Herb to 10 cm, glabrous. Branchlets often pustulate. Leaves linear, slightly channelled above, 8–12 mm long, 1–2 mm wide, pustulate. Flowers solitary, shortly pedicellate. Perianth lobes ovate to triangular, free almost to base, acuminate, green outside, white or pink inside. Stamens 4–12, in 4 bundles alternate with lobes; filaments slightly dilated towards base. Capsule ovoid, sometimes ribbed, 3 mm diam.; valves deeply bifid when open, membranous. Seeds comma-shaped, light to dark brown, colliculate.