Slender, tufted, sweet-scented annual 0.5-2 dm; lvs few, all borne near the base, mostly 0.5-2(-2.5) mm wide, up to as long as or a little longer than the stems; invol bracts elongate, some or all of them much surpassing the infl; spikelets in dense, capitate clusters, the terminal cluster sessile, the others (if present) on slender rays to 3 cm; spikelets 4-10 mm, flattened, 6-20-fld; scales evidently (5)7-9-nerved, 1.0-1.7 mm exclusive of the recurved, slender awn-tip, this 0.3-1 mm; rachilla wingless, ±persistent, the scales falling from it at maturity; stamen 1; anthers 0.2-0.3 mm; achenes trigonous, 0.6-1 mm; 2n=48, 56, 64. Moist or wet, often sandy soil; nearly cosmop., and throughout our range. (C. aristatus; C. inflexus)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.