Rhizomatous herb 2-5 dm, usually simple to the infl; lvs elliptic, 1-3(-4) cm, a third to half as wide, obtuse or rounded at both ends or somewhat tapering below, not revolute; cymes with few-many fls; bracts linear or lanceolate; sep oblanceolate to narrowly obovate, to 6 mm; pet 5-7 mm; stigmas 3(4), minute; fr unilocular (the placentas slightly intruded), ovoid, 5-6 mm, rounded to a short beak; 2n reported as 16, 18. Wet shores and marshes; Nf. and N.S. to w. Ont., s. to Conn., N.Y., Mich., Minn., and at higher altitudes to W.Va. and N.C. July-Aug.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.