Plants cespitose in clumps of fewer than 40 culms. Culms erect, 35-140 cm; vegetative culms few, inconspicuous, usually fewer than 12 leaves, not strikingly 3-ranked, leaves clustered at apex. Leaves: sheaths usually with white intervenal areas abaxially, conspicuously green-veined adaxially nearly to collar, Y-shaped hyaline area at collar, adaxially firm, summits truncate and prolonged to 2 mm beyond collar, rounded, proximal sheath loose, smooth; distal ligules 2-5.5 mm; blades 3-7 per fertile culm, 20-65 cm × 2.2-6(-6.5) mm. Inflorescences erect to arching, compact to open, green, 1.5-5 cm × 5-16 mm; proximal internode 3.5-10(-11.5) mm; 2d internode 2-8 mm; proximal bracts scalelike with bristle tips shorter than or equaling inflorescences. Spikes 4-10, overlapping to distinct, globose to ellipsoid, 7-13 × 4-7 mm, base rounded or occasionally tapered, apex obtuse to rounded. Pistillate scales white-hyaline, with green midstripe, ovate, 2.1-3.3 mm, much shorter by 0.7-1.6 mm and narrower than perigynia, margins hyaline or pale, sometimes involute, apex obtuse to acute. Perigynia 15-80 on larger spikes, spreading, green distally, conspicuously 4+-veined on each face, narrowly to broadly ovate, plano-convex, 2.7-4.1 × 1.3-2.3 mm, 0.35-0.5 mm thick, margin flat, including wing 0.25-0.45 mm wide, smooth; beak pale green at tip, flat, ciliate-serrulate, abaxial suture with conspicuous white-hyaline margin, distance from beak tip to achene 1.2-2.2 mm. Achenes elliptic, 1.3-1.6 × 0.9-1.2 mm, 0.35-0.5 mm thick. 2n = 68.
Tufted, aphyllopodic, leafy-stemmed, 3-8 dm; main lvs 2.5-6 mm wide, shorter than the stem; sheaths ventrally hyaline; spikes 5-10, gynaecandrous, subglobose, 6-9 mm, sessile, loosely aggregated in an infl 3-5 cm, or the lowermost occasionally separate; pistillate scales ovate, much (ca 1.5 mm) shorter than the perigynia, hyaline, slightly brown-tinged, with green midnerve, acute or obtuse; perigynia ascending, planoconvex, ovate, green or pale greenish-brown, 3.3-4.4 mm, 2-2.5 times as long as wide, broadest at a fourth to a third their length, finely nerved dorsally, lightly or obscurely nerved ventrally, gradually tapering to the flat, serrulate beak; achene lenticular, 1.5-2 נ1 mm. Open woods and meadows; Me. to Mich. and S.D., s. to N.C., O., Mo., and Okla. (C. mirabilis, a preoccupied name) C. tincta Fernald, with brown scales pale at the margin, may be a hybrid with C. foenea.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Very common in dry or moist woods and thickets. In the eastern part of its range this species seems to be partial to dry open habitats, but in Indiana it has been most often collected in low or flat woods, shaded ravines, marshy habitats on the borders of ponds, and on the flood plains of streams.