Trees or shrubs; latex 0. Lvs usually alternate, rarely opposite, simple, often unequal-sided, stipulate. Fls fasciculate, arising from 1 year old branches, ☿ or unisexual, apetalous. Perianth 4-8-merous, subcampanulate; segments imbricate, persistent. Stamens as many as or a few more than perianth segments and erect in bud; anthers 2-celled; rudimentary ovary present in ♂ fls. Ovary superior, of 2 connate carpels, 1-(2)-locular; styles 2; ovule 1, pendulous. Fr. compressed, membranous, dry or thinly fleshy, often winged or appendaged. Seeds usually without endosperm; embryo straight.