Herbs annual or subshrubs. Leaves alternate, sessile, subulate. Flowers solitary in leaf axils, minute, bisexual; bracteoles 2, scarious. Perianth segments 5, free. Stamens (1-)3(-5), inserted on an annular, hypogynous disk. Stigmas 2; style extremely short. Fruit a utricle; pericarp thin, scarious, indehiscent. Seed vertical, black when ripe; testa leathery, granulate; embryo annular; perisperm present.

Between six and eight species: C Asia and Siberia, Europe; one species in China.