Betula pumila
The American shrub birch (Betula pumila ) is a small shrub of the genus of birch trees in the birch family ( Betulaceae ). The distribution area is located in Canada and the United States.
Description
The American shrub birch is a 3 meter tall shrub with dark reddish-brown, smooth bark, bright Korkporen and dichtfilzigen, not warty shoots. The leaves are elliptic to obovate, 2.5 to 5 cm long and 1-5 cm wide, obtuse to rounded or broadly wedge -shaped base and coarsely serrated edge. The upper leaf surface is more or less hairy, the hairy underside whitish and usually tight, but recently often bare. Each sheet can be formed 4 to 6 pairs of nerves. The petiole is about 2 to 3 millimeters in length. The female inflorescences are erect, 1.5 to 2.5 centimeters long, cylindrical, stalked kitten. The middle lobe of the fruit scales are longer than the side lobes. The fruits are samaras with wings slightly narrower than the body. The chromosome number is.
Distribution and ecology
The distribution area is located in Canada and the United States. Where it grows in swamp forests on wetlands and wet meadows and marsh locations on sunny, cool locations.
Systematics and history of research
The American shrub birch (Betula pumila ) is a species from the genus of birch (Betula ) in the birch family ( Betulaceae ). The first description was in 1767 by Linnaeus in Mantissa Plantarum. Generum Editionis vi et specierum Editionis ii .. Some authors distinguish two varieties, in addition to the type species Betula pumila south settled var pumila with mostly hairy and glandular loose sheets and the north is moved Betula pumila var glandulifera variety with less hairy and glandular leaves.
Use
The species is rarely used.