Trees or shrubs without latex. Stems sympodial. Leaves alternate, simple, often asymmetrical at base; stipules soon deciduous. Flowers hermaphrodite or unisexual, fasciculate in axillary cymes or solitary. Perianth often sepaloid, (3-) 4-6 (-9)-lobed. Stamens (3-) 4-6 (-9), opposite perianth segments. Ovary superior, 2-carpelled, l-2-celled, each cell containing a single pendulous ovule; styles short, 2-fid or 2-partite with filiform stigmas. Fruit a samara, nut or drupe. Seeds with or without endosperm; embryo straight.