Bouteloua griffithsii Columbus

Cathestecum prostratum Presl, Rel. Haenk. 1: 295. 1830
Annual; culms slender, in small dense tufts, decumbent-spreading, geniculate at the nodes, freely branching, 4-35 cm. long, glabrous; sheaths, except the lowermost, shorter than the internodes, glabrous or sparsely pilose near the margins and in the mouth, with a pubescent line across the collar; ligule ciliate, about 0.3 mm. long; blades flat, acute, glabrous on the lower surface, scabrous and sparsely pilose on the upper, scabrous on the margins, 1.5 cm. long, 1-2 mm. wide, the upper ones and those on the short branches much reduced; inflorescence terminal and axUlary from the upper sheaths; spikes 3-7, ascending or finally spreading, about 4 mm. long, not including the awns; first glume of the lateral spikelets narrow, acuminate, about 2 mm. long, that of the central floret broad, scale-like, less than 1 mm. long; second glume 3 mm. long, hirsute, those of the lateral spikelets acuminate, that of the central spikelet broader, abruptly acute or subobtusc, sometimes lobed, mucronate; florets 3 mm. long, dissimilar; lower floret of the lateral spikelets sterile, the lemma glabrous or sparsely pilose, shallowly lobed, the awns equaling or only slightly exceeding them; upper floret staminate, the lemma cleft to the middle, the awns extending I mm. beyond the lobes, hispid on the lower part; lower floret of the central spikelet pistillate, the lemma sparsely pilose on the back and on the margins, the lobes 1 mm. long, the awns subequal, 1.5 mm. long, scabrous and more or less hispid; upper florets staminate, the lemmas similar to those of the upper florets of the lateral spikelets, but more deeply lobed, the awns e.xtending 2-3 mm. beyond the lobes; stamens 1.5 mm. long.
Type locality: Mexico (Haenke). Distribution: Limestone hills, central Mexico.