Mexicali Muhly

Muhlenbergia crispiseta Hitchcock, sp. nov
Annual; culms erect, cespitose, glabrous, very slender, 10-20 cm. tall, much-branched near the base, the branches erect; sheaths glabrous, longer than the internodes, the lower much overlapping; ligule rounded, about 1.5 mm. long; blades flat or loosely involute, glabrous beneath, pubescent on the upper surface, less than 5 cm. long, 1 mm. wide or less; panicles numerous, terminating the culms and the short basal branches, ovoid, rather loose, 1-3 cm. long, the branches ascending, mostly floriferous from near base, the short pedicels often curved; glumes pale, unequal, glabrous, the first lanceolate, acute, I-nerved, about 1 mm. long, the second broader, oblong, 3-nerved, 3-toothed, a little longer than the first; lemma terete, lanceolate, acuminate, densely pilose on the lower half or two-thirds, glabrous above, a little less than 2 mm. long, the minute callus short-pilose, the apex bifid, the awn slender, flexuous below, much-crisped or curled in the upper part, 1-1.5 cm. long.
Annua; culmi graciles erecti caespitosi 10-20 cm. alti, basi ramosi; laminae planae vel paulluminvolutae,subtus glabrae, supra pubescentes, 1-5 cm. longae 0.5—1 mm. latae; paniculae numerosae ovatae vel oblongae 1-3 cm. longae; gluma secunda 3-dentata; lemma lanceolatum acuminatum, in dimidio inferiore dense pilosum, supra glabrum, vix 2 mm. longum; arista gracillima crispa 1-1.5 cm. longa.
Type collected on thin soil of porphyry ledges. Sierra Madre, State of Chihuahua, Mexico, October 23, 1887, Pringh 1411 (U. S. Nat. Herb. no. 9(15491). Other specimens are Pringle 824 and Hitchcock 7663 from Chihuahua; Schaffner 181 and Parry o' Palmer 032 from San Luis Potosi.