Description from Flora of China
Herbs or subshrubs, glandular pilose or pubescent. Flowering stems erect, slender. Leaves alternate; stipules membranous at base, adnate to petiole; leaf blade 1–3 times 3-parted into narrow segments. Inflorescence cymose, corymbose, or paniculate, rarely a solitary flower. Flowers small. Hypanthium obconic, tubular, or campanulate. Sepals 5, erect, valvate, persistent. Petals 5, white or purple. Disk lining mouth of hypanthium, setose with long, rigid hairs, margin thickened. Stamens 5, opposite petals. Carpels 4–10 or more; ovule ascending from base of locule; style basal, articulate at base, deciduous; stigma capitellate. Achenes few or many, ovoid, glabrous, enclosed by hypanthium. Seed erect.
About eight species: Asia, North America; five species in China.
(Authors: Li Chaoluan (Li Chao-luang); Hiroshi Ikeda, Hideaki Ohba)