178 TROPICAL AGRICULTURE 



increasing. In India, Bombax maiibaricum, a plant closely 

 related to kapok, and like kapok pnducing large pods with 

 black seed covered with a silky lint, is nsed as a substitute for 

 kapok. The bombax fiber, however, is a reddish-brown, while 

 the kapok is ivory white. 



Kapok is often called silk-cotton, but this is a rather mis- 

 leading term. The kapok pods are 3 to 5 inches long, spindle- 

 shaped, and 2 inches in diameter at the center. Unlike true 

 cotton the valves of the pod do not open on the tree to 

 allow the picking of the lint, but the pods must be picked 

 whole before the valves, open, otherwise the lint would be 

 blown away and lost. The pod is tightly packed with a soft 

 and silky white lint very loosely attached to the small black 

 seed. 



MILKWEEDS 



Several species of Asclepiadacese, as well as Beaumontia, 

 Strophanthus, and certain other Apocynaceae bear a soft fiber 

 on the seed which has been used under the general term vege- 

 table silk. Calotropis gigantea, native of China, India, and 

 Africa, possesses a bast fiber which splits into fine silky threads 

 which have been used for fabrics and also for cordage. Thus 

 far this fiber has been removed entirely by hand. The yield 

 obtained from wild areas of the tree is about 500 pounds per 

 acre. The fiber has a high degree of resistance to moisture. 

 The tree also yields a latex from which a low grade of rubber 

 has been produced. 



Asdepias curassavica, native of Central America and South 

 America and now generally distributed throughout the Tropics, 

 has sometimes been used locally as a source of fiber. Cryptos- 

 tegia grandiflora yields a fine, strong fiber from bast which is 

 sometimes used for cordage and yarn. This plant is a hand- 

 some woody climber which attains a great length, climbing 

 from the branches and crowns of trees and bears large, pretty, 



