Plants glabrous (or sheathing leaf bases sometimes pubescent). Stems creeping or floating, not bulbous-based, without bulbils. Roots nodal, never tuberous. Leaves cauline, either simple and laminate (with expanded blade), or completely dissected into filiform segments, or with proximal leaves filiform-dissected and distal leaves laminate; laminate leaves petiolate, undivided or 3-parted, segments entire to shallowly cleft and crenate; filiform-dissected leaves petiolate or sessile. Inflorescences axillary, solitary flowers. Flowers pedicellate; sepals deciduous soon after anthesis, 5; petals 5, white or white with yellow claws; nectary scale attached on 3 sides, forming ridge or shallow pocket not covering nectary, glabrous, free margin entire; style present. Fruits achenes, 1-locular; achene body ellipsoid or flattened-ellipsoid, 1-2 times as wide as thick, not prolonged beyond seed; wall thick, with coarse transverse ridges; margin low narrow ridge; beak much shorter than achene body.

Distribution

Widespread except lowland tropics.

Discussion

Species ca. 15 (3 in the flora).

Unlike most species of Ranunculus, members of this subgenus are not poisonous.

Selected References

None.

Lower Taxa

Ranunculus aquatilis, Ranunculus hederaceus, Ranunculus lobbii

Key

1	Leaves all dissected into filiform segments.	Ranunculus aquatilis var. diffusus
1	Leaves not all filiform-dissected, all or some laminate and shallowly to deeply 3-lobed or -parted.	> 2
2	Leaves all laminate, margins shallowly crenate-lobulate, segments rounded; e North America.	Ranunculus hederaceus
2	Leaves of 2 types: laminate and filiform-dissected (filiform-dissected leaves sometimes few and inconspicuous in R. lobbii); laminate leaves 3-parted, segments elliptic, obovate, or fan-shaped; w North America.	> 3
3	Receptacle glabrous; style 1–1.5 mm.	Ranunculus lobbii
3	Receptacle hispid; style 0.1–0.8 mm.	Ranunculus aquatilis var. aquatilis