Plants annual, not rhizomatous, stoloniferous, or bulbiferous. Stems decumbent, freely branch-ing or simple, 1-10 cm, often rooting at nodes, forming small, loose mats. Leaves alternate, not distinctly petiolate, with clasping leaf sheaths; blade linear, 5-25 × 1-2 mm. Inflorescences axillary, 1-bracteate; bract minute, scarious. Flowers 2-8; sepals 1-2 mm; petals 2-5, often absent, white, 0.7-1.5 mm; stamens (2-)3(-5), anther pink. Seeds 0.5-1 mm, tuberculate; elaiosome minute, shorter than 0.5 mm.

Flowering spring. Moist woods; 0-500 m; B.C.; Calif., Oreg., Wash.