A genus of small, rain-forest trees in which the leaves are alternate, usually pinnate, and without stipules. The regular flowers are held in cymes and have 3–5 petals and the same number of sepals. The fruit is usually a capsule or drupe. Some species have edible fruits. Several species appear to reproduce only vegetatively (e.g. O. acidula, emu apple, which has an edible pulp) and their seeds may be infertile. There are 6 species, endemic (see endemism) to tropical eastern Australia.
Subjects: Plant Sciences and Forestry.