Herbs annual. Stem erect, much branched, glabrous or arachnoid hairy. Leaves alternate, sessile, terete, fleshy, base expanded, apex obtuse or aristate awned; leaf axil fascicular pilose. Flowers borne in axillary glomerules, bisexual and female (plants polygamous), with 2 bractlets. Perianth conic, 5-parted; segments lanceolate or broadly so, in fruit with a membranous wing near apex abaxially. Stamens 2 or 5; anthers oblong, without an appendage. Ovary ovoid, laterally compressed; style short; stigmas 2, filiform. Fruit a utricle, enclosed by perianth; pericarp membranous, adnate to seed. Seed vertical or horizontal, orbicular; testa membranous or subleathery; embryo spiral; perisperm absent.

About three species: N Africa, C and SW Asia, S Europe; two species in China.