LEGUMINOUS PLANTS. 13 
applied, it is evident that continuous crops of Timothy would rapidly 
deplete the soil, and the same is true, in a general way, of other 
grasses. Leguminous plants (see page 18) accumulate nitrogen 
from the air and are of great importance as soil improvers. Clovers 
return nitrogen to the soil, and thus to a certain degree maintain its 
fertility. 
LEGUMINOUS PLANTS. 
Name: These plants belong to a large family of a distinct type, 
called Leguminose. Peas, Vetches, Beans, Red Clover, Alsike and 
Alfalfa belong to this great family—that is, the plants which farmers 
commonly term legumes and clovers. As generally used, the name 
“clovers’”’ includes Red Clover, Alsike, Dutch Clover, Crimson 
Clover, Alfalfa, Trefoil, Sweet Clover and other leguminous plants. 
Botanically, however, only the first four are clovers in the true sense; 
that is, they belong to the genus Trifolium, whereas Alfalfa, Trefoil 
and Sweet Clover belong to other genera. 
Seed: When splitting a bean or a pea, the two halves seem 
to be kept together by the seedcoat only. One of them has a 
smooth, more or less shiny surface, on 
which no special texture can be dis- 
covered by the naked eye. Near the 
upper end of the other half is a peculiar 
organ consisting of two distinct portions. 
The upper is a bud (Fig. 5, B.), which 
corresponds to the similar formation in 
the grass embryo (see page 8.). The 
lower, which lies close to the seed- 
coat, has a thicker upper part (Fig. 5, 
St.) and a tapering end (Fig. 5, Rad.), 
Fig. >. Section through a Beax. the former being the stem of the em- 
Four times natural size. 5 
Atha ech bryo, the latter its root or radicle. By 
StStem. —_ Col.—Cotyledon. far the greatest part of the seed (Fig. 5, 
Cot.) consists of the two cotyledons of the embryo. A leguminous 
embryo has thus two cotyledons whereas a grass embryo has only one. 
But a leguminous plant has no endosperm. The function of the en- 
dosperm of a grass seed, as stated on page 8, is to supply the embryo 
with food during germination. This function in a leguminous plant is 
performed by the two cotyledons, which are thick and filled with food. 
Germination: When the seed of a leguminous plant germinates 
the bud (Fig. 5, B.) develops into stem and leaves and the radicle 
(Fig. 5, Rad.) into the root of the plant. The stem of the embryo 
