Britton: Studies of West Indian Plants 3 



2. Leaflets linear to oblong, small, 5-16 mm. long, 

 6-many pairs to each pinnule. 

 Leaflets 2-3 mm. long, oblong, coriaceous. 11. P. nipense. 



Leaflets 5-16 mm. long, thin, dull. 



Leaflets obliquely oblong, narrowed at base. 12. P. as pi eni folium. 

 Leaflets linear, linear-lanceolate or oblong, 

 obtuse, rounded or subcordate at the base. 

 Leaflets oblong, 5-7 mm. long. 13. P. trinitense. 



Leaflets linear. 

 * Pinnae 2 pairs; leaflets acute, strongly 



veined; pod compressed. 14. P. guantanamense. 



Pinnae 3-1 1 pairs; leaflets obtuse, not 



strongly veined; pod swollen. 15. P. arbor eum. 



B. Pods straight, or curved, indehiscent, or dehiscent, the valves not twisting. 



Unarmed trees. 



Pod straight or a little curved, compressed, turgid, 



fleshy; leaflets oblong to obovate, large. 16. P. Saman. 



Pod straight, thin, very flat, chartaceous; leaflets 



linear, small, very numerous. 17. P. Berterianum. 



Trees or shrubs, armed with spinescent stipules (P. tortum 



sometimes unarmed). 

 Pod coriaceous, tardily dehiscent; stamens 2 cm. long 



or less, the tube short; leaflets many; spines straight. 18. P. tortum^- 

 Pod chartaceous, thin and flat, dehiscent; stamens 5-6 



cm. long, the tube much exserted; leaflets few; 



spines curved. 19. P. prehensile. 



1. Pithecolobium circinale (L.) Benth. Lond. Journ. Bot 



3: 201. 1844 



Mimosa circinalis L. Sp. PI. 517. 1753. 



Thickets in dry districts at low elevations, southern Oriente; 

 Hispaniola. 



Bentham's record of this species for the Bahamas appears 

 to refer to P. mucronatum Britton, which has quite different 

 leaves. The Oriente plant differs from the typical one of His- 

 paniola in having smaller, thicker leaflets, less cuneate at the 

 base, and is either glabrous or densely pubescent. 



2. Pithecolobium Unguis-cati (L.) Mart. Hort. Monac. 188. 



1829 



Mimosa Unguis-cati L. Sp. PI. 517. 1753. 



Cayo Sabinal, Camagiiey (Shafer 1063); recorded by Richard 

 as in various parts of the island, but is apparently rare. West 

 Indies (except Bermuda) ; northern South America. 



