veronica;, 624 
 
 Septosporiella, 518 
 Septosporium, 616, 620 
 
 Heterosporium, 620 
 
 Sequoia, 243, 632 
 
 Service Berry, 191 
 
 Sesame, 34, 47 
 
 Setaria, 90, 209, 213, 305 
 
 Shad Bush, 39 
 
 Sida, 488 
 
 Sigmoideomyces, 570 
 
 SilHa, 283 
 
 Simblum, 464 
 
 Sircoccus, 482 
 
 Sirodesmium, 615 
 
 Siropatella, 536 
 
 Sirothecium, 500 
 
 Sirozythia, 526 
 
 Sisil, 552 
 
 Sistotrema, 413 
 
 Skepperia, 406 
 
 Slime Flux, 120 
 
 Slime Fungi, 3 
 
 Slime Molds, 1 
 
 Smut Fungi, 298 
 
 Smuts, 64 
 
 Snapdragon, 101, 492, 522, 553 
 
 Snowdrops, 141, 581 
 
 Sobralia, 270 
 
 Soft Rot, 105 
 
 Solanaceous, 86 
 
 Solanum, 322, 323, 408 
 
 Solenia, 406 
 
 Sohdago, 179, 338 
 
 Solomon's Seal, 488 
 
 Sorbus, 235, 255, 336, 368, 371, 607 
 
 Sordaria, 224 
 
 Sordariacese, 222, 224 
 
 Key to, 224 
 
 Sorghum, 49, 121, 221, 305, 310, 311, 
 312, 314, 384, 613 
 
746 
 
 INDEX 
 
 Sorokina, 151 
 Sorolpidium, 8 
 
 Betae, 8 
 
 Sorosphsera, 6, 8 
 
 Graminis, 8 
 
 Sorosporium, 302, 312, 812 
 
 Consanguineum, 312 
 
 Dianthi, 312 
 
 Ellisii, 312 
 
 Everhartii, 312 
 
 Sorothelia, 227 
 Sparassis, 412 
 Spathularia, 131 
 Speira, 615 
 Spelt, 206 
 Spermatia, 325 
 Spermodermia, 655 
 Spermogonia, 324, 325 
 Sphacelia, 196, 211, 212, 640, 643 
 
 Segetum, 213, 643 
 
 Typhina, 643 
 
 Sphacelotheca, 302, 303, 310 
 
 Reiliana, 312, 312 
 
 Sorghi, 311, 311 
 
 Sphaerella, 244 
 Sphaeriaceffi, 222, 225 
 
 Key to, 225 
 
 Sphseriales, 124, 195, 221, 475 
 
 Key to, 222 
 
 Sphscridium, 641 
 Spha?rioidacese, 479, 480 
 — Key to, 480 
 
 Amerosporae, 480 
 
 Dictyospora?, 480 
 
 Didymospora?, 480 
 
 Helicospora>, 480 
 
 Hyalodictya?, 480 
 
 Hyalodidymff, 480, 505 
 
 Key to, 505 
 
 Hyalophragmia?, 480, 513 
 
 Key to, 513 
 
 Hyalosporae, 480 
 
 Key to, 480 
 
 Phffiodictyaj, 480, 516 
 
 Key to, 516 
 
 Pha^odidymse, 480, 509 
 
 Sphserioidacea?, Phseodidymse, Key 
 
 to, 510 
 
 Phffiophragmise, 480, 514 
 
 Key to, 514 
 
 Phaeospora;, 480, 500 
 
 Key to, 500 
 
 Phragmosporse, 480 
 
 Scolecosporae, 480, 517 
 
 Key to, 517 
 
 Staurosporse, 480 
 
 Sphajrita, 68, 238 
 Sphffirocolla, 640 
 Spha;rographium, 517 
 Sphajromyces, 656 
 Sphseronema, 482, 494 
 
 Adiposum, 495 
 
 Fimbriatum, 494, ^95 
 
 Oryzse, 495 
 
 — — Phacidioides, 148, 494 
 
 Pomarum, 495 
 
 Spurium, 152, 495 
 
 Sphaironemella, 527 
 Spha;ropeziza, 156 
 Sphajrophragmium, 454 
 Sphaeropsdidales, 479, 564 
 
