Plants perennial; cespitose, not rhizomatous. Culms 40-100(120) cm tall, 2-4(5) mm thick near the base. Sheaths rounded below, margins hairy, particularly distally, hairs to 3 mm, apices with conspicuous tufts of hair; ligules 0.4-1 mm; blades (2)4-35 cm long, 3-8 mm wide, flat to involute, glabrous on both surfaces, margins whitish, somewhat scabridulous. Panicles all terminal, (10)15-45(50) cm long, 0.2-0.8(1) cm wide, contracted, spikelike, dense, usually included in the uppermost sheath; lower nodes with 1-2(3) branches; primary branches 0.3-1.5 cm, appressed, spikelet-bearing to the base; secondary branches appressed; pulvini glabrous; pedicels 0.2-2 mm, appressed, scabridulous. Spikelets 1.7-3.2 mm, whitish to plumbeous. Glumes unequal, narrowly lanceolate, membranous, prominently keeled; lower glumes 0.7-1.7 mm, usually 1-veined, acute to acuminate; upper glumes 2-3.2 mm, at least 2/3 as long as the florets; lemmas 2-3.2 mm, linear-lanceolate, membranous, glabrous, acute; paleas 1.8-3 mm, linear-lanceolate, membranous, glabrous; anthers 3, 0.3-0.5 mm, light yellowish. Fruits 0.8-1.2 mm, ellipsoid, laterally flattened, light brownish or translucent. 2n = 36.

Sporobolus contractus grows in dry to moist, sandy soils, at elevations from 300-2300 m. It is found occasionally in salt-desert scrub, desert grasslands, and pinyon-juniper woodlands. Its range extends to the states of Baja California and Sonora in Mexico.

Dr. David Bogler, USDA NRCS PLANTS Database

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.

FNA 2003, Gould 1980

Common Name: spike dropseed Duration: Perennial Nativity: Native Lifeform: Graminoid General: Tufted perennial grass, stems 40-120 cm tall and 2-4 mm in diameter at the base, in small clusters to large clumps. Vegetative: Sheaths rounded, open, glabrous with one pubescent margin and a conspicuous tuft of hair at the apex; blades 2-5 mm wide, 10-30 cm long, flat or involute, glabrous, tapering to a slender tip; ligule a dense fringe of short hairs 0.5-1 mm. Inflorescence: Dense, contracted, spikelike terminal panicle, 1 cm or less thick and 15-50 cm long; basal portion of spike and sometimes entire spike remain enclosed in upper leaf sheath; spikelets light brownish or lead-colored, 2-3 mm long; glumes thin, membranous, unequal, first usually about half as long as second; second equaling the lemma or slightly shorter; caryopsis 1 mm in length, broad and flattened. Ecology: Found in dry, open, sandy or rocky slopes and washes, and frequent along roads from 2,500-6,500 ft (762-1981 m); flowers August-October. Distribution: sw US from CA, NV east to TX and OK; south to c MEX. Notes: Sporobolus species have single seeded spikelets with unequal glumes, no awns, and most often small seeds which readily fall after maturing, hence the common name "dropseed.- This species is distinguished by being a perennial with tightly contracted inflorescences, 0.2-1 cm wide, and stems to 1.2 m tall. Similar to S. cryptandrus but that species usually has an open panicle by the time it matures; Gould claims that the two species intergrade. Also similar to S. giganteus but that species is larger, up to 2 m tall and the panicles are wider (1-4 cm wide). Ethnobotany: Seeds used as food by various Native American groups; ground and mixed into a porridge, combined with with corn meal, or used for flour. Synonyms: Sporobolus cryptandrus var. strictus Editor: SBuckley 2010, FSCoburn 2014, AHazelton 2015 Etymology: Sporobolus is Greek for "seed-caster" while contractus means contracted.