Betula lenta (Sweet or Black Birch) is native to eastern North America, from Nova Scotia west to southeast Manitoba, and south to Maryland and Delaware, and in the Appalachian Mountains to northern Georgia and Alabama.
It is a medium-sized deciduous tree reaching 20 m tall with a trunk up to 60 cm diameter. In younger trees the bark is characteristic of most birches with smooth bark and horizontal fissures. It can sometimes be mistakenly identified as a cherry tree. In older tree specimens the bark can developes a strong, peeling, exfoliation. The twigs, when scraped, have a strong scent of wintergreen. The leaves are alternate, ovate, 5-12 cm long and 4-8 cm broad, with a finely serrated margin. The twigs and buds are somewhat hairy. The flowers are wind-pollinated catkins 3-6 cm long, the male catkins pendulous, the female catkins erect. The fruit, maturing in early summer, is composed of numerous tiny winged seeds packed between the catkin bracts.
Betula lenta was used commercially in the past for production of oil of wintergreen before modern industrial synthesis.
Betula lenta's leaves serve as food for some lepidopteran caterpillars; a number of lepidopteran species feed on birches, in general.