Herbs, annual, cespitose, not rhizomatous. Culms (5-)15-30(-55) cm, smooth. Leaves flat to V-shaped, 4-20(-30) cm × 1.5-3(-3.6) mm. Inflorescences: spikes 1-3, pale greenish, (3-)5-8(-11) × 5-7 mm; bracts (3-) 4(-5), horizontal to ascending at 30°, flat, (1-)3-10(-22) cm × 1-2.5(-3) mm. Spikelets 50-150, lanceolate to ovate-lanceolate, (1.9-)2.4-2.8(-3.8) × 0.6-0.9 mm; floral scales pale brownish to transparent, midvein not winged, laterally 2-3(-4)-veined, ovate, (1.8-)2.2-3.1(-3.4) × 1-1.7 mm; stamens 2; anthers elliptic, (0.2-)0.3-0.4 mm; style 0.5-0.8 mm; stigmas 0.5-0.9 mm. Achenes light brown, stipitate, oblong, 1-1.2(-1.4) × 0.5-0.6(-0.7) mm, base cuneate to rounded, stipe to 0.1 mm, apex subtruncate, apiculate, finely papillose. Fruiting summer. Damp grasslands, shorelines, ditches, lawns, gardens; 0-200 m; Ala., Ark., Del., Fla., Ga., Ill., Ind., Kans., Ky., La., Md., Miss., Mo., N.J., N.Y., N.C, Ohio, Okla., Pa., S.C., Tenn., Tex., Va., W.Va.; Mexico; West Indies; Central America; South America; Africa.
From Flora of Indiana (1940) by Charles C. Deam
Infrequent in southern Indiana and rare or absent from many of our northern counties. It is usually found in moist or wet soil along streams, on bars in streams, along ditches, and sometimes in cornfields along streams.
Tufted slender annual 0.5-3 dm; lower sheaths bladeless, the upper with soft blades 1-3 mm wide; bracts 2-4, widely spreading, 3-10 cm; spikes 1 or sometimes 2 or 3, ovoid to subglobose, strictly sessile, 5-10 mm; spikelets very numerous, flattened, 2-3 mm, 1- fld; scales very thin, with a ±denticulate keel and hyaline margins; stamens 2; anthers 0.2-0.4 mm; achenes tan, lenticular, elliptic, 1.1-1.4 mm, half as wide. Muddy or sandy shores; trop. Amer. and Afr., n. to Del., Pa., O., Mo., and Kan. (C. densicaespitosus; Kyllinga pumila)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
