Sporobolus contractus Hitchc.

Sporobolus contractus Hitchc. Am. Jour. Bot. 2: 303. 1915
Sporobolus cryptandrus var. strictus Scribn. Bull. Torrey Club 9: 103. 1882.
Sporobolus strictus Merr. Circ. U. S. Dep. Agr. Agrost. 32: 6. 1901. (Based on Sporobolus cryptandrus var. strictus Scribn.; also the basis of 5. contractus Hitchc.) Not 5. strictus Franch., 1893.
Perennial, resembling S. cryptandrus; culms erect; panicle dense and spikelike, as much as 50 cm. long, usually included at the base, rarely entirely included in the sheath.
Type locality: Camp Lowell. Arizona (Pringle).
Distribution: Mesas, dry bluffs, and sandy fields, Colorado to Nevada, and southward to western Texas, southeastern California, and Sonora.

Perennials, 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 internodes hollow, Stems with inflorescence less than 1 m tall, Stems with inflorescence 1-2 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 hairy at summit, throat, or collar, Leaf sheath and blade differentiated, Leaf blades linear , Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blade margins folded, involute, or conduplicate, Leaf blades mostly glabrous, Ligule present, Ligule a fringe of hairs, Inflorescence terminal, 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, Flowers bisexual, Spikelets pedicellate, 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 solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating above the glumes, glumes persistent, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes distinctly unequal, Glumes shorter than adjacent lemma, Glumes equal to or longer than adjacent lemma, Glumes 1 nerved, Lemmas thin, chartaceous , hyaline, cartilaginous, or membranous, Lemma similar in texture to glumes, Lemma 1 nerved, Lemma glabrous, Lemma apex acute or acuminate, Lemma awnless, Lemma straight, 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.

Sporobolus contractus is a species of grass known by the common name spike dropseed. It is native to western North America, including the southwestern United States and northern Mexico. It grows in desert and plateau habitat, in woodlands, scrub, and dry, sandy, open areas.

Sporobolus contractus là một loài thực vật có hoa trong họ Hòa thảo. Loài này được Hitchc. miêu tả khoa học đầu tiên năm 1915.