Annual, biennial or perennial, with slender taproot. Stems prostrate to ascending or erect, 5–15(–25) cm long. Leaves sessile to petiolate, obovate to oblong-spathulate, 4–18 mm long, 3–10 mm wide, obtuse; petioles to nearly as long as lamina; stipules 1–2 mm long. Inflorescence much-branched; bracts 1–2 mm long. Flowers 3–4 mm diam.; pedicels 0.5–4 mm long; sepals mucronate, 2–3 mm long with a broad, green midrib and membranous margins; petals white, entire or emarginate, less than half sepal length; stamens 3–5. Capsule ovoid, c. 2 mm long; seeds pale brown, 0.4–0.6 mm long. Flowers most of year.