Trees or large shrubs, monoecious or polygamous. Leaves simple, alternate. stipulate, usually with oblique bases, petiolate. Flowers small, bisexual or unisexual. solitary, cymose or in axillary fasciculate clusters. Perianth 4-8, campanulate, persistent. Stamens as many as and opposite the perianth lobes or fewer. Ovary superior, unilocular with solitary ovule; styles 2, linear, stigmatose along inner surface. Fruit a drupe or a broadly winged samara.