Betula lenta is a species of birch native to eastern North America, from southern Maine west to southernmost Ontario, and south in the Appalachian Mountains to northern Georgia.

A birch is a thin-leaved deciduous hardwood tree of the genus Betula, in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus Betula contains 30 to 60 known taxa of which 11 are on the IUCN 2011 Red List of Threatened Species. They are typically short-lived pioneer species and are widespread in the Northern Hemisphere, particularly in northern areas of temperate climates and in boreal climates. Birch wood, the wood of the birch, is used for a wide range of purposes.