Plant dioec. or polygamous; umbels compound; primary rays us.∞; general involucre of few bracts, or 0; secondary us. ∞. Calyx-teeth minute or 0; petals white to greenish. Fr. dorsally much compressed; commissure broad; mericarps almost flat, with 2 broad marginal wings and 3 prominent dorsal ribs. Vittae various in number. Perennial herbs or subshrubs with us. ternately or pinnately compound lvs. Some 70 spp., mainly of northern hemisphere; the N.Z. spp. endemic.

Glabrous or tomentose biennial to perennial herbs, with stout taproots. Lvs 2-3-pinnate or ternate; segments usually broad. Umbels compound, pedunculate; bracts usually 0, sometimes present, linear; bracteoles usually numerous, entire, rarely pinnate or 0. Petals usually white or green, sometimes pink, purple or violet, regular, with entire, acuminate, inflexed apex; calyx teeth evident, minute or 0. Fr. ovate, oblong or globose, strongly flattened dorsally, not beaked, spineless, but sometimes tomentose; commissure broad; ribs 5 per mericarp; dorsal ribs slender or slightly winged; lateral ribs with a broad, thin, or corky wing; lateral wings of opposing mericarps not appressed; vittae few to numerous in furrows.