Britt Slattery, USFWS

Norway Maple
Acer platanoides

Origin: Europe and Western Asia

Background
Introduced for use as an ornamental landscape plant.

Distribution and Ecological Threat
Norway maple is found in 13 states in the eastern United States, from Maine to Virginia and west to Wisconsin. It is recognized as an invasive plant in many of these states. Norway maple has escaped cultivation and invades forests, fields, and other natural habitats. It forms monotypic stands that create dense shade and it displaces native trees, shrubs and herbs.

John M. Randall, TNC

Description and Biology

• Plant: grows up to 90 feet in height, has a broadly-rounded crown and bark that is smooth at first but becomes black, ridged and furrowed with age.
• Leaves: deciduous, dark green, palmate or hand-shaped, generally broader than long, opposite (in pairs) along stem, milky sap in veins.
• Flowers, fruits and seeds: flowers are bright yellow-green and appear in spring; fruits mature during the summer into typical winged "samaras" that look like helicopter blades with a seed in the center.
• Spreads: expands locally by vegetative reproduction and to new areas by seed.
• Look-alikes: Norway maple can be confused with many maples species, especially sugar maple (Acer saccharum), because of similar looking leaves. It can be distinguished from native maples by the presence of a milky white sap that oozes out of leaf veins and stalks when broken. Norway maple is easily spotted in the autumn when its leaves turn yellow late in the season.

Prevention and Control
Don't plant Norway maple. To control existing stands, manual, mechanical and chemical means are available. Seedlings can be pulled by hand and small to large trees can be cut to the ground, repeating as necessary to control any re-growth from sprouts. Glyphosate and triclopyr herbicides have been successfully used to control Norway maple.

Native Alternatives

American beech (Fagus grandifolia) Chris Miller, NRCS	red maple (Acer rubrum) Britt Slattery, USFWS	sourwood (Oxydendrum arboreum) USDA, NRCS
sweet gum (Liquidambar styraciflua) Chris Miller, NRCS	willow oak (Quercus phellos) Chris Miller, NRCS	black gum (Nyssa sylvatica) Chris Miller, NRCS

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Publication by USFWS BayScapes Conservation Landscaping Program
http://www.nps.gov/plants/alien/pubs/midatlantic/acpl.htm
Last updated: 7 October 2004