MEDICAGO FALCATA, A YELLOW-FLOWERED ALFALFA. ley 
with the scanty production of pollen in the case of many of the 
flowers, may be responsible to some extent for the paucity with 
which the seed of the species is produced. 
Leaves.—The leaves vary in shape from ovate to linear-cuneate. 
(Pl. I.) The type and stage of growth of the plant and the posi- 
tion in which the leaves are borne on the stem all influence their 
size and shape. During the first few weeks of growth in the spring 
they are larger and more ovate than they are later in the season. 
They also appear to diminish in size and become more elongated as 
the end of the stem is approached. In general, they are more elon- 
gated or hnear than those of I/edicago sativa, although there are some 
Fig. 5.—Seed of Medicago falcata. Note the prominence of the radicle and the rough- 
ness and irregularity as compared to those of Medicago sativa (fig. 4). (HEnlarged.) 
marked exceptions, as will be noted in the illustration. <A series of 
measurements indicates the range of proportion of length to width 
to be from 1.8 to 1 to 16 to 1. The more ovate leaves are common 
in groups of plants represented by S. P. I. Nos. 24454 and 20725 
(Pls. II, C and D, and III, A and C), while the more linear leaves 
are abundant in the group represented by S. P. I. Nos. 20718 and 
24455 (Pls. II, A and B, and IV, B and Cy. The large leaflets are 
approximately 27 mm. long by 12 mm. wide, and the smaller ones 
approximately 9 mm. long by 1.5 mm. wide. The plants having the 
larger leaflets approach Medicago sativa in general characteristics. 
The margins of the leaves are more or less serrate; the apex deeply 
notched, mucronate, or in some cases nearly entire. In some leaves 
55890°—Bull. 428—17 —3 | 
