167 
nearly an inch wide; spikes 3 to 4, about 2 inches distant, 
spreading and becoming widely divergent, 5 to 8 inches long, 
and rigid; rhachis nearly straight; spikelets crowded, mostly in 
two rows, about two lines long, ovate, obtuse, smooth; sterile 
glumes five-nerved. 
(a.) Spikes more numerous—7 to 20. 
24. P. purpurascens, El\l.—Culms decumbent and ascending, 
2 feet high, branching, glabrous; leaves long and rather broad, 
glabrous, or hairy near the base, more or less of a purplish hue, 
as are also the lower joints of the stem; panicle 4 to 6 inches 
long; spikes variable in number, 5 to 7, sometimes I0 to 12, 
rarely on poor specimens,.or on the branches, 3 or 4, 2 to 3 
inches long, closely flowered; rhachis straight, wide ; spikelets 
mostly in four rows, crowded, about 1 line long, obovate, obtuse ; 
sterile glumes five-nerved, smooth, of a livid hue; flowering 
glume becoming black. 
25. P. virgatum, L., var. PUBIFLORUM.—Culms tall and 
stout, 3 to 4 feet high, smooth; leaves long and narrow, smooth, 
hairy at the throat, joints dark; panicle 6 to 9 inches long, vir- 
gate; spikes 12 to 25, erect and appressed, semi-verticillate, 
flexuous, the lower 3 to 4 inches long, diminishing upwardly ; 
rhachis narrow, straight ; spikelets about 11% lines long, acute, 
ovate, in four rows; sterile glumes white-hairy, especially on the 
margins, longer than the obtuse flowering glume. 
SPECIES LITTLE KNOWN. 
26. P. elatum, Richard. —Culms erect, sub-compressed, striate, 
glabrous; sheaths and leaves glabrous, the leaves linear, 
elongated, narrowly acuminate; spikes 5 to 7, sub-fasiculate, 
sessile, approximate, erect, or subfalcate spreading, elongated ; 
spikelets in twos, short-pedicelled, narrowly obovate, twice as wide 
as the axis; glumes obovate, five-nerved, smooth. In Herb. 
Gray is a specimen from Key West, and another from Texas, 
(No. 364 Drummond.) The description is from Doell’s Gram. 
Bras. 
27. P. BUCKLEYANU.M—Culms decumbent at the base, sim- 
ple, 2 to 3 feet high, smooth; leaves long and narrow, condu- 
plicate ;. panicle 7 inches long, erect ; spikes 6, alternate, erect or 
little spreading, 1 to 134 inches distant, the lower nearly 3 inches 
