Perennial herb with rhizomes 40 cm - 3 m tall Leaves: alternate, two-ranked. Sheaths longer than lower internodes, sometimes softly hairy, often bearing a marginal fringe of hairs. Ligules 2 - 6 mm long, membranous, fringed with hairs. Blades firm, upright, spreading or ascending, 10 cm - 0.6 m long, 2 - 15 mm wide, linear with a rounded to slightly tapering base, flat, parallel-veined, sometimes hairy, marginally rough. Inflorescence: a branched arrangement of spikelets (panicle), open, 10 cm - 0.5 m long, 4 - 20 cm wide, exserted. Primary branches thin, straight, spreading to ascending, rough, and often rebranching once. Fruit: a caryopsis, indehiscent, enclosed within the persistent lemma and palea. Culm: upright or decumbent, solitary or forming clumps, usually unbranched, sometimes purplish, 40 cm - 3 m long, 3 - 5 mm wide, round in cross-section, hard, sometimes with a waxy coating (glaucous). Spikelets: on 0.5 mm - 2 cm long stalks, 2.5 - 8 mm long, 1 - 2.5 mm wide, narrowly lance-shaped with a pointed apex. Glumes: unequal, herbaceous. Lower glumes 2 - 3 mm long, one-half to four-fifths as long as spikelets, pointed at the apex, five- to nine-veined. Upper glumes extending beyond the upper florets by up to 3 mm, seven- to eleven-veined. Lemmas:: Lower lemmas similar to upper glumes, extending beyond the upper florets by up to 3 mm, pointed at the apex, seven- to eleven-veined. Upper lemmas clasping at the base of the paleas, shiny, with rolled-up margins on the upper surface. Paleas:: Lower paleas 3 - 3.5 mm long, egg-shaped to arrowhead-shaped, transparent. Upper paleas longitudinally lined. Florets:: Lower florets male. Upper florets bisexual, 2 - 3 mm long, about 1 mm wide, narrowly egg-shaped with a pointed apex, shiny. Anthers three. Stigmas red.
Similar species: No information at this time.
Flowering: late June to early October
Habitat and ecology: A common native grass in the Chicago Region. It is found in tall-grass prairies and Black Oak savannas.
Occurence in the Chicago region: native
Etymology: Panicum comes from the Latin word panis, meaning bread, or panus, meaning "ear of millet." Virgatum means wand-like.
Stout, erect, to 2 m, from hard, scaly rhizomes, often forming large tufts; ligule a dense zone of silky hairs; blades 2-5 dm, to 15 mm wide; glabrous or pilose near the base; infl open, freely branched, pyramidal, 2-4 dm; spikelets ovoid, soon widened distally by spreading of the glumes and sterile lemma, 2.2-5.6 mm; first glume half to nearly as long; second glume and sterile lemma subequal, conspicuously veined, acute to long-acuminate; 2n=18-108. Open woods, prairies, dunes, shores, and brackish marshes; N.S. and Que. to Man. and Mont., s. to Ariz., Mex
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.