68 
12. M. gracillima Torr. (Coul. Rocky Mt. Fl. p.410.) Culms 6 to 12 inches high, 
tufted and much branched at the ground, radical leaves numerous and crowded, 
short (1 inch), filifurm and curved; cauline about 2; panicle purplish, more than 
half the length of the culm; branches erect-spreading, sparsely flowered, mostly 
single, branched above the middle; spikelets 14 to 14 lines long; empty glumes one- 
half to two-thirds as long, lanceolate, acuminate, or the upper 3-toothed; awn 
of the flowering glume about as long as the glume.—New Mexico and Texas to 
Nebraska. 
13. M. pungens Thurb. (Bot. Cal. u. p. 227.) In habit like the preceding 
but large and coarser; culms 10 to 18 inches high; leaves 1 to 2 inches long, involute, 
rigid, pungently-pointed; panicle 4 to 6 inches long, pyramidal, the branches 
single, somewhat fasciculated, divided from the base into long-pediceled, diverging, 
1-tlowered tays; spikelets 2 to 24 lines long, empty glumes about half as long, bris- 
tle-pointed, or the lower 3-toothed; awn of the flowering glume about 1 Kne long; 
palet with two setose teeth.—Texas and New Mexico to Nebraska. 
14. M. comata Benth. (Vaseya comata Thurb. Bot, Cal. mu. p. 278.) Culms 2 to 3 
feet high; nodes slightly pubescent, not branched; leaves 5 or 6 on the culm, flat, 4 
to 6 inches long, 1 to 3 lines wide, erect; ligule a short lacerate fringe; sheaths 
equaling or the upper shorter than the internodes; panicle 3 to 4 inches long, sil- 
very, narrow, sometimes interrupted below, the branches sessile, $ to 1 inch long, 
densely flowered; spikelets sessile or very short pediceled, 14 lines long; empty 
glumes narrowly lanceolate, acute, 14 lines long ; flowering glume, nearly as long, 
obtuse, somewhat 2-toothed at apex, surrounded at base with copious white hairs 
two-thirds as long as the flowering glume; awn 2 to 3 lines long, flexuous.— Rocky 
Mountains, Colorado to Montana, Oregon and California. 
15. M. glomerata Trin. (Gray’s Manual, 6th ed., p. 643.) Culms 2 to 3 feet high, 
rather stiff, usually very leafy and often much branched ; panicle 2 to 3 inches long, 
oblong-linear, contracted into an interrupted glomerate false spike, the branches 
sessile ; leaves often 10 to 12, 3 to 4 inches long, narrow, rather rigid; empty glumes 
about 2 lines long, including the bristle-like point, hispid on the keel; palet one- 
half to three-fourths as long as its glume, narrow, very acute, mucronate or short- 
pointed.—Common. 
Var. RAMOSA, stout, much branched below, very leafy.—Prairie regions. 
16. M. Wrightii Vasey. Bull. Torr. Club, xu. p. 53. Culms erect, or rarely 
somewhat decumbent below, simple or branching below, 1 to 24 feet high, rather 
wiry; leaves 3 to 6 inches long, narrow, appressed; sheaths shorter than the inter- 
nodes; ligules short; panicle spike-like, cylindrical, densely flowered, more or less in- 
terrupted, the lower branches of thrifty specimens 4 to 1 inch long, appressed, florif- 
erous to the base; spikelets 1 to ¢ lines long, sometimes 2-flowered ; empty glumes 
nearly equal, about 1 line long, with a thin ovate base, contracted into a narrow, 
acuminate point; flowering glume a little longer and thicker, tipped with a very 
short, stiff awn, 4 to 4 line long, 3-nerved below, slightly pubescent; palet about as 
long as its glume.—Rocky Mountains, New Mexico, Arizona, Colorado and Mexico. 
17. M. Willdenovii Trin. (Gray’s Manual, 6th ed., p. 643.) Culms upright, 3 feet 
high, frequently much branched, slender; panicle contracted, linear, elongated, 4 to 
10 inches long, loosely flowered ; leaves spreading, 3 to 4 lines long; spikelets 2 lines 
long; empty glumes slightly unequal, about 1 line long, ovate; flowering glume 2 
lines long, scabrous or pubescent; awn 4 to 5 lines long.—New England to Missouri. 
18. M. diffusa Willd. (Gray’s Manual, 6th ed., p. 644.) Culms diffusely much 
branched (8 to 18 inches); contracted panicles slender, rather loosely many-tlowered, 
terminal and lateral; empty glumes extremely minute, the lower obsolete, the upper 
truncate; awn once or twice longer than the flowering glume.—Dry hills and woods, 
from New England to Michigan, Iowa and southward to Texas. 
19. M. sobolifera Trin. (Gray’s Manual, 6th ed., p. 643.) Culms 1 to 2 feet high, 
often much branched, slender; leaves rather short, 3 to 6 inches; panicle linear, 
