Stems erect, glabrous, rooting at base, only very rarely rooting at proximal nodes. Leaves basal and cauline, basal and proximal cauline leaf blades reniform to semicircular in outline, 3-lobed or -parted, 1-5 × 1.6-6.8 cm, base truncate to cordate, segments usually again lobed or parted, sometimes undivided, margins crenate or crenate-lobulate, apex rounded or occasionally obtuse. Flowers: receptacle pubescent or glabrous; sepals 3-5, reflexed from or near base, 2-5 × 1-3 mm, glabrous or sparsely hirsute; petals 3-5, 2-5 × 1-3 mm; nectary on petal surface, scale poorly developed and forming crescent-shaped or circular ridge surrounding but not covering nectary; style absent. Heads of achenes ellipsoid or cylindric heads, 5-13 × 3-7 mm; achenes 1-1.2 × 0.8-1 mm, glabrous; beak deltate, usually straight, 0.1 mm.
Distribution
North AmericaEurasia.
Discussion
Ranunculus sceleratus varieties were used by the Thompson Indians as a poison for their arrow points (D. E. Moerman 1986).
