(Sub)shrubs to trees, monoecious or dioecious. Leaves alternate to opposite to verticillate, simple or palmate, petiolate. Stipules absent or present, persistent or caducous. Inflorescences axillary fascicles, spikes, racemes, cymes and panicles, bracteate. Flowers unisexual, actinomorphic, pedicellate; Fruits dehiscent capsules, rarely drupaceous. Seeds 1 (or 2) per locule, with or without caruncle;
Africa: present Asia-Tropical:, New Guinea ‒ present Australasia: Central and South America: present Madagascar: present New Caledonia: present West Malesia: present southern hemisphere: present
A family (or subfamily) with c. 100 species. Most species are found in the Southern Hemisphere, with many endemic genera and species in Australia, New Caledonia, Madagascar, Africa, Central and South America. In Malesia only four genera, three of which with a single species in New Guinea only; Austrobuxus (3 species) is the only one also found in West Malesia.
The family was generally regarded as part of the Euphorbiaceae s.l. (Webster 1994; Radcliffe-Smith 2001), and classified as the subfamily Oldfieldioideae, including four tribes and several subtribes. Most typical for this otherwise indistinct family is the pollen (see below). Croizatia Steyerm. (originally belonging here in tribe Croizatieae; central and southern America) differed with 5 petals, an extrastaminal disc, divided stigmas, and lacking the pollen type (Levin 1992) and, based on molecular phylogenetic analysis (Wurdack et al. 2004), is currently placed in the Phyllanthaceae (Euphorbiaceae s.l. subfam. Phyllanthoideae). Also deviating is Paradrypetes Kuhlm. (tribe Podocalyceae subtribe Paradrypetinae; monotypic, Brazil), which probably belongs to the Rhizophoraceae, but agrees in wood anatomy and pollen details with Podocalyx Klotzsch (same tribe, subtribe Podocalycinae, monotypic in Amazonia; Levin 1992).