Annual, slender herbs. Leaves spuriously whorled, linear; stipules small, scarious. Cymes terminal, dichasial, loose. Sepals 5, free, herbaceous and often somewhat fleshy, scarious at margin. Petals 5, white or whitish, entire. Stamens (5-)10, inserted on a perigynous ring. Ovary 1-celled, many-ovuled; styles (3-)5, alternating with sepals. Capsule (3-) 5-valved or toothed. Seeds small, more or less lenticular, keeled to winged.