Muhlenbergia articulata Scribn.

Muhlenbergia articulata Scribn. Proc. Acad. Phila. 1891: 298 1892.
Perennial; culms closely cespitose, erect, glabrous, about 60 cm. tall; sheaths puberulent, slightly roughened, overlapping, the old blades disarticulating at the collar; ligule firm or indurate, obtuse, 3-7 mm. long ; blades involute, elongate, slender, glabrous on the outer surface, puberulent on the inner surface, ending in a fine stifT point; panicles narrow, contracted, pale, inclosed at base in the uppermost sheath, 30-40 cm. long, glabrous below, scabrous-puberuknt above, the branches slender, appressed, closely overlapping, the lateral pedicels shorter than the spikelets; glumes unequal, acuminate or awn-pointed, more or less scaberulous, the first 3-4 mm. long, the second a little longer; lemma acuminate, faintly scaberulous, short-pilose on the callus, 4-5 mm. long, the awn slender, scabrous, flexuous, 2-4 cm. long ; palea acuminate, as long as the lemma.
Type locality: Cardenas. Mexico (Pringle 3477). Distribution: Dry calcareous hills, Cardenas, Mexico.