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
Pteryx Pteryx Pteryx is a genus of beetles that is typically found in northern bogs in the Northern Hemisphere. They belonging to the family Ptiliidae which is referred to as feather-winged beetles as the hindwings are narrow and feather-like. Like most of the rest of the family, "Pteryx" are very small and live in rotting vegetative matter. They prefer rotting wood and are generally found under the bark of rotting logs or stumps. The "Pteryx" are less than 1 mm in length. They are polymorphic, in that they frequently occur in two forms, a normal variety, and a neonate form that