OBDEB 156.~GRAMINB^E. 787 



1J" Jong, green; lower glume ovate, not half as long as the upper; abortive 

 pales subequal, usually with 3 stamens. In moist, shady places, U. S. and Can. 

 Jn., Jl. (P. scoparium and nervosum Lam. P. ciliatum Ell., etc.) 



20 P. xanthoph^sum Gray. Culm generally simple, glabrous, 9 to 15' high ; 

 Ivs. lanceolate, 3 to 6' by 5 to 7", not dilated at the eiliate, clasping base, smootli, 

 9 to 11-veined; pan. long-exserted, simple, raceme-like, few-flowered; spkl. round- 

 ish-obovate !" long; lower glume ovate, 3-veined, acutish, as long as the up- 

 per many- veined one ; abortive pales oftener with 3 stamens. Dry soils, X. Eng. 

 to "Wis. (Lapham). Rare. Jn. 



21 P. viscidum Ell. Hoary, with a dense, short, soft, viscid pubescence; culm 

 decumbent, assurgent 2 to 4f, stout ; joints a smooth brown ring ; Ivs. lance- 

 linear, 3 to 6' by 6 to 16'' ; sheaths much shorter than the internodes; pan. rather 

 large (4 to 6' long); loose; spkL light green. 1" long, oval, acutish, lower glume 

 very small, upper pale very small, truncate. If Damp places, X. J. to Ga. (Feay). 



22 P. clandestinum L. Culm with short, axillary, appressed branches, 2 to 3f 

 high, rigid, leafy ; Ivs. 3 to 6' by 1', lanceolate, subcordate at base ; sheaths his- 

 pid with papillae in the grooves bearing bristly hairs, and enclosing the short 

 lateral panicles ; spkl. elliptical, acutish, !-" long, striate, often purple ; upper 

 pale of the neutral fl. obtuse. 2 Moist woods, Mass, and Mid. States. JL, Aug. 



23 P. microcarpon MuhL, Darl. Culm 18 to 30' high, erect, simple, glabrous; 

 joints glabrous ; Ivs. lanceolate, veined, eiliate at base, undulate and scabrous on 

 the margin, scabrous above, smooth beneath, 6 to 10" wide; sheaths deeply 

 striate, smooth ; stip. ; pan. much branched, nearly smooth ; spkl. small, (4-" 



' long), roundish-obovate, purple, numerous, scarcely pubescent ; upper sterile pale 

 minute; fr. shining, bluish white. 1. 



24 P. Walter! Ell. Culm slender, glabrous, erect, 2f ; Ivs. linear 3 to 6' by 2 to 

 3", glabrous as well as the open sheaths ; spikes thick, dense, 1-sided, alternate 

 (the 2 lower sometimes opposite), 6 to 12" long; spkl. imbricated in 3 rows, 

 broad-ovate ; glumes minutely hispid, the lower half as large, upper 3-veined ; 

 abortive pales unequal, staminate ; fertile fl. roundish. Damp grounds, Can. to 

 Fla. and La. Jn. Aug. (Nearly allied to Oplismenus.) 



25 P. ATireliarmm Hale (MS.). Culm decumbent, geniculate, slender, branched, 

 glabrous; Ivs. lanceolate, glabrous, 1 to 2' by 3 to 4". sheaths ciliate ; spikes 

 slender, 6 to 12" long, alternate, 1-sided; spkl. ovate, acute; lower glume as 

 long as the upper, smooth and 5-veined one ; abortive pales equal, staminate : 

 fertile fl. ovate. Damp soils, about N. Orleans (Hale). 



26 P. miliaceum L. MILLET. Lvs. lance-linear and sheaths hairy ; culm 

 2 to 3f high ; pan. large, open, nodding ; spkl. solitary, ovate ; gls. acuminate- 

 mucronate, eubequal ; pales obtuse. Cultivated, f Turkey. 



27 P. Jumentonim Pers. Another cultivated species, from N. I Africa. 

 Much valued South. It is tall, stout, smooth. The spikelets aro singularly 

 arranged in 2s or 3s, one or two sterile to each fertile. Seeds black. 



19. OPLIS'MENUS Beauv. COCK-SPUR GRASS. (Gr. o^Xioiia, ar- 

 mament, i^evog^ courage ; alluding to the stout awns.) Spikelets, <fcc. 

 as in Panicum, except that the lower abortive pale (and often the 

 glumes) is prolonged more or less into an awn. Coarse grasses with 

 the fls. in dense paniculate racemes. 



1 O. Crus-galli Kunth. BARX-YARD GRASS. Terete, smooth, 3 if high; lc*. 

 linear-lanceolate, flat, serrulate, with smooth, slriate sheaths and no stipule ; pan. 

 simple or apparently so, branches spike-form, compound, alternate and in pairs; 

 rachis hairy and rough ; glumes scarcely awned, hispid-bristly ; lower abortive 

 palea ending in a rough awn, 6" to 18'' long; fertile fl. ovate. CD A coarse, weedy 



trass, introduced into cultivated grounds, barn-yards, &c., common. Aug., Sept. 

 Variable. (Panicum, L.) 



/?. MUTICUS. Awns very short, or the pale merely subulate-pointed. Common. 

 7. HISPIDUS. Sheaths very bristly ; awns very long. 



2 O. hirtellus R. & S. Culm glabrous, decumbent, branched; Ivs. lanceolate. 

 flat, 1 to 2' by 2 to 4", with scattered, appressed hairs on the upper surface; 



