302 TROPICAL AGRICULTURE 



sheer wanton wastefulness. No part or portion of any for- 

 age plant is allowed to go to waste in the Oriental Tropics. 

 All this material is utilized either for human food, as feed 

 for stock, or for some technical purpose, and ultimately every 

 scrap of the by-product is returned to the soil as a source of 

 fertility. All kinds of oil cakes, particularly those obtained 

 from oil palm, coconut, peanut, soy bean, Para rubber, etc., 

 are utilized for feed and for other purposes to the fullest 

 extent. Moreover, such unpromising materials as sisal waste, 

 obtained in the decortication of sisal fibers add to the list of 

 forage materials. Then, too, there is the wide use of ti leaves, 

 banana trunks and leaves, fern trunks, and even the trunks of 

 the papaya tree. All of these materials furnish more or less 

 valuable additions to the list of forage products. 



LEGUMES 



Of the various leguminous trees which have been utilized 

 for commercial purposes in the Tropics, the algaroba is per- 

 haps the most important. This tree, in the form in which it 

 occurs in Hawaii, is commonly referred by botanists to Proso- 

 pis juliftora. Much difference in opinion prevails, however, 

 as to the correct botanical name for the tree, and until this 

 point is settled it may as well be known by the scientific name 

 just mentioned. Algaroba is native to Central America and 

 South America, and related forms are of wide occurrence in 

 Arizona, New Mexico, and Texas, where at least two species 

 are known under the common names mesquite and screw bean. 



It is in Hawaii, however, that the representative tree of 

 this group, known as algaroba, has attained its greatest sig- 

 nificance. The tree reaches a height of 15 to 50 feet and a 

 trunk diameter up to 30 inches. The cream-colored or pale 

 yellow flowers are borne in slender axillary spikes or catkins. 

 The leaves are bi-pinnate and the pods are linear or curved, 

 4 to 9 inches long, somewhat flattened but thick, and slightly 



