31 



glume equaling the spikelet, seven-nerved ; fertile flower as long as the 

 spikelet. 



(d) Variety villosum (P. villosiim Mill— Culms decumbent, branching 

 from the first, leaves scabrous above, ciliate, sheaths and culms villose, 

 panicle thinner and fewer-flowered. 



(e) Var. elatum.— Culms tall (2 to 3 feet), erect, smooth; cauline 

 leaves 4 to 5 inches long, 5 to G lines wide, smooth, very acute ; pan- 

 icle 4 inches long, smooth, the branches long, erect-spreading, rather 

 sparsely flowered; spikelets a little more than 1 line long, smooth, 

 oblong, acutish, the lower glume ovate, acute or acutish, nearly half as 

 long as the spikelet, fertile flower shorter than the spikelet. 



36. P. neurauthum Oris. — Erect or ascending, about 1 foot high, 

 slender, smooth; leaves linear-acuminate, 2 to 4 inches long, firm, flat 

 or subinvolute; terminal panicle long exserted, 1 to 2 inches long, 

 with few-flowered, divergent branches, the lateral panicles numerous, 

 narrow, short (less than 1 inch long), oval, pubescent, lower glume mi- 

 nute, deltoid, nearly nerveless, one-third to one-fourth as loug as the 

 spikelet, second and third seven-nerved, equaling the fertile flower, 

 which is ovoid, obtuse, and smooth. 



(a) Variety ramosum Gris. — Ascending, much branched, leaves fiat or 

 involute, very narrow; spikelets 1 line long, elliptical, obtuse. 

 South Carolina, Florida to Texas. 



37. P. Joorii, Vasey. — Culms about 1 foot high, much branched above, 

 very leafy; leaves 4 to 6 inches long, 6 to 10 lines wide, thinnish, 

 smooth, those of the extreme branches smaller; panicles numerous, 

 small, inclosed in the sheaths, few-flowered; spikelets oblong, over 1 

 line long, sparsely pubescent. 



Louisana (Dr. J. F. Joor); Mississippi (Professor Tracy). 

 This is very unusual in its abundant, large leaves, and condensed 

 form, growing in dense tufts. 



38. P. nudicaule, Vasey.— Culms 1J to 2 feet high, slender, with 2 or 3 

 long internodes; leaves mostly near the base, linear lanceolate 2 to 4 

 inches long, 2 to 3 lines wide, smooth, light green, the 2 to 3 culm-leaves 

 distant, narrow, giving the culm a naked appearance ; panicle long ex- 

 serted, small, smooth, 2 to 3 inches long, 1 inch wide, sparsely flowered, 

 branches alternate; spikelets elliptical-oblong, acute, 1J lines long, 

 smooth, the lower glume very small (one-fifth as long as the spikelet), 

 second glume seven nerved, third, five nerved, fertile flower one-fourth 

 shorter than the spikelet. 



Swamps, Santa Kosa County, Fla. (A. H. Curtis). 



39. P. consanguineum, Kth. (P. villosum Ml.). — Culms about 1J feet 

 high, erect, branching in age ; leaves linear-lanceolate, mostly about 3 

 inches long, 2 to 5 lines wide, the later ones almost filiform, somewhat 

 pubescent, sheaths villose ; panicle 2 to 3 inches long, open, rather thin ; 

 spikelets 1 to 1J lines long, pubescent. 



South Carolina to Florida. 



