u NATURAL HISTORY OF PLANTS. 



or cylindrical spikes. But the pod is linear, compressed, and flat- 

 tened, straight or slightly curved, with a thin sub membranous pericarp, 

 whose two valves, continuous or dividing off into transverse joints, 

 separate at maturity from the entire persistent border of the fruit. 



Acacia heterophylla. 



Fio. 33. 

 Leaf-bearing branch. 



Some half score species of this genus are known,' unarmed shrubs 

 from equinoctial America and the Antilles. 2 



JPitkecolobium* too has hermaphrodite or polygamous flowers 4 in 

 spikes or capitula, and bipinnate leaves, as in Lydloma and Colli- 

 andra. But the fruit is flat or compressed, falciform circinate or more 

 or less distorted, rarely almost straight, coriaceous or nearly fleshy, 

 indehiscent or more frequently two-valved, or dehiscing along the 



1 K., Mimos., t. 24. — Benth., Sulph., v. t. 

 31 —Griseb., Fl. Brit. W. hid., 223.— Waxp., 

 Rep., v. 594 ; Ann., iv. 635. 



2 In its flowers this genus does not differ from 

 tbe mouadelpbous Acacias ; but the structure and 

 dehiscence of its fruit suffice to distinguish it 

 from them. 



3 Mart., Serb. Flor. Bras., 114 ; Cat. Eort. 



Monac., 188.— E>T)L., Gen., n. 6837 c— B. H., 

 Gen., 597, n. 395. — Cathormion Hassk., Rctzia, 

 i. 231. 



4 The stamens united with the corolla below 

 contain in their anthers a pollen, in masses 

 analogous to that of Inga (see above, p. 42, 

 note 11). 



