Erect, branched, 5-12 dm; lvs ovate, 5-10 cm, coarsely serrate and commonly shallowly 3-lobed, velvety; fls several in peduncled clusters from the upper axils, pink, 3 cm wide; bractlets narrowly lanceolate; 2n=42. Native of Europe; naturalized in salt marshes from Mass. to Va., and locally inland. July-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.