Herbs annual, cespitose, (8-)20-60 cm. Culms erect or spreading, slender, stiff. Leaves: sheaths hirsute; principal blades linear to lance-linear, 5-12 cm, hirsute-hispid-ciliate, surfaces strigose-hispid or glabrous. Inflorescences in solitary terminal clusters or several terminal clusters, less often from proximal 1-2 nodes, principal involucral bract mostly exceeding compound or cluster. Spikelets lance-ovoid to cylindric, 5-8(-12) mm, apex acute; fertile scales oblong to obovate, 2.5-3 mm; cusp excurved, nearly length of scale, scabridulous; median ribs 3, strong. Flowers: perianth bristles extending at least to base of perianth blades, often near to tips, retrorsely barbellate; perianth blades long-clawed, mostly ovate, base 3-5-ribbed, apex slenderly acuminate, incurved, awned; anthers 1-3, 0.5-0.7 mm. Achenes: stipe slender; body angles wirelike, faces lustrous, deep brown to red-brown, 1 mm; beak slender, stiff, tip papillate. 2n = 46. Fruiting summer-fall. Moist to wet pond shores, seeps, savannas and swales, moist sandy waste places; 0-200 m; Ont.; Ala., Del., Fla., Ga., Ind., La., Md., Mass., Mich., N.J., N.Y., N.C., R.I., S.C., Tex., Va.
Tufted annual 1-6 dm; sheaths hispid-hirsute to subglabrous; larger blades 5-12 cm נ3-5 mm, hairy or scabrous at least along the margins; spikelets 7-15 mm, in 1-3 clusters (or solitary); scales 2.5-3.5 mm, the usually 3 strong median nerves convergent and exserted to form a recurved-spreading awn nearly as long as the scale; bristles retrorsely barbellate, reaching at least to the base of the pet-blades, these ovate, slenderly incurved into an apical bristle; anther 1, 0.5-0.7 mm; 2n=46. Moist to wet, usually sandy places, sometimes weedy; Mass. to Fla. and Tex., chiefly on and near the coastal plain, and disjunct to s. Mich. and n. Ind.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.