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
Jesuit's bark Jesuit's bark Jesuit's Bark, also known as cinchona bark, as Peruvian Bark, and as China Bark, is a former name of the most celebrated specific remedy for all forms of malaria. It is so named because it was obtained from the bark of several species of the genus "Cinchona", of the Rubiaceae family, that have been discovered at different times and are indigenous in the Western Andes of South America and were first described and introduced by Jesuit priests who did missionary work in Peru. Other terms referring to this preparation and its source were "Jesuit's Tree", "Jesuit's Powder" and