Muhlenbergia setifolia Vasey

Muhlenbergia setifolia Vasey, Bot. Gaz. 7: 92. 1882
Perennial ; culms densely cespitose, erect, .slender, wiry, puberulent, 50-80 cm. tall ; sheaths glabrous, overlapping at base of plant; ligule thin, 8-10 mm. long, widely decurrent on the sheath; blades involute, fine, scarcely 0.5 mm. thick, scabrous, flexuous or curly, as much as 20 cm. long; panicle narrow, open, erect, 10 to 15 era. long, the axis puberulent, the branches capillary, ascending, flexuous; naked below, rather few-flowered, the pedicels longer than the spikelets; glumes one third to one half as long as the lemma, obtuse to subacute, often with a short delicate awn; lemma acuminate, glabrous, minutely pubescent on the callus, the awn slender, scabrous, flexuous, 1.5-2 cm. long.
Type locality: Guadalupe Mountains, Texas (Havard).
Distribution: Rocky hills, western Texas to Arizona and northern Mexico.

Perennials, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, 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 sheath smooth, glabrous, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades very narrow or filiform, less than 2 mm wide, 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 t erminal, 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 bracts, 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 glabrous, Lemma apex acute or acuminate, Lemma distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn 1-2 cm long, Lemma aw n 2-4 cm long or longer, Lemma awned from tip, 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.

Muhlenbergia setifolia là một loài thực vật có hoa trong họ Hòa thảo. Loài này được Coult. mô tả khoa học đầu tiên năm 1882.