Cadellia is a monotypic genus of trees in the botanical family Surianaceae. The sole species, Cadellia pentastylis, commonly known as ooline, is a medium to large tree with bright green leaves and rough tile-pattern bark. It has rain forest origins dating from the Pleistocene Era when much of Australia was wetter than it is today. It grows on moderately fertile soils, preferably those suited for agriculture or pasture development. Due to extensive forest clearing, it is now considered a vulnerable plant in Australia.