460 



BOTANY OF CROP PLANTS 



shaped seeds 8 to 12 millimeters l(jng. In catjang, the pcjds 

 are small, 3 to 5 inches long, and usually erect or ascending 

 (Fig. 194). In the cowpea, the pods are 8 to 12 inches long, 

 and become pendant with age. The cowpea is by far the 

 most important, economically. 



Fir.. 194. — .1, flowers and fruit of catjang (Vigna catjaiiK')". H- flower 

 fruit of cowpea (Vigna sinensis). (After U. S. Dcpt. of Aari.) 



VIGNA SINENSIS (Cowpea) 



Description. — The cowpea is a vigorous annual herb with 

 a strong tap root which sends out large side roots almost 

 horizontally for i or 2 feet (Fig. 195). The greater part of the 

 root system lies in the first i}4 feet of soil. The varieties vary 

 in habit from prostrate traihng herbs to tall and half-bushy 

 forms. The cowpea has an indeterminate growth, that is, 

 it continues to grow indehnitely, providing environmental 

 conditions are favorable. As in the majority of plants 

 vegetative growth is favored by an abundance of water and 



