Black birch
| Black birch | ||||||||||||
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Black birch |
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| Scientific name | ||||||||||||
| Betula nigra | ||||||||||||
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The black birch ( Betula nigra ), also called river birch, is a medium-sized deciduous tree . It is found in the eastern United States.
description
The black birch is a deciduous, graceful deciduous tree that reaches heights of 20 to 25 meters. Individual specimens can have a height of 30.5 meters and a trunk diameter of 1.5 meters. The growth is usually multi-stemmed with a rounded, loose crown. The bark on the trunk and branches is red to yellow-brown, dense and curled up. It becomes darker to black, hard and coarse with age. The trunk shows black, horizontally widened cork pores . The shoots are densely hairy with gray shaggy hair. The leaves are diamond to egg-shaped, 4 to 8 inches long and 3 to 6 inches wide, pointed with a wedge-shaped base, double serrated and narrowly lobed. The upper side of the leaf is glossy green, the underside blue-green. Seven to nine hairy pairs of nerves are formed per leaf. The petiole is about 1 centimeter long and also hairy. The autumn color is yellow. Cylindrical, 2.3 to 4 centimeters long, upright catkins are formed as fruits. The fruit scales are narrow, all about the same length and directed forward.
The number of chromosomes is .
Distribution and ecology
The natural range of the black birch extends from the northeast to the southeast of the United States and extends to the Prairie States and Florida. There it grows in species-rich forests and groups of trees on fresh to moist, acidic to neutral, sandy-gravelly soils at heights of up to 300 meters. It is frost hardy but loves warmth and prefers sunny locations. The black birch is a characteristic tree of the river meadows, often also in temporarily flooded areas. However, it tolerates flooding only moderately, which should explain its absence in many of the Mississippi floodplains. Like other species in this habitat, such as the sugar maple ( Acer saccharum ) or the American elm ( Ulmus americana ), it spreads its fruits in the early summer and the seeds begin to germinate immediately when the surrounding land is usually not flooded.
Systematics
The black birch ( Betula nigra ) is a kind from the kind of birch ( Betula ), which to the subfamily Betuloideae the family of birch plants is counted (Betulaceae).
use
The wood of the species is widely used, and it is also planted as an ornamental tree due to the remarkable autumn colors .
swell
Individual evidence
- ↑ a b Betula nigra L. In: Silvics of North America, Vol. 2. USDA Forest Service, accessed on November 21, 2010 (English).
- ↑ a b c Roloff et al .: Flora of the Woods , p. 140
- ↑ a b c d e Betula nigra. In: Flora of North America Vol. 3. www.eFloras.org, accessed on November 21, 2010 .
- ↑ Betula nigra. In: Germplasm Resources Information Network (GRIN). United States Department of Agriculture, accessed November 21, 2010 .
literature
- Andreas Roloff , Andreas Bärtels: Flora of the woods. Purpose, properties and use. With a winter key from Bernd Schulz. 3rd, corrected edition. Eugen Ulmer, Stuttgart (Hohenheim) 2008, ISBN 978-3-8001-5614-6 , p. 140.
Web links
- Black birch. In: Online database for trees and shrubs. Baumkunde.de, accessed on November 21, 2010 .