Fr linear to oblong, hispid or scabrous, the ±quadrate to subcylindric, evidently ribbed body tipped by a long, nearly ribless beak; oil-tubes solitary in the intervals, or obsolete; carpophore entire, or cleft at the top; infl of compound or simple umbels, the ultimate umbels aggregated into a usually few-rayed primary umbel or ±scattered, often paired; invol wanting, or of a small leafy bract; involucel of several lobed or dissected foliaceous bractlets; sep minute or obsolete; pet white, the outer ones of the outer fls enlarged; small annuals; lvs pinnately dissected, with ±linear, small and rather short ultimate segments. 10, Old World.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.