Betula papyrifera the genus "Betula". Several varieties are recognized "Betula papyrifera" is mostly confined to Canada and the far northern United States. It is found in interior (var. "humilus") and south-central (var. "kenaica") Alaska and in all provinces and territories of Canada, except Nunavut, as well as the far northern continental United States. Isolated patches are found as far south as the Hudson Valley of New York and Pennsylvania, as well as Washington. High elevation stands are also in mountains to North Carolina, New Mexico, and Colorado. The most southerly stand in the Western United States is located in Long Canyon in
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