62 
sheaths conduplicate, compressed, ciliate above and at the ligule; panicle erect- 
spreading, at length contracted; empty glumes acuminate, the upper equaling the 
1-line long spikelet, the lower half as long; flowering glume acute.—Florida (4. H. 
Curtiss, Dr. Chapman). 
17. S. Wrightii Munro in MS. Culms stout, erect, 3 to 4 feet high, from a stout 
creeping rhizoma, leafy; sheaths long, smooth; ligule nearly obsolete or sparsely 
hairy ; lower blades 1 foot or more long, narrow, smooth without, scabrous within, 
tapering into a long filiform point; panicle lanceolate, 12 to 15 inches long, open, 
the branches very numerous, racemose, narrow, scattered on the smooth axis, 2 to 
4 inches long, approximate, erect-spreading at an angle of about 45 degrees, flower- 
bearing nearly to the base; spikelets nearly a line long, on very short pedicels; 
empty glumes unequal, the lower 4 and the upper two-thirds as long as the flower- 
ing glume, thin; flowering glume obtusish, smooth, little thicker than the empty 
glumes.—New Mexico, Texas and Arizona. 
18. S. airoides Torr. (Bot. Cal., 11 p. 269.) (Agrostis airoides Torr.; Vilfa airoides 
Steud.) Perennial; culms tufted, often stout, from strong-rooting rhizomas, | to 3 
feet high; leaves rather rigid, strongly revolute and attenuate; panicle broadly 
pyramidal, soon exserted, 6 to 12 inches long, open and diffuse; rays solitary or in 
pairs, slender, spreading, rather distantly subbranched, naked below; spikelets a 
line long, on slender pedicels; empty glumes obtusish, somewhat unequal, the lower 
one-third to one-half as long as the glume, the upper a little shorter than the flower- 
ing glume.—In the Rocky Mountain region; Great Plains; Texas to Montana; Cali- 
fornia to Oregon, 
19. S. cryptandrus Gray. (Gray’s Manual, 6th ed., p. 646.) Perennial strongly 
rooted; culms erect or decumbent below, 2 or 3 feet high, sometimes with a few 
lateral branches, uyper nodes distant ; leaves flat, 3 to 6 inches long, commonly par- 
tially inclosed in the upper sheath, and sometimes permanently and wholly in- 
Icosed, the lower branches 2 inches long, flowering nearly to the base; spikelets nearly 
1 line long, nearly sessile; empty glumes lanceolate, acute, the lower } as long and 
the upper as long as the spikelet.—New England, westward and southward to New 
Mexico. 
Var. STRICTUS Scribn. Panicle 6 to 12 inches long, the branches permanently 
strict.— Western Plains. 
Var. ROBUSTUS Vasey. Culms remarkably robust, erect, 3 feet high; leaves wider 
and longer, rigid; panicle partially expanding, 10 to 12 inches long, dense, the 
branches closely approximate,—Texas ( Nealley). 
Var. FLEXUOSUS Thurb. Panicle 6 to 15 inches long, expanded, and becoming re- 
, flexed, longer and more slender, the lower ones sometimes 6 inches long; spikelets 
rather shorter and more acute, and on pedicels equal to or longer than the spikelets.— 
Dry Western plains, Colorado, New Mexico, Arizona to Texas. 
20. S. heterolepis. (Gray’s Manual, 6th ed., p. 646.) Culms erect, 2 to 3 feet high, 
slender, naked above; leaves involute, thread form, the lowest nearly as long as the 
culm, panicle 4 to 6 or even 10 inches long, open, loose, the branches alternate or several 
together, at first erect, becoming widely spreading, naked below ; Spikelets 24 lines 
long ; empty glumes very unequal, the lower narrow or setaceous, about half as long 
as the upper, the latter taper-pointed and longer than the floral glume.—Connecticut 
and New York to Illinois and Wisconsin, Minnesota, and all the prairie region, Texas 
to British America. 
21. S. tricholepis Torr. (Vilfa tricholepis Torr.) (U.S. Geol. Surv., Wheeler, vr. 
p. 232.) Perennial, tufted, culms erect, simple; leaves mostly radical short (3 to 6 
inches), erect or curved, rigid, involute; the lower sheaths inflated, ligule short, 
auriculate; panicle oblong, open, 4 to 6 inches long, the branches more or less 
spreading, scattered, the lower 1 to 2 inches long, loosely flowered ; the spikelets on 
slender pedicels, 1} to 14 lines long; empty glumes thickish, oblong, obtuse or obtus- 
ish, nearly equal, a little shorter than the spikelet; flowering glume and palet nearly 
