430 



GRAMINEjE. 



Pennisetum. 



12. PENNISETUM. L. C. Rich, in Pers. syn. 1. p. 72 ; R. Br. prodr. p. 195. 



BOTTLE-GRASS. 



Setaria, Beauv. 



[ From pe?ma, a pen, and seta, a bristle ; in allusion to the involucre.] 



Spikelets 2-flowcred, with an involucre of several distinct bristles. Glumes two, unequal, 

 membranaceous. Lower flower staminate or neuter : paleae 1-2, the outer one resembling 

 in texture the glumes : upper flower perfect, coriaceous. — Inflorescence a dense simple or 

 compound spike-like panicle. 



1. Pennisetum glaucum, R. Br. Bottle-grass. Foxtail-grass. 



Spike cylindrical, simple (tawny); involucre of 6 - 10 fasciculate bristles which are much 

 longer than the spikelets ; glumes smooth ; perfect flower transversely rugulose. — R. Br. 

 prodr. p. 195 ; Nutt. gen. 1. p. 55. Panicum glaucum, Linn. sp. 1. p. 56 ; Michx. Jl. 1. 

 p. 46 ; MuU. gram. p. 100 ; Ell. sk. 1. p. 112 ; Bigel. Jl. Bost. p. 46 ; Trin. diss. 2. 

 p. 162, and ic. 17. t. 195. Setaria glauca, Beauv. Agrost. p. 51 ; Rosm. Schult. syst. 2. 

 p. 490 ; Torr. jl. 1. p. 152 ; Beck, hot. p. 397 ; KuntJi, enum. 1. p. 149 ; Darlingt.fi. Cest. 

 p. 51. 



Annual. Culm 1-3 feet high. Leaves 3-4 lines wide, hairy at the base : sheaths 

 smooth : ligule bearded. Spike 2-3 inches long ; the rachis angular and hairy. Bristles 

 of the involucre 2-3 times as long as the spikelets, rough upwards, tawny or dull orange- 

 yellow when old. Paleas of the staminate or neuter flower nearly equal. 



Fields and cultivated grounds : common. Fl. July - August. Probably a naturalized 

 exotic. 



2. Pennisetum viride, R. Br. Green Foxtail. Bottle-grass. 



Spike cylindrical (green); involucre of 4 - 10 fasciculate bristles, much longer than the 

 spikelets ; perfect flower longitudinally striate, dotted ; margin of the sheaths hairy. — R. Br. 

 prodr. p. 195 ; Nutt. gen. 1. p. 55. Panicum viride, Linn. sp. (ed. 2.) 1. p. 83 ; Pursh, 

 fi. 1. p. 66 ; Muhl. gram. p. 102 ; Trin. diss. 2. p. 163, and ic. 17. t. 203. Setaria viridis, 

 Beauv. Agrost. p. 51 ; Rosm. Schult. syst. 2. p. 490 ; Torr. Jl. I. p. 152 ; Beck, hot. 

 p. 397; Kunth, enum. 1. p. 151 ; Darlingt. fl. Cest. p. 50. 



Annual. Culm 2-3 feet high, erect, mostly simple. Leaves smoothish, 3-4 lines wide : 

 ligule bearded. Spike 2-3 inches long ; the rachis hairy. Bristles of the involucre upwardly 

 rough. Lower glume broadly ovate, 3-nerved ; upper glume 5-nerved. Lower flower neuter ; 

 the upper palea small. Palese of the perfect flower smooth, only obscurely rugose transverse- 

 ly ; the longitudinal lines and dots very distinct. 



Cultivated grounds : frequent. Fl. July - August. This species also is probably of foreign 

 origin. 



