Shrubs and trees with opposite toothed leaves, which can be opposite or simple. Inflorescence usually flat-topped, cymose, with many small flowers, flowers 5-merous or 4-merous, calyx open during development, rotate corolla, style short, with a drupaceous fruit.
This order has been undergoing revision in recent years. Current research indicates that the entire lineage has been undergoing major diversification in relatively recent times (about 10 million years). The synapomorphies of the order are that the leaves are opposite and often basally connate, the margins are gland toothed, the inflorescence is cymose, with often monosymmetric flowers, and the calyx is persistent in fruit. There are between 2 and 7 familes (depending on the phylogeny), 45 genera, and about 1100 species. Adoxaceae was recently segregated from Caprifoliaceae.
