>
03
'3 o.
£ ft
O k,
(H O _
« CO 3
B O 03
g k, M
sa
b a
CO
0)
t. B
S_3
3 M
o a)
£ ft
o ffl
3_
« 4)
o
73-a
a ^
41
o73^-*
3 ll
£
03
fe
H
2;
<
O
O
*q
J
«
w
03
t-.
5 B
3 Q0
: 3oO
>>
5
>1
'3
e B
.
02
0)
B
11
Q
^"3
<
g2
§
>>
!>>
o 5
4100
u, B
Cj Tj*
CH
£
B
J3 -
'►J
(2
Q
^°
■a
cn
00
■*
iO
CO
t^
CXI
05
O
5
«
A Classification of the Cultivated Varieties of Barley 383
5. The classification of cultivated varieties by Beaven, wherein the
treatment of the main groups was superior to that of Kornicke.
6. The discovery by Neergaard of the stability of the long- and the
short-haired rhachillas, and the smooth and the barbed lateral nerves.
7. The researches of Harlan in regard to pigmentation in barleys.
8. The reclassification of barleys by Harlan wherein the main groups
were established on the basis of fertility alone.
The relative weight given the different characters by the various
investigators are summarized in the table on the opposite page. It is
seen that there is a very marked lack of agreement in the use of the
various characters for classification purposes, with the one exception
of fertility, which is used as a basis of separation for the main groups or
species in every case but one.
MATERIAL USED IN THE PRESENT CLASSIFICATION
In the present study 627 specimens were under observation, many of
which were alike in name and in all observable morphological characters.
These so-called varieties were largely collected in 1915 by Professor
E. G. Montgomery, of Cornell University, for the purpose of classification.
The most valuable individual collections were those obtained from the
California Experiment Station at Berkeley, California, the E. Clemens
Horst Company of San Francisco, and the Okonomisch-botanische Garten
of Halle University in Germany. From these three sources alone an
aggregate of 475 specimens were obtained, including all the types of any
economic importance and practically all the rarer types. This original
collection has been enlarged by additions from the Department of Plant
Breeding at Cornell University, from the Office of Foreign Seed and Plant
Introductions and the Office of Cereal Investigation of the United States
Bureau of Plant Industry, from the state agricultural experiment stations,
particularly those of Virginia and Wisconsin, and from other minor sources,
all of which have aided materially in completing the collection.
The collection has been in the hands of the writer since 1915 and
has been grown each year in rod rows, one foot apart. Since yield was
not a factor in the present study, the rate of planting was adjusted
in all cases so that good development of individual plants might be
obtained.
384 Roy Glen Wiggans
MORPHOLOGY OF THE BARLEY PLANT
The first thing necessary in making a key for a group of plants is a
detailed study of the morphological characters of the plants. This study
is necessary for two reasons — to acquaint the investigator with the plants
with which he expects to work, and to learn the characters that are not in-
fluenced by environmental conditions. These are the characters that must
be given the important places in the classification. Therefore a considera-
tion of the morphological characters is of much importance in this paper.
The various discussions herein not only include a description of the
individual characters, but also consider their value taxonomically and
the use made of them in the present and in previous classifications.
However, the relative taxonomic value of the various characters is not
given any weight in the arrangement of this section.
The morphological characters as discussed herein are divided into three
groups and are treated according to the following order: gross characters,
spike characters, and spikelet characters.
GROSS CHARACTERS
The gross characters of barley, which include color, shape, and size
of the leaves, number and size of culms, roots, and some other characters,
are the least valuable among the three groups of characters from a
taxonomic standpoint. The differences in these characters are usually
not sufficient to warrant taxonomic divisions. Furthermore, they are
the most variable of all the characters under different environmental
conditions. Their chief value is to be found in varietal descriptions.
Foliage
The foliage of barley varieties presents a rather wide range of variations,
all of which are difficult not only to describe but also to recognize. Varia-
tions occur in color, length, width, and number of leaves. Kornicke
(1885), in his varietal descriptions, used four shades of green —
bright, dark, bluish, and yellowish. Difficulties immediately arise in
such descriptive terms, because the personal factor is too great in describing
or recognizing such a character for it to have much value. Other investi-
gators have recognized difficulties in using such characters, and as a
A Classification of the Cultivated Varieties of Barley 385
consequence have used color of foliage with much precaution. The length
and the width of the leaves are variables which, like color, are largely
dependent on environment and are limited in their use in the same way.
For them to be of any value, accurate statistical work must be done.
As a rule, when significant differences are found, it is between the larger
groups, where no such detailed observations are necessary for the distinction.
The most marked variation in leaves is between the spring and the winter
barleys, which are discussed later. The variation in the number, exclusive
of the basal leaves, is identical with the number of nodes, which is discussed
in connection with culm characters.
Culm characters
The culms of barley, vary in several characters, but, in general, greater
variations are produced by different environments than exist between
closely related forms. For this reason these variations are, like the
variations in the foliage, of minor importance in classification. Their
only value is in varietal description. Such characters as height of the
plant, number of culms to the plant, diameter of the culms, thickness
of the culm wall, number of nodes, and length of the last internode, have
been used more or less extensively in descriptions. Kornicke (1885,
1895, and 1909) made use of many varying vegetative characters in
descriptive work.
Height of 'plant
The height of certain varieties in a particular locality varies as much
as 100 per cent and for this reason may be of importance locally, but these
same varieties grown in another region may have a reverse relationship
in regard to height. This has been well shown by Harlan, who in 1911
selected thirteen pedigreed barleys representing a wide range of types and
planted them at four widely separated points. He found a marked
regional response For example, Odessa was short and unpromising in
Minnesota and little better in California, but was very tall and vigorous
in both Montana and North Dakota. The Abyssinian varieties, on the
contrary, grew well in California but were very short elsewhere, as is seen
from the accompanying table taken from Harlan (1914) :
386
Roy Glen Wiggans
Influence of Geographical Location on the Length of the Culm in 13
Representative Selections of Barley Grown at Four Widely Separated Points,
the Selections Being Arranged in the Order of Their Height at Each Point
St. Paul,
Minnesota
Williston,
North Dakota
Moccasin,
Montana
Chico,
California
Hordeum vulgare
Servian
Odessa
Hordeum vulgare
Surprise
Summit
Servian
S. P. I. No. 20375 . . .
Kitzing, 6-rowed. . . .
