260 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Bristles barbed forwards. 
Blades broad, the larger ones 4 cm. or more wide, plaited, 
tapering at both ends. (§PrycHopHyYLLuM.) 
Panicle rather compact, the branches ascending or 
appressed, 1 to 4. cm. long........... 1. C. sulcata. 
Panicle loose and open, the branches slender and 
spreading, 10 to 20 cm. long............. --. 2. C. effusa. 
Blades narrow, not plaited. 
Plants annual. 
Fertile lemma transversely striate but not 
deeply rugose. 
Panicle rather compact, the branches short. 6. C. grisebachii. 
Panicle looser, the branches1to3cm.long. 6a.C. grisebachii ampla, 
Fertile lemma deeply transversely rugose. 
Blades pilose beneath..................... 5. C. latifolia. 
Blades scabrous but not pilose. 
Panicle dense, spike-like; blades nar- 
rowed at base, spreading, a dense 
tuft of hairs 2 to 3 mm. long in 
the region of the ligule and 
0) 3. C. longipila. 
Panicle loosely spike-like; blades cor- 
date at base, appressed, the 
ligule short..............2.22.. 4. C. liebmanni. 
Plants perennial. 
Inflorescence a close cylindrical spike-like 
panicle, 
Blades flat, averaging 1 cm. in width. .... 11. C. imberbis. 
Blades mostly involute, narrow........... 10. C. gracilis. 
Inflorescence loose, tapering at apex. 
Sheaths smooth around the collar; panicle 
compact, usually less than 10 cm. 
long; blades usually narrow and 
folded. ..... 2.2.22... eee eee. 9. C. composita. 
Sheaths hispid or villous around the collar; 
panicle loose and interrupted, usu- 
ally more than 15 cm. long. 
Spikelets ovate-globose; blades usually 
broad and flat..........2...... 7. C. macrostachya. 
Spikelets elliptic..................... 8. C. setosa. 
1. Chaetochloa sulcata (Aubl.). 
Panicum sulcatum Aubl. Pl. Guian. 1:50. 1775. 
Type locality, British Guiana, the species growing *‘au bord des rivieres.’ 
Rance: Mexico to South America, 
HERBARIUM SPECIMENS FROM MEXICO: 
San Luis Porosi: Las Canéas, by streams, Pringle 3921. 
VERACRUZ: Jalapa, along railway in low woods, Hitchcock 6685. Mirador, Lieb- 
mann 459, 
Cutapas: Turubula, Nelson 3359. 