 Key to, 479 
 
 Sphaeropsis, 284, 501 
 
 Japonicum, 503 
 
 Magnolia?, 503 
 
 Malorum, 284, 502, 502, 546 
 
 Mori, 503 
 
 Pseudodiplodia, 503 
 
 Ulmi, 503 
 
 Vincae, 503 
 
 Viticola, 284 
 
 SphsDrosoma, 132 
 Sphaerosporium, 639 
 Sphajrostilbe, 195, 196, 198, 207 
 
 Flavida, 207 
 
 Repens, 207 
 
 Sphajrotheca, 172, 175 
 
 Castagnci, 115 
 
 — Humuli, 175, 569 
 
 Var. Fuliginea, 176 
 
 Lancstris, 177 
 
 Mali, 184 
 
mDEX 
 
 747 
 
 Sphirrotheca, Mors-uvse, 176, 176 
 
 Pannosa, 176, 5G9 
 
 Sphajrulina, 236 
 Sphinetrina, 153 
 Spicaria, 201, 584, 585 
 
 Colorans, 205, 585 
 
 Solani, 585 
 
 Spicularia, 571 
 
 Spilomium, 655 
 
 Spinach, 90, 321, 487, 551, 590, 605, 
 
 611, 628, 629 
 Spinellus, 104 
 Spirea, 175, 176, 184, 336, 524, 
 
 637 
 Spirechnia, 354 
 Spirillacese, 19 
 Spirilli, 13 
 Spirillum, Cholerse-asiatica;, 19 
 
 Volutans, 13 
 
 Spirodelia, 315 
 Spondylocladium, 609, 614 
 
 Atrovirens, 614, 614 
 
 Spongospora, 6, 8 
 
 Subterranea, 8 
 
 Sporidium, 326 
 Sporocybe, 630 
 Sporoderma, 640 
 Sporodesmium, 257, 615, 61S, 617 
 
 Brassicse, 617 
 
 Dolichopus, 617 
 
 Exitiosum, 258, 616 
 
 Var. Solani, 616 
 
 Glomerulosum, 610 
 
 Ignobile, 617 
 
 Melongense, 617 
 
 Mucosum, 617 
 
 Piriforme, 260, 616 
 
 Putrefaciens, 617 
 
 Scorzonerse, 617 
 
 — — Solani Varians, 617 
 Sporoglena, COO 
 Sporonema, 274, 534, 535 
 
 Oxycocci, 535, 535 
 
 Phacidioides, 148, 535 
 
 Platani, 274, 535 
 
 Pulvinatum, 536 
 
 iSporormia, 224 
 Sporormiella, 224 
 Sporoschismea), 609 
 Sporotrichella, 576 
 Sporotrichuni, 230, 576, 577 
 
 Poa', 577, 578 
 
 Spruce, 145, 162, 230, 391, 418, 423, 
 
 424, 431, 432, 434, 436, 438, 440, 
 
 509, 524 
 Spumaria, 11 
 
 Alba, 11 
 
 Spumariacea;, 10, 11 
 
 Spurge, 544 
 
 Squash, 95, 105, 179, 247, 540, 548 
 
 Stachybotryella, 598 
 
 Stachybotrys, 598 
 
 Stachylidieaj, 595 
 
 Stagonospora, 514, 514 
 
 Carpathica, 514 
 
 Iridis, 514 
 
 Staurochseta, 482 
 Staurosporse, 633 
 Steccherinum, 414, 416 
 
 Ballouii, 416 
 
 Stemmaria, 630 
 Stemonitaceae, 10 
 Stemphyliopsis, 592 
 Stemphylium, 616, 617, 617 
 
 Citri, 618 
 
 Ericoctonum, 617 
 
 Tritici, 618 
 
 Stenocybe, 153 
 Stereum, 405, 409 
 
 Frustulosum, 409, 410 
 
 Hirsutum, 409 
 
 Purpureum, 410 
 
 Quercinum, 409 
 
 Rugosum, 410 
 
 Sterigma, 298 
 
 Sterigmatocystis, 167, 310, 572, 573 
 
 Ficuum, 573 
 
 Luteo-nigra, 573 
 
 Niger, 573 
 
 Stictidaceffi, 154 
 Stictis, 154, 155 
 Panizzei, 155 
 
748 
 
 INDEX 
 
 Stigmatea, 150, 236, 243, 2^3, 244 
 
 Alni, 243 
 
 Juniperi, 243 
 
 Stigmatella, 641 
 Stigmella, 615 
 Stigmina, 608, 610, 610 
 
 Briosiana, 610 
 
 Stilbacese, 565, 632 
 
 Key to, 632 
 
 Amerosporse, 632 
 
 Key to, 633 
 
 Didymosporse, 632 
 
 Helicospora?, 632 
 
 Hyalostilbea^, 632, 633 
 
 Phaiostilbese, 632 
 
 Phragmospora}, 632 
 
 Stilbella, 633, 635 
 
 Flavida, 635 
 
 — Nanum, 635 
 
 Populi, 635 
 
 Thea;, 635 
 
 Stilbonectria, 198 
 
 Stilbospora, 558 
 
 Stilbothamnium, 630 
 
 Stilbum, 207 
 
 Stone Fruits, 139, 278, 569 
 
 Stoneworts, 3 
 
 Strawberry, 11, 52, 100, 176, 486, 
 
 494, 507, 519, 529, 542, 555, 590, 
 
 591 
 Streptococcus, 18 
 Streptothrix, 599 
 
 Dassonvillei, 599 
 
 Stromatinia, 137 
 Stropharia, 448 
 Strumella, 655, 656 
 
 Sacchari, 666 
 
 Stuartella, 226 
 Stypinella, 393 
 
 Mompa, 393 
 
 Stypinellese, 392 
 Stysanus, 630, 636, 638 
 
 Stemonites, 637 
 
 Ulmaria}, 637 
 
 Veronicae, 637 
 
 Sugar-beet, 22, 36, 37, 41, 408 
 
 Sugar Cane, 37, 47, 206, 209, 227, 228, 
 248, 258, 305, 374, 392, 448, 463, 
 464, 495. 499, 503, 512, 554, 560, 
 596, 606, 620, 630, 656 
 
