782 Oedeb 156.— GRAMINE^. 



3 P. oetSceum Mx. Culm asoending from a decumbent base, very slender, 1 W 

 2f, with very remote joints; Ivs. lance-linear, 3 — 7' by 2 — 3 ', ciliate and soft 



. hairy ; slieatlis pubescent, upper one very long ; spike generally solitary, often 3, 

 on a long, very slender peduncle, sometimes witli auotlier scarcely esserted from 

 the sheaths ; spikelets plano-convex, with the flat side out, ^" diam., 1 or 2 on 

 each very short pedicel, appearing 2 — 3-rowed in the 1-sided spike. — Dry fields, 

 Mass., to 111. and S. States. Aug. (P. debile and ciliatifolium Mx.) 

 /3. LONGiPEDUNOULATUM. Larger, less hairy, and spikelets evidently 3-rowed. 

 — S. States. (P. longip. LeC.) 



4 P. laBve Mx. Culm erect, rather firm, 18' — Zf, glabrous ; Ivs. generally smooth, 

 pilous only at the base, broadly linear; lower sheaths sometimes hairy, spikes 

 2 — 6, alternate, spreading, with a few long, white hairs at the base ; spikelets in 2 

 rows; rachis flexuous, flat on the back; pedicels undivided, with one spikelet; 

 spikelets twice as large (1|'' diam.) as in the preceding ; glume orbicular-ovate, 

 3-veiued. — Grassy banks of rivers, ConiL to Ind. and S. States. Aug. Quite vari- 

 able, including several reputed species.' 



/8. UNDULoSijM. Lvs. rather long and broad, with wavy-margins. (P. Leoon- 



tianum Schult.) 

 y. Ploridaxuh. Spikelets enlarged (near 2" long), glumo 5-veined. (P. ma- 



crospermum Flgg.) 

 £. ALTISSIMUM. Strict and tail ; sheaths much compressed. (P. altissimum LeC.) 



5 P. angustifolium Le Conte. Culm erect, wiry, glabrous, 2f high ; lvs. glab- 

 rous, narrowly linear, almost setaceous, compressed carinate, 9 to 18' long; sheaths 

 long, smooth; spikes 2 or 3, alternate, divaricate, 1 to 2' long, with a few hairs at 

 base ; spikelets orbicular, 1" diam. in 2 rows, with a very narrow rachis. — H Wet 

 places, Ga., Ha. to La. A distinct species. Seeds blackish. 



6 P. dasyphyllum Ell. Culm decumbent at base, 12 to 30' high, glabrous 

 lvs. broadly linear, clothed with copious soft hairs as well as the long sheaths 

 spikes 2 to 4, large, spreading, the ped. slightly exserted from the upper sheath 

 spikelets oval, obtuse, large, in 3 rows ; teeth of the rachis 2-flowered. — Dry fields, 

 S. States, common. J)? JL — Oct. 



7 P. latifolium Le Conto. Glabrous; culm erect, stout, tall (3 to 3f), from a 

 slightly decumbent base; lvs. flat, large, lance-linear, G to 12' hy 5 to 10", margins 

 ciliate ; sheaths hairy at throat, shorter than the long internode.s ; spikes 2 to 4, 



2 to 4' long, alternate, suberect, pilous at base; spikelets largo {l\" diam.), in 



3 rows on the narrow, flexuous rachis. — If Car. to Pla, and La. , 



8 P. tenue Kunth. Glabrous; culm erect, very slender; lvs. narrow, very long, 

 ciliate on the margins, sheath ciliate; spikes 4 or 5, very slender, alternate, 

 spreading, hairy at base ; spikelets orbicular, in 3 rows ; rachis flexuous, narrow, 

 the teeth 2-flowered. — If N. J. to Ga. (Le Conte). Differs from No. 5, in its ciliate 

 lvs. and 3-nerved spikelets. 



9 P. arundiuaoeum Poir. "Glabrous; lvs. somewhat sword-shaped (arm- 

 pressed-carinate), the margin scabrous ; spikes alternate, elongated ; spikelets in 

 3 rows ; gls. (gl. and pale) equal, obtuso. — Carolina." Poiret. 



10 P. precox Walt. Glabrous throughout; culm erect; lvs. lance-linear, \eTj 

 long ; spikes 3 to 5, alternate, dense-flowered, with a tuft of long hair at base ; 

 rachis linear, straight (not flexuous), narrower than the 3 rows of very smooth, 

 orbicular, compressed spikelets; gls. 3-veined. — y Wet places. Car. to Fla. May. 

 — Aug. (P. lentiferum Lam.) 



11 P. fliiitana Kunth. Culm decumbent and ascending 10 to 20', generally 

 floating; lvs. scabrous, lance-linear, 2 to S' by 4 to (J"; sheaths inflated, open, 

 ciliate at base; spikes 20 to 50, 1 to 2 J' long, the lower somewhat verticiflate; 

 rachis foliaceous, nearly 1" broad, covering the 2 rows of ovate, acute spikelets 

 and projecting in a point beyond ihem. — (1.) Elver swamps, S. Ill to Va. and S. 

 States. Oct. (P. mucronatum Muhl Ceresia, EU.) 



12 P. 'Waltei'ianuin Schult. Culm decumbent, branching, ascending; lvs. 

 glabrous, lance-linear, 2 to 4' by 3 to 5" ; sheaths open, all glabrolis; spikes 2 or 

 3 on each branch', 1 to 2' long; rachis very broad (near 2"), covering tlie 2 rows 

 of oval, acute spikes but not projecting beyond thein. — (J) Wet soUs, Car. to Fla. 

 and La. Jl. — Sept. (P. vaginatum Ell.) 



