Betula populifolia multiple trunks branching off of an old stump. The leaves are 5-7.5 cm long by 4–6 cm wide, alternately arranged, ovate, and tapering to an elongated tip. They are dark green and glabrous above and paler below, with a coarsely serrated margin. The bark is chalky to grayish white with black triangular patches where branch meets trunk. It is most easily confused for the paper birch ("Betula papyrifera") by means of its bark; it is smooth and thin but does not readily exfoliate like paper birch does. The flowers are wind-pollinated catkins 5–8 cm long, the male catkins pendulous and
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