This plant has white flowers, sometimes tinged with pale pink or pale lilac.  Each flower has three dainty petals with rough, ragged edges and fairly short sepals. Flowers are typically 12 to 16 mm across. The seeds are rather like those of buttercups. Leaves are in a basal rosette, lanceolate, tapered at both ends and stalked.

Bare muddy edges of freshwater bodies such as pools and ponds.

Flowers May to October.

Perennial herb.

Fairly widespread but quite local in Britain.

Rare as introduced plant in Leicestershire and Rutland.

It was on the 2011 VC55 Rare Plant Register (Jeeves, 2011) but is not on the current RPR (Hall & Woodward, 2022) because records are of introduced plants