Leaves opposite or subopposite or rarely ternate, usually with 2–4 glands on the under surface near the base, petiolate or sessile, with or without interpetiolar stipules.
Inflorescences terminal or axillary, usually forming many-flowered corymbs, umbels or panicles; bracts and bracteoles usually present, usually deciduous.
Petals 5, unguiculate, usually with fringed or denticulate margins; pedicels as long as, or longer than, the peduncle and articulated with it.
Ovary hairy or glabrous, 3-locular (or sometimes 2-locular outside our region); styles 3 (2), somewhat curved, with incurving stigmas.
Samara with a circular or ovate membranous or coriaceous lateral wing; dorsal wing shorter and narrower or absent.
Stamens 10; anthers basifixed, usually glabrous; filaments subulate, glabrous or finely-pubescent.
Small trees, woody climbers, or scandent or semiscandent shrubs.
Flowers actinomorphic or zygomorphic, bisexual.
Sepals 5, almost always without glands.