Ricinocarpos undulatus, commonly known as wedding bush,[2] is a species of flowering plant in the family Euphorbiaceae and is endemic to the south-west of Western Australia.

Ricinocarpos undulatus is an erect, monoecious or dioecious spindly shrub that typically grows to a height of up to 1.5 m (4 ft 11 in), its young branchlets hairy.

[3] Ricinocarpos undulatus was first formally described in 1848 by Johann Georg Christian Lehmann in his Plantae Preissianae.

[6] This species grows in heath, shrubland, mallee and open woodland between Green Head, Wubin, Fremantle and Merredin in the Avon Wheatbelt, Geraldton Sandplains, Jarrah Forest, Mallee and Swan Coastal Plain bioregions of south-western Western Australia.

[3][2] Ricinocarpos undulatus is listed as "not threatened" by the Western Australian Government Department of Biodiversity, Conservation and Attractions.