 Maple, 415 
 
 Sulla, 277, 630 
 
 Sunflower, 179, 321, 523 
 
 Swamp Cedar, 416 
 
 Sweet Pea, 37, 268 
 
 Pepper, 37 
 
 Potato, 82, 105, 204, 337, 408, 
 
 ■ 486, 492, 495, 513, 574, 597, 606, 
 663 
 
 William, 508 
 
 Sycamore, 275, 498, 524, 525, 541, 
 546, 560, 580, 603 
 
 Sydowia, 236 
 
 Symphoricarpus, 187 
 
 Symphytum, 178 
 
 Synchytriacea;, 67, 69 
 
 Key to, 70 
 
 Synchytrium, 70, 70 
 
 Endobioticum, 70 
 
 Papillatum, 71 
 
 Vaccini, 71, 71 
 
 Sj^nsporium, 598 
 
 Synthetospora, 593 
 
 Syringa, 35, 186 
 
 Syzygites, 104 
 
 Tamarind, 250, 546 
 Tapesia, 146 
 Taphrina, 126 
 
 Aurea, 127 
 
 Bassei, 130 
 
 Bullata, 130 
 
 Coerulescens, 127 
 
 Communis, 130 
 
 Cratajgi, 130 
 
 Decipiens, 130 
 
 Deformans, 127, 128, 129 
 
 Farlowii, 130 
 
 Insititia), 130 
 
INDEX 
 
 749 
 
 Taphrina, Johonsonii, 127 
 
 Longipes, 129 
 
 Maculans, 130 
 
 Mirabilis, 129 
 
 Pruni, 128 
 
 Rhizipes, 129 
 
 Rostrupiana, 130 
 
 Theobromae, 130 
 
 Ulmi, 127 
 
 Taphrinopsis, 126 
 
 Taraxacum, 176 
 
 Taxus, 192, 259, 493 
 
 Tea, 8, 231, 243, 263, 287, 403, 409, 
 
 411, 415, 418, 438, 448, 544, 553, 
 
 614, 630, 635 
 Teasel, 100 
 Tecoma, 631 
 Teleutospore, 326, 327 
 Telia, 326 
 
 Terfeziacese, 165, 166 
 Testicularia, 303 
 Testudina, 167 
 Tetracium, 593 
 Tetracladium, 593 
 Tetracoccosporium, 616 
 Tetradia Salicicola, 252 
 Tetramyxa, 6, 8 
 Tetraploa, 615 
 Thalictrum, 321, 389 
 Thallophyta, 2 
 Thamnidieae, 105 
 Thaxteria, 227 
 Thecaphora, 302, 313, SIS 
 
 Deformans, 313 
 
 Thecospora, 641 
 Thelephora, 406, 410 
 
 Galactina, 411 
 
 Laciniata, 4iO, 411 
 
 Thelephoracese, 402, 405, 433 
 
 Key to, 405 
 
 Theleporus, 440 
 Thelocarpon, 197 
 Theobroma, 205 
 Therrya, 251 
 Thielavia, 166, 167 
 Basicola, 167, 168 
 
 Thielaviopsis, 595, 596 
 
 Ethaceticus, 228, 696 
 
 Paradoxa, 590 
 
 Podocarpi, 597 
 
 Thiobacteriales, 19 
 
 Thistle, 328 
 
 Thoracella, 505 
 
 Thozetia, 641 
 
 Thyridella, 278 
 
 Thyridium, 278 
 
 Thyrococcum, 658 
 
 Sirakoffi, 658 
 
 Thyronectria, 198 
 
 Thyrsidium, 553 
 
 Tiarospora, 505 
 
 Tichothecium, 236 
 
 Tilachlidium, 633 
 
 Tilia, 193, 202, 489, 509, 524, 545, 
 631, 658 
 
 Tilletia, 301, 314, 315 
 
 FcEtens, 315, 316 
 
 Glomerulata, 315 
 
 Hordei, 317 
 
 Horrida, 317 
 
 Panicii, 315 
 
 Secalis, 317 
 
 Texana, 316 
 
 Tritici, 316, 317 
 
 Tilletiaceae, 302, 314 
 
 Key to, 314 
 
 Tilmadoche, 12 
 
 Timber, 415 
 
 Timothy, 24, 310, 385, 550 
 
 Titania, 280 
 
 Tites, 593, 593 
 
 Maxilliformis, 593 
 
 Toad Stool, 398 
 
 Tobacco, 27, 33, 44, 45, 48, 50, 52, 69, 
 89, 143, 260, 486, 506, 521, 570, 
 573, 581, 619, 621, 624, 627, 654 
 
 Tolypomyria, 576 
 
 Tolyposporella, 303 
 
 Tolyposporium, 302, 313, S14 
 
 BuUatum, 313 
 
 Filiferum, 314 
 
 Volkensii, 314 
 
750 
 
 INDEX 
 
 Tomato, 21, 27, 30, 36, 41, 42, 44, 47, 
 52, 86, 268, 497, 522, 540, 551, 564, 
 605, 608, 623, 624, 643, 653 
 
