This tree was bred by Karl Sax, Arboretum director from 1946-1954. First employed at the Arboretum as a professor, Sax worked in the nurseries of the nearby Bussey Institute hybridizing numerous ornamental species. One of the parent plants of this hybrid is the Sargent crabapple, named for Arboretum founding director Charles Sprague Sargent. Sax dubbed the offspring hybrid—the tree before you—‘Mary Potter,’ after Sargent’s daughter. In spring, the tree grows pink buds, which open to white flowers. The small red fruits emerge in fall.