Scientific Name: Acer platanoides
Family Name: Aceraceae
Identifying characteristic: When it is plucked from the tree, Norway maple exudes a milky sap from the leaf stem, which distinguishes it from the very similar Sugar maple, Acer saccharum.
Tree: Rough gray or brown bark, which makes narrow ridges. The tree grows to a height of up to 70 feet (5 m.) with a diameter of up to 2 feet (0.6 m.).
Fruit: The seeds are contained in paired keys, which spread widely. They are light brown and fall in the summer.
History and Comments: Norway maple is native to Europe and grows from Norway to Turkey. Settlers introduced this tree to eastern Pennsylvania in the year 1762. Norway maple is not affected by smoke or dust. Because of its ability to thrive in city conditions and its dense shade providing crown, Norway maple is often planted beside roads in residential neighborhoods. Norway maple out competes native species because it has a high tolerance for shady environments.
The United States Department of Agriculture, Forest Service, (http://plants.usda.gov/cgi_bin/plant_profile.cgi?symbol=ACPL) classifies Norway maple as highly invasive. Thus far it has only been reported from Massachusetts to Washington, D.C. However, because Norway Maple is often mistaken for Sugar maple, it is difficult to know the extent of its penetration in the United States.