214 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



There are two additional labels with Wright 3879 in the Sauvalle Herbarium, ''Low 

 marshy savannas, Guanimas, Nov.," and "Margin of mangrove swamp, Trinidad, 

 Mar. 13." 



32. PANICUM L. Sp. PI. 55. 1753. 



Axis of the panicle branches extending beyond base of uppermost 



spikelet as a short point or bristle 11. P. distantiflorum. 



Axis of panicle branches not extended into a bristle. 



Inflorescence consisting of several spike-like, more or less 

 secund racemes. 



Fruit smooth and shining; spikelets not over 1.5 mm. 

 long. (Laxum group.) 



Rachis pilose; pedicel short, subequal 32. P. pilosum. 



Rachis not pilose; pedicels unequal, panicle less 



regular 23. P. laxum. 



Fruit transversely wrinkled; spikelets turgid. (Rep- 

 tans GROUP.) 



Nodes bearded .29'. P. numidianum. 



Nodes sometimes pubescent, but not bearded. 



Glumes and sterile lemma prominently trans- 

 versely reticulate-veined 15. P. fasciculatum. 



Glumes and sterile lemma not cross- veined. 

 Spikelets hispidulous, pointed, first glume 



acute — 2. P. adspersum. 



Spikelets glabrous, first glume truncate. 

 Blades ovate-lanceolate, 5 to 10 mm. 

 wide, 2 to 7 cm. long; prostrate- 

 spreading 35. P. reptans. 



Blades elongated, 10 to 20 cm. long, 

 narrow; flowering culms erect or as- 

 cending; inflorescence of numerous 

 erect-appressed racemes on an elon- 

 gated axis; spikelets in 2 distinct 



rows 17 . P. geminatum. 



Inflorescence a more or less diffuse panicle, sometimes nar- 

 row and rather compact, but not consisting of spike- 

 like racemes. 



Stems woody, resembling bamboos. (Divaricatum 



GROUP.) 



Sheaths villous. 



Stems tall, blades 1 to 2 cm. wide, not distich- 

 ous 42. P. swartzianum. 



Stems creeping, blades distichous, 2 to 3 cm. 



long, about 5 mm. wide, velvety 36. P. rugelU. 



Sheaths smooth or pubescent only. 



Panicle compact; blades ovate-lanceolate, 1.5 

 to 4 cm. wide, velvety-puberulent beneath; 



spikelets globular 8. P. compactum. 



Panicle open, blades lanceolate. 



Stem creeping, sending up erect flowering 



culms 19. P. grisebachii. 



Stem climbing or trailing. 



Panicle large and spreading, 10 to 20 

 cm, long; blades 1.5 to 2.5 cm. 

 wide 39. P. sloanei. 



