26 
! PANICUM VIRGATUM, L.; var. MACRANTHUM.—Whole plant 
glabrous and glaucous, apparently 4 to 5 feet high, leaves rigid, 
the upper part long setaceous involute; panicle 1% feet long, 
diffuse, the lower branches 6 to 8 inches long, flowering chiefly 
toward the extremities; spikelets very large, 3 lines long, the 
lower glume five-nerved, very acute, two-thirds as long as the 
second glume, which is strongly nine-nerved; third glume seven- 
nerved; perfect flower oblong, 2 lines long. A striking form, 
with very large spikelets, collected by Dr. Havard, in the Guada-. 
lupe Mountains, Texas. 
Var. CONFERTUM.—A form with a close panicle, observed 
particularly on the sea-coast. 
Var. ELONGATUM.—Panicle elongated and narrow, with the . 
spikelets unusually slender; perhaps this is the Panicum clonga- 
tum of Pursh. 
Var. DIFFUSUM.—Panicle longer and diffuse, spikelets more 
distant, and the lower glume nearly or quite as long as the sec- 
ond and third. Sandy prairies, Kansas, Colorado, etc. 
IMPERATA BREVIFOLIA.—Culms 3 to 4 feet high, erect from a 
creeping rhizome, firm, smooth; radical leaves numerous, 4 to 10 
inches long, plain, smooth, very acute, 4 to 5 lines wide, contracted 
and long ciliate at the base, ligule short, membranaceous; cauline 
leaves, four or five, short, first about 4 inches, second 3 inches, 
third 2 inches, fourth 1 inch long, rather rigid, acute, with a few 
long hairs at the base; ligule short ciliate, sheaths smooth, the up- 
per ones elongated, (6 to 7 inches long) ; panicle erect, nearly cylin- 
drical, 5 to 9 inches long, %4 to 34 inches wide; branches of the 
panicle appressed, sparsely short-hairy below, with spikelets in 
pairs, one sessile, and the other pedicellate, toward the apex the 
spikelets single; the pedicels slightly hispid, and emitting a few 
long silky hairs; the outer glumes about 1% lines long, the , 
upper a little longer, lance-oblong, obtusish ; the lower five- 
nerved; upper three-nerved and ciliate at the apex ; both villous 
on the back with long silky hairs, which are about 3 lines long; 
third glume smooth, very thin, hyaline, about as long as the 
first; fourth glume two-thirds as long, narrow ; palet bifid, broad, 
hyaline, nerveless, 34 line long; stamen one. 
Southern California, 1031 Parish; New Mexico, 2001 C. 
Wright; also from Arizona and Western Texas. : 
