Korea Flora: Tree or shrub, evergreen or deciduous. leaves opposite, simple, palmate, or trifoliate. inflorescence raceme, spike, or cyme. flowers usually unisexual but occasionally bisexual. calyx (4-)5(-12) sepals, and corolla (4-)5(-12) petals or  absent. stamen number 4-13, and pistil 2 carpels, 2 styles, and superior ovary with 2 locules and 4 ovules. fruit follicle with 2 seeds, and seeds oval and tightly attached to each other. The seed coat thin, and endosperm sometimes hard.  cotyledons thin and leaf-like.