celastraceae the staff-tree family, in the order celastrales, comprising about 55 genera of woody vines, shrubs, and trees, native in tropical and temperate zones but best known for ornamental forms of the genera "euonymus" and "celastrus" (bittersweet). fruit of the family is often colourful. leaves are frequently leathery and flowers are small, with four to five sepals and petals; alternating between the petals, stamens rise from a usually conspicuous nectar disk.