Much like no. 18 [Cyperus retrofractus (L.) Torr], but the rays, prophylls, and upper side of the bracts shortly rough-puberulent or scabrid; stem obtusely trigonous to rounded, rough-hairy to the base; spikes tight, bur-like, only slightly or scarcely longer than thick, tapering downward from the broad top, the axis 7-13 mm; spikelets 6-8 mm, with 1(2) fertile scale; scales 4-4.5 mm; bracts up to as long as the rays; rachilla-wings clasping the achene for half its length. Dry, sandy places; N.J. to Fla., w. to Ky., s. Mo., se. Okla., and e. Tex. (C. retrofractus var. p.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.