An order of flowering plants, division Magnoliophyta (Angiospermae), in the subclass Rosidae of the class Magnoliopsida (dicotyledons). The order consists of three families: the Rhamnaceae with about 900 species, the Vitaceae with about 700, and the Leeaceae with about 70. The Rhamnales have a single set of stamens, opposite the petals, and usually a well-developed intrastaminal disk. The ovary has two or more locules, with one or two erect, bitegmic ovules from the base in each locule. The seeds have a well-developed endosperm. The Rhamnaceae are mostly shrubs or small trees with simple, entire or merely toothed leaves, as in cascara (Rhamnus purshiana) and the common buckthorn (R. cathartica). The Vitaceae are mostly tendril-bearing climbers with compound or lobed leaves, as in grapes (Vitis), the Virginia creeper (Parthenocissus quinquefolia), and Boston ivy (P. tricuspidata).