Manchuria
Oderbrucker
S. P. I. No. 20375
Odessa
Oderbrucker
Manchuria
Hordeum vulgare
Abyssinian
Servian
Oderbrucker
Manchuria
Smyrna
Manchuria
Summit
Summit
S. P. I. No. 20375
Surprise
Odessa
Kitzing, 2-rowed
Kitzing, 6-rowed
Kitzing, 6-rowed. . . .
S. P. I. No. 20375. ..
Princess
Abyssinian
Kitzing, 6-rowed
Abyssinian
Kitzing, 2-rowed. . . .
Princess
Kitzing, 2-rowed
Surprise
Kitzing, 2-rowed ....
Hordeum vulgare
Length of last internode
The relation of the spike to the leaf sheath depends entirely on the
length of the last internode — the one on which the spike is borne. The
shorter the last internode, the less the spike will be exserted. The failure
of the spike to be exserted from the leaf sheath has been used repeatedly
in describing such barleys as the Smyrna and Princess varieties. The
fact that this character occurs in the same varieties in widely differing
localities is evidence enough that it is a true varietal character, but there
is considerable variation within the variety. It is, however, characteristic
enough in a few instances to determine a variety. In the present
classification the length of the last internode is used in varietal descriptions.
Number of nodes
The number of nodes varies from three to seven in different varieties,
but in all cases there is sufficient variation within the varieties to cause
an overlapping, thus making the character uncertain. The number of
leaves to a culm is identical with the number of nodes and consequently
varies in the same way.
Roots
So far as it was determined, there are no varietal differences of roots
that can be employed in classification. The ratio between tops and roots
A Classification of the Cultivated Varieties of Barley 387
may vary to some extent between varieties, but similar variations occur
within the variety as a result of local conditions. Consequently, root
characters are of no value either for classification or for descriptive purposes.
Habit of plant in early growth
The habit of the plant in early growth is very important because it is
by this character that spring and winter varieties are separated. The
difference appears both in the number and the attitude of the culms and
in the number of leaves. The ordinary spring varieties of barley have
a small number of culms which stand erect at all stages of growth, and
only a few basal leaves. Winter varieties, on the other hand, have a
large number of culms and leaves which are more or less decumbent
during the early part of the development of the plant. It is at this stage
that such varieties pass the winter period. In the spring, when new
growth begins, a few of the many culms elongate, producing the flowering
stalks and the grain of the plant, while the others remain undeveloped
and sooner or later disappear as a vital part of the plant.
If these same varieties are seeded in the spring, a large tuft of leaves
and very short culms are produced early in the season. The plants will
remain at this stage for a considerable period before the flowering stalks
are produced; in some cases, in fact, the flowering stalks entirely fail
to appear, while those that do appear are usually infertile or produce
very little grain. For this reason, it seems that a dormant period is
needed for the proper development of these varieties.
An intermediate condition, which may be called semi-erect, is also
found in some varieties, in which the number of culms and leaves is above
the average for barleys and the culms tend to spread out to some extent.
All of such varieties are, however, spring varieties. This character can
be used only in varietal description.
The distinction between winter barleys and spring barleys was made
by Kornicke (1885) and by Carleton (1916) in describing varieties, but
has never been used as an important distinction between large groups of
varieties. In the present classification the habit of the plants in early
growth is used only in minor separations.
388 Roy Glen Wiggans
Emergence of awns and spikes
The date at which the head appears is a note that has been generally
taken by all barley breeders as well as by those studying varietal differences.
More recently this has been replaced by a note on the date of appearance
of the awns. Harlan (1914) showed that the latter is more nearly accurate
and easier to obtain than the former. This has proved to be true in the
present investigation. The only objection to using the date of the
emergence of the awns, instead of the date of the appearance of the head,
is that hooded and awnless varieties cannot be compared with awned
varieties. This is not a serious objection, however, as this character can
be used only to distinguish strains within a variety. The relationship
of strains in this regard varies with the locality. In the few cases of
awnfess and hooded varieties, it is necessary to use the date of the appear-
ance of the spike as the distinguishing character. The date of appearance
of either the awn or the spike is so variable that it has no taxonomic value.
Time of maturity
Ordinarily the time of maturity is correlated with the date of emergence
of the awns, but, as is the case with most other correlated characters,
some exceptions occur. This character is of value at times, not only in
distinguishing different varieties or strains in a given environment, but
also in detecting mixtures in the field. A pure strain will mature all
spikes within a very few days. This character is much more reliable
when used in connection with early-maturing than with late-maturing
varieties. Late-maturing varieties are often ripened abnormally by
unfavorable weather conditions. This character is used in the present
classification only in distinguishing strains otherwise similar, and in varietal
descriptions.
Production
The yield of varieties, although in a given region varying from very
small to very large, cannot be employed for classification purposes because
it is almost wholly dependent on environment. Consequently, production
has no place in the present investigation.
SPIKE CHARACTERS
The characters of the spike, including variations in fertility, density,
and rhachis, are far more important from the standpoint of classification
A Classification of the Cultivated Varieties of Barley 389
than the gross characters already discussed. Some of these spike char-
acters which are the most conspicuous and the easiest to recognize, have
been used in all previous barley classifications. In most instances
either density or fertility has been given first place in the formation of
groups.
The differences in the characters of the spike are great and have been
found to be constant under different environmental conditions. Because
of these facts they have proved to be of much taxonomic value, and are so
considered in the present classification.
Fertility
Barley varieties, as stated above, have been divided into groups according
to the fertility of the spikelets, by all investigators who have worked on
their classification. The first pre-Linnaean divisions were made on this
character when only two groups were recognized, the two-rowed and the
six-rowed. Linnaeus likewise followed this scheme, but used in connection
with it the density of the spike, thereby making four groups or species.
In 1885 Steudel (cited by Kornicke, 1885) fully described a third degree
of fertility, which he designated as deficiens. Kornicke (1885) recognized
a fourth degree of fertility in his group, known as intermedium. Thus,
four definite stages of fertility have been recognized as important in the
formation of groups in the case of barley.
