Annual, rarely biennial or perennial, taprooted herb. Stems glabrous, geniculate, erect to ascending, much-branched, 5-20 cm long. Lvs green or reddish, rarely purplish, glabrous, in whorls of 4 or rarely in opposite pairs, obovate to suborbicular, obtuse or shortly apiculate, petiolate, sometimes falling at fruiting, (2)-5-10-(15) × (1)-3-8-(10) mm. Stipules scarious, triangular to ovate, acuminate, 2-3 × 1-1.5 mm. Infl. many-flowered, lax or rarely compact. Pedicels c. = calyx, = or > the ovate acuminate scarious bracts. Sepals apiculate, hooded, green or reddish, rarely purplish, with scarious margins, 2-2.5 × 1 mm. Petals white, narrow-elliptic, entire, 1 mm long. Stamens 3-5, 0.5-0.7 mm long. Ovary 0.5 mm long; style 0.3-0.4 mm long, 3-lobed, deciduous. Capsule ovoid, c. 2 mm long. Seeds curved, brown, finely papillate.