Hypanthium cupulate; fls 5-7-merous; sep ovate or oblong, reflexed; pet spreading; stamens 20-40, inserted at various levels in 10 longitudinal rows opposite the perianth-members; pistils 5-15, in a circle, the ovaries erect; styles clavate, outcurved; stigmas large, capitate; frs 1-seeded, resembling a follicle in appearance but indehiscent; perennial, rhizomatous herbs with stipulate, pinnately compound lvs (some tiny lfls commonly intermingled with the principal ones) and large panicles of white to pink fls, the lateral branches of the panicle surpassing the axis. 10, Temp. Eurasia and N. Amer.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.