 Tomentella, 403 
 
 Torsellia, 483 
 
 Torula, 191, 595, 596, 597 
 
 Exitiosa, 597 
 
 Sphasrclla, 597 
 
 Torulea;, 594, 595 
 
 Key to, 595 
 
 Toxins, 2 
 
 Toxosporium, 557, 568 
 
 Abietinum, 558 
 
 Trabutia, 276 
 
 Trachyspora, 354 
 
 Tracya, 315 
 
 Tracyella, 528 
 
 Tragopogon, 178, 310, 378 
 
 Trametes, 417, 437 
 
 Pini, 401, 437 
 
 Radiciperda, 401, 431 
 
 Robinophila, 438 
 
 Suaveolens, 438 
 
 Thea;, 438 
 
 Tranzschelia, 354, 356 
 
 Punctata, 356, 357 
 
 Trees, 193, 407, 409, 411, 426, 428, 
 432, 451, 452, 453, 454, 460, 568, 
 662 
 
 Coniferous, 418, 419, 424, 433, 
 
 440, 456 
 
 Deciduous, 414, 418, 419, 421, 
 
 425, 427, 430, 452, 454, 456 
 
 Forest, 132, 153 
 
 Fruit, 418, 421, 439 
 
 Nut, 420, 439 
 
 Orchard, 419 
 
 Ornamental, 421 
 
 Shade, 419 
 
 Timber, 419, 448 
 
 Treleasiella, 527 
 
 Tremellales, 323 
 
 Trichsegum, 616 
 
 Trichiacese, 9 
 
 Trichobelonium, 146 
 
 Trichobotrys, 598 
 
 Trichocladium, 602 
 Trichocollonema, 517 
 Trichocomacea', 165 
 Trichoderma, 571 
 Trichodytes, 562 
 Tricholoma, 123, 450, 460, 460 
 
 Rutilans, 460 
 
 Saponaceum, 460 
 
 Trichopeltulum, 528 
 Trichopezizese, 135 
 Trichophila, 529 
 Trichopsora, 336 
 Trichoseptoria, 517, 518 
 
 Alpei, 518 
 
 Trichosphseria, 226, 228, 228, 554, 
 596 
 
 Sacchari, 228 
 
 Trichosporiea}, 594, 598 
 
 'Key to, 598 
 
 Trichosporium, 599 
 Trichostroma, 655 
 Trichotheca, 639 
 Trichothecium, 586 
 Trichurus, 630 
 Tridentaria, 593 
 Trientalis, 315 
 
 TrifoHum, 168, 178, 313, 373, 374 
 Trigonella Coerulea, 168 
 Trimmotostroma, 657, C57 
 
