Fr linear-oblong to elliptic or lanceolate, flattened laterally; ribs paler than the intervals; oil-tubes usually solitary in the intervals, 2 on the commissure; carpophore ±cleft; umbels lateral and terminal, compound or by reduction simple; invol none; bractlets conspicuous; sep obsolete; fls white, the marginal ones sometimes irregular; stylopodium conic; annuals or biennials with ternate-pinnately decompound lvs. 40, N. Temp.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.