Description from Flora of China
Herbs perennial, rhizomatous or sometimes stoloniferous. Rhizomes branched. Leaves several, basal, long petiolate, 3- or 5-sect. Scapes 1 to several, erect. Inflorescences terminal, monochasial, 1- to few flowered. Flowers small, actinomorphic, bisexual. Sepals 5(--8), white or greenish yellow, often petaloid. Petals 5--10 or more, clawed, adaxially often nectariferous. Stamens numerous, glabrous; filaments filiform; anthers broadly elliptic. Pistils 8--14, stipitate; ovules several per ovary. Styles recurved. Follicles stipitate, oblong, transverse veins inconspicuous; persistent styles short. Seeds brown, ellipsoid, shiny, nearly smooth.
Fifteen species: E Asia, North America; six species (five endemic) in China.
(Authors: Fu Dezhi; Orbélia R. Robinson)