In order to understand the variation in fertility, it is necessary first
to know the structure of the barley head. Barley, in common with all
other members of the genus Hordeum, produces three single-flowered
spikelets at each node of the flattened rhachis. Structurally the spikelets
are very similar, each having two outer glumes, a lemma, and a palea,
which inclose the sexual organs. In all cultivated barleys, the central
spikelet of the series of three at each internode is always fertile. The
variation in fertility is found only in the side spikelets, which present
four stages of fertility, as has already been stated. These different con-
ditions of fertility are as follows: (1) all three spikelets equally fertile,
with the lemmas of each projected into a terminal appendage, either an
awn or a hood as the case may be, and with the kernels of the side spikelets
almost as large as the kernels of the medium spikelets (fig. 51, A and B,
and fig. 69, H. vulgare) ; (2) all three spikelets fertile, but the lemmas of
390
Roy Glen Wiggans
B CD
Fig. 51. the structure of six-rowed barleys
A, Dorsal view of perfect condition of fertility, where all spikelets are equally fertile and
awned; B, ventral view of same; C, dorsal view of second condition of fertility, where side
spikelets are fertile but about one-half the size of median spikelets and not awned; D, ventral
view of same
the side spikelets without terminal appendages, ending either in a point
or bluntly, and the kernels of the side spikelets about one-half the size
of the kernels of the median spikelets (fig. 51, C and D); (3) the side
spikelets infertile, but possessing rudimentary sexual organs and all the
structural parts of the fertile spikelets except the terminal appendages
of the lemma (fig. 52, A and B) ; (4) the side spikelets infertile, without
rudimentary sexual organs and with all structural parts very much
reduced. In some cases, only the two outer glumes and a rudimentary
rhachUla remain as evidence of the side spikelet (fig. 52, C and D). The
relative position and size of the spikelets in the various types is diagram-
matically shown in figure 53.
These four conditions of fertility, previously recognized, have remained
practically stable since they were first described. For this reason, and
because they have been constantly used in all early classifications, they
A Classification of the Cultivated Varieties of Barley 391
are of the greatest taxonomic value. Some intermediates between these
stages have been described from time to time by different authors,
especially Kornicke (1885). Most of these which were the results of
crosses have proved to be unstable and have gone out of existence as
varieties. Crosses between two of the above-named conditions of fertility
give in the second generation practically all steps between the two parent
types, but these intermediates have proved heterozygous in future
generations and have broken up in a similar manner to the original first-
generation cross.
In the present classification, these four conditions of fertility are used
as the first and most important character in the subdivision of cultivated
barleys, for three reasons: (1) stability in all environmental conditions;
(2) ease of recognition; and (3) weight given by all earlier investigators.
A BCD
Fig. 52. the structure of two-rowed barleys
A, Dorsal view of third condition of fertility, where side spikelets are infertile but possess
all structural parts except terminal appendage of lemma; B, ventral view of same; C, dorsal
view of fourth condition of fertility, where side spikelets are very rudimentary; D, ventral
view of same
392
Roy Glen Wiggans
Fig. 53.
D E F
DIAGRAMMATIC SKETCH OF CROSS SECTIONS OF SPIKES OF VARIOUS TYPES OF BARLEY
A, H. vulgare (dense form*) ; B, H. vulgare (lax form); C, H. intermedium; D, H. distichon
(dense form) ; E, H. distichon (lax form) ; F, H. deficient
Branch-headed barleys
One other structure sometimes arises in barleys, which has caused
descriptions to be written of what were termed seven-rowed, eight-rowed,
or nine-rowed barleys. Such a condition, which might be called a stage
of fertility, is brought about by repetitions of the three spikelets at a node.
In other words, instead of one series of three spikelets at each node of the
rhachis, there are three series (fig. 54). In the case of the two-rowed
barleys, if this occurs regularly a six-rowed barley would be produced,
but instead of only three spikelets at one internode, all of which were
fertile, there would be three fertile and six infertile spikelets. If the
same thing were to happen in the case of the six-rowed barleys, an eighteen-
rowed barley would result. At each node of the rhachis nine kernels
would appear. No instances have been reported in which there was
such a replication at every node. The change usually comes at or near
the base of the spike, and at only a small number of nodes. A further
deviation occurs when a true branch is formed which bears spikelets at
A Classification of the Cultivated Varieties of Barley 393
each internode just as the main axis of
the spike does. These likewise arise
near the base of the spike.
Occasionally such deviations as are
mentioned above are more or less con-
stant, but more often they are found
to be variable, due to environmental
conditions. In either case they have
no economic importance and very little
taxonomic value. Consequently they
are not used in the present classifi-
cation as characters of importance in
separating groups or even varieties.
Density
The density of the spike in barley, by
which is meant the number of florets
to the unit length of rhachis, has been
employed by all taxonomists in the
classification of barleys, in one form
or another. In the greater number of
cases it has been given equal weight
with fertility in the formation of either
species or subspecies. In fact, density
has been considered by many authors
as a result of varying degrees of fer-
tility. This, however, can easily be
disproved by making comparative
weights of the kernels of the lateral
and central spikelets of either com-
mon or erect six-rowed varieties. There
is .just as much difference between
these two groups of spikelets in the
erect varieties as in the common. The
groups according to density have gen-
erally been divided into dense and lax
forms. For the sake of varietal descrip-
tion, Kornicke (1885) even mentioned
a division of the dense forms into
dense and very dense.
Fig. 54. two-bowed barley
A, Spike of branch-headed two-rowed
barley; B, one internode of the rhachis
with its abnormalities
394
Roy Glen Wiggans
>J
It was not until Atterberg (1899) presented his new system of classifica-
tion that the density of the spike was made a character of minor importance.
In the earlier works, density and fertility were given about the same weight.
In Atterberg's new system, density was considered only after the characters
of terminal appendage, outer glume, fer-
tility, and side spikelets. * Following
Atterberg, both Beaven and the investi-
gators at Svalof went back to the old
system of considering fertility and den-
sity as practically of equal importance.
In Harlan's recent paper (1918), density
is again employed only as a distinguish-
ing characteristic between subvarieties.
That there is a decided variation in
this character of the spike in barley
varieties cannot be denied. The diffi-
culty in the use of this character lies in
the intergradations between the dense
and the lax forms. In a large collection
of barleys it is possible to find prac-
tically all degrees of density, from the
very lax to the very dense. This diffi-
culty has been mentioned by earlier
writers. Kornicke, however, based his
several subdivisions on the variation in
the density of the spike. In the present
classification, density is used in the sep-
aration of rather large groups of com-
mercial varieties but is not considered
as important as either fertility, adher-
ence of glumes to the caryopsis, terminal
appendage, or color.
