26 



ond and third, which are five-nerved, smooth, and one-third longer than 

 the obtuse fertile flower; sterile flower of a gluine only. 

 Texas (E. Hall, GL C. Nealley). 



17. P. plantagineuin, Link. — Much like the preceding, but stouter and 

 larger, with larger and wider leaves (6 to 10 inches by 6 to 9 lines), 

 the spikes more remote, longer (2 to 4 inches), and the lower peduncled 

 in the sheaths; spikelets much like the preceding. 



Introduced on ballast ground at Philadelphia. 



Section V. — Brachiaria. 



18. P. prostratum, Lam, (P. csespitosum Sivz?).— Culms creeping 

 and rooting at the base, then ascending, 1 to 2 feet long, with rather 

 distant leaves, which are 1J to 2 inches long, lanceolate or ovate-lance- 

 olate, acute, clasping at the ciliate base, sheaths shorter than the inter- 

 nodes; panicle exserted, short, about 2 inches long, of five to eight simple 

 or subsimple branches, the lowest of which are 1 to 1^ inches long, 

 closely flowered ; rachis frequently with stiff hairs ; spikelets three- 

 quarters of a line long, smooth, first glume one-quarter as long as the 

 spikelet, second and third equal; perfect flower striate-punctulate, ma- 

 cronate-pointed. Our specimens agree with Triuius, Fig, 185 A. 



Louisiana (Langlois), Texas (Nealley). 



19. P. csespitosum, Sicz.f — Culms numerous, succulent, and thickish, 

 rooting at the base, ascending to 1 or 2 feet long ; leaves crowded below, 

 erect, linear-lanceolate, 2 to 4 inches long, 3 to 4 lines wide, ciliate 

 on the margins, striate, lower sheaths inflated, panicle about 2 inches 

 long, of five to eight branches becoming long exserted, rhachis and 

 branches hairy and angular, lower branches about 1 inch long; spike- 

 lets 1 J to 1J lines long, ovate-oblong, acute, lower glume one-third as 

 long as the spikelet, perfect flower as in the preceding but larger. The 

 whole plant pale green. 



Probably in Texas and New Mexico, certainly in Chihuahua, Mexico. 

 (Pringle, No. 375.) 



20. P. fuscum, Swz. (P. fasciculatum Sw.). — Culms 1 to 3 feet high, de- 

 cumbent and branching at base ; leaves linear or lanceolate-linear, 3 to 

 10 inches long, glabrous or pubescent; panicle 3 to G inches long, spread- 

 ing, the branches simple or more or less fasciculated below, the lower 

 about 2 inches long ; rhachis hairy ; spikelets in pairs or in small clust- 

 ers, l.£ lines long, acutish, lower glume about one-third as long as the 

 spikelet, deltoid, second and third glumes five to seven nerved, and 

 cross-nerved. 



Texas. 



Variet3 T major; culms stouter, 2 to 3 feet high, branched, sheaths 

 and leaves scabrous-punctulate or smoothish, leaves broader, acumi- 

 nate; panicle fuller, 3 to G inches long, branches more numerous (up to 

 twenty or thirty), scattered and fasciculate, rhachis and branches 

 scabrous, and with scattered hairs. 



Mexico (Dr. E. Palmer). 



