Annuals, 3-5(-10) cm tall, fascicled, glabrous. Stolons slender, short, rooting from nodes. Leaves basal, fascicled or rosulate. Petiole 1-4(-9) cm; leaf blade broadly linear to narrowly spatulate, 3-15 mm, fleshy, margin entire, apex obtuse. Flowers 3-10. Pedicel 0.7-1.3 cm, slender. Calyx 1.5-2.5 mm, membranous; lobes ovate-triangular, 0.5-0.8 mm, apex acuminate. Corolla white, pale lilac, or reddish, 2-3.5 mm; lobes oblong to oblong-ovate, 1-1.5 mm, apex obtuse. Capsule ovoid, ca. 3 mm. Seeds fusiform. Fl. and fr. Apr-Sep.

Along streams, wet grassland at edge of forests, sometimes floating; 1700-2400(-4000) m. Heilongjiang, Jilin, Qinghai, Sichuan, Xizang, Yunnan [throughout temperate zones of northern and southern hemispheres].