Betula cordifolia Betula cordifolia Betula cordifolia (mountain paper birch, also known as mountain white birch or eastern paper birch) is a birch species native to Eastern Canada and the Northeastern United States. Until recently it was considered a variety of "Betula papyrifera" (paper birch), with which it shares many characteristics, and it was classified as "B. papyrifera" var." cordifolia" (Regel) Fern. "Betula cordifolia" is a deciduous tree that reaches heights of about 25 m and a trunk diameter of about 70 cm. Mature bark is white or bronze-white, peeling in thin layers. The inner surface of the bark is copper-coloured and the
Northern celestial hemisphere Northern celestial hemisphere The northern celestial hemisphere, also called the Northern Sky, is the northern half of the celestial sphere; that is, it lies north of the celestial equator. This arbitrary sphere appears to rotate westward around a polar axis due to Earth's rotation. At any given time, the entire Northern Sky is visible from the geographic North Pole, while less of this hemisphere is visible the further south the observer is located. The southern counterpart is the southern celestial hemisphere. In the context of astronomical discussions or writing about celestial cartography, this celestial hemisphere may also simply then be