Cathayeia Ohwi Idesia is a genus of flowering plants in the family Salicaceae (formerly placed in the family Flacourtiaceae), comprising the single species Idesia polycarpa.

It is native to eastern Asia in China, Japan, Korea, and Taiwan.

[1] It is a medium-sized deciduous tree reaching a height of 8–21 m, with a trunk up to 50 cm diameter with smooth greyish-green bark.

The flowers are small, yellowish green, fragrant, and born in panicles 13–30 cm long.

[3] The species is occasionally grown as an ornamental tree in other temperate regions including Europe.