1
Fig. 55. relative length of rhachis
internodes of barley of different
densities ( x 6)
A, Lax; B, erect; C, very dense
Length of internodes of rhachis
The length of the internodes of the
rhachis varies directly with, and is the de-
ciding factor in, density. This character
A Classification of the Cultivated Varieties of Barley 395
Fig. 56. variation in the angle op inclination ov kernel with rhachis
A, Chevalier; B, Goldthorpe; C, Fan barley
396
Roy Glen Wiggans
has been used in the determination of density by several investigators,
especially Atterberg (1899) and Harlan (1914). Atterberg used the aver-
age length of the internodes as the chief character in separating his sub-
varieties. In the present classification, the length of internodes has been
found very useful. In two-rowed forms, three quite distinct groups were
found centering around the lengths 3.3, 2.5, and 1.7 centimeters to ten
internodes, or, in other words, giving a ratio of almost 2:1.5:1 (fig. 55).
In the six-rowed forms the very dense group was not so distinct. Varia-
tions from the general averages were found in many cases. These lesser
variations can be used only in descriptions of varieties under like environ-
mental conditions, and would not necessarily hold if the specimens were
grown in different localities. The larger differences, however, are little
influenced bv environment and can consequently be used in classifica-
tion with a considerable degree of certainty.
Fig. 57. variations in the attitude of the spike in lax and dense forms
A Classification of the Cultivated Varieties of Barley 397
Angle of inclination of kernel
The angle of inclination of the
kernel is only another expression of
density. It increases directly with
the density and inversely with the
length of the internode. The shorter
the internode, the greater is the
angle of inclination of the kernel
(fig. 56). This character is, how-
ever, harder to determine and less
accurate than the length of the in-
ternode. For this reason, length of
internode is given preference in the
present study in the determination
of density. The angle of inclination,
nevertheless, has been used by the
Svalof investigators in describing
varieties.
Attitude of spike
The variations in the attitude or
the relative position of the spike in
regard to the culm, some of which
are shown in figure 57, are likewise
closely correlated with the length of
the internodes of the rhachis, and
for this reason may be disregarded
in most cases. They are of value
in descriptions of varieties and in
the comparison of widely different
types. One advantage which this
character in its extreme conditions
has over the length of the rhachis
internodes is that of ease in deter-
mination. It is not reliable, how-
ever, except under very favorable
growing and ripening conditions,
and is used in the present classi-
fication only in connection with the
HORDEUM SPONTANEUM
A, Entire spike; B, one internode of rhachis
with spikelets attached
398 Roy Glen Wiggans
length of the internode. This character has been used in connection
with density by practically all previous investigators.
Articulation of internodes of rhachis
In the wild types of barley known at present, the rhachis separates at
maturity into as many segments as there are internodes in the rhachis.
This separation is by disarticulation and not by rupture (fig. 58). Each
separate segment remains attached to one spikelet. In the cultivated
types of barley this separation does not take place; the rhachis either
remains entire, or, if threshed, may be broken to pieces by rupture but
seldom by disarticulation. In either case, however, no part of it remains
with the spikelets. Nevertheless, there is considerable variation in this
character of the rhachis in cultivated barleys. Although no part of the
rhachis remains with the threshed grain, there is a tendency in certain
varieties for the rhachis to separate easily into the various segments at
maturity. This difference is a matter of degree, and as a consequence
cannot be used as an important taxonomic character. But it has con-
siderable value in varietal distinctions, and is used in that connection
in the present paper.
This character has not been used by previous investigators either as
a group characteristic or as a varietal difference.
SPIKELET CHARACTERS
The spikelet in the case of barley presents several characters which
are very important from the standpoint of classification, second only to
the two principal spike characters already discussed. The most valuable
spikelet characters in barley are those of the caryopsis, the glumes, and
the rhachilla. These present wide differences, many of which have been
found to remain constant under all environmental conditions. They
have found second place in classifications because of difficulty in
determination, and in some cases of intermediacy
The grain
The term grain, as used in this paper, when applied to hulled barleys
includes both the caryopsis and the adhering lemma and palea; but
when the term is applied to hull-less varieties, only the caryopsis is con-
A Classification of the Cultivated Varieties of Barley 399
sidered. In other words, grain is the term applied to the threshed product.
The grain of barley presents several important characters, both com-
mercially and taxonomically — composition, size, shape, and color.
Corn-position
The composition of barley grain of the hulled varieties is a subject that
has been given much study in connection with malting. The composition
of hull-less varieties has not, however, been given equal consideration.
For this reason, and because the same variations occur in each form,
data for only the hulled type are given herein. Beaven (1902), and
Le Clerc and Wahl (1909), report a large number of analyses of barleys.
From these data it is apparent that composition is influenced much more
by environment, rainfall, temperature, sunshine, and fertilizers, than by the
variety. The following table from Le Clerc and Wahl illustrates this fact:
Variety and State
Water
(per
cent)
Fat
(per
cent)
Fiber
(per
cent)
Starch
(per
cent)
Protein
(per
cent)
Hulls
(per
cent)
Weight of
1000
grains
(grams)
Ash
(per
cent)
Bay Brewing
California
Kansas
Two-rowed
8.23
10.32
8.82
10.00
2.06
2.02
2.15
2.23
6.72
7.31
5.52
5.38
58.23
59.66
60.38
55.91
9.77
13.69
10.66
17.69
14.46
15.00
11.08
11.70
35.82
30.56
35.28
35.07
3.03
3.41
2.72
Kansas
3.13
The difference in the composition of the same variety in different
localities is much greater than the difference in the composition of different
varieties in the same locality. This is especially true of water, protein,
and ash contents. These data verify previous work along the same line.
Regardless of this truth, there is a strong tendency for some varieties
to possess heritable differences in composition. This character may in
some instances be used in differentiating varieties that are grown under
exactly the same environment, but in a classification of barley varieties
it has little place. In the present investigation the composition of the
grain is not used.
Size
The average size of the grain has been used by agronomists generally
in describing varieties and strains, but the differences are usually very
400 Roy Glen Wiggans
small in closely related samples, making its value doubtful. It is, however,
more 1 significant in the case of widely different groups. But in such
instances other more reliable and less variable characters are usually
present. For these reasons, and because it varies greatly with the
environment, it is used in the present classification only in varietal
descriptions.
The variation of the size of grain within a variety may, however, be
significant as an aid in determining the groups to which a variety belongs,
if the sample is threshed. All grains are of approximately the same size
in the two-rowod groups, while in the six-rowed groups one-third of the
grains are noticeably h.rger than the other two-thirds, and in the inter-
mediate group one-third are approximately twice the size of the other
two-thirds. These distinctions are valuable only in connection with
threshed grain. In the case of threshed samples of hull-less types, this
variation in size may be the only way of distinguishing two-rowed from
six-rowed varieties. With threshed samples of hulled types, however, the
shape of the grain, as described later, is more reliable in determining groups.
