Perennial tufted, rhizome-bearing herb to 1.85 m tall Leaves: borne along the culm, with hairless sheaths and ligules that are 0.7 - 1 mm long, membranous, and lined with hairs along the margins. The blades are 7 - 22 cm long, 4 - 22 mm wide, flat, and often hairless but occasionally soft-haired on the upper surface. Inflorescence: 8 - 35 cm long, open, with nodding branches. Fruit: a laterally compressed caryopsis, 2.9 - 5 mm long, usually not exposed when mature. Culm: to 1.5 cm long, 2 - 4 mm across at the nodes, usually unbranched. Spikelets: 1.5 - 5 cm long, 0.6 - 2 cm wide, laterally compressed. Glumes: nearly equal, hairless, with a five- to seven-veined lower glume 4.2 - 9.1 mm long and a five- to nine-veined upper glume 4.7 - 8.7 mm long. Florets: six to 26 per spikelet, with one anther 0.4 - 3.5 mm long and two reddish purple, feather-like styles. The lowest one to three florets on a spikelet are sterile. Lemma: of fertile florets 9 - 12.5 mm long, straight, hairless, eleven- to fifteen-veined, with rough- to hairy-winged longitudinal ridges. Palea: 4.6 - 7.7 mm long, hairless, swollen on one side near the base, with two winged longitudinal ridges.
Similar species: No information at this time.
Flowering: July to October
Habitat and ecology: Rare on shaded floodplains.
Occurence in the Chicago region: native
Etymology: Chasmanthium comes from the Greek words chasma, meaning yawn, and anthos, meaning flower. Latifolium means wide-leaved.
Loosely colonial from short, stout rhizomes, 10-15 dm; sheaths glabrous; lf-blades 1-2 dm נ1-2 cm; infl open, nodding or drooping; spikelets green, nodding on slender pedicels, ovate or lance-ovate, 6-17-fld, (15-) 20-40 mm; glumes and the 1-2 sterile lemmas lance-linear, subequal, two-thirds as long as the lance-ovate fertile lemmas, these 11-15-veined, with pilose callus; palea much shorter than the lemma; grain 3-5 נ2-2.5 mm, mostly enclosed between the lemma and palea; 2n=48. Moist woods and streambanks; N.J. to Ga. and nw. Fla., w. to s. O., Ind., Ill., Kans., and Tex. (Uniola l.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.