Sep 5-9, petaloid; pet none; stamens many; staminodes none; pistils 4-many, the style very short; follicles compressed to subterete; low perennial poisonous herbs of wet places, with alternate, petiolate, entire or merely toothed lvs and peduncled, axillary or terminal fls. 15, circumboreal.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.