Obdeb 156.— GRAMMES. 785 



ipikdets oblong-lanceolate, acute, glabrous; glumes veiny, very unequal, tho lower 

 aiinute. — Sand hills, Mason Co., 111. (Mead, in Gray's Manual). 

 J» P. proliferum Lam. Culm assurgent, geniculate at base, very smooth, thick 

 and succulent; lvs. linear-lanceolate, 4 to 6' wide, 10 to 15' long, on tumid 

 sheaths, hairy at throat; pan. large, pyramidal, terminal and axillary, smooth; 

 spikelets oblong, acute, veiny, 1" long, densely racemed ; lower glume \ as long 

 as the upper ; abortive fL, with 1 pale. — CD Marshes, especially brackish and 

 sand v. Mass. to La., also along the Western rivers. Aug., Sept. (P. geniculatum 

 Muhlj 



4 P. gibbum Ell. Culm terete, assurgent, 2 to 3f, with black joints ; lvs. lance- 

 linear, glabrous, 4 to 8' by 4 to 8', on smooth, strongly striate sheaths; pan. 

 densely contracted, often purple, fusiform, about 6' long, strict ; spikelets near 2" 

 long, obtusish, lower glumo very small, upper very large, 11-veined, remarkably 

 gibbous at base, upper pale nearly as long as the lower. — CD Wet soils, S. States. 

 Jl.— Sept. (P. Elliottianum Schl.) 



5 P. hians Ell. Culm very slender, almost filiform, decumbent and rooting at 

 the lower joints, about 2f high ; lvs. narrowly linear, 8 to 16' long, glabrous; 

 sheaths hairy only at tho throat; panicle pyramidal, spikelets racemed, -\" long; 

 lower glume half as long as the upper, neutral pales equal, conspicuous {gaping), 

 a little longer than the fertile. — Damp pine barrens, S. States, common. Aug. — 

 Oct. (P. debiie Poir. P. divaricatum Mx.) 



6 P. agrostoides Muhl. Culm compressed, glabrous, li — 3f high, often genicu- 

 late at base ; lvs. long and numerous, caulino linear-lanceolate, carinate, rough- 

 edged, on short, striate sheaths; panicles terminal and lateral, pyramidal, com- 

 posed of racemed, spreading or deflexed branches; spikelets 1" long, purple, lance- 

 ovate, acute, crowded ; upper glume 3-veined, ^ longer than the lower ; upper neu- 

 tral, pale, nearly as long as the lower. — If Meadows, frequent. July. (P. fusco- 

 rubens Nutt.) 



7 P. anceps Mx. Culm compressed, 2 to 3f; lvs. linear, carinate, very long, 

 rough-edged ; sheaths ancipital, pilous on the throat and margin ; pan. erect, 

 pyramidal, with subremote, subsimple, interruptedly racemous branches ; spikelets 

 l-£-" long, lanceolate, very acuminate, and vjhen mature, forked; lower glume and 

 upper pale half as long as the lower pale, scarcely shorter than the fertile fiower ; up- 

 per glume 1 -veined. — Wet soils, N. J. and S. States. Aug. — Nov. 



8 P. vilfiforme. Glabrous throughout; culm decumbent, ascending 2 to 3f, 

 branched ; lvs. long, linear, scarcely rough-edged ; sheaths with a tuft of hairs at 

 throat ; pan. simple, with racemed, spreading branches ; spikelets 2" long, lan- 

 ceolate, acute ; lower glume \ to ^ as long as the upper, "i-veined glume which is 

 shorter than the lower pale (while in Nos. 6 and 7 it is longer than tho lower 

 pale !). — Wet meadows, E. Tenn. I Jl., Aug. 



9 P. amarum Ell. Glabrous, leafy ; culm 2 to 3f high, stout ; lvs. glaucous, cor- 

 iaceous, rigid, linear, 10 to 18' long, margins involute, not scabrous; sheath some 

 shorter than the joints ; pan. large, contracted, its very smooth branches appressed; 

 spikelets thick, 2" long, ovate, acuminate, lower glume nearly as long as the 

 sterilo pales, which contain 3 orange-colored stamens. — 2£ Sandy shores, Conn, 

 to Fla. and La. (Hale). Lvs. excessively bitter (Elliott). Aug. — Oct. 



10 P. virgatum. L. Glabrous and often purple ; culm 3 — ufhigh: lvs. flat, long, 

 linear-lanceolate, hairy at base ; sheaths striate ; stip. with long, white cilia? ; 

 pan. pyramidal, loose, spreading, diffuse, very large; Us. acuminate, the glumes 

 2 V long, very pointed, divaricate, the lower § as long as the upper; pales of tho 

 abortive flower nearly equal enfolding the purple stamens.— Z[ Salt-lick prairies, 

 fields,' &o, N. Y. to lud., S. to the Gulf. Aug. 



11 P. verruccsum Muhl. Culm slender, decumbent and geniculate, branching 

 from tho base, 1 — 2f high; lvs. lance-linear, flat, 4 to 6' by 2 to 4", spreading, 

 smooth ; pan. much expanded, few-flowered ; spikelets % to \" long, covered with 

 warty points (verrucous) obovate, bluish ; abortive liower of one palea, and neuter. — 

 CD? Swamps and thickets, Mid. and S. States. Panicles terminal and lateral, loose 

 and capillary. Aug. (P. debilis Ell. nee Poir. P. ramulosum Mx.) 



12 P. fragile Kunth. Culm geniculate at base, assurgent, branched, very brittle^ 



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