521 
deciduous; the second about equaling the glume and palet.—Low land near water, 
western Texas to California and Idaho. 
15. S. Buckleyi Vasey. Culms 6 to 10 dm. high: leaves flat, attenuate pointed: 
panicle one-third as long as the culm, loose; branches alternate or subverticillate, | 
bearing numerous short-pedicelled spikelets on the short curved subdivisions: 
spikelets about 1.5 mm, long; second glume slightly shorter than the floral glume: 
grain nearly as long as the palet,—Southwestern Texas to Mexico. 
16. S. heterolepis Gray. Culms slender, 8 to 5 dm. high: leaves mostly from the 
base, involute-filitorm, nearly equaling the culm: panicle 1 to 3 dm. long, narrowly 
pyramidal; branches spreading, bearing the large dark-colored spikelets more or 
less crowded near the extremities: spikelets 3 to 4mm. long; second empty glume 
acuminate, at least twice as long as the narrow first glume, and slightly exceeding 
the subequal floral glume and palet: utricle subglobose, coriaceous, 2 mm, in 
diameter,—Rare in central and northern Texas, more common northward. 
+ + Pedicels longer than the scattered spikelets: empty glumes subequal, except in 8. 
Tecana, 
++ Empty glumes broad, thin, dark-colored, nearly equaling the floret: panicle rather 
close, 
17. S. tricholepis Torr. Culms 3 to6dm. high, simple: leaves mostly radical, 
jnvolute, 1 to 2 dm. long: panicle oblong, 1 to 2 din, long; branches subverticillate, 
spreading: spikelets 3 mm. long; empty glumes subequal, nearly as long as the 
equal pubescent floral glume and palet.—Mountain valleys, western Texas to Col- 
orado and Utah. 
++ ++ Empty glumes membranaceous, much shorter than the floret: panicle diffuse with 
long capillary branches and long pedicels, 
18. S. auriculatus Vasey. Culms 2 to3 din. high, branching below, from peren- 
nial, running rootstocks: leaves crowded, narrow, 2 to 4 cm. long; ligule somewhat 
lacerate with two prominent acute lateral lobes: panicle about 1 dm. long, broadly 
spreading, open: spikelets 2 mm. long; empty glumes obtuse, about one-half as long 
as the truncate toothed floral glume and palet.—Sandy plains, western Texas. 
19. S. asperifolius (Nees. et Mey.) Thurb. Culms ascending from a decumbent 
branching base, 1 to 3 dm. high, leafy to the panicle: leaves mostly flat, not rigid: 
panicle 1 to 2 dm. long, inclosed below in the upper sheath; branches spreading: 
spikelets 1 mm. long; empty glumes two-thirds as long as the obtuse mucronate 
floral glume. (Vila asperifolia Nees. et Mey.)—Banks of streams, western Texas to 
‘alifornia and northward to Montana, Spikelets attacked by a fungus ( Ustilago) 
are 2 to 3-flowered, Var, MAJOR Vasey is larger than the species, with long run- 
ning rootstocks, spikelets nearly.2 mm. long, and empty glimes little more than 
one-half as long as the floret. —Western Texas. 
20. S. confusus Vasey. Culms 1 to4dm. high: leaves few and short: panicle 
oblong, more than one-half as long as the culm, diffusely spreading; branches 
spreading, 2 to5 cm, long: spikelets 1mm. long; empty glumes usually minutely 
ciliate fringed.—Western Texas to southern California and north to Colorado, 
21. S. Texanus Vasey. Culms 3to5dm. high, branching, leafy: leaves mostly 
tlat; sheaths thinly pubescent: panicle one-halfas long as the culm, inclosed at base 
in the upper sheath, open, diffusely spreading: spikelets 2.5 mm. long; second empty 
glume acute, more than twice as long as the first, and slightly exceeding the floret.— 
Western Texas to Oklahoma. 
33. MUHLENBERGIA Schreb. (DRoOp-SEED GRASS.) 
Spikelets 1-flowered in an open spreading or narrow contracted 
panicle: empty glumes usually persistent, shorter than the narrowly 
