Description from Flora of China
Herbs perennial or weakly defined subshrubs, sometimes dioecious. Rhizomes large. Stems erect, sparsely to densely branched. Leaves simple, alternate, petiolate; leaf blade reniform, orbicular-reniform, or orbicular-cordate, margin entire or nearly so; ocrea tubular, membranous, margin entire, apex oblique or truncate. Inflorescence terminal, paniculate. Pedicel articulate. Flowers bisexual or unisexual. Perianth persistent, accrescent in fruit. Stamens 6. Ovary compressed; styles 2; stigmas penicillate. Achenes biconvex, ovoid, margin broadly winged.
About two species: Asia, Europe, North America; two species (one endemic) in China.
(Authors: Li Anjen (李安仁 Li An-ren); Alisa E. Grabovskaya-Borodina)