Lower lvs twice ternate, the upper once ternate or irregularly compound; lfls ovate to lanceolate, finely serrate, the ascending teeth averaging 5-10 per cm of margin; rays 10-18, the outer ones of the terminal umbel becoming 3-5 cm and stiffly ascending; fr oblong-ovoid, 3-4 mm, half as wide; 2n=22. Moist fields and meadows; Que. and Me. to Sask., s. to Fla. and Tex. May, June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.