Schizachyrium cirratum (Hack.) Wooton & Standl.

Schizachyrium cirratum (Hack.) Nash
Andropogon cirratus Hack. Flora 68 : 119. 1885. Sorgum cirratum Kuntze, Rev. Gen. 791. 1891.
A tufted perennial with erect stems. Stems up to 7 dm. tall, somewhat branching, smooth and glabrous, terete; leaf-sheaths glabrous, shorter than the internodes; blades flat, or sometimes complanate, those on the innovations sometimes sparsely long-ciliate at the base, those on the stem up to 1.5 dm. long, 2-4 mm. wide; spike-like racemes 4-6 cm. long, usually exserted, the internodes of the rachis glabrous, or with a few hairs on the outer margin near the apex, the pedicels with the outer margin long-hairy near the apex; sessile spikelet 8-9 mm. long, including the hairy callus, the first scale lanceolate, rough, hispidulous on the keels, acute, the fourth scale cleft for two thirds to three fourths of its length, the teeth ciliate, the awti 13-20 mm, long, the spiral column about as long as the subula; pedicellate spikelet 6-8 mm. long, usually enclosing a staminate flower.
Type locality : Between eastern Texas and El Paso.
Distribution : Western Texas to Arizona, Durango, Chihuahua, and Lower California.

Andropogon lolioides Fourn. Mex. PI. Gram. 62. 1881
Andropogon scoparius maritimus divergens Hack, in DC. Monog. Phan. 6 : 385. 1889.
Sorgum scoparium Kuntze, Rev. Gen. 792. 1891.
Andropogon scoparius poly cladus Scribn. & Ball, Bull. U. S. Dep. Agr. Agrost. 24 : 40. 1901.
Andropogon scoparius villosissimus Kearney; Scribn. & Ball, Bull. U. S. Dep. Agr. Agrost. 24:
41. 1901. Schizachyrium villosissim,um. Nash, in Small, Fl. SKU. S. 59. 1903.
A green or purplish, rarely glaucous, extremely variable, tufted perennial, with extravaginal innovations. Stems 4.5-15 dm. tall, the branches in rs-4's and often subdivided; leaf-sheaths glabrous or pubescent, keeled, smooth or rough; blades 5 dm. long or less, up to 8 mm. wide, glabrous or pubescent; racemes 2-6 cm. long, the rachis straight or flexuous, the internodes from one half as long as the sessile spikelets to equaling them, straight or ciu-ved, ciliate with grayish hairs on the margins throughout or on the upper portion only, those at the apex 1-3 mm. long, sometimes hispidulous on the back, the pedicels erect or recurved, shorter than the sessile spikelets, usually glabrous below, ciliate above with long grayish hairs; sessile spikelet commonly 5-7 mm. long, rarely shorter or longer, the first scale often more or less roughened, the fourth scale entire or 2-toothed for one quarter of its length, the awn geniculate, 8-15 mm. long, the column closely or loosely spiral, included or exserted; pedicellate spikelet 2-6 mm. long, usually small, consisting of 1 or 2 scales and empty, very rarely nearly as large as the sessile spikelet and staminate.
Type locality : Carolina.
Distribution : Maine and Vermont to Saskatchewan, Montana, and "Washington, and south to Florida, Texas, and New Mexico.

Perennials, Terrestrial, n ot aquatic, Rhizomes present, Rhizome short and compact, stems close, Stems nodes swollen or brittle, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes solid or spongy, 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 blades 2-10 mm wide, Leaf blade margins folded, involute, or conduplicate, Leaf blades mostly glabrous, Leaf blades glaucous, blue-green, or grey, or with white glands, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence lateral or axillary, Inflorescence with 2 or more spikes, fasci cles, glomerules, heads, or clusters per culm, Inflorescence single raceme, fascicle or spike, Flowers bisexual, Spikelets pedicellate, Spikelets sessile or subsessile, Spikelets laterally compressed, Inflorescence or spikelets partially hidden in leaf sheaths, subtended by spatheole, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets with 2 florets, Spikelets paired at rachis nodes, Spikelets in paired units, 1 sessile, 1 pedicellate, Pedicellate spikelet rudimentary or absent, usually sterile, Spikelets bisexual, Spikelets disarticulating below the glumes, Spikelets falling with parts of disarticulating rachis or pedicel, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes equal to or longer than adjacent lemma, Glume equal to or longer than spikelet, Glumes keeled or winged, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma 1 nerved, Lemma glabrous, Lemma apex de ntate, 2-fid, Lemma distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn 1-2 cm long, Lemma awn from sinus of bifid apex, Lemma awn twisted, spirally coiled at base, like a corkscrew, Lemma awn once geniculate, bent once, Lemma margins thin, lying flat, Lemma straight, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis.

Schizachyrium cirratum là một loài thực vật có hoa trong họ Hòa thảo. Loài này được (Hack.) Wooton & Stand. miêu tả khoa học đầu tiên năm 1912.