Shape
The difference in .shape of the grain between the two-rowed and the
six-rowed hulled types has become well established as a group distinction
(fig. 59). The grains from the lateral spikelets are all more or less twisted
in the six-rowed varieties, while those from the central spikelets are all
symmetrical in contour. In the two-rowed varieties all the grains are
symmetrical in contour, since they are produced by the central spikelets.
There is a difference even between the shape of the grains of the two-
rowed varieties and the grains of the central spikelets of the six-rowed
varieties. The grains of the central spikelets of the six-rowed varieties
are broadest near the tip, while those of the two-rowed varieties are
broadest near the base. This difference has been used by the Swedish
investigators as a group distinction, and is used in the present investiga-
tion only for a study of threshed grain. It has no value in identifying
threshed samples of hull-less barley, because all grains are symmetrical,
due to lack of compression by the glumes.
The differences in shape to be found between varieties in the lesser
groups are very small and must be based on measurements of the various
A Classification of the Cultivated Varieties of Barley ' 401
Fig. 59
A, Grain of two-rowed barley; B, grain of lateral spikelets of six-rowed barley
DIFFERENCE IN APPEARANCE OF VENTRAL VIEW, OF GRAIN OF TWO-ROWED BARLEY
AND OF GRAIN OF LATERAL SPIKELETS OF SIX-ROWED BARLEY
dimensions. The most reliable and least influenced by environmental
conditions, as found by Harlan (1914), is in length. By this measurement
it is possible in a few instances to distinguish between certain very similar
varieties or strains. This character is used only in varietal description
in the present classification.
Color
The color of both the caryopsis and the glumes (lemma and palea)
has been used in practically all classifications that have appeared. The
use, however, has not been consistent, probably because the nature of
the pigmentation of barley was not understood. The following colors
have been used in classifications by various investigators: white, yellow,
black, violet, purple, and blue-gray. The use of color by Beaven (1902)
may be given as a typical instance:
Colour of (1) the paleae*; (2) the seed (caryopsis).
(a) Yellow or white paleae and seed.
(b) Yellow or white paleae with bluish-grey seed.
(c) Brown paleae.
(d) Black paleae. The colour of the seed (caryopsis) when naked in the two latter cases
also varies.
*Beaven used the term paleae to include both lemma and palea.
402 Roy Glen Wiggans
It remained for Harlan (1914) to make a detailed study of the pig-
mentation of barleys. This work has aided materially in giving an
understanding of the variations in color, and in clearing up inconsistencies.
As a result of his work, Harlan found that all pigmentation was the result
of only two pigments, anthocyanin and a melanin-like pigment. He
found four color conditions to exist as a result of the total absence or
the different location and combination of the pigments, as follows:
1. (a) Hulled varieties without pigment in either lemma or aleurone
layer.
(b) Hull-less varieties without pigment in the aleurone layer or in
the pericarp.
Either of these conditions results in a white or a yellow barley.
* 2. (a) Hulled varieties with a blue aleurone layer showing through the
superimposed lemma.
(b) Hull-less varieties with a blue aleurone layer showing through
a pericarp containing no pigment.
Either of these conditions results in a blue barley.
3. (a) Hulled varieties with purple lemmas.
(b) Hull-less varieties with blue aleurone and red pericarp.
Either of these conditions results in a purple barley.
4. (a) Hulled varieties with black lemmas,
(b) Hull-less varieties with black pericarp.
Either of these conditions results in a black barley.
Another color condition sometimes appears in' immature white or
yellow barleys. The lack of maturity cautees the development of a greenish
color which is probably not due to any pigment. The blue and purple
color -conditions mentioned above are due to one pigment, anthocyanin.
In an acid condition this appears red and in an alkaline condition it appears
blue. The combination of the two produce purple. The black color is
due to the melanin-like pigment, which is unchanged by treatment with
either an acid or an alkali. The brown color as used in some classifications
is without doubt a black, and consequently has in most cases, if not in all,
very little taxonomic value.
Color as used in the present classification follows the grouping as given
above. Because of the ease of recognition and the distinct condition
of color, it is given an important place herein in making the various groups.
The blue condition is the only one which is at times difficult to recognize.
In the case of hulled barleys, the color may be obscured by weathering
A Classification of the Cultivated Varieties of Barley 403
at harvest time unless conditions are very favorable. In these instances
it is necessary to remove the glumes in order to detect the color. If there
is still doubt in regard to the presence or the absence of the blue pigment,
the question may be determined by a simple chemical test which consists
in dropping into a weak acid solution some kernels whose seed coats
have been cut through. In a few minutes, according to the strength
of the solution, a pink ring will appear in the region of the aleurone layer
if any pigment is present; if no pigment is present there will be no color.
If barleys under study are immature, another difficulty may arise in
determining color, since pigmentation is developed in the last stages of
maturity. If harvest takes place too soon the development is somewhat
arrested, and this may cause difficulty.
Pigmentation likewise occurs in other parts of the plant, particularly in
the leaves and the stems. The pigment concerned is usually, if not
always, anthocyanin. The appearance of coloration is, however, not
normal in most cases and is never reliable as a taxonomic character. It
usually appears as a result of arrested development, hastened maturity,
or other abnormal conditions due to malnutrition.
The lemma, 6 or flowering glume
No other single structure in barley gives so many morphologically
important characters as does the lemma. Some of the characters of this
structure have been used by all investigators who have attempted either
classifications or descriptions since the time of Linnaeus. Their relative
importance has not been the same in all cases, but without exception the
separation of large groups has been made by the use of one or more of
the lemma characters.
The color of the lemma has already been discussed in connection with
the color of grains, and need only be mentioned here. The remaining
important lemma characters, the variations of which are constant in
different varieties or groups, are the adherence of the lemma and the
palea to the caryopsis, the terminal appendage, the number of nerves,
the barbing of the lateral nerves, and the base. These characters are
discussed in the above order.
6 The term lemma is used throughout this paper instead of the term flowering glume. • Not only is lemma
a shorter term than flowering glume, but it serves to distinguish this structure from the outer glumes of
the spikelet. It is also the term now commonly used by agronomists. It is, however, morphologically
the same as the outer, or empty, glumes, all of which are reduced structures on the main axis of the spikelet.
The palea differs from the other glumes of the spikelet by arising from the secondary axis of the spikelet
(fig. 60).
