Stems glabrous. Leaves all laminate, filiform-dissected leaves absent. Leaf blade reniform, 0.4-1 × 0.6-1.7 cm, margins shallowly crenate-lobulate, segments rounded. Flowers: receptacle glabrous; sepals recurved, 1.5-2 × 1-1.5 mm, glabrous; petals 5, 2-4 × 1-1.5 mm; style 0.1 mm. Fruiting pedicels recurved. Heads of achenes globose or depressed-globose, 3-4 × 3-4 mm; achenes 1.2-1.6 × 1-1.2 mm, glabrous; beak deciduous, sometimes leaving stub to 0.1 mm. 2 n = 16 (Europe).

Flowering spring-summer (Apr-Aug). Edges of lakes and ponds on the coastal plain; 0-150 m; Nfld.; Md., N.C., Pa., S.C., Va.; Europe.