Stout to very slender, 4-15 dm; lf-blades deltoid, the larger 1-2 dm, on elongate petioles, mostly 2-3 times compound, the upper once or twice compound, on short, broadly winged petioles; lfls lanceolate to ovate, 1.5-4 cm, pinnatifid; umbels few, 3-12 cm wide, long-peduncled; rays and pedicels many; fr elliptic or oblong, 2.5-4.5 mm; 2n=44. Swamps, bogs, and wet meadows; Lab. and Nf. to Minn., s. to Pa., Ind., and Io., and in the mts. to N.C. Aug., Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Very rare. Two of my specimens were collected in dense shade on the south banks of streams in springy places in sandy-gravelly soil made miry by large springs, and I found it in a tamarack bog in La Porte County. Grimes collected a specimen in damp soil on a rocky slope along Sugar Creek in Montgomery County. It has also been reported from Carroll and Noble Counties and from the area of Delaware, Jay, Randolph, and Wayne Counties.