Betula populifolia Betula populifolia Betula populifolia (gray or grey birch) is a deciduous tree native to eastern North America. It ranges from southeastern Ontario east to Nova Scotia, and south to Pennsylvania and New Jersey, with disjunct populations in Indiana, Virginia, and North Carolina. It prefers poor, dry upland soils, but is also found in moist mixed woodlands. Living only about 30 years, it is a common pioneer species on abandoned fields and burned areas. Gray birch grows quickly to 20 to 30 feet tall and 15 inch trunk diameter, with an irregular open crown of slender branches. The tree often has
Northern celestial hemisphere referred to as the Northern Hemisphere. For the purpose of celestial mapping, astronomers may conceive the sky as the inside of a sphere divided into two halves by the celestial equator. The Northern Sky or Northern Hemisphere is therefore the half of the celestial sphere that is north of the celestial equator. Even if this geocentric model is the ideal projection of the terrestrial equator onto the imaginary celestial sphere, the northern and southern celestial hemispheres is not to be confused with descriptions of the terrestrial hemispheres of Earth itself. Northern celestial hemisphere The northern celestial hemisphere, also called the