404
Roy Glen Wiggans
Adherence of lemma and palea to caryopsis
Two very different and easily distinguishable conditions exist in regard
to the adherence of the lemma and the palea to the caryopsis. The
condition that is probably the more characteristic and the more primitive
is the one in which both
the lemma and the
palea are grown fast to
the caryopsis at ma-
turity. This union
takes place near the
time of maturity, when
the caryopsis has
reached its maximum
size. Varieties with
this characteristic are
known as hulled bar-
leys. In contrast to
these, some varieties
fail to form a union
between the lemma
and palea and the cary-
opsis. In such cases the
caryopsis at maturity
is easily separated from
the lemma and the
palea. Varieties with
this characteristic are
known as hull-less, or
naked, barleys.
Fig. 60. diagrammatic sketch of barley spikelet These contrasting
1, Rhachis, or primary axis of spike; 2, primary axis of spike- characters were first
let; 3, outer glumes; 4, lemma of flowering glume; 5, awn; 6, rprorf l Pf ] K v t j nn „ P11 «
palea; 7, stamens; 8, pistils; 9, rhachilla recorded Dy .Linnaeus
(1753). By their use
he made two groups each of lax six-rowed and lax two-rowed barleys,
but did not consider them sufficiently important for the establishment
of species. They have since been used in all classifications as import-
ant taxonomic characters.
A Classification of the Cultivated Varieties of Barley 405
There is never any question in determining this character in mature
grain because intermediates do not occur. Even in crosses the inter-
mediate condition is not found, a fact which is not true with many other
characters in hybrids. No established variety from crosses of hulled and
hull -less types shows
intermediacy. Because
this character can be
readily observed both
in threshed and in un-
threshed grain, and
because of the total
lack of intermediates,
it is second to no
other character taxo-
nomically; but because
of precedence and the
probable evolutionary
development, it is given
second place in the
present classification.
Terminal appendage
The terminal append-
age of the lemma in
barleys may be divided
into thvee types: the
normal, or awned (fig.
66), the awnless (fig. 68),
and the hooded (fig. 67,
B and D).
The normal type is
produced simply by an
extension of the vascular system of the lemma into a long, pointed proc-
ess known as the awn, or beard. The awns of most barleys are barbed
from the base to the tip. This, however, does not hold for all varie-
ties. A few cultivated varieties have smooth awns (fig. 61, B), and
many more are being produced by hybridization. The smooth-awned
VARIATION IN BARBING OF AWNS
A, Barbed; B, smooth
406 Roy Glen Wiggans
character seems to be of recent origin, as it was not described by the
early writers on this subject. Recently Kornicke (1885), Regel (1908),
and Harlan (1918) have described this condition as characteristic of
some varieties. Professor F. P. Bussell, of the Department of Plant
Breeding at Cornell University, has recently produced a smooth-awned
type from a cross between two varieties with barbed awns. This
character, whenever found, seems to be constant and is of considerable
importance in distinguishing varieties, and is so used in the present classifi-
cation. In certain varieties the awns are only sparingly barbed or are
barbed only for a part of their length. Usually the upper third is barbed
in such cases, while in other varieties, particularly in the dense-headed
types, the barbing is very profuse. Thus, considerable variation is found
in the degree of barbing. These lesser variations have little taxonomic
value, as they are usually associated with more important characters.
They have never been used in previous classifications. In the present
classification they are used in varietal description.
A marked difference likewise occurs in both the deciduousness and the
rigidity of the awns of different varieties. Some varieties, when mature,
drop their awns very readily, and by threshing time the spikes are practi-
cally bare of awns. Most varieties, however, hold their awns very
securely, some being broken off with difficulty even by threshing. This
second condition is usually associated with a very rigid, coarse awn.
These differences can be used only in varietal descriptions.
Some noticeable variations occur between varieties in the length and in
the width of awns, but these are significant in varietal descriptions only
when associated with other characters.
In the awnless type, as the term signifies, the lemma ends either in a
point or bluntly. The awnless lemmas are always found on the sterile
side spikelets of the two-rowed barleys, and occasionally on the fertile
side spikelets of the six-rowed. The awnless type was described by
Kornicke (1885), and has been used since in describing certain types and
often in differentiating large groups and even species.
The third type of terminal appendage is found on what are known
as hooded barleys. Here the normal awn is replaced by a trifurcate
structure known as the hood. The morphological significance of this
A Classification of the Cultivated Varieties of Barley 407
appendage is not fully understood, but it seems that there is a partial
repetition of the spikelets of a node, the three parts of the appendage
representing the lemmas of the three spikelets. These glume-like structures
frequently bear rudimentary sexual organs, but are seldom if ever fertile.
The origin of this type is unknown, but it dates well back in cultivated
barleys, since it was described by both Schlibler (1818) and Seringe (1819).
Since that time it has been used by all investigators along this line. The
hooded condition usually appears on all fertile spikelets, but in certain
six-rowed forms only the median spikelets are hooded. The only varia-
tion of importance in the hooded types is that found in the location of
the hood. Commonly this structure is sessile, but in certain varieties
it is elevated on an awn to a greater or less extent.
The three main types of barleys in regard to terminal appendage are
of very great importance in the systematic grouping of cultivated barleys,
both because of their constancy and because of the ease of determination.
They are second only to fertility and adherence of the lemma and palea
to the caryopsis, in the present classification.
Number of nerves of lemma
It is generally characteristic of the entire Hordeum genus to have five
nerves in the lemma — one dorsal, and two lateral on either side, all of
which are usually rather obscure. In cultivated varieties of barley, the
number occasionally is increased from five to seven, and in some cases
the nerves become very conspicuous. The latter variation is a matter
of degree and can be used only in varietal descriptions. The increase
in the number of nerves is, however, very definite and noticeable. For
this reason it could be used in making more important divisions were it
not for the fact that it occurs very infrequently.
Neither the variation in the number of nerves nor that in their
prominence has been used in previous classifications for the purpose
of forming main divisions or in describing varieties. In the present
classification these variations are employed in order to separate certain
varieties in the larger groups.
Barbing of lateral nerves of lemma
The variation in the character of the two lateral nerves next to the
dorsal nerve was first pointed out by Neergaard (1889). After careful
408
Roy Glen Wiggans
study, he found that in certain varieties these nerves were toothed or
barbed, while in other varieties they were perfectly smooth (fig. 62).
