Male and female flowers occur in separate catkins on the same plant with or before the leaves in spring. The hanging male catkins are brownish, and are borne in groups of 2 or 3. Female catkins are greenish and erect. Catkins are usually borne at the tips of twigs and are visible during winter. Leaf scars are small and semicircular, with 3 bundle scars.
Terminal buds are present only on spur shoots.
Lateral buds are ovoid and 0.25 inches long, with 3 or 4 smooth, chestnut-brown, imbricate scales. The bark becomes black and furrowed at the base of old trees. This is the only native birch with white bark. It has the widest east-west distribution of all the native North American birches. It is native to northeastern Iowa and on sheltered bluffs in Hardin county along the Iowa River.