Bouteloua annua Swallen

Bouteloua annua Swallen, Jour. Wash. Acad. 25: 414. 1935
Annual; culms in dense clumps, branching, erect or geniculate-spreading at the base, 3-25 cm. tall; sheaths shorter than the internodes, glabrous; ligule ciliate, 0.2 mm. long; blades flat, 1-3.5 cm. long, 1.5-2 mm. wide, acute, pubescent on the upper surface or nearly glabrous; spikes 2-7, falling entire, rather distant, ascending or spreading, 1.5-2 cm. long, bearing 4-7 usually appressed, green or purple spikelets; glumes acuminate, scabrous on the keel, the first narrow, 3.5-4 mm. long, the second much broader, 6-7 mm. long; lemma 7-9 mm. long, 3-toothed, densely pubescent at the base, pilose in lines on both sides of the midnerve and on the margins; rudiment cleft to the base, the lobes with their awns 5-7 mm. long, sparsely appressed-pilose in lines along the nerves, the rachilla appressed-pilose on the margins.
Type locality: San Ignacio, Baja California (Shreve). Distribution: Known only from the type locality.