16 FODDER AND PASTURE PLANTS. 
families. The lower part (Fig. 7, Sep.) is insignificant. It is com- 
posed of five green, toothlike organs, called sepals, connected at their 
base. The upper part, popularly called the flower, consists of five 
mostly showy petals. One of these is much larger than the others 
and encloses them in the bud. It is called the standard (Fig. 7, St.). 
The lateral ones are irregular in shape and are called wings (Fig. 7, 
W.). The two others grow together, forming a boatlike organ called 
Fig. 7.—The different parts of a flower of Pea. 
atural size. 
Sep.—Sepals W.—Wing. St—Stamens. 
S.—Standard. K.—Keel. O.— Ovary of pistil. 
P.—Stigma of pistil. 
the keel (Fig. 7, K.), which encloses the stamens (Fig. 7, St.) and the 
pistil. Nine of the ten stamens grow together in their lower parts, 
forming a tube that encloses the pistil. Each flower has only one 
pistil. It consists of a broad lower part, the ovary (Fig. 7, O.) and 
a narrow upper part, strongly knee-bent and developed at its top 
into a stigma (Fig. 7, P.). 
Fertilization: Fertilization in leguminous plants is never per- 
formed by air currents. In a few genera, such as peas and vetches, 
the flowers are self-fertilized; that is, the pollen automatically 
fertilizes the pistil of its own flower. In most leguminous plants, 
however, the pollen is transported from one flower to another by 
insects, which visit the blossoms for the nectar stored at their base. 
When the flowers are large and showy, the standard acts as a sign, 
announcing to the insect the location of the honey. In other species 
the comparatively small flowers are very numerous, and are thus 
visible at a long distance. Still others have insignificant flowers 
borne close to the ground. Such plants, like Trefoil, grow under 
taller neighbours, and are therefore more or less hidden. But in 
