sourgum
sour gum |ˈsou (ə )rˌgəm ˈsaʊərɡəm |(also sour gum ) ▶noun a tupelo of eastern North America, with dark bark that has a deeply checkered pattern. Its bitter blue fruits are eaten by black bears and numerous species of birds. Also called black gum, black tupelo, pepperidge. [Nyssa sylvatica, family Nyssaceae. ]