14 BULLETIN 428, U. S. DEPARTMENT OF AGRICULTURE. 
COMPOSITE DETAILED DESCRIPTION. 
The flowers of the numerous forms of the species vary consider- 
ably in color, size, and shape of banner, length of calyx teeth, and 
slightly in length of calyx tubes. There is also a variation in the 
length of pedicels, the number and compactness of the racemes, the 
number of flowers in the raceme, and the date of blooming. In 
color the flowers range from a light yellow to a deep chrome yellow, 
the pale yellow color being the most prevalent in the individuals that 
more nearly approach Medicago sativa in general appearance. 
On the steppes of northern Russia and Siberia occur forms that 
have variegated flowers. These forms are found apparently remote 
from forms of Medicago sativa and so closely associated with forms 
of Medicago falcata having pure yellow flowers that Prof. Dilit- 
winoff,! of the Academy of Sciences, Petrograd, is of the opinion 
that they are true forms of the latter. Meyer, however, who has 
studied them in their native habitat, believes them to be hybrids of 
Medicago sativa and Medicago falcata, and a study of the progeny 
of these plants grown from the seed collected by the department’s 
explorers indicates quite definitely that Meyer’s opinion is well 
founded. The progeny exhibits a diversity of forms, some of which 
closely resemble Medicago sativa, while others present the appear-: 
ance of true Medicago falcata. But regardless of this, the wild 
variegated forms are regarded with interest in connection with the 
study of the origin of the cultivated alfalfas and the botanical 
relationship existing between the above species. 
Flowers.—The individual flowers of Medicago falcata are smaller 
than those of J/edicago sativa. The lines which mark the banners 
are shorter in the former than in the latter and are light to dark 
brown, varying directly with the color of the flower. A large num- 
ber of careful measurements show that the banners vary from 6.25 
to 12 mm. in length and from 2.20 to 8 mm. in width. The ratio of 
length to width of the banner also varies, ranging from approxi- 
mately 1.2 tol to3tol. The calyx averages about 1.75 mm. in length | 
and varies from approximately 1.3 to 2.6 mm. There is a greater 
variation, however, in the length of the calyx teeth, the range being 
from 1.25 to 3.75 mm. The pedicels are from 1.25 to 3.75 mm. in 
length. 
There appears to be little uniformity in the number of flowers in 
the raceme. In some cases as few as five are found, while in others as 
many as 36 may be present. Racemes with the largest number of 
flowers have been noted to be compact and of medium size. The 
very fine leaved plants and the plants with long procumbent stems 
have small racemes, with comparatively few flowers. Likewise, the 
1In letter on file in the United States Department of Agriculture. 
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