Bouteloua trifida Thurb. ex S. Watson

Bouteloua trifida Thurber, in S. Wats. Proc. Am. Acad 18: 177. 1883.
Bouteloua Burkii Scribn., in S.Wats. Proc. Am. Acad. 18: 179. 1883. (Type from Laredo, Texas,
Berlandier 1427.) Chondrosium Trinii Foum. Mex. PI. Gram. 2; 136. 1886. (Type from Laredo, Texas, Berlandier
1427.) Chondrosium Virlelii Fourn. Mex. PI. Gram. 2: 136. 1886. (Type from San Luis Potosf, Mexico,
Virlet 1373.) Bouteloua trifida var. Burkii Vasey; L. Dewey, Contr. U. S. Nat. Herb. 2: 532. 1894. (Based on
B. Burkii Scribn.) Bouteloua Trinii D. Griff. Contr. U. S. Nat. Herb. 14: 387. 1912. (Based on Chondrosium Trinii
Foum.)
Perennial; culms densely tufted, erect, 10-35 cm. (mostly about 20 cm.) tall, scaberulous; sheaths glabrous or scaberulous, the lower ones longer, the upper shorter than the internodes; ligule ciliate, about 0.5 mm. long; blades flat, acute, scabrous, 0.8-5 cm. long, 0.5-1 mm. wide; spikes 3-6, 1-3 cm. long, appressed to spreading; spikelets spreading or nearly appressed; glumes acuminate, glabrous, the first 3.5 mm. long, the second 4.5 mm. long, scarcely broader than the first; body of lemma about 2 mm. long, glabrous, or pubescent toward the base, the 3 slender lobes gradually narrowed into awns, these about 5 mm. long; rudiment cleft to the base, the lobes gradually narrowed into the awns, about as long as those of the fertile lemma.
Type locality: Monclova, Coahuila (Palmer 1355 in 1880).
Distribution: Dry prairies, chaparral, and rocky slopes, western Texas to southwestern Utah, Arizona, and northern Mexico.