Betula pendula Betula pendula Betula pendula, commonly known as silver birch, warty birch, European white birch, or East Asian white birch, is a species of tree in the family Betulaceae, native to Europe and parts of Asia, though in southern Europe it is only found at higher altitudes. Its range extends into Siberia, China and southwest Asia in the mountains of northern Turkey, the Caucasus and northern Iran. It has been introduced into North America, where it is known as the European white birch, and is considered invasive in some states in the United States and in parts of Canada. The tree
Alnus incana Alnus incana Alnus incana, the grey alder or speckled alder, is a species of alder with a wide range across the cooler parts of the Northern Hemisphere. It is a small- to medium-sized tree tall with smooth grey bark even in old age, its life span being a maximum of 60 to 100 years. The leaves are matte green, ovoid, long and broad. The flowers are catkins, appearing early in spring before the leaves emerge, the male catkins pendulous and long, the female catkins long and one cm broad when mature in late autumn. The seeds are small, long, and