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
White-winged swallow White-winged swallow The white-winged swallow ("Tachycineta albiventer") is a resident breeding swallow in tropical South America from Colombia, Venezuela, and Trinidad south to northern Argentina. It is not found west of the Andes. This swallow is largely non-migratory. The genus "Tachycineta" was established for this group of swallows by German ornithologist Jean Cabanis in 1850. The genus name derives from Ancient Greek "takhukinetos", "moving quickly"; the specific name "albiventer" is from Latin "albus", "white", and "venter", "belly". This swallow is monotypic, and no subspecies are currently recognized. The adult white-winged swallow is long and weighs . It has iridescent blue-green