Fr ovate to oblong, flattened laterally; ribs 5 per mericarp; oil-tubes solitary in the intervals, 2 on the commissure; carpophore bifid half its length; umbels compound, without invol; rays several to many, the inner often short; umbellets many-fld, with very unequal pedicels, the central fl commonly sessile; bractlets few, short, lance-linear; sep short, triangular; pet bright yellow; stylopodium wanting; branching perennials 3-8 dm, glabrous or nearly so, from a cluster of thickened roots, some of or all the lvs once to thrice ternately compound. 4, N. Amer.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.