Panicle branches appressed to ascending, occasionally divergent. Lower glumes 2.2-3.4 mm, midveins excurrent for 0.1-0.6 mm; upper glumes 2.7-4 mm, midveins excurrent for 0.2-1 mm; lower lemmas glabrous or sparsely appressed pubescent along both sides of the veins, awns (3.2)4-6.6 mm; anthers 0.3-0.4 mm. Caryopses 1.3-1.5 mm long, 0.4-0.5 mm wide, grooved adaxially. 2n = unknown.
Bouteloua trifida var. trifida grows in dry plains and rocky slopes, mostly at 300-1500 m, from southern California, Nevada, and Utah to Texas and Mexico.