Sixweeks Muhly

Muhlenbergia depauperata Scribn. Bot. Gaz. 9: 187. 1884
Muhlenhergia Schaffneri F'ourn. Mex. PI. Gram. 85, 1886. fType from Tacuhaya, Mexico.) Muhlenbergia Schaffneri var. longiseta Scribn. Proc. Acad. Phila. 1891: 297. 1891. (Type from
near City of Mexico, Pringle in 1890,) Lycurus Schaffneri Mez, Repert, Sp, Nov, 17: 212. 1921. (Based on Muhlenhergia Schaffneri
Fourn .)
Annual; culms densely cespitose, scaberulous, branching at all the nodes, erect or in large tufts, the outer culms spreading, the branches mostly appressed, the whole plant usually pale or tawny; sheaths glabrous, striate, mostly longer than the internodes; ligule thin, 1-2 mm. long; blades fiat or folded, .scabrous beneath, puberulent on the upper surface, mostly less than 3 cm. long, about 1 mm. wide; panicle narrow, loosely spikelike, usually more than half the entire length of the culm, the branches appressed; glumes narrow, scabrous, the first irregularly bidentate or entire, mostly 1-3 mm. long, occasionally reduced, the second a little longer; lemma narrow, terete, prominently 3-nerved, slightly pubescent along the internerves, 3-4 mm. long, the delicate awn straight, about 1 cm, long.
Type locality: Arizona (Pringle).
Distribution: Open gravelly places, Colorado and Arizona to southern Mexico.

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, Stem nodes bearded or hairy, 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 or blade keeled, Leaf sheath and blade differentiated, Leaf sheath enlarged, inflated or distend ed, 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 a contracted panicle, narrowly paniculate, branches appressed or ascending, Inflorescence a dense slender spike-like panicle or raceme, branches contracted, 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 body or surface hairy, Lemma apex acute or acuminate, Lemma mucronate, very shortly beaked or awned, less than 1-2 mm, Lemma distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn less than 1 cm long, 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.