Stoloniferous perennial. Basal leaves with petioles 1–15 cm long, ± glabrous; lamina palmatisect, 1–5 cm diam., glabrous or with few hairs beneath; ultimate segments 0.5–2 mm wide. Flowering stems 5–30 cm high, 1–3-flowered, glabrous, ± pilose at base. Sepals 5, spreading to reflexed, 2–3.5 mm long, glabrous. Petals 5–12, narrowly obovate to oblanceolate, 4–10 mm long, yellow, obtuse; nectary near petal-base, c. 1 mm long, with lobe obtuse, often oblique, free for 1/2–2/3 its length. Stamens 20–30. Pistils 20–45. Receptacle shortly hirsute in stamen zone, subglabrous between achenes. Achenes ± lenticular, 1.5–1.8 mm long; lateral faces almost smooth or irregularly warty; beak reflexed, about 1/2–2/3 as long as achene-body.
Grows in shallow water, in mud, along creeks or in ponds, sometimes with the leaves floating or temporarily submerged.
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