Real Dictionary

tupelo in American English
any of a genus (Nyssa) of the sour-gum family of tall North American trees found in moist forests or swamps, including the black gum and cotton gum
noun: any of several trees of the genus Nyssa, having ovate leaves, clusters of minute flowers, and purple, berrylike fruit, esp. N. aquatica, of swampy regions of the eastern, southern, and midwestern U.S.

tupelo in British English
noun: any of several cornaceous trees of the genus Nyssa, esp N. aquatica, a large tree of deep swamps and rivers of the southern US