Annual, 8-35 cm tall, erect or somewhat decumbent, branched herb of moist places. Stem and branches mostly pinkish, glandular pubescent, rarely sub-glabrous. Leaves opposite, subsessile or shortly petiolate, oblong-obovate, elliptic oblong, lanceolate or oblanceolate, 4-25 mm long, 2-15 mm broad, apex acute, margin minutely and distinctly serrate, glandular pubescent or almost glabrous; stipules triangular lanceolate, hairy with serrate margins, acute, 2-4 mm long. Inflorescence dense or loose axillary fasciculate cyme of 6-12 or more flowers. Flowers reddish, usually 5-merous, 0.5-2 mm long and c. 2 mm across; pedicels slender, 1-5 mm long, glandular pubescent. Sepals 5, free, 1.5- 2.5 mm long, linear-lanceolate to ovate-oblong, acute, the keel and often coloured margins ciliolate, glandular pubescent. Petals 5, lanceolate or oblanceolate, 1-2.5 mm long, obtuse or sub-acute, white or pink. Stamens usually 5, rarely more. Carpels 5, united; styles 5, free, recurved. Capsule reddish, ovoid or subglobose, margins of the valves incurved. Seeds minute, with rounded ends, dark brown, shining, somewhat reticulate.