Polygamodioecious, unarmed, pubescent or glabrous, terrestrial or epiphytic, deciduous or evergreen shrubs or trees. Stems usually branched, pachycaulous. Leaves alternate, petiolate, the bases enlarged, stipulate or exstipulate; blades simple, palmately lobed or palmately compound, highly variable in shape, membranaceous, chartaceous to coriaceous, the margins entire or variously toothed. Inflorescences terminal, usually erect, paniculate, the ultimate units capitula; bracts well-developed, variously shaped; pedicels lacking. Calyx obsolete or forming an annular margin; petals 5–7, valvate, free; stamens 5–7; carpels 2–12; ovaries inferior, styles free or connate basally; the disc flat or convex. Fruits drupes, glabrous to stellate, globose or ovoid; endocarp crustaceous. Endosperm ruminate. 2n = 48 (known only for O. reticulatus Decne. & Planch.).