Slender glab. branching herb up to 15 cm. or more tall, forming dense or loose tufts. Lvs opp., 0·5-2.5 cm. long, linear-lanceolate to spathulate to narrow-ovate, acute or subacute. Fls axillary or terminal, solitary or in 2-3-(5)-fld cymes, ± 2-3 mm. diam.; petals slightly > sepals, greenish white. Capsules hardly = sepals; seeds 3, c. 1 mm. diam., black.

Annual or perennial. Stems slender, weak, decumbent, not rooting at nodes, (1)-5-50 cm long. Lvs opposite, spreading, linear-oblanceolate to obovate-spathulate, acute, (5)-10-20-(25) × (1)-2-5 mm, cuneately narrowed to slightly sheathing base. Fls axillary, solitary or in 2-3-(5)-flowered cymes. Bracts obovate-subulate, scarious, 1-2 mm long. Sepals suborbicular, 1.5-2 mm long. Petals greenish white, obovate, 2-3 mm long. Anthers introrse, white. Capsule globose, slightly > calyx. Seeds 3, ovoid, black with white aril, either smooth and shiny or tuberculate and dull, 0.9-1.4 mm long.