Description from Flora of China
Shrubs or subshrubs, much branched; woody branches without spines; herbaceous branchlets of current year with leaves and flowers. Leaves simple, opposite, nearly sessile, linear or scale-like, united with ocrea at base or free; ocrea membranous. Inflorescence axillary. Pedicel slender, jointed. Flowers bisexual. Perianth persistent, 5-parted, not accrescent in fruit. Stamens 12-18; filaments connate at base. Ovary tetragonous. Styles 4, short; stigmas capitate. Achenes trigonous, ellipsoid or oblong-ovoid, woody; ribs with wings or bristles, rarely overgrowing a thin bladderlike membrane on surface of reduced wings or bristles.
The reader can refer to Borodina (Rast. Tsentral. Azii 9: 122–130. 1989) for taxa in adjacent Central Asian countries.
About 35 species: N Africa, Asia, S Europe; 23 species (eight endemic) in China.
(Authors: Bao Bojian (包伯坚); Alisa E. Grabovskaya-Borodina)