 Abietina, 657 
 
 Trinacrium, 593 
 Triphragmium, 354, 358 
 
 Ulmariaj, 358, 358 
 
 Triplicaria, 655 
 
 Triticum, 180, 260, 262, 379 
 
 Trochila, 156, 157, 158, 539 
 
 Craterium, 157, 541 
 
 Popularum, 157, 555 
 
 Trogia, 443, 444 
 
 Faginea, 443 
 
 Tropajolum, 37, 81, 362, 621 
 Trullula, 553, 554 
 
 Vanillae, 554 
 
 Tryblidiaceae, 151, 154 
 Tryblidiella, 150 
 Tsuga, 229, 391, 416 
 
INDEX 
 
 751 
 
 Tubaria, 449 
 
 Tuberales, 124 
 
 Tubercularia, 196, 201, 396, 639, 642, 
 642 
 
 Fici, 6Jt2, 642 
 
 Vulgaris, 202, 642 
 
 Tuberculariaceffi, 565, 638 
 
 Key to, 638 
 
 Dematiese, 638 
 
 Key to, 655 
 
 Amerosporse, 638, 654 
 
 Dictyospora;, 639, 658 
 
 DidymosporEe, 638 
 
 Helicospora?, 639 
 
 Phragmosporip, 639, 657 
 
 Key to, 657 
 
 Scolecosporie, 639 
 
 Staurospora), 639 
 
 Mucedinese, 638 
 
 Amerosporese, 638, 639 
 
 Key to, 639, 
 
 Dictyosporse, 638 
 
 Didymosporse, 638 
 
 Helicosporaj, 638 
 
 Phragmosporse, 638, 645 
 
 Key to, 645 
 
 Staurosporae, 638 
 
 Tuberculina, 335, 640, 643 
 
 Tuburcinia, 315 
 
 Tulip, 143, 310, 389, 564, 661 
 
 Tumeric, 130 
 
 Tupelo, 412 
 
 Turnip, 25, 26, 36, 41, 42, 44, 46, 81, 
 95, 177, 568, 592, 619 
 
 Tympanis, 151 
 
 Typha, 188 
 
 Typhula, 412 
 
 Graminum, 412 
 
 Variabilis, 412, US 
 
 U 
 
 Uleomyces, 199 
 Ulmaria, 358 
 Ulmus, 188, 202, 610 
 
 Umbellifers, 6, 74, 91, 377, 592, 
 
 607 
 Uncigera, 583 
 Uncinula, 175, 180 
 
 Aceris, 182 
 
 Circinata, 182 
 
 Clandestina, 182 
 
 Flexuosa, 182 
 
 Mori, 182 
 
 Necator, 181, 181 182, 569 
 
 Prunastri, 182 
 
 Salicis, 182 
 
 Uredinales, 137, 323, 394, 475, 643 
 
 Key to, 335 
 
 Biologic Specialization, 332 
 
 Cytology, 330 
 
 Form Genera, 334 
 
 Imperfecti, 335 
 
 Key to, 389 
 
 Infection Experiments, 334 
 
 Uredinium, 325 
 
 Uredinopsis, 341, 391 
 
 Uredo, 334, 335, 389, 390, 392 
 
 Arachidis, 392 
 
 Aurantiaca, 392 
 
 Autumnalis, 392 
 
 Kuhnii, 392 
 
 Muelleri, 361 
 
 Orchidis, 392 
 
 Satyrii, 392 
 
 Tropajoli, 392 
 
 Uredospore, 327 
 Urobasidium, 403 
 Urocystis, 301, 314, 318 
 
 Agropyri, 320 
 
 Anemonis, 320 
 
 Cepula?, 318, 318, 319 
 
 Colchici, 320 • 
 
 Gladioli, 320 
 
 Italica, 320 
 
 Kmetiana, 320 
 
 Occulta, 319, 319 
 
 Ornithogali, 320 
 
 Primulicola, 320 
 
 Violffi, 319 
 
 Urohendersonia, 515 
 
752 
 
 INDEX 
 
 Uromyces, 355, 371, 375, 390 
 
 Appendiculatus, 371, S72, 373 
 
 Betse, 374, 374 
 
 Caryophyllinus, 328, 375 
 
 Colchici, 375 
 
 Dactylidis, 374 
 
 Ervi, 375 
 
 Erythronii, 375 
 
 Fabse, 373 
 
 Fallens, 374 
 
 Ficariaj, 375 
 
 Jaffrini, 375 
 
 Kuhnei, 374 
 
 Medicaginis, 374 
 
 Minor, 374 
 
 Pallidus, 375 
 
 — Pisi, 329, 330, 372, 374 
 Pose, 375 
 
 Scillarum, 375 
 
 — Trifolii, 373, 373, 374 
 Uromycladium, 327 
 Urophlyctis, 73 
 
 — Alfalfa?, 74 
 
 Hemispherica, 74 
 
 Kriegeriana, 74 
 
 Leproides, 73 
 
 Major, 74 
 
 Pluriannulata, 74 
 
 Pulposa, 74, 74 
 
 Rubsaameri, 74 
 
 Trifolii, 74 
 
 Uropyxis, 354 
 Urospora, 251 
 Urosporium, 608 
 Ustilaginacese, 301, 302 
 
 Key to, 302 
 
 Ustilaginales, 214, 299, 326, 392 
 
 Key to, 302 
 
 Ustilaginoidea, 199, 213, 214, 640, 643 
 
 Virens, 214, 214, 643 
 
 Ustilaginoidella, 199, 214, 650 
 
 Graminicola, 214 
 
 Musaeperda, 214 
 
 (Edipigera, 214 
 
 Ustilago, 299, 300, 301 302, 303, 310, 
 311, 312, 313, 315 
 
 Ustilago, Avena;, 303, 303, 306 
 
 Bulgarica, 305 
 
 Crameri, 304 
 
 Cruenta, 310 
 
 Crus-galli, 305 
 
 Esculenta, 310 
 
 Ficuum, 310 
 
 Fischeri, 310 
 
 Hordei, 305, 306 
 
 La;vis, 306, 306 
 
 Macrospora, 306 
 
 Medians, 305 
 
 Nuda, 306, 308 
 
 Panici Miliacei, 310 
 
 Perennans, 307 
 
 Phoenicus, 310 
 
 Rabenhorstiana, 307 
 
 Sacchari, 305 
 
 Scorzonorse, 305 
 
 Secalis, 310 
 
 Shiriana, 310 
 
 Sphajrogena, 310 
 
 Striajformis, 309 
 
 Tragopogonis, 310 
 
 Pratensis, 305 
 
 Tritici, 307, 307 
 
 Tulipae, 310 
 
 — Vaillantii, 310 
 
 Violacea, 310 
 
 Vrieseana, 310 
 
 Zese, 308, 308, 309 
 
 Ustulina, 285, 286 
 Zonata, 287 
 
 Vaccinium, 184, 234, 242, 347, 397, 
 
 543, 569 
 Valerian, 101 
 Valeriana, 178 
 Valerian ella, 101 
 Valsa, 208, 277, 278 
 
