Stems creeping or floating, rooting nodally, glabrous, not bulbous-based. Tuberous roots absent. Basal leaf blades linear to obovate, undivided or 3-lobed, 1.5-3.6 × 0.3-2 cm, lobes lanceolate or elliptic, margins entire, apex rounded to acuminate. Flowers: receptacle glabrous; sepals spreading, 6-10 × 4-7 mm, glabrous; petals 7-11, white or pink, 8-13 × 3-6 mm. Heads of achenes globose or hemispheric, 5-12 × 9-15 mm; achenes 4.2-5.2 × 2.4-3.2 mm, glabrous; beak persistent, lanceolate, straight or curved, 1-1.2 mm. 2 n = 32.

Flowering summer (Jul-Aug). Shallow water of bogs and pools in muskeg and tundra; 0-700 m; Man., Nfld., N.W.T., Ont., Que., Yukon; Alaska; Eurasia.