Sp. Pl. 1: 554. 1753.
Stems erect, never rooting nodally, strigose or hirsute, base bulbous and cormlike. Roots never tuberous. Basal leaf blades ovate to cordate in outline, 3-foliolate, rarely merely deeply divided, 2–5.3 × 2.4–5.4 cm, leaflets 1–2×-lobed, ultimate segments oblong to obovate, margins toothed, apex rounded in outline. Flowers: receptacle pubescent; sepals reflexed 2–3 mm above base, 6–9 × 2–4 mm, pilose; petals 5, yellow, 9–13 × 8–11 mm. Heads of achenes ovoid, 6–9 × 5–7 mm; achenes 2.2–3.2 × 2.2–2.8 mm, glabrous, margin forming narrow rib 0.1–0.2 mm wide; beak persistent, lanceolate to deltate, 0.2–0.8 mm, slender tip hooked when present.
Phenology: Flowering spring (Apr–Jun).
Elevation: 0–700 m
Introduced; B.C., Nfld. and Labr. (Nfld.), N.S., Ont., Que., Ala., Ark., Calif., Conn., Del., D.C., Ga., Ill., Ind., Kans., Ky., La., Maine, Md., Mass., Mich., Mo., Nebr., N.H., N.J., N.Y., N.C., Ohio, Oreg., Pa., R.I., S.C., Tenn., Vt., Va., Wash., W.Va., South America, native to Eurasia, Pacific Islands, Australia.
Ranunculus bulbosus is native to Europe and the Near East but has become naturalized in many other parts of the world. It is considered an introduced weed in the flora.
The Iroquois used Ranunculus bulbosus as a toothache remede and as a a treatment for venereal disease (D. E. Moerman 1986).