Stems prostrate, buried, rooting nodally, glabrous, not bulbous-based. Tuberous roots absent. Basal leaf blades reniform, deeply 3-parted, 1.1-2.6 × 1.6-4.3 cm, segments undivided or 1× cleft, margins crenate, apex rounded. Flowers: receptacle glabrous; sepals spreading or reflexed from base, 4-7 × 2-5 mm, glabrous; petals yellow, 5-6 × 2-3 mm. Heads of achenes hemispheric, 5-7 × 8-10 mm; achenes 3.8-4.2 × 2-2.2 mm, glabrous; beak persistent, lanceolate, curved, tip hooked, 1.6-2.4 mm. 2 n = 16. Flowering late spring-summer (Jun-Jul). Boggy places and lakesides in tundra, muskeg, and boreal forest; 0-900 m; Greenland; Alta., B.C., Man., N.B., Nfld., N.W.T., Ont., Que., Sask., Yukon; Alaska, Maine, Mich., Minn.; Eurasia. Starving individuals among western Eskimo groups ate the soaked plant of Ranunculus lapponicus as a dietary aid before consuming other food (D. E. Moerman 1986).
Rhizomes elongate, bearing at each node a solitary stem 1-2 dm and 1(-2) basal lvs; lvs petioled, reniform, deeply 3-parted, the flabellate-obovate segments coarsely crenate to shallowly lobed; cauline lf 1 or none, smaller, short-petioled; fls 8-12 mm wide; sep 3; achene-body oblong, 2-3 mm, turgid below, flattened above; beak slender, sharply curved or hooked; 2n=16. Wet soil; circumboreal, s. in Amer. to n. Me., n. Mich., n. Minn., and B.C. June, July.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.