(soapberry), a family of dicotyledonous plants including trees, shrubs, and woody (less frequently, herbaceous) lianas. The alternate leaves are pinnate or, rarely, simple. The aromatic flowers are most often small and irregular; they are borne in terminal or axillary cymose inflorescences. There are usually five sepals and five petals. The plants are characterized by a disk that usually forms between the petals and the stamens. The gynoecium has three (sometimes two or four) carpels. The ovary is superior.
There are about 140 genera, embracing nearly 1,600 species. The plants are distributed predominantly in tropics and sub-tropics, especially in Asia and the Americas. In the USSR only a few species of the genus Koelreuteria are cultivated (as ornamentals). The bark, leaves, and fruits of soapberry plants contain a milky juice and resins. The fruits, seeds, or caruncles of many species are edible. A number of species yield a valuable lumber, and some are rich in saponins (for example, Sapindus).