Perennial; lvs 5(7)-parted (or even compound), doubly serrate, or toward the apex incised; bractlets like the bracts but smaller; fls greenish-white, the fertile ones sessile, the staminate 12-25 in each umbellet and surpassing the frs; sep lance-subulate, 1-1.5 mm, shortly connate below, equaling the pet, or nearly so; anthers greenish-white; fr subsessile, 4-6 mm, narrowed and with rudimentary bristles toward the base; styles recurved, exceeding the bristles. Woods; Que. and Nf. to B.C., s. to n. Fla., Mo., and N. M. June-Aug.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.