180 GRAMINEAE. 
1. Bouteloua hirsuta Lag. Hairy Mesquite-grass. (Fig. 411.) 
Bouteloua hirsuta Lag. Var. Cienc. y Litter. 2: Part 4, 
141. 1805. 
Culms 6/-20’ tall, erect, simple or sometimes 
sparingly branched at the base, smooth and gla- 
brous. Sheaths mostly at the base of the culm, 
the lower short and crowded, the upper longer; lig- 
ule a ring of short hairs; leaves 1/-5’ long, 1’’ wide 
or less, erect or ascending, flat, scabrous, spar- 
ingly papillose-hirsute near the base, especially on 
the margins; spikes 1-4, 14’-2’ long, usually erect 
or ascending, the rachis extending beyond the 
spikelets into a conspicuous point; spikelets nu- 
merous, 234//-3’’ long, pectinately arranged; first 
scale hyaline, shorter than the membranous second 
one, which is strongly papillose-hirsute on the 
keel; third scale pubescent, 3-cleft to the middle, the 
nerves terminating in awns; rachilla without a tuft 
of hairs under the rudimentary scales and awns. 
In dry soil, especially on prairies, Illinois to Dakota, Texas and Arizona. July-Sept. 
2. Bouteloua oligostachya (Nutt.) Torr. Grama-grass. Mesquite-grass. 
(Fig. 412.) 
Atheropogon oligostachyus Nutt. Gen. 1:78. 1818. 
Bouteloua oligostachya Yorr.; A. Gray, Man. Ed. 2, 553. 
1856. 
Culms 6/-18/ tall, erect, simple, smooth and gla- 
brous. Sheaths shorter than the internodes; ligule a 
ring of short hairs; leaves 1/-4/ long, 1’’ wide or less, 
involute, at least at the long slender tip, smooth or 
scabrous; spikes 1-3, 1/-2’ long, often strongly curved, 
the rachis terminating in a short inconspicuous point; 
spikelets numerous, pectinately arranged, about 3// 
long; first scale hyaline, shorter than the membranous 
second one, which is scabrous and sometimes long- 
ciliate on the keel, and sometimes bears a few papillae; 
third scale pubescent, 3-cleft, the nerves terminating in 
awns; rachilla with a tuft of long hairs under the rudi- 
mentary scales and awns. 
On prairies, Manitoba to Alberta, south to Wisconsin, 
Texas and Mexico. July—Sept. 
3. Bouteloua curtipéndula (Michx.) Torr. Racemed Bouteloua. (Fig. 413.) 
Chloris curtipendula Michx. F1. Bor. Am. 1:59. 1803. 
Bouteloua racemosa Vag. Var. Cienc. y Litter. 2: Part 
4, 141. 1805. 
Bouteloua curtipendula Torr. Emory’s Rep. 153. 1848. 
Bouteloua.curtipendula var. aristosa A. Gray, Man. 
Ed. 2, 553. 1856. 
Culms 1°-3° tall, erect, simple, smooth and gla- 
brous. Sheaths shorter than the internodes; ligule 
a ring of short hairs; leaves 2/-12’ long, 2’’ wide 
or less, flat or involute, rough, especially above; 
spikes numerous, 3/’-8’’ long, widely spreading or 
reflexed; spikelets 4-12, divergent from the rachis, 
314’’-5”’ long, scales scabrous, especially on. the 
keel, the first shorter than or equalling the 
second; the third 3-toothed, the nerves extended 
into short awns; rachilla bearing at the summit a 
: small awned scale, or sometimes a larger 3-nerved 
F ) scale, the nerves extended into awns; anthers 
; Ss vermillion or cinnabar-red. 
In dry soil, Ontario to Manitoba, south to New Jersey, Kentucky, Texas and Mexico. July-Sept. 
