Gray birch ( Betula populifolia )
The gray birch ( Betula populifolia ) is also called the poplar-leaved birch (English gray birch ). This plant belongs to the genus of birch ( Betula ) and thus to the family of the birch family (Betulaceae).
It is a type of birch originally native to North America . The main distribution area extends from southeastern Ontario to Nova Scotia in the east, in the south to Pennsylvania and New Jersey . There are individual occurrences in the American states of Indiana , Virginia and North Carolina .
The gray birch prefers dry highland soils, but it can also be found in moist mixed forests. As a short-lived pioneer plant , it can be found on fallow fields and burned areas. It needs a sunny location and does not grow well in the shade of competing trees. Floods are not tolerated.
The gray birch grows very quickly up to a height of 9 m and a trunk diameter of 30 cm. The irregular treetop consists of narrow branches, and several trunks often branch off from the original trunk. The bark of young trees is still dark brown, later it becomes white-gray with black triangular marks where the branches branch off from the trunk.
The oval leaves are pointed at the end, 5 to 7.5 cm long and 4 to 6 cm wide. They are dark green, with a smooth top and a lighter bottom, and an irregularly fluted edge. The autumn color is a bright yellow.
Like all birch trees, it is pollinated by the wind and is single sexed ( monoecious ). The inflorescences are catkins. The male inflorescences are 5 to 8 cm long, pendulous catkins, the female are short and erect. The many small winged seeds that ripen in autumn are located between the bracts in the fruit cluster.
Just like other North American birch species, the gray birch is very resistant to the jeweled birch beetle ( Agrilus anxius ). The wood is flexible and is used for coils and as firewood . The use of the bark as medicine is reported by the Indians .
The chromosome number is 2n = 28.
- EL Little: Atlas of United States Trees. (PDF; 722 kB) 1971, accessed on September 26, 2007 .
- Native American Ethnobotany. University of Michigan, accessed September 26, 2007 .
- J. Dickerson: Gray Birch. (PDF; 87 kB) In: USDA Plant Fact Sheet. 2002, accessed September 26, 2007 .
- JJ Furlow: Betula. In: Flora of North America. Volume 3. Oxford Univ. Press, New York 1993, ISBN 0-19-505713-9 , pp. 516-530.