524 
12. M. Lemmoni Scribn. Culms 3 to 5 dm. high, with few ereet branches above 
the base, leafy throughout: leaves L dim. long or less: panicle 1 to 1.5 dm, long, 
harrow, interrupted; branches single or in twos or threes and unequal, 3 em. long 
or less, closely Howered to the base except the longer ones: spikelets 3 to 3.5 mim. 
long, scabrid; empty glumes acute, prominent!y keeled, nearly as long as the floret; 
floral glume and palet pubescent below the middle: awn 2 to 3mm, long. —Moun- 
tains, western Texas to Arizona, 
+ + Awns at least tivice as long as the spikelets, 
13. M. pauciflora Buckl. Culms 3 to 5 dm. high, spreading or erect: leaves 
involute, rather rigid, about 5 em. long: panicle 5 to 10 em, long, narrow, flexuous, 
interrupted; branches single, closely flowered: spikelets 3 to 4 min, long, neawy 
sessile; empty glumes acute, bristle-pointed, seabrid on the keels, about one-half as 
long as the scabrid or smooth floral glume; awn 6 to & mm, long; callus rather 
prominent.—Mountains, western Texas to Arizona. 
I4. M. monticola Buckl. Culms 3 to6 dm. high, erect, rarely simple, leafy : leaves 
flat or involute, erect: panicle 5 to 10 em. long, erect or slightly flexnous; branches 
single or in twos and threes and unequal, 2 em. long or less, ereet, Closely flowered : 
spikelets 2.5 to 3 mm. long; empty glumes obtuse or minutely toothed, one-half to 
two-thirds as long as the floret; floral glume and palet finely pubescent below the 
middle; awn about 1,5 em, long.—Mesas and foothills, western Texas to Arizona. 
15. M. parviglumis Vasey. Culms 3 to 6 din. high, sparingly branched through- 
out: leaves 1 dm. long or less: panicle 1 to 2 dm. long, erect, narrow not dense; 
branches subverticillate, subdivided to the base, 3 cm. long or less: spikelets 3mm. 
long; empty glumes obtuse, often denticulate, one-fourth as long as the seabrid 
floret; floral glume and palet minutely pubescent near the base; awn about 2 em. 
long.—Western Texas. Difticnlt to distinguish from young and unexpanded forms of 
M. affinis. 
* * Culms simple in strongly-rooted tufts: ligule about 1 em. long. 
+ Leaves closely involute: panicle rather loose or interrupted, 
16. M. setifolia Vasey. Culms 3 to 6 dm. high, simple, tufted: leaves from the 
base 1 to 3.dm, long, tiliform involute, setaceously pointed, scabrid, often curved ; 
culm leaves 2 or 3, shorter; sheaths long: panicle 1 to 2 dm. long, erect, often vagi- 
nate below; branches single or subverticillate, 4 em, long or less: spikelets 3.5 to 
4 min. long; empty glumes obtuse, denticulate, one-third as long as the smooth 
floret; awn about 2 em, long.—Mountains, western Texas, 
17. M. gracilis(HBK.) Trin. Culms3 to 5dm., high: leaves mostly from the base, 
with open scarious sheaths and scabrous involute blades 1 to 3 din. long; leaves of the 
culm 1 or 2; sheaths long, scabrous: panicle1 to 1.5 dm. long, erect; branches mostly 
single, 4 cm. long or less: spikelets 3 to 4 mm. long; first empty glume acute, some- 
what erose; second empty glume distinctly 3-awned, one-third larger than the first 
and about one-half as long as the floret; floral glume seabrid, pubescent on the 
nerves; awn 1 to 1.5 em. long. (Podosewmum gracilis HBK.)—Mountains, west- 
ern Texas to California and Montana. 
~ + Leaves coriaceous, flat or conduplicate: panicle usually dense, plumelike. 
18. M. Berlandieri Trin. Culms nearly 1m, high: leaves tte 3dim. long, flat or con- 
duplicate, mostly from the base, nearly smooth: panicle 1.5 to 2.5 dm. long, erect; 
branches 5 em. long or less, subdivided nearly to the base: spikelets 4 mm, long; 
empty glumes equal, obtuse, denticulate, one-third as long as the prominently 3- 
nerved floral glume; awn nearly lem. long; hairs of the callus few and short.—Foot 
hills, western Texas and New Mexico. 
19. M. distichophylla (Presl.) Kth. Culms about Im. high, robust, leafy: leaves 3 
to 6 dm. long, tlat or conduplicate, hispid on the margins: panicle 2 to 3 dm. long, 
