Annual. Stems ascending or rarely decumbent, filiform, glabrous or hairy, (1)-2-8-(15) cm tall; axillary fascicles of lvs 0; adventitious roots 0. Rosette lvs short-lived. Cauline lvs linear, hyaline with long cilia at base, very rarely glabrous, aristate at apex, 1-10-(12) × 0.2-0.5 mm; upper lvs becoming subulate. Fls small, 4-(5)-merous, often very numerous. Pedicels with glandular hairs or glabrous, 3-15 mm long. Sepals obtuse or acute, 1-2 × 0.5-1 mm, glabrous or with glandular hairs; hyaline margins often purplish, sometimes green. Petals 0, very rarely minute. Stamens 4-(5). Capsule ovoid, slightly > calyx; styles and valves 4-(5). Seeds brown, triangular-ovoid, papillate, 0.3-0.4 mm long.