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.

Annuals, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems erect or ascending, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stems branching above base or distally at nodes, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sh eath smooth, glabrous, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades very narrow or filiform, less than 2 mm wide, Leaf blades mostly flat, Leaf blade margins folded, involute, or conduplicate, Leaf blades mostly glabrous, Leaf blades scabrous, roughened, or wrinkled, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence an open panicle, openly paniculate, branches spreading, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence branches more than 10 to numerous, Flowers bisexual, Spikelets pedicellate, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating above the glumes, glumes persistent, Spikelets disarticulating beneath or between the florets, Rachilla or pedicel glabrous, Glumes present, empty bract s, Glumes 2 clearly present, Glumes equal or subequal, Glumes shorter than adjacent lemma, Glumes 1 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma similar in texture to glumes, Lemma 3 nerved, Lemma body or surface hairy, Lemma apex dentate, 2-fid, Lemma distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn less than 1 cm long, Lemma awn 1-2 cm long, Lemma awn from sinus of bifid apex, Lemma awns straight or curved to base, Lemma margins thin, lying flat, Lemma straight, Callus or base of lemma evidently hairy, Callus hairs shorter than lemma, Palea present, well developed, Palea membranous, hyaline, Palea about equal to lemma, Palea 2 nerved or 2 keeled, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.