Paper birch has white, peeling bark, though it can be dark colored in young trees. Leaves are ovate in shape with a toothed margin. Flowers are produced on small cylindrical catkins which hang from the branches in spring.
There are two ways to identify the two species of birches:
Bark: On mature trees, paper white birch bark is white and peeling. Black birch bark is smooth and brown to black.
Smell: When broken or scratched, the twig or leaf of a black birch will smell like wintergreen.