Description from Flora of China
Herbs or subshrubs. Stem erect, densely tomentose; branches ascending. Leaves alternate, solitary, or fascicular on dwarf branches, sessile, linear, semiterete. Inflorescence spicate, without bractlets. Flowers bisexual. Perianth 4-lobed, herbaceous; segments equal, or lateral 2 longer than others, oblong, remaining unchanged in fruit. Stamens 4; filaments exserted, filiform; anthers oblong. Ovary ovoid; ovule sessile; style long; stigmas 2, filiform. Utricle compressed; pericarp membranous, free from seed. Seed vertical; testa leathery; embryo horseshoe-shaped; radicle inferior.
About ten species: C and SW Asia extending to China, Mongolia, and Russia, S Europe; one species in China.