Betula cordifolia that "Betula cordifolia" and "Betula papyrifera" hybridise, however this is unlikely given the more recent evidence of different chromosome numbers. The most conclusive method of identification is from chromosome analysis. 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
Northern Hemisphere Northern Hemisphere The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's North Pole. Owing to the Earth's axial tilt, winter in the Northern Hemisphere lasts from the December solstice (typically December 21 UTC) to the March equinox (typically March 20 UTC), while summer lasts from the June solstice through to the September equinox (typically September 23 UTC). The dates vary each year due to the difference between