This character proved to be constant and reliable. As a consequence it
has been used widely in Sweden in recent years in differentiating certain
varieties which were similar in all readily observable characters. Some
workers following Neergaard, particularly Broili (1906), have held that
this character was not constant, while others have supported Neergaard.
As a consequence of this doubt as to the constancy of the character, it
has not been used widely by recent investigators. In the present
classification it is used to
make rather important divi-
sions of agricultural varieties,
particularly of the two-rowed
sorts.
In employing this char-
acter, it is necessary in many
cases to use a hand lens in
order to be sure of the pres-
ence or the absence of the
barbs. The character varies
in a similar manner to the
Fig. 62.
VARIATION IN BARBING OF LATERAL NERVES
OF LEMMA
A, Smooth lateral nerves; B, barbed lateral nerves
barbs on the awns. In some
varieties the barbs extend
along the lateral nerves
nearly to the base of the kernel, while in other varieties there is a
complete absence of barbs. Between these two conditions there are
practically all degrees of barbing. This character, however, seems to be
independent of the barbing of the awns, as some smooth-awned varieties
have barbed lateral nerves and many varieties with barbed awns have
smooth lateral nerves.
Base of lemma
The variation in the shape of the base of the lemma was first used to
distinguish large groups of barleys by the Swedish investigators. They
differentiated the erect compact forms from the nodding lax forms of two-
rowed barleys by the character of the base. The first work on the Swedish
system was begun by Atterberg (1889) and Bolin (1893). The narrow
A Classification of the Cultivated Varieties of Barley 409
lax forms of the two-rowed barleys are characterized by a slight horseshoe-
shaped depression at the base on the dorsal side of the kernel (fig. 63,
A and B). (As reported by Atterberg and Bolin, this difference was for
hulled varieties only.) Associated closely with this character is the type
of basilar connection of the kernel to the rhachis. The attachment is
reduced to a narrow band of tissue, which separates at maturity leaving
a smooth surface. Contrasted with these two characters of the narrow
Fig. 63. variation in shape of lemma base
A, Dorsal view of lemma base of lax-headed barley, showing horseshoe-like depression;
B, lateral view of same; C, dorsal view of lemma base of dense-headed barley, showing cross
crease; D, lateral view of same
lax forms, the dense erect forms have a base which is often pinched in
appearance, with a transverse crease or furrow just above the point of
attachment but with no horseshoe-like depression (fig. 63, C and D).
The basilar connection associated with this type of lemma is broader,
and when separated leaves a rougher surface than does the basilar
connection of the lax forms.
Although these characters have been used for differentiating only
threshed two-rowed hulled types, they hold equally true for threshed six-
410 Roy Glen Wiggans
rowed hulled barleys and for hull-less types which are still in the spike.
Their value in classification is somewhat limited because they are
associated so closely with density.
The outer glumes
Each spikelet in barley, in common with practically all members
of the grass family, is subtended by a pair of empty glumes, or bracts
(fig. 60). These glumes in the case of barley are usually covered with
fine hairs, are lanceolate in shape, and end either in awn points or in short
awns. However, all three of these characters of the outer glumes vary.
Occasionally varieties appear with expanded outer glumes which are
almost ovate in shape. This ovate shape appears in a few varieties on
all six of the outer glumes, in others on the outermost two, and in rarer
cases on the middle spikelet only. The shape of the outer glumes was
first used by Kornicke (1885) for the separation of varieties, but was not
considered of very great importance. More recently Beaven (1902) and
Harlan (1918) have given it more weight as a taxonomic character.
Another variation in shape of the outer glumes, which has not been
previously described so far as the present writer knows, is in the ter-
minal appendage. In very rare cases, hoods appear instead of awns
on the two outermost outer glumes. This variation has been found in only
one variety, and at present it has no value in classification.
Again, varietal differences occur in the length of awn on the outer
glumes. This was first illustrated by Munro and Beaven (1900). In
some cases the awns on the outer glumes are almost as long as the awns
on the lemmas. This variation may occur on the outer glumes of the
two lateral spikelets, on the median spikelets only, or in rare cases on
all three spikelets of both the two-rowed and the six-rowed types.
The difference in hairiness of the outer glumes is only in degree.
In many varieties, the glumes are well covered with long, straight hairs,
while in many' others the hairs are much shorter and not .nearly so
abundant; in rare cases the glumes are practically glabrous. These
variations, so far as observations have gone, are always associated with
similar but more apparent characters of the rhachilla.
All the variations in the characters of the outer glumes are of minor
importance in classification, either because they occur so rarely or because
A Classification of the Cultivated Varieties of Barley 411
they are closely associated with other structural characters. For these
reasons they are used in the present' classification only in varietal
descriptions.
The rhachitta
The rhachilla, which is often known as the basal bristle, is the prolongation
of the primary axis of the spikelet beyond the last floret — in the case
of barley the only floret. The entire structure of a barley spikelet is
shown diagrammatically in figure 60. In perfectly sessile barleys the
rhachilla is the only evidence of the primary axis of the spikelet. It is
more or less hidden
in the groove on the
ventral side of the
kernel, remaining
undisturbed in the
case of hulled bar-
leys when the grain
is threshed. The
rhachilla presents
one pair of differen-
tiating characters
which is of very
great taxonomic
value. In one group
of varieties the rha-
chilla is short and is
abundantly covered with long, straight, hairs; while in another group it
is almost twice as long and is covered sparingly with short, curly hairs,
giving a woolly appearance to the whole structure. This difference is
illustrated in figure 64.
This pair of characters, like the variation in the character of the barbing
on the lateral nerves, was discovered by the Swedish investigators. They
have found the' variation in the rhachilla even more reliable and of greater
value than the variation in the barbing of the lateral nerves, in the
identification of barley varieties grown in Sweden. In the present classi-
fication this pair of characters is employed in the separation of the lesser
groups of varieties.
A B
Fig. 64. the rhachilla'
A, Long-haired rhachilla; B, short-haired rhachilla'
412 Roy Glen Wiggans
Occasionally another variation occurs in the rhachilla, in that a rudi-
mentary second floret is produced. This variation has been used occa-
sionally in describing varieties, but, so far as the observations made in
the present study go, it is of little or no value. It seems to be the result
of either a sterile first floret or poor adaptation. Whenever it appears it
is usually in connection with poorly developed heads, not as a
characteristic of any variety or group of varieties.
