GRAMINE.E. (GRASS FAMILY.) .",71 



3-nerved, more or less pubescent; calms diffuse, creeping ; leaves flat, glaucous, 

 rough above, and, like the sheaths, smooth or hairy. (P. tristachyum, Lecontt i) 

 — Swamps and low grounds, Florida to North Carolina, and westward. Aug. 

 and Sept. y — Flowering stems 1° high. 



6. P. pr£BCOX, Walt. Spikes 3-6; spikelets by pairs, in 3 rows, orbicu- 

 lar, compressed, as wide as the straight and flat rachis; glumes smooth, 3-nerved, 

 often discolored; culms erect (3° -4° high), simple; leaves long and narrow; 

 sheaths purple, smooth or hair}-. — Pine-barren swamps, May and June. y . 



*" 7. P. laeve, Michx. Spikes 3-5, long (3' -4') and slender; spikelets 

 single, in 2 rows, orbicular, wider than the flexuous rachis ; glumes smooth and 

 even, 5-ncrvcd ; culms simple, erect (3° -4° high); leaves (deep green) and 

 sheaths smooth, or the latter hairy. — Dry woods and margins of fields, Florida, 

 and northward. July and Aug. y — Spikelets 1^" long, larger and thicker 

 than the last. 



8. P. Floridanum, Michx. Spikes 2-3, thick, erect; spikelets large (2" 

 long), mostly in 3 rows, broadly oval, tumid, wider than the flexuous rachis : 

 glumes smooth, 5-nerved, more or less rugose; culms rigid, erect (2° high); 

 leaves narrow, rigid, and, like the sheaths, rough-hairy. (P. macrospermum, 

 Fluegge.) — Damp soil, near the coast, Florida. Aug. and Sept. y — Plant 

 glaucous. 



A 9. P. racemulosum, Nutt. Spikes 2-3, slender, erect (4' long); spike- 

 lets single or by pairs, obovate, distant on the filiform and somewhat flexuous 

 rachis, distinctly pedicelled ; glumes smooth, obtuse, 7-nerved ; culms simple, 

 erect (2° -3° high) ; leaves long, linear, keeled, glaucous, and, like the sheaths, 

 sprinkled with long white hairs. (Panicum Alabamense, Trin.) — Dry sandy 

 soil, Florida to North Carolina, and westward. Aug. and Sept. y . 



10. P. undlllatum, Poir. Spikes 2-12, spreading (2' -3' long); spike- 

 lets small (1" long), oval or roundish, crowded in 3-4 rows under the broad 

 and flat rachis ; glumes smooth, 5-nerved ; palea? of the neutral flower often ru- 

 gose ; culms erect or ascending, mostly branching ; leaves deep green, broadly 

 linear, flat, mostly fringed on the margins or near the base, and, like the smooth 

 or hairy sheaths, often purple. (P. purpuraseens, Ell. P. plicatulum, Michx. 

 P. confertum, Leconte. P. Boscianum, Fluegge. ) — Low cultivated grounds, Flor- 

 ida to North Carolina. Sept. ® — Culms J° -3° high. 



11. P. Blodgettii, n. sp. Spikes 4, filiform ; spikelets minute (£" long), 

 in 3 rows, elliptical, as wide as the straight rachis ; glumes 3-nerved, minutely 

 pubescent and granular; culms tufted, simple, erect (1°-1J° high) ; leaves flat, 

 fringed on the margins. — Key West, Dr. Blodgett. y — Spikes 1' long. 



12. P. ciliatifolium, Michx. Spikes slender, mostly solitary, rarely 2- 

 3, on long lateral and terminal peduncles, of which 2-3 often project from the 

 upper sheath ; spikelets orbicular, in 2 - 3 rows, wider than the narrow flexuous 

 rachis; glume 3-nerved, commonly pubescent ; culms tufted (l°-2° long), erect 

 or spreading, simple or branched ; leaves 2"- 9" wide, flat, wavy and fringed on 

 the margins, or, like the sheaths, hairy all over. (P. setaceum, and P. debile, 

 Michx. P. dasyphyllum, Eli, $*c.) — Wet or dry soil, very common. June- 

 Sept. (D and y. 



