Norway maple

Sapindales > Aceraceae > Acer platanoides L.

Norway maple is a deciduous tree that grows 40-60 ft. (12.2-18.3 m) tall. The opposite leaves are palmately lobed with 5-7 lobes. The margins are marked with a few large teeth. Flowering occurs in the early spring before the leaves emerge. The flowers are inconspicuous and develop into large double samaras that mature in the late summer. Norway maple is very similar to sugar maple but can be distinguished by the fruit, sap and bark. The angle of seed wings of Norway maple is approximately 180 degrees, while the angle between the seed wings of sugar maple is near 120 degrees. Broken leaf petioles of Norway maple ooze white sap while the sap of sugar maple is clear. Norway maple bark is regularly grooved, and sugar maple bark has irregular plates. Norway maple has invaded forested ecosystems throughout the northeastern United States and parts of the Pacific Northwest. Once established into a forest, it has the ability to shade out the native understory and out-compete the native tree species. Norway maple is native to Europe and was first introduced into the United States in 1756. It has been, and continues to be, widely sold as an ornamental.


Identification, Biology, Control and Management Resources

  • Weeds of the Week - USDA Forest Service, Northeastern Area, Forest Health Protection

Selected Images from Invasive.org

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Foliage;
Jan Samanek, State Phytosanitary Administration, Bugwood.org
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Foliage;
Paul Wray, Iowa State University, Bugwood.org
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Foliage;
Joseph O'Brien, USDA Forest Service, Bugwood.org
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Bark;
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
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Bark;
Paul Wray, Iowa State University, Bugwood.org
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Diagram or Graphic; 1. Branchlet with corymb, terminating developing young shoots (a - e) with deciduous (typically green) transitional leaves at their base (k). - 2. Branchlet with mature leaves and ripe fruits (double samaras). Stalk exuding a milky sap when broken. Wings of the samaras spread perpendicular to the pedicels (horizontally spreading), with conspicuously flat nutlets. - 3. Seedling with cotyledons (c) and first pair of ordinary leaves. - 4. Winter-branchlet; buds are reddish-brown, glossy, terminal bud is larger. Leaf-scars are opposite, horseshoe- or heart-shaped and connected extreme laterally. After Hempel & Wilhelm, 1889. Photos and explanations from the book: Zelimir Borzan. "Tree and Shrub Names in Latin, Croatian, English, and German, with synonyms", University of Zagreb, 2001.
Zelimir Borzan, University of Zagreb, Bugwood.org
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Twig(s)/Shoot(s);
Bill Cook, Michigan State University, Bugwood.org
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Twig(s)/Shoot(s); Buds
Paul Wray, Iowa State University, Bugwood.org
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Fruit(s);
Paul Wray, Iowa State University, Bugwood.org
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Flower(s);
Jan Samanek, State Phytosanitary Administration, Bugwood.org
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Flower(s); with new foliage
Jan Samanek, State Phytosanitary Administration, Bugwood.org
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Flower(s);
Jan Samanek, State Phytosanitary Administration, Bugwood.org
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Flower(s);
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
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Flower(s);
The Dow Gardens Archive, Dow Gardens, Bugwood.org
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Foliage;
Bill Cook, Michigan State University, Bugwood.org
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Fruit(s);
Paul Wray, Iowa State University, Bugwood.org
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Fruit(s);
Bill Cook, Michigan State University, Bugwood.org
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Seed(s);
Steve Hurst, USDA NRCS PLANTS Database, Bugwood.org
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Tree(s);
Richard Old, XID Services, Inc., Bugwood.org
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Tree(s);
Jan Samanek, State Phytosanitary Administration, Bugwood.org
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Tree(s); with fall color
Jan Samanek, State Phytosanitary Administration, Bugwood.org
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Foliage; with fall color
Jan Samanek, State Phytosanitary Administration, Bugwood.org
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Foliage; with fall color
Jan Samanek, State Phytosanitary Administration, Bugwood.org
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Infestation;
Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
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Invasive Reference(s):

Check Invasive.org for most current lists.
  • Massachusetts - Noxious Weed Law
  • New Hampshire - Noxious Weed Law
  • Rhode Island - Noxious Weed Law
  • Virginia - Invasive Alien Plant Species
  • Mid-Atlantic - EPPC List
  • Invasive Plants: Guide to Identification and the Impacts and Control of Common North American Species
  • Invasive Plants of the Upper Midwest
  • Invasive Plant Atlas of New England


External Links


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