Betula cordifolia young bark is shiny brown with pale brown lenticels. The leaves are alternate, ovate, 6–12 cm long, and double-toothed. As the specific epithet suggests, the leaf base is generally cordate (heart-shaped), however this can be misleading as it is occasionally flat or rounded. The leaves are dotted with many resin glands and the buds are ovoid and blunt. The twigs are yellow-brown to dark-brown and are dotted with resin glands and gray lenticels. They lack the hairs found on "Betula papyrifera". The flowers are catkins, with pollen catkins 2–4 cm long and seed catkins 1–2 cm long. The seed catkins
Beech bark disease The woolly, white tufts and broad strips are the colonies of the beech scale insect that are formed in tiny crevices along the bark. An adult beech scale insect has a soft body, is yellow in color, ranges from 0.5 to 1.0 millimeter long, and has an elliptical shape. The beech scale insect also has a stylet that it uses to penetrate the bark of the tree for feeding purposes. There are no male beech scale insects and the female insects reproduce parthenogenetically. In mid to late summer, the beech scale insect lays its eggs and dies. The eggs are