Description from Flora of China
Herbs perennial, mostly stoloniferous, polygamo-dioecious, usually spreading or appressed hairy. Stolons often rooting at nodes and forming plantlets. Leaves alternate, petiolate; stipules adnate to base of petiole, often membranous, sheathing; leaf blade 3-foliolate or pinnately 5-foliolate. Inflorescence erect, cymose or corymbiform, few flowered, rarely a solitary flower. Hypanthium obconic or turbinate. Sepals 5, valvate, persistent; epicalyx segments 5, alternating with and smaller than sepals, margin entire. Petals 5, white, rarely yellow, broadly obovate or suborbicular. Stamens numerous; anther 2-loculed. Carpels numerous, free, borne on convex receptacle; ovule ascending from middle of locule; style adaxial, short, persistent. Aggregate fruit formed from enlarged receptacle, berry-like, long conic to globose, fleshy. Achenes numerous, seated in pits on surface of aggregate fruit, minute, brittle. Seed testa membranous; cotyledons convex. x = 7.
About 20 species: temperate and subtropical regions of N hemisphere, extending to South America; nine species (three endemic, one introduced) in China.
(Authors: Li Chaoluan (Li Chao-luang); Hiroshi Ikeda, Hideaki Ohba)