Description from Flora of China
Spiraea Linnaeus sect. Sorbaria Seringe, Prodr. 2: 545. 1825; Schizonotus Lindley, nom. rej.
Shrubs deciduous. Branchlets yellow to green when young, later dark reddish or yellowish brown, terete; buds ovoid to cylindric, with several exposed, alternate scales, glabrous or slightly pubescent at apex. Leaves alternate, stipulate, pinnate; leaflets opposite, sessile or subsessile, doubly serrate. Inflorescence a large, terminal panicle. Flowers small, numerous. Hypanthium shallowly cupular. Sepals 5, reflexed, short, broad, persistent. Petals 5, imbricate, white, ovate to orbicular, base cuneate, apex obtuse. Stamens 20–50, nearly equaling or longer than petals. Carpels 5, opposite sepals, basally connate, glabrous or subglabrous. Follicles glabrous, dehiscent along adaxial suture. Seeds several.
Rahn, K. 1989. A survey of the genus Sorbaria (Rosaceae). - Nord. J. Bot. 8: 557–563.
About nine species: temperate Asia; three species (two endemic) in China.
(Authors: Gu Cuizhi (Ku Tsue-chih); Crinan Alexander)