Tufted perennial 3-8 dm; lvs elongate, often surpassing the stem, mostly 4-6 mm wide but conduplicate; bracts 4-8, much surpassing the infl; rays usually well developed, each bearing a terminal glomerule of spikes, or occasionally suppressed, producing a compact infl; spikes ovoid or subglobose, very dense, 7-15 mm; spikelets flat, ovate, 2-5 נ1.5-3 mm, closely imbricate with their flat sides together, (6-)10-22-fld; scales 1.5-2.5 mm, falcately incurved-ascending with divergent tip, in side-view with parallel sides, distinctly bicarinate basally; rachilla persistent, wingless; stamen 1; achenes linear-trigonous, 1-1.5 mm. Swamps and marshes; N.J. to Fla., w. to Ill., Mo., Okla., and Tex. Sometimes confused with C. virens, a more s. sp. not reaching our range.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.