Stems erect to prostrate, 0.8-3 mm thick. Leaf blades lanceolate to oblanceolate, 1.8-4.5 × 0.3-1 cm. Flowers: sepals 3-4 mm; petals 5-7 × 3-4 mm. 2 n = 32.

Flowering late spring-summer (Jun-Sep). Shallow water or muddy shores of ponds; 0-1000 m; St. Pierre and Miquelon; B.C., Nfld., N.S.; Calif., Idaho, Oreg., Wash.; Eurasia.

L. D. Benson (1948) reported Ranunculus flammula var. flammula only from eastern Canada and referred all material from the Pacific Slope to Ranunculus flammula var. ovalis . Benson's treatment is not tenable, however, because some western collections are indistinguishable from the eastern plants.