Lvs rather deeply set, ascending, linear, mostly 5-70 cm נ0.5-2.5 mm, flat or slightly twisted, with soft, thin, keeled, pale to anthocyanic base; scapes 8-15 dm, twisted and evidently multi-ribbed below, flattened and 2-3(4)-ridged above, the ridges tuberculate-scabrid, harsh to the touch; spikes 1-2.5 cm at maturity, ovoid or broadly ellipsoid, many-fld; keel of the lateral sep broad, slightly thickened, long-fimbriate (and usually crisped) especially toward the prominently exserted tip, making the spike appear dull and fuzzy; pet-blades yellow, 5-6 mm, obovate, unfolding in the morning; seeds 0.8-1 mm, slender, with ca 12 broad, pale, flattened, longitudinal wavy lines nearly as broad as the intervals; 2n=18. Wet low places, the base often submersed; coastal plain from N.J. to Fla. and Miss. Midsummer-fall.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.