Annual or perennial slender herbs. Stems rigid. Leaves narrow. Inflorescences panicu-late to capitate. Calyx with or without bracts at base (epicalyx), 5-toothed, 5-15-nerved, with scarious commissures (intervals between nerves or groups of nerves). Petals 5, with entire to 2-fid limb and without corona] scales. Stamens 10. Ovary 4-celled at base, 1-celled at apex; styles 2. Capsule many-seeded, oblong or ovoid, dehiscent, with 4 teeth. Seeds shield-shaped; embryo eccentric, straight.