27 



Variety fasciculatum (P. fasciculatum, Swz.); leaves longer and wider 

 (8 to 10 lines wide), panicle 4 to 5 inches long, the branches very numer- 

 ous, spikelets becoming dark brown. 



Southern Florida. 



21. P. grossarium, Linn. 



Specimens from ballast ground at Philadelphia have been referred to 

 this species, but if correct it seems too near P. fuscum. 



Section VI.— Polystachya. 



[Small forms of P. anceps might come in this group.] 



22. P. barbiuode Trin. (Para-grass).— Culms 2 to G feet high, stout, 

 ascending; nodes villous; leaves linear-acuminate, glabrescent; panicle 

 lax, 6 to 8 inches long, branches mostly simple or a few, fascicled, 

 spreading, about 2 inches long, somewhat distant, spikelets 1 to 1£ 

 lines long, glabrous, one-sided, spreading, lowest glume deltoid, one- 

 fourth as long as the spikelet, one nerved, second and third equaling the 

 spikelet, five-nerved ; fertile flower ellipsoidal, bluntish. Introduced 

 and cultivated in the South. 



23. P. gymuocarpon, Ell. — Perennial. Culms 2 to 4 feet high, erect, 

 rigid, smooth ; leaves lanceolate, smooth, 1 foot long or more, 1 inch or 

 more wide, cordate at base, sheaths shorter than the internodes, striate, 

 nodes black ; panicle large, 9 to 15 inches long, branches 4 to G inches 

 long, erect-spreading, scattered or 2 to 3 together, racemose, spikelets 

 in nearly sessile clusters of 3 to 6, appressed along the branches, some- 

 what one sided, 2J to 3 lines long, lanceolate, outer glumes nearly alike, 

 lanceolate-subulate, rough-keeled, two to three times longer than the 

 perfect flower, first glume three-nerved, a little to one-third shorter than 

 the second and third, which are about five-nerved, the third glume or 

 neutral flower with a palet one-half as long. 



Florida to Texas. 



24. P. repens, L. — Culms 1£ to 2 feet high, from strong creeping rhi- 

 zomas, leafy, covered below with loose sheaths with short or deficient 

 blades, the blades becoming longer upward, conduplicate or involute, 

 the uppermost 3 to 4 inches long, sometimes pubescent at the base; 

 panicle erect, thin, 3 to 4 inches long, the branches alternate, naked at 

 base, erect or slightly spreading, the lower ones each with two or three 

 rather long, appressed branchlets; spikelets short-pedicelled and ap- 

 pressed, interrupted or racemose along the slender branches, 1 line 

 long, oval, acute, smooth, the lower glume broad, obtuse, one-third as 

 long as the spikelet, second and third about seven-nerved. 



Sandy shores of the Gulf, Florida to Texas. 



Variety confertum, Vasey. 



Culms shorter, leaves very divergent and rigid, panicle more con- 

 densed, the branches shorter and spikelets more crowded, lower glume 

 rather longer and less obtuse. 



Mobile, Ala., to Vera Cruz, Mex. (2177 F. Muller.) 



