LEGUMES AND OTHER FORAGE PLANTS 309 



Jack bean {Canavaiia ensiformis) is an annual, bushy 

 legume, native to the West Indies and attaining a height of 

 2 to S feet. It bears handsome, purple flowers and sword- 

 like pods 9 to IS inches long and an inch or more wide, with 

 about 12 large pure white beans in each pod. The beans bear 

 a brown hilum. The jack bean is cultivated in the West In- 

 dies, southern United States, Java, Hawaii, and quite gen- 

 erally throughout the Tropics, chiefly as a green manuring 

 crop. The jack bean is particularly well favored for growth 

 in tropical countries on account of its hardiness and relative 

 immunity to insect attacks. Plant lice seldom appear in in- 

 jurious numbers on the jack bean. The plant yields fropi 

 i6 to 20 tons of green forage per acre and about i,200 pounds 

 of seed. Usually only one crop is obtained from a single 

 planting. In fact, the plant is considered an annual. Occa- 

 sionally, however, a good rattoon crop has been obtained, 

 particularly if the first cutting is made before the plants are 

 mature. Jack bean is particularly valuable as a green manure 

 crop for planting between rows of sugar cane, coffee, rubber, 

 and sisal, where it can be plowed under as a source of plant 

 food. The plant is quite strongly resistant to drought but 

 is not equal to velvet beans in this regard. Perhaps the 

 largest yields are obtained by planting the beans in rows 

 i8 inches apart and 6 to lo inches apart in the individual 

 row. 



The sword bean (C gladiata) has often been grouped to- 

 gether with the jack bean, which it closely resembles. This 

 plant is widely cultivated in tropical Asia, Africa, Hawaii, 

 and generally in the Tropics. The plant closely resembles 

 the jack bean, but the pods are somewhat shorter and wider 

 and the beans are either red, gray, or white. The sword 

 bean is somewhat used as a vegetable, the young, green pods 

 and beans being employed for this purpose, especially in In- 

 dia, Ceylon, Burma, Japan, and Mauritius. Otherwise, the 

 sword bean is chiefly used as a cover crop and as forage for 



