LEGUMES FOR FOE AGE AND GRAIN 



313 



variety from a single upright, branching stem to a pro- 

 fusely trailing form. Almost all varieties have the trail- 

 ing habit of growth, and under favorable conditions of 

 climate and soil some of them produce stems 15 feet or 

 more in length. The stems are marked with longitu- 

 dinal grooves, and the color of the stems is associated with 

 that of the leaves, varying in this 

 respect from pale to dark green. 

 The leaves are trifoliate and are 

 larger than those of the soy bean. 

 The flowers are borne singly and 

 are much larger than those of the 

 soy bean, being more nearly the 

 size of those of the sweet pea. The 

 flowers are whitish, violet, or yellow 

 in color, and rival the sweet pea 

 in beauty. The pods are long, 

 straight, or slightly curved, and 

 many seeded. The seeds vary 

 greatly in size and may be either smooth or wrinkled. 

 They vary also in color, the common colors being white, 

 yellow, green, brown, and mottled. The stem, leaves, and 

 pod of the cowpea, unlike those of the soy bean, are not 

 covered with hair. In appearance the cowpea more closely 

 resembles the field and garden bean than it does the soy 

 bean. 



The root system of the cowpea consists of a well-devel- 

 oped tap root, which gives off lateral branches from the 

 upper part. These grow out horizontally for some distance 

 and then grow downward rather deeply. The roots of 

 the cowpea are more extensive than those of the soy 

 bean, being more numerous and penetrating more deeply 

 into the soil. 



FIG. 114. Pods of cow- 

 peas and soy beans. 



