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
Beech bark disease to spread to the south and west. The first case of beech bark disease in the United States was reported in 1929 in Massachusetts. By 2004, the disease had spread as far west as Michigan and as far south as western North Carolina. For beech bark disease to occur, two components are required, an insect and a fungus. The beech scale insect, "Cryptococcus fagisuga", is invasive to North America and is host-specific, feeding exclusively on beech trees. It can be observed on the trunk and limbs of the tree as woolly, white tufts that will later develop into broad strips.