Sourwood or sorrel tree, Oxydendrum arboreum, /ˌɒksᵻˈdɛndrəm ɑːrˈbɔəriəm/ is the sole species in the genus Oxydendrum, in the family Ericaceae. It is native to eastern North America, from southern Pennsylvania south to northwest Florida and west to southern Illinois; it is most common in the lower chain of the Appalachian Mountains. The tree is frequently seen as a component of oak-heath forests.