514 The Cats-Claws 



Filaments distinct or the inner ones sometimes tmited at the base. 



Ovary stalked; pod dry; seeds not in 2 distinct rows. 6. Acacia. 



Ovary sessile; pod swollen, nearly cylindric, pulpy; seeds in 2 distinct 

 rows. 7. Vachellia. 



Stamens only as many as the calyx-lobes or twice as many. 

 Pods straight, or but slightly curved, in loose dusters. 

 Pod flat, compact; seeds transverse, not enclosed in a sac. 8. Leuccena. 



Pod thick, spongy; seeds oblique, enclosed in a sac; spines above the 

 leaf-stalk. 9. Prosopis. 



Pods coiled into a close spiral, in dense clusters; spines below the leaf- 

 stalks. 10. Strombocarpa. 



I. THE CATS-CLAWS 



GENUS PITHECOLOBIDM MARTIUS 



?nTHECOLOBIUM consists of about 100 species of trees or shrubs, 

 with or without spines. The leaves are alternate, bipinnate, typically 

 few-foliolate, usually glandular; stipules deciduous, or persistent and 

 spinescent. The flowers are perfect or polygamous, in globose heads; 

 the calyx is bell-shaped or tubular, 5-, or sometimes 6- toothed; the corolla con- 

 sists of 5 petals, partly united; stamens very numerous, long-exserted, the filaments 

 thread-hke, united at the base into a tube; anthers small; ovary with many ovules, 

 borne at the bottom of the calyx- tube, contracted into a slender style; stigma 

 small, capitate; ovules in two rows. The fruit is a compressed, narrow legume, 

 often greatly contorted, sometimes with pulpy or mealy partitions between the 

 seeds, tardily dehiscent. The seeds are partly enclosed by the bright colored aril- 

 Kke funicle, ovate to orbicular, compressed, and suspended transversely in the 

 pod. 



The genus Pithecolobium is widely distributed in the tropical and subtropical 

 regions of both hemispheres, but is most abundant in tropical America. One of 

 the best known and most valuable species is the Mexican rain tree, Pithecolobium 

 Saman (Jacquin) Bentham, of Central America, planted and widely naturalized 

 throughout the West Indies; it is a magnificent shade tree, and its pulpy pods, 

 edible but insipid, are valued as food for cattle. 



The name is Greek, in reference to the much contorted pods of most of the 

 species. The type species is considered to be P. Unguis Cati (Linnaeus) Martius. 

 The oldest generic name for these plants is Zygia P. Browne, but it is unavaila- 

 ble for use because the author established no type species. 

 Our arborescent species are : 



Twigs spiny; leaflets thin, 2.5 to 5 cm. long. i. P. Vnguis-Cati. 



Twigs not spiny; leaflets leathery, 3 to 7 cm. long. 3. P. guadalupense. 



