GKAMINE.E. (grass FAMILY.) 579 



elliptical, Y' lo"S ! glumes 3-nerved, minutely pubescent aud granular. 

 (P. Blodgectii, Floni.) — Soutii Florida. 



14. P. Drummondi, Vasey. Culms 2° -4° high, branching below; 

 leaves broadly linear, G''-10' long; spikes 3-4, 3'-4' long; spikelets in 2-3 

 rows, oval,!" long, pubescent aud grauular. — South Florida (Fasey), and 

 westward . 



15. P. virgatum, L. Culms 3° -5'^ high; leaves long, 3" -4" wide; 

 spikes numerous (20 or more), 2' -3' long, the lower mostly germinate; ra- 

 chis sleuder; spikelets 1" long, in 4 rows, ovate; glumes acute, hairy along 

 the margin. — Mississippi, and westward. 



= = Spikelets exceeding a line in lencjth. 



16. P. prsecox, Walt. Very smooth and somewhat glaucous, or the 

 lower leaves aud slieaths hairy; culms simple, slender, 2° -4° high; leaves 

 long aud narrow ; sjjikes 3-6, 1'- 3' long, bearded at the base; spikelets in 

 2-3 rows, orbicular, flat ; glumes 3-nerved. — Low pine barrens. May -Oct. 



17. P. laeve, Michx. Mostly glabrous; culms simple, 2° -3^ high; 

 leaves flat, 2" -3" wide, of varying length; spikes 2-5, slender, 2' -4' long, 

 bearded iu the axils ; spikelets in 2 row.*, orbicular, 1 J" long ; glumes 5-nerved. 

 — ]Moist grouud, commou. 



18. P. dififorme, Leconte. Culms 2° -3° high, from creeping root- 

 stocks; leaves broadly linear; spikes 2-4, 2' -3' long; spikelets in 2-3 rows, 

 obloug-oval, 1 Y' loug; glabrous. — Low ground near the coast. North Carolina, 

 and westward. 



19. P. Floridanum, Michx. Culm stout, erect, 2° -4° high; leaves 

 rigid, broadly linear, l°-2° long, smooth and glaucous, or the lowest densely 

 villous; s])ikes 3-5, 2' -4' long; spikelets in 2-3 rows, oval or roundish, 

 about 2" long ; glumes glabrous. — Damp or dry soil in the lower districts. 



20. P. dilatatum, Poir. Culms stout (3° -4° high) ; leaves flat, linear- 

 lanceolate, smooth; spikes 4-6, racemose; spikelets iu 4 rows, ovate, acute, 

 villous on the margins, much wider than the flat rachis ; glumes 5-uerved, 

 longer than the roundish floret. — Alabama, New Orleans, and westward. 

 Introduced. 



21. P. pubiflorum, Rupr., var. glabrum, Vasey. Culms stout, erect 

 from a creeping base, 2° -3° high ; leaves spreading, 6' -9' long, 4" -6" wide, 

 flat ; spikes 3 - 6, thick, spreading, 2' - 3' long ; rachis broad and flat ; spike- 

 lets in 3-4 rows, barely more than \" long, oblong, obtuse, smooth or pubes- 

 cent. — Tennessee, and westward. 



22. P. giganteum, Baldw. Culms very stout, 4° -6° high ; leaves 1°- 

 2° long, 1' wide, papillose-ciliate on the margins; spikes 3-4, 5' -8' long, dis- 

 tant, spreading ; spikelets iu 2 - 3 rows, about 2" long, OA-al, acute. — East 

 Florida. Rare. 



•!-•(-■*- Rachis of ihe spikes broad, membranous, concave, covering the ininute 

 spikelets: ndiiis branching, creeping, or floating : spikelets in 2 rows. 



23. P. fluitans, Kuuth. Culms mostly floating; leaves lanceolate, 4' -6' 

 long ; spikes numerous : spikelets pubescent, concealed under the rachis. — 

 Along rivers in still water. 



