140 TRIANDRIA. DIGYNIA. atheroposon. 



oblong, sessile, arranged on 2 opposite sides of the common 

 racMsy but secund, reflected downwards, each containing 6 — 8 

 spikelets. Partial rachis compressed, terminating in a sharp 

 naked point. Inferior glume of the calyx adhering to the 

 rachis, very narrow, and resembling a bristle ; superior valve 

 oblong-lanceolate, acuminate and mucronate, with a hispid 

 keel. Perfect floret lanceolate, somewhat scabrous ; the in- 

 ferior valve terminating in 3 equal points, one of which pro- 

 ceeds from the midrib, the other 2 from the margins ; superior 

 valve as long as the inferior, bicuspidate at the tip. Stamens 3 ; 

 anthers bright-red. Seed oblong, not sulcate. Inferior valve 

 of the abortive floret ovate, a little bifid at the tip, with a 

 straight bristle as long as the valve between the teeth ; lateral 

 bristles proceeding from the margin of the valve about half 

 way down ; superior valve minute, ovate, obtuse, 2-cleft. 

 Sometimes there are two perfect florets, besides the abortive 

 one, in each spikelet. 

 Hab. On rocky hills near Poughkeepsie, New-York. August. 

 Dudgeon. In the western parts of Pennsylvania. It is also 

 found in Ohio, Illinois, and up the Missouri as far as its sources. 

 J\ru tt all. I have specimens collected by Dr. James during 

 Maj. Lon g's Expedition, as far west as the base of the 

 Rocky Mountains. 



This species is nearly allied to A. racemosus R. isf S., 

 (BouTELOUA racemoaa Lag as c.) a native of Peru. Four 

 other South- American species are described by Humb. & 

 B nju under the generic name of Dinebra. 



48. PANICUM. L. 



Calyx 2-valved, 2-fiowered ; the inferior glume often 

 very small. Florets dissimilar ; the lower one abortive, 

 or antheriferous, 1 — 2-valved; the inferior valve re- 

 sembling in texture the glumes ; the superior mem- 

 branaceous. Perfect Jioret with cartilaginous valves, 

 unarmed. Ge?i. pi. 108. Nut t. Gen! I. ^. 52. JR. 

 Brown Prod. I. p. 189. Poem, b' Schult. Gen. 

 260. P. de Beauv. t. X. f. 1—5. Trin. Agrost. 

 147. EcHiNocHLOA P. de B. Flowers generally in 

 a compound racemose panicle. Glumes of the calyx 

 sometimes nearly equal. Panic-grass, 



1. P. Cms gain L.: racemes alternate and in pairs, 

 compound ; rachis 5-angled ; glumes terminating in hispid 

 bristles ; sheaths glabrous. Willd, Spec. L p. 337. Smith 

 Fl. Brit. 1. p. 65. E/ifif. Bot. t. 876. Mich, Ft. I. p. 46. 

 Big. Bost. p. 19. Pursh Fl. I. p. 66. Muhl Gram, 

 p. 105. E 1 1 i 1 1 Sk. I. p. 114. EcHiNOCHLOA Cru5 £^a//i 

 P. de Beauv, Roem. ^ Schult, II. p. 478. 



