Editing Acer platanoides (section)

=== As an invasive species in North America ===
[[File:Feral-Norway-maple-Philadelphia.jpg|thumb|Feral Norway maple in Philadelphia.]]
The Norway maple was introduced to northeastern North America between 1750 and 1760 as an ornamental shade tree. It was brought to the Pacific Northwest in the 1870s.<ref name=NorthAmer>{{cite web |url=http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Acer_platanoides_2.htm |title=Introduced Species Summary Project: Norway maple (''Acer platanoides'') |last=Love |first=R |date=2003 |website=Columbia University |access-date=27 August 2018 |archiveurl=https://web.archive.org/web/20160821204339/http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Acer_platanoides_2.htm|archive-date=2016-08-21 }}</ref> Today, Norway maples tend to be most common in the Pacific Northwest, in southern Ontario, and along the Kennebec river in southern Maine. The roots of Norway maples grow very close to the ground surface, starving other plants of moisture. For example, lawn grass (and even weeds) will usually not grow well beneath a Norway maple, but [[Hedera helix|English ivy]], with its minimal rooting needs, may thrive. In addition, the dense canopy of Norway maples can inhibit [[understory]] growth.<ref name="Shannon L. Galbraith-Kent and Steven N. Handel 2008 293–302">{{cite journal | doi = 10.1111/j.1365-2745.2007.01337.x |author1=Shannon L. Galbraith-Kent |author2=Steven N. Handel | journal = Journal of Ecology | title = Invasive ''Acer platanoides'' inhibits native sapling growth in forest understorey communities | volume = 96 | pages = 293–302 | issue=2| year = 2008| doi-access = free |bibcode=2008JEcol..96..293G }}</ref> Some have suggested Norway maples may also release chemicals to discourage undergrowth,<ref>{{cite web|url=http://treetesting.com/Controlling_Invasive_Plants.pdf |title=Controlling Invasive Plants}}</ref> although this claim is controversial.<ref name="Shannon L. Galbraith-Kent and Steven N. Handel 2008 293–302" /> ''A. platanoides'' has been shown to inhibit the growth of native saplings as a canopy tree or as a sapling.<ref name="Shannon L. Galbraith-Kent and Steven N. Handel 2008 293–