Cal gamosepalous, campanulate, 5-toothed; pet 5, distinct or slightly connate at the very base; stamens 5 (in ours) or 10, usually long-exserted; fr oblong to linear, smooth; seeds few-several; unarmed perennial herbs or shrubs with bipinnate lvs, with a prominent gland on the upper side of the rachis between the 2 lowest pinnae (and sometimes between the next pair); fls white or greenish-white, in long- peduncled axillary heads. 25, New World.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.