Oenanthe L.
Glabrous annual, biennial or perennial herbs, with fibrous or tuberous roots, often aquatic. Lvs 1-4-pinnate, sometimes reduced to linear fistulose petioles; segments broad to narrow. Umbels compound, often shortly pedunculate and lf-opposed, sometimes terminal; bracts present or 0, entire; bracteoles usually numerous, entire. Petals white or pale pink, somewhat irregular, with apex notched and inflexed; calyx teeth evident, acute. Fr. ovoid, cylindric or globose, terete, not beaked, spineless; commissure broad; ribs 5 per mericarp, the lateral usually grooved or thickened; vittae solitary in furrows.
Key
1
Terrestrial; stem lvs entire or 1-2-pinnate and segments linear; rays and pedicels much thickened at fruiting
Aquatic; aerial lvs 1-4-pinnate and segments broad; rays and pedicels not or somewhat thickened at fruiting
2
Styles < ⅓ length of mature fr.; aerial lvs 2-4-pinnate; ultimate segments pinnatifid or crenate, up to 10-(15) mm long
Styles > ⅔ length of mature fr.; aerial lvs usually 2-pinnate, sometimes 3-pinnate at base; ultimate segments lobed or not lobed, serrate, 10-35 mm
c. 45 spp., temperate Eurasia, mountains of tropical Africa, N. America. Naturalised spp. 3.
