MEDICAGO FALCATA, A YELLOW-FLOWERED ALFALFA. 37 
Medicago sativa, although in a few of the erect forms there is com- 
paratively little difference in this respect. From a similar stand of 
the same height of mass growth Medicago falcata will produce a 
heavier yield than Medicago sativa, partly because of the thicker 
growth of stems and partly because of the texture of the herbage. 
Estimates of yields based upon appearance therefore commonly err 
in favor of Medicago sativa. Conditions of soil and stand being 
equal, individual cuttings of the best upright forms of J/edicaqo 
falcata frequently outyield those of varieties of Medicago sativa. 
A characteristic of considerable importance in any hay crop is the 
proportion, by weight, of leaf to stem. The plants of Medicago fal- 
cata show great variation in this respect, making the character of 
little value in any system of classification. However, in the very low 
forms the proportion is greater than in the more erect ones. <A crit- 
ical study of 27 S. P. I. introductions indicates that the leaves com- 
pose from 34.5 per cent to 67.5 per cent of the total dry weight of 
the herbage. The highest percentage of leaves was found in group 1 
in plants of S. P. I. Nos. 20717 and 20725. McKee (42) presents data 
on the percentage of leaves by weight for three varieties of Medicago 
sativa, as follows: 
1B) E10 VATS ay gunn UURBUMI CoP Ma tig Ne Mg RRC lee tae Maree ae 52. 5 per cent. 
PEROVGEDIL) UAT 0 aL Lass canes ee MR 4 Ca UN oe ae GC Ten CORSE 
Comimon GWU talhiono wayicese = sw Ne ee 49. 8 per cent. 
According to the investigations of the Utah Agricultural Experi- 
ment Station (67) the percentage of leaves by weight in common 
alfalfa ranges from 22.7 to 38.4, depending upon the stage of matur- 
ity. It is safe to assume that the erect forms of Medicago falcata are 
not essentially different from the common varieties of J/edicago 
sativa with respect to the above character. The leaves of the former, 
however, are retained after curing to a greater degree than those of 
the latter, which is a very important factor. 
STEM CHARACTERISTICS. 
The size and number of stems of the plant vary greatly with its 
habit of growth. (Fig. 17.) In the very procumbent or prostrate 
plants the stems usually are finer and more abundant than in the 
more erect ones. An actual count made on plants 4 years old indi- 
cates the number of stems to range from 292 in S. P. I. No. 20718, a 
large ascending form, to 1,682 in S. P. I. No. 20717, a broad-crowned 
form. Plants of Turkestan alfalfa of the same age and grown under 
similar conditions had approximately 225 stems per plant. In this 
agronomic character also Medicago falcata compares very favorably 
with Medicago sativa. 
