Fibrous-rooted perennial, slender, prostrate and rooting at the nodes, or ascending to 3 or 4 dm; lvs petiolate, ovate to lanceolate, 1-4 cm, entire or toothed, innocuous; peduncles axillary, 1-3 cm; bracts linear-oblong, 2-10 mm; head cylindric, 4-8 mm; bractlets minute, subulate, not protruding beyond the fls; 2n=16. Wet, sandy or muddy soil, shores, and bogs; Fla. to Tex., n. to se. Va., Ky., and Mo. July-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.