Cerastium aquaticum Linnaeus, Sp. Pl. 1: 439. 1753; Malachium aquaticum (Linnaeus) Fries; Stellaria aquatica (Linnaeus) Scopoli.

Stems 20--80 cm, weak, apically glandular hairy. Proximal leaves petiolate; distal leaves sessile; leaf blade 2.5--5.5 × 1--3 cm, pubescent or glabrous, base rounded or subcordate, margin undulate, apex acute. Flowers terminal or axillary; bracts leaflike, margin glandular hairy; pedicel 1--2 cm, slender, densely glandular hairy. Sepals ovate-lanceolate, 4--5 mm, to ca. 7 mm in fruit, abaxially glandular pubescent, margin narrowly membranous. Petals bifid to base; lobes lanceolate, 3--3.5 mm. Stamens shorter than petals. Ovary ovoid; styles linear. Capsule pendent from spreading pedicel, exceeding sepals. Seeds rusty brown, globose, ca. 1 mm, mammillate. Fl. May--Jun, fr. Jun--Aug. 2n = 20*, 28.

This species is used medicinally, as a wild vegetable, and as fodder.

Mountain slopes, valleys, forests, floodlands, field margins; 300--2700 m. Throughout China [cosmopolitan].