Cossinia is a genus of four species known to science, of rainforest trees, constituting part of the plant family Sapindaceae. The four species have an apparently ancient Gondwanan origin and present day distribution, consisting of an endemic, distinct, species in each of the southern hemisphere regions of the Mascarene Islands, Australia, New Caledonia and Fiji. They grow naturally in rainforests, including seasonally drought–prone rainforests, and associated non–fire–adapted vegetation types.