SUMMARY
In order to eliminate possible confusion in regard to the characters
used in the present classification and to gain some idea of their relative
importance, the following brief summary of their use herein is given:
To distinguish species and subspecies:
1. Articulation of rhachis
2. Fertility of lateral spikelets
3. Presence of sexual organs in side spikelets
4. Presence of terminal appendages on lemmas of side spikelets
To distinguish the several varieties within large groups:
1. Adherence of lemma and palea to caryopsis
2. Variations in terminal appendage
3. Color
4. Density of spike as determined by
a. Base of lemma, or flowering glume
b. Length of rhachis internode
c. Width of spike
5. Character of rhachilla
6. Presence or absence of barbs on awns
7. Habit of early growth
8. Presence or absence of barbs on lateral nerves of lemma
To distinguish the subvarieties or strains within the more important varieties:
1. Attitude of spike
2. Date of emergence of awns and spikes
3. Time of maturity
4. Outer glumes
5. Grain characters:
a. Composition
b. Size
c. Shape
6. Variations in size and color of foliage
7. Culm characters:
a. Length of last internode
b. Total length of cuim
c. Number of nodes
8. Variation in articulate character of rhachis
9. Branch-headed character
10. Productivity
Many of the last-named characters are influenced to such a degree by
environment that they cannot be used alone to make differentiations,
A Classification of the Cultivated Varieties of Barley 413
but when combined with other characters they may be employed in
separating subvarieties. These characters are more valuable in varietal
description than for any other purpose, and can be employed only for local
identification.
CLASSIFICATION OF BARLEY FORMS
The classification as given in the following pages is very largely of
cultivated varieties, this being the main purpose of the study. Some
unimportant varieties are included, however, in order to make the classifica-
tion more nearly complete. It has likewise been considered better to
construct the keys to groups and varieties in such a way that they may
easily be expanded to include new introductions and new productions
which are certain to arise. For this reason, and because of a lack of
specimens possessing all the possible combinations of characters, the
keys are left incomplete, some divisions failing to appear in certain instances.
The cultivated species of barley (fig. 65), and the one wild species
{Hordeum spontaneum, fig. 58) which is most closely related, may be
distinguished according to the following key:
PAGE
A. Rhachis articulate Hordeum sponianeum. 415
AA. Rhachis non-articulate.
B. All spikelets fertile.
C. Lemmas of all spikelets awned or hooded, kernels of all spikelets equal or
nearly equal in size H. vulgare. 416
CC. Lemmas of central spikelets awned or hooded, lemmas of lateral spikelets
bearing neither awns nor hoods, kernels of lateral spikelets much reduced
in size (x) H. intermedium 1 . 430
BB. Only the central spikelets fertile.
C. Lateral spikelets possessing nonfunctional rudimentary sexual organs
H. distichon. 433
CC. Lateral spikelets much reduced in structural parts and possessing no rudi-
mentary sexual organs H. deficiens. 443
The general relationship of the species may be graphically shown as
follows:
Family
Genus
Species
Gramineae
Hordeum
spontaneum
vulgare
(x) intermedium
distichon
deficiens
7 The (x) before H. intermedium indicates the hybrid origin of this species, also that it is not of equal rank
with the other species.
A B C D
Fig. 65. four cultivated species op barley
A, Hordeum deficient; B, H. distichon; C, H. intermedium; D, H. vulgar e
414
A Classification of the Cultivated Varieties of Barley 415
In the present classification the number of species of cultivated varieties
is placed at four, one of which, H. deficiens, is at present of lesser agronomic
importance than the others. These groups are given the species distinction
largely because (1) all the best evidence seems to point to the very early
origin and to the parallel development of these types; (2) the numerous
distinct varieties are less confusing when placed in four rather than in
one species; (3) most of the earlier investigators have used more than
one species. It is evident, however, that these species are not so distinct
as are many species of other plants, especially in the wild state, since in
many cases interspecies crosses are impossible. In barley, the species
as designated in the present classification readily cross.
HORDEUM SPOXTANEUM
Hordeum spontaneum C. Koch (fig. 58) differs from all the cultivated
forms of barley by the articulation of the rhachis. At or near maturity
the rhachis separates at each node but the segments remain attached
at the upper end to the spikelets. The rhachises of cultivated barleys, on
the other hand, do not readily disarticulate at maturity. If the spikelets
are forced apart, they break loose from the rhachis and leave it entire.
It seems that in the evolution of cultivated barleys the rhachis has become
solidified into a single structure.
The character of the brittle rhachis is found in several wild grasses,
among the most interesting of which is the wild wheat of Palestine, the
possible progenitor of cultivated wheats. This characteristic makes these
grasses especially adapted for reseeding, and may account for the
continued existence of these forms in nature.
H. spontaneum has been known to botanists for many years, having
been described by Post (1883), by Boissier (1884), and by Hochstetter
(1848). By both Boissier and Post it was designated as Hordeum
Ithaburense. It may be briefly described as follows:
Leaves weak, linear, tapering at tip; spikes awned, flattened, two-
ranked; rhachis brittle, plumose; lateral spikelets pointed, without awns,
staminate, pedicillate; central spikelet awned, perfect, sessile; awns very
long and excessively barbed; dorsal nerves of flowering glumes of lateral
spikelets smooth; outer glumes of all spikelets very hairy, awned; awns
H times as long as lateral florets; rhachilla long, covered with long,
straight hairs; kernel long, slender.
416
Roy Glen Wiggans
The only interest in this type from an economic standpoint lies in the
possibility of its being the ancestor of some if not all of the cultivated
barleys.
HORDEUM VULGARE
Hordeum vulgare L. (figs. 66 and 67), one large species of cultivated
barleys, is differentiated from the wild species just described principally
a b CD
Fig. 66. varieties of hordeum vulgare
A and B, Dense hulled forms; C, lax hulled; D, lax hull-less
by the presence of a solidified rhachis, one which holds together at maturity
and remains intact even though the kernels are broken off. Another
important difference between the two is found in the fertility of the
spikelets. In H. vulgare all three spikelets at each node of the rhachis
are fertile, thus forming six rows of fertile spikelets instead of two. The
species may be briefly described as follows :
A Classification of the Cultivated Varieties of Barley 417
Spike erect and nodding, six- or four-ranked according to arrangement
of spikelets: rhachis, or central axis of spike, made up of a number of
short internodes which are solidified at the joints; spikelets arranged in
groups of three at each joint in the rhachis, all equally fertile, all awned
or hooded, all sessile or nearly so, awns usually barbed; lateral nerves
of flowering glumes barbed or smooth; rhachilla hairy; grains of lateral
•
- i*"
■)'■'■
Jtv\« '
% ' (,