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
Eucalyptus rigidula Eucalyptus rigidula Eucalyptus rigidula, commonly known as stiff-leaved mallee, is a mallee that is native to Western Australia. The mallee typically grows to a height of . The bark of the tree is smooth and white-grey brown in colour and peels in ribbony strips at the base. It blooms between December and April producing inflorescences with white flowers. The bark is smooth and powdery with no pith of bark glands. The disjunct, glossy, green or yellow-green adult leaves have a lanceolate to broad lanceolate shaped blade that is basally tapered. The thick concolorous blade is in length and wide. The