 Ambiens, 278 
 
 Caulivora, 278 
 
 (Eutypa) Erumpens, 278 
 
INDEX 
 
 753 
 
 Valsa (Eutypolla) Prunastri, 278 
 
 Leucostoma, 278 
 
 Oxystoma, 278 
 
 ValsaceiE, 223, 277 
 
 Key to, 277 
 
 Valsaria, 279 
 
 Valsonectria, 198, 208, 208, 484 
 
 Parasitica, 208 
 
 Vanda, 205, 544 
 Vanguicria, 356 
 Vanilla, 204, 205, 253, 280, 375, 510, 
 
 553, 554, 607 
 Vegetables, 51, 105 
 Velutaria, 150 
 Venturia, 251, 253, 227 
 
 — Cerasi, 255, 606 
 
 Chlorospora, 606 
 
 Crata?gi, 255 
 
 Ditricha, 255, 607 
 
 Fraxini, 255, 606 
 
 Insequalis, 253, 354, 607, 611 
 
 Cinerascens, 255, 607 
 
 Pomi, 253 
 
 Pyrina, 253, 607 
 
 Tremula^, 255, 607 
 
 Verbena, 176, 178, 187, 570 
 Vermicularia, 482, 496, 564 
 
 Circinans, 497 
 
 Concentrica, 497 
 
 Dematium, 496, 496 
 
 Dcnudata, 497 
 
 Melicffi, 497 
 
 Microchffita, 497 
 
 Polygoni-virginica, 497 
 
 Subeffigurata, 497 
 
 Telephii, 497 
 
 — Trichella, 496 
 
 Varians, 497 
 
 Veronica, 8, 69, 523, 524, 637 
 Verticillieffl, 566, 583 
 
 Key to, 583 
 
 Verticilliopsis, 583, 584 
 
 Infestans, 584 
 
 Verticillium, 196, 200, 583, 684, 587 
 
 ■ Albo-atrum, 584 
 
 Vetch, 99, 373, 409, 506 
 
 Viala-a, 277 
 
 Vibernum, 404 
 
 Vibrio Rugula, 15 
 
 Vicia, 99, 178, 313, 372, 375, 408, 
 
 508, 582 
 Vigna Sinensis, 168 
 Vinca, 101, 488, 503 
 Violet, 72, 73, 96, 99, 168, 176, 320, 
 
 388, 416, 488, 507, 544, 556, 591, 
 
 599, 620, 630 
 Virgaria, 599 
 
 Vitis, 181, 238, 323, 620, 624 
 Volutella, 497, 564, 641, 644 
 
 Buxi, 204 
 
 Concentrica, 645 
 
 Dianthi, 645 
 
 Fructi, 644, 644 
 
 Leucotricha, 644 
 
 Volutellaria, 641 
 Volutina, 641 
 Volvaria, 449, 452 
 Bombycina, 453, 4^4 
 
 W 
 
 Walnut, 28, 275, 419, 421, 428, 430, 
 524, 555, 606 
 
 Water Lilies, 322 
 
 Oak, 435 
 
 Watermelon, 247, 408, 490, 521, 540, 
 598, 629, 651 
 
 Weinmannodora, 501 
 
 Wheat, 21, 73, 90, 180, 200, 205, 206, 
 207, 213, 257, 258, 304, 307, 308, 
 316, 329, 333, 349, 379, 380, 382, 
 412, 491, 493, 520, 550, 571, 572, 
 587, 600, 613, 618 
 
 Willia, 121 
 
 Willow, 36, 44, 155, 157, 158, 159, 
 182, 284, 340, 342, 344, 421, 428, 
 433, 438, 454, 509, 530, 560, 582 
 
 Wisteria, 21 
 
 Witches Broom, 126, 130, 191, 211, 
 215, 330, 348, 349, 369, 648 
 
 Wojnowicia, 515 
 
754 
 
 INDEX 
 
 Woronina, 70 
 Woroniniella, 70 
 Wound Parasites, 399 
 
 Yeasts, 120, 121 
 Yew, 249 
 Ypsilonia, 482 
 Yucca, 503 
 
 Z 
 
 Xanthoxylum, 188 
 Xenodochus, 355, 361 
 
 Carbonarium, 361 
 
 Xenopus, 575 
 Xenosporium, 615 
 Xerotus, 445 
 Xylariaceae, 224, 284 
 
 Key to, 285 
 
 XylarieiE, 285 
 Xylocladium, 637 
 Xylostroma, 657, 663 
 Xylotroma, 659, 633 
 
 Yam, 543 
 Yeast, 301 
 
 Zea, 384 
 Zignoclla, 227 
 Zingiber, 46, 52, 130 
 Zinnia, 141 
 Zizania, 310 
 Zopfia, 189 
 Zopfiella, 189 
 Zukalia, 190, 191 
 
 Stuhlmanniana, 191 
 
 Zygochytriacea?, 67 
 Zygodesmus, 599 
 
 Albidus, 599 
 
 Zygomycetes, 66, 101, 114 
 
 Key to, 102 
 
 Zygorhynchus, 104 
 Zygosaccharomyces, 121 
 Zythia, 527 
 Fragaria;, 527 
 
T 
 
 HE following pages contain advertisements of books 
 by the same author or on kindred subjects. 
 
Diseases of Economic Plants 
 
 By F. L. STEVENS, Ph.D. 
 Professor of Botany and V(>gctable Pathology of the North Carolina 
 College of Agriculture and Mechanic Arts and Biologist of the Agri-'.'. 
 cultural Experiment Station • • = 
 
 AND 
 
 J. G. HALL, M.A. 
 
 Assistant in Vegetable Pathology in the North Carolina Agricultural 
 
 Experiment Station 
 
 Cloth, illustrated, 12mo, 523 -pp., $2.00 net; hy mail, $2.19 
 
 Students of Plant Diseases are naturally divided into two categories. 
 First: Those who wish to recognize and treat diseases, without the bur- 
 den of long study as to their causes; Second: Those who desire to study 
 the etiologj^ of diseases, and to become familiar with the parasites which 
 are often their cause. 
 
 The present book is designed to meet the needs of the first of these 
 two classes of readers, and particularly for such students in the Agri- 
 cultural Colleges and Agricultural High Schools. It indicates the chief 
 characteristics of the most destructive plant diseases of the United States 
 caused by crj^ptogamic parasites, fungi, bacteria, and slime mouldsj iii 
 such a way that reliable diagnoses may be made, and fully discusses the 
 best methods of prevention or cure for these diseases. 
 
 In this volume only such characters are used as appear to the naked 
 eye or through the aid of a hand lens, and all technical discussion is 
 avoided in so far as is possible. No consideration is given to the causal 
 organism, except as it is conspicuous enough to be of service in diagnosis, 
 or exhibits peculiarities, knowledge of which may be of use in prophylaxis. 
 
 While, in the main, non-parasitic diseases are not discussed, a few of 
 the most conspicuous of this class are brieflj^ mentioned, as are also 
 diseases caused by the most common parasitic flowering plants. 
 
 A brief statement regarding the nature of bacteria and fungi and the 
 most fundamental facts of Plant Physiology are given in the appendix. 
 Nearly 200 excellent illustrations greatly increase the practical value of 
 the book. 
 
 CONTENTS 
 
 Preface — Introductory — Historical — Damage Caused by Plant Dis- 
 eases — Symptoms of Disease — Prevention or Cure of Plant Diseases — 
 Public Plant Sanitation — Fungicides — Spraying Machinery — Cost of 
 Spraying — Profits from Spraying — Soil Disinfection — General Diseases — 
 Diseases of Special Crops: Pomaceous Fruits; Drupaceous Fruits; Small 
 Fruits; Tropical Fruits; Vegetable and Field Crops. Cereals: Cereal 
 Smuts, General; Cereal Rusts, General; Anthracnose of Cereals; Special 
 Diseases of Cereals; Forage Crops; Fiber Plants; Trees and Timber: Gen- 
 eral Diseases, Special Hosts; Ornamental Plants — Appendix — Index. 
 
 PUBLISHED BY 
 
 THE MACMILLAN COMPANY 
 
 Publishers 64-66 Fifth Avenue New YorJe 
 
Diseases of Cultivated Plants and Trees 
 
 By GEORGE MASSEE 
 
 Assistant Keeper, Herbarium, Royal Botanic Gardens, Kew. Author of 
 
 "British Fungus Flora," "Text-Book of Plant Diseases," "Plant 
 
 World" and "Text-book of Fungi" 
 
 Cluth, illustrated, 8vo, xii-\-602 pp., indexes, $2.25 net; by mail, $2.44 
 
 A practical work, embodying the results of the researches of 
 scientists in all parts of the world, prepared by a writer who, 
 through long continued personal investigations and experiments, 
 not only represents accurately the views of others but gives rea- 
 sons for the statements which he himself advances. 
 
 This volume takes the place of the author's " Text-book of Plant 
 Diseases," the issue of which has become exhausted, but follows 
 somewhat different lines, and covers a much wider field. In addi- 
 tion to a discussion of the causes and cure of the various fungi and 
 parasitic diseases, there are chapters on Wounds (caused by prun- 
 ing, wind, snow, etc.); Drought; Injuries due to Frost and Hail; 
 Injury by Smoke, Acid, Fumes, Gas, etc.; Injuries caused by 
 Animals and Birds; The Bacteriology of the Soil; and other val- 
 uable topics. 
 
 The treatment though technical, is sufficiently concise and clear 
 to be easily comprehended by the least scientific. 
 
 BY THE SAME AUTHOR 
 
 A Text-Book of Fungi 
 
 Illustrated, 8vo, $2.00 net 
 
 This book supplies not only botanical information as to the various 
 fungi which attack useful and ornamental plants, but gives the gardener 
 and orchardist a manual for the cure and prevention of these pests. The 
 author is a specialist of wide reputation and one of the assistants at the 
 Kew Botanical Gardens. 
 
 PUBLISHED BY 
 
 THE MACMILLAN COMPANY 
 
 Publishers 64-66 Fifth Avenue New York 
 
Plant Physiology 
 
 By 
 
 B. M. DUGGAR 
 Professor of Plant Physiology in Cornell University 
 
 Cloth, 12mo, $1.60 net 
 
 FROM THE PREFACE 
 
 " The engineer who does not understand his machine cannot expect 
 to get effective work out of it. He should know its intimate structure, 
 what work it can perform under all conditions, and how it may he 
 controlled. In the same way the plant producer who knows the struc- 
 ture of the plant and its behavior is provided with the means of inter- 
 preting the effects of conditions upon the organism. The plant is a 
 delicate physical, chemical, and living mechanism and as such is 
 responsive to practically all kinds of stimuli." 
 
 In this book the author discusses the Ufe relations of plants and 
 crops from a fundamental point of view. The important physio- 
 logical activities of the plant are demonstrated experimentally, 
 and the requirements of the agricultural crop examined as far as 
 practicable from the point of view of physiology. The main agri- 
 cultural and horticultural practices of the crop grower, so far as 
 they involve the plant itself, are reviewed, either with the purpose 
 of explaining the scientific principles involved or of offering an 
 opinion on them. Laboratory and field experiments and general 
 observations are drawn on in these discussions. Some of the special 
 topics that are considered are as follows: The relation of the plant 
 and the crop to water; the relation to soil nutrients, stimulants, and 
 inhibiting agents; the relation to light and air; the relation to heat 
 and cold; the relation to the disease environment. 
 
 PUBLISHED BY 
 
 THE MACMILLAN COMPANY 
 
 Publishers 64-66 Fifth Avenue New York 
 
NOW READY FOURTH ENGLISH EDITION 8 VO. $5.00 NET 
 
 A Text-Book of Botany 
 
 By Dr. EDWARD STRASBURGER Dr. LUDWIG JOST 
 
 Professor in the University of Bonn Professor in the University of 
 
 Strasburg 
 
 Dr. HEINRICH SCHENCK Dr. GEORGE KARSTEN 
 
 Professor in the Technical Academy of Professor in the University of 
 
 Darmstadt Halle 
 
 Fourth English Edition, Revised with the Tenth German Edition 
 
 By W. H. LANG, M.B., D.Sc, F.R.S. 
 Barker Professor of Cryptogamic Botany in the University of Manchester 
 
 With 782 illustrations, in part coloured 
 
 PREFATORY NOTE 
 
 The first edition of the English translation of this text-book was the work of 
 Dr. H. C. Porter, Assistant Instructor of Botany, University of Pennsylvania. 
 The proofs of this edition were revised by Professor Seward, M.A., F.R.S. The 
 second English edition was based upon Dr. Porter's translation, which was revised 
 with the fifth German edition. The present edition has been similarly revised 
 throughout with the tenth German edition. Such extensive changes, including the 
 substitution of completely new sections on Physiology and Phanerogamia, have 
 however been made in the work since it was first translated, and in the third and 
 fourth English editions, that it seems advisable to give in outline the history of the 
 English translation instead of retaining Dr. Porter's name on the title-page. 
 
 The ofhcial plants mentioned under the Natural Orders are those of the British 
 Pharmacopceia instead of those official in Germany, Switzerland, and Austria, 
 which are given in the original. ... 
 
 PRESS NOTICES OF FORMER EDITIONS 
 
 "The translator has been most successful in his work, the book reading as though 
 originally written in English. . . . One of the best, if not the best, text-book ex- 
 tant." — Nature. 
 
 "The whole style of the book is admirable; the type, illustrations, and general 
 arrangement leave nothing to be desired, while the coloured pictures of typical 
 cryptogams and phanerogams, which are scattered throughout the text, are life-like 
 in their beauty. . . . We have not the slightest doubt that this text-lDook will be 
 long regarded as a standard work, and we wish it all the popularity it deserves." — 
 Knowledge. 
 
 "It would be not doing justice to the present book if we did not place it in the 
 foremost rank. . . . We may cordially commend the book as one worthy to take a 
 place on the shelves of the expert and on the work-table of the student." — Athenceum. 
 
 "This work includes the most essential knowledge of several special books, it is 
 almost a library in itself, and is moreover, a guide to botanical literature. It is well 
 worth its price, and should be looked upon as a necessary possession." — Garden. 
 
 PUBLISHED BY 
 
 THE MACMILLAN COMPANY 
 
 Publishers 64-66 Fifth Avenue New York 
 
Household Bacteriology 
 
 By 
 
 ESTELLE D. BUCHANAN, M.S. 
 Recently Assistant Professor of Botany, Iowa State College 
 
 ROBERT EARLE BUCHANAN, Ph.D. 
 
 Professor of Bacteriology, Iowa State College, and Bacteriologist of the 
 
 Iowa Agricultural Experiment Station 
 
 Cloth, 8uo, xv-\-53G pp., index, $2.25 net 
 
 The word Household is used as an extension rather than a limitation of 
 the title. In a thoroughly scientific manner the authors treat the subject- 
 matter of general as well as of household bacteriology and include, there- 
 fore, the true bacteria as well as the yeasts, molds, and protozoa. The 
 volume is, therefore, a general textbook of micro-biology in which special 
 attention is given to those problems which are of particular interest to the 
 student of household science. The main divisions of the book treat (1) the 
 micro-organisms themselves, (2) fermentations with special reference 
 to those affcctirg foods, (3) the relations of bacteria and other micro- 
 organisms to health. A fully illustrated key (comprising 37 pages) to the 
 families and genera of common molds, supplements the unusually ex- 
 tended discussion of the morphology and classification of yeasts and 
 molds, and makes possible the satisfactory identification of all forms or- 
 dinarily encountered by the student. The work embodies the results of 
 the most recent researches. The book is exceptional!}^ well written, the 
 different topics are treated consistently and with a good sense of propor- 
 tion. While concise in statement, it is thorough in method and scope. It 
 is, therefore, well adapted for use as a text not only /or students of horisehold 
 science, but also for those to whom it is desired to present the science of 
 bacteriology from an economic and sanitary rather than from a strictly 
 medical ipoint of view. 
 
 "The book is a concisely written work on micro-biology, a branch of 
 economic science that the public is beginning gradually to understand, 
 has important relationship to the total welfare and prosperity of the com- 
 munity. . . . The manual can be recommended as a very. good elementary 
 bacteriology. It comprises about all there is of practical domestic value." 
 
 — Boston Advertiser. 
 
 PUBLISHED BY 
 
 THE MACMILLAN COMPANY 
 
 Publishers 64-66 Fifth Avenue New York 
 
NOV 6 1913 
 
-mm