Creeping herb forming thick loose mats, either in very wet ground or floating. Stems 2-20 cm long, creeping and rooting below, with short bristly hairs all round. Lamina of lf elliptic to narrowly-ovate, 6-15 × 3-8 mm. Floral tube 1.3-2 mm deep, glabrous or somewhat hairy. Petals usually white, very rarely pink at first, but flushed pink after pollination, 6.5-12 × 4-8 mm. Capsule glabrous, (3)-4-6.5 cm long; fruiting pedicel (1)-2.5-12 cm long.