Description from Flora of China
Shrubs or small trees, evergreen, sometimes with a glandular resinous exudate on leaves and inflorescences. Leaves simple or pinnate, estipulate. Flowers bisexual or unisexual and plants dioecious, actinomorphic, solitary and axillary or arranged in terminal and axillary racemes, corymbs or panicles. Sepals (3-)5(-7), valvate or sometimes imbricate, deciduous when mature. Petals absent. Disk inconspicuous, absent in male flowers. Stamens (male flowers) 5-8; filaments short; anthers ellipsoid, obtusely 4-gonous, connectives prominent. Ovary (female flowers) ellipsoid, obcordiform, or transversely ellipsoid, 2- or 3(or 5 or 6)-gonous, 2- or 3(or 5 or 6)-loculed; ovules 2 per locule, one ascending, and one pendulous; style apical, much longer than ovary, often twisted, deciduous; stigma 2-6-lobed. Capsules samaralike, 2- or 3(-6)-loculed, septifragal, boatlike. Seeds 1 or 2 per locule, obovoid, lenslike, or subglobose; testa crustaceous, arillode present or absent; hilum thick; embryo revolute, cotyledons linear. 2n = 28, 30, 32.
About 65 species: mainly in Australia and neighboring islands; one species in China.