Stems creeping; submersed lvs none; floating lvs long- petioled, shallowly 3-5-lobed; fls white, 5-7 mm wide; receptacle glabrous; 2n=16. Shallow water and wet shores; coastal plain from se. Pa. to S.C.; also Nf. and Europe. May-Aug.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.