Colonial from well developed creeping rhizomes, 6-15 dm, tending to be somewhat succulent; stem puberulent in lines, at least above; lvs glabrous beneath, scaberulous above, serrate, the lowermost ones enlarged, long-petiolate, with elliptic blade to 25 נ5 cm, but sometimes early deciduous, the cauline ones ±reduced upwards, becoming sessile or nearly so with ±sheathing but not auriculate base; infl corymbiform or paniculiform; invol 8-11 mm, its bracts not much if at all imbricate, glabrous except for the sometimes ciliolate margins, narrow with long-attenuate, loose or somewhat squarrose green tip (this well under 1 mm wide), or the inner purplish instead of green; rays 25-45, pink or sometimes lavender, 7-12 mm; achenes glabrous or sparsely hairy; 2n=16. Swamps and other moist low places; se. Va. to Fla. and Ala.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.