Plants loosely cespitose or not, short-rhizomatous. Culms solitary or not, erect, 20-100(-130) cm. Leaves 4-8; basal sheaths reddish to brownish; sheath of distal leaf (1.3-)1.7-10(-25) cm; ligules triangular, 3.5-18 mm; blades 15-64 cm × 4-15 mm. Inflorescences 4-40 cm; peduncles of proximal spikes 0.5-20 cm, basal 2 peduncles 1-20 cm apart of terminal spike 0.5-6(-7) cm, shorter than or exceeding distal pistillate spike by 2 cm or less; bracts leafy, sheaths 0.5-15 cm, blades 13-55 cm × 3-11 mm. Spikes: proximal pistillate spikes (1-)2-5, distal spikes usually ± crowded, ascending, densely (4-)8-80-flowered, ovoid to cylindric, 1.5-6.5 × 1.3-3 cm; terminal staminate spikes 1(-2), 1.5-8.5 cm × 1-5 mm. Pistillate scales 1-7-veined, lanceolate to lanceolate-ovate, 6-15 × 1-2.7 mm, apex acute to awned, awns rough, to 6 mm. Anthers 3, 3-5.5 mm. Perigynia ascending, strongly 13-22-veined, ± stipitate, lance-ovoid, 11-19 × 3-6 mm, shiny, glabrous; beak conic, 6-10 mm. Achenes stipitate, rhomboid, flat to concave faces, angles smoothly thickened, not pointed or nobbed, 3-4(-4.5) × 1.7-2.6(-2.8) mm; style same texture as achene. Fruiting late spring-summer. Wet, deciduous or mixed swamp forests, forest openings, wet meadows; 0-700 m; N.B., N.S., Ont., Que.; Ala., Ark., Conn., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., Tenn., Tex., Vt., Va., W.Va., Wis. Occasional specimens have been seen that appear to be sterile hybrids of Carex lupulina with C. retrorsa or C. lurida.
From Flora of Indiana (1940) by Charles C. Deam
Very common in swamps, ditches, and low open woods and on borders of ponds and rivers.
Stems 2-13 dm, smooth, solitary or few together from long, dark, scaly, sympodial rhizomes; basal sheaths persistent, reddish to brownish; lvs evidently septate-nodulose, 4-15 mm wide, the uppermost nonbracteal one with a sheath 1.5-25 cm; terminal spike staminate, 1.5-8.5 cm, its peduncle 0.5-6 cm and surpassed by to about equaling the uppermost pistillate spike; pistillate spikes (1)2-5, ascending, ovoid to cylindric, 1.5-6.5 נ1.3-3 cm, pedunculate but the upper generally crowded, their subtending bracts leafy, 13-55 cm, basally sheathing; pistillate scales 6-15 mm, slender, acute or with a rough awn to 6 mm; perigynia 8-80, ascending, smooth and shiny, strongly 13-22-nerved, 11-19 נ3-6 mm, including the conic beak, this 6-10 mm, bidentate, its teeth smooth or nearly so; achene loosely enveloped, 3-4(-4.5) נ1.7-2.8 mm, ±stipitate, somewhat rhomboid, trigonous with flat to concave faces and smoothly curved, somewhat thickened lateral angles; style persistent and becoming bony, strongly contorted at or near the base; 2n=56. Moist to wet woods, meadows, and marshes; N.S. and N.B. to Minn. and Nebr., s. to Fla. and Tex.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.