Ordes 1&6.— GaAKINEiQ. 785 



trpikehts dblong-lamceolate, aeuto, glabrous ; glumes veiny, very unequal, the lower 

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



i P. proHferum Lam. Culm assurgent, geniculate at base, very smooth, thick 

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

 sheaths, hairy at throat; paiL large, pyramidal, \ terminal and axillary, smooth; 

 apikelets oblong, acute, veiny, 1" long, densely raeemed ; lower glume \ as long 

 as the upper ; abortive fl., with 1 pale. — Q) Marshes, especially brackish and 

 sandy, Mass. to La., also along the Western rivers. Aug., Sept. (P. genioulatum 

 Muhl.) 



4 P. gibbum En. Culm terete, assurgent, 2 to 3f, with black joints ; Ivs. lanoa- 

 Hnear, 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 glume very small, upper very large, 11-veined, remarkably 

 gibbous at base, upper pale nearly as long as the lower.— -(1) Wet soils, S. States. 

 Jl.— Sept. (P. EUiottianum Sohl.) 



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

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

 sheaths hairy only at the throat; panicle pyramidal, spikelets raeemed, -J" long; 

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

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

 Oct. (P. debile Poir. P. divarioatum Mx.) 



6 P. agrostoides Muhl. Culm compressed, glabrous, 1^ — 3f high, often genicu- 

 late at base; Ivs. long and numerous, cauline linear-lanceolate, carinalo, rough- 

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

 posed of raeemed, spreading or defiexed branches : spikelets 1" long, purple, lanoe- 

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

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

 rubens Kutt.) 



7 P. ^nceps Mx. Culm compressed, 2 to 3f; Ivs. linear, carinate, very long, 

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

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

 1-J-" long, lanceolate, very acuminme, and when mature, forked ; lower glume and 

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

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



8 P. Tilfiforme. Glabrous throughout; culm decumbent, ascending 2 to 3[, 

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

 throat ; pan. simple, with raeemed, spreading brandies ; spikelets 2" long, lan- 

 ceolate, acute ; lower glume ^ to ^ as long as the upper, l-veified glume which is 

 shorter than the lower pale (while in Nos. 6 and 1 it is longer than the lower 

 pale !). — Wet meadows, B. Tenn. ! Jl., Aug. 



9 P. amarum Ell. Glabrous, leafy; culm 2 to 3f high, stout; Ivs. 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 

 sterile pales, which contain 3 orange-colored stamens. — 71 Sandy shores, Conn, 

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



10 P. virg^tum L. Glabrous and often purple ; culm 3 — 5fhigh; Zra. flat, long, 

 linear-lanceolate, hairy at base; sheaths striate; slip, with long, white cilias; 

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

 2 J" long, very pointed, divaricate, the lower f as long as tho upper; pales of the 

 abortive flower nearly equal, enfolding the purple stamens. — If Salt-lick prairies,: 

 fields, &c., N. Y. to Ind., S. to tho Gulf Aug. 



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

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

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

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

 d) ? 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. frdgile Eunlh. Culm geniculate at base, assurgent, branched, very brittle, 



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