Perennial with solitary or clustered stems 3-7 dm, with alternate branches or dichotomous above the middle, rarely with a few opposite branches; lvs lanceolate or narrowly elliptic, 2-5 cm; fls (8)9-12-merous, cal-lobes narrowly oblanceolate to spatulate, 1-3 mm wide, conspicuously 3-5-nerved; cor-lobes pink (white), red and yellow at base, rather narrowly oblanceolate, 16-22 mm, usually 1/4 or 1/5 as wide; 2n=38. Salt or brackish marshes near the coast; Conn. to Fla. and La. July, Aug. Ours is var. dodecandra.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.