Annual or perennial herbs or dwarf-shrubs. Leaves mostly opposite; stipules and bracts conspicuous, scarious, often silvery. Flowers small, usually clustered in head-like inflo-rescences. Calyx lobes (4-)5, almost free, more or less hooded, sometimes aristate at apex. Petals 5, sometimes less, inserted at base of calyx. Ovary 1-celled, containing a basal, anatropous ovule; style short, 2-cleft at apex, sometimes the 2 stigmas sessile. Utricle included in calyx, 1 -seeded, membranous. Seeds oblong, lenticular to globular.