2 Britton: Studies of West Indian Plants 



long, maturing 2 achenes; lower empty scales broadly ovate, the 

 others lanceolate, acuminate; bristles none; achenes obovate- 

 orbicular, 1 mm. long, pale brown, shining, finely cancellate; 

 tubercle triangular-lanceolate, acuminate, flat, about one- third 

 longer than the achene, its base nearly truncate. 



Rocky banks in the Blue Mountains of Jamaica; type, from 

 Hardware Gap, N. L. Britton 3322, collected .Sept. 9, 1908. Re- 

 lated to R. elongata (Boeckl.) Clarke, and to R. polyphylla Vahl, 

 but at once distinguished from them by its pubescent sheaths. 



24. THE GENUS PITHECOLOBIUM IN CUBA 



A. Pods curved or coiled, dehiscent, the valves twisting after 



1. Seeds with a fleshy aril; stipules spinescent; pinnae i 



or 2 pairs; leaflets 2-4 pairs. 

 Leaflets 1-6 cm. long (species perhaps confluent). 

 Leaflets spinulose-mucronate. 

 Leaflets obtuse or mucronulate. 



Leaflets chartaceous; petioles of the lower 



leaves, at least, longer than the petiolules. 

 Leaflets coriaceous; petioles shorter than the 

 petiolules or as long. 

 Petioles and petiolules stout; leaflets large, 



2.5-6 cm. long. 

 Petioles and petiolules slender; leaflets small, 

 1-3 cm. long. 

 Leaflets only 3-7 mm. long. 



2. Seeds without a fleshy aril; stipules not spinescent; 



pinnae 2 pairs or more; leaflets 3 pairs or more. 

 1. Leaflets obovate to oval, large, 1.5-6 cm. long, 3-6 

 pairs to each pinna. 

 Calyx subtruncate at base; seeds oblong, about 



twice as long as wide. 

 Calyx narrowed at base; seeds suborbicular to 

 obovate. 

 Pinnae 3 or 4 pairs; leaflets 4-6 pairs; calyx 



narrowly campanulate, thin. 

 Pinnae 1 or 2 pairs; leaflets 2-4 pairs; calyx 

 broadly campanulate, coriaceous. 

 Calyx truncate, its teeth minute, mucronu- 

 late. 

 Calyx teeth large, broadly ovate. 



Calyx short-campanulate; stamen-tube 



short; leaflets broadly obovate. 

 Calyx long-campanulate; stamen-tube 

 5-6 mm. long; leaflets oblong to obo- 

 vate. 



separating. 



1. P. circinale. 



2. P. Unguis-cati. 



3. P. guadalupense. 



4. P. bahamense. 



5. P. Hystrix. 



6. P. savannarum. 



7. P. discolor. 



8. P. truncatum. 



9. P. obovale. 



10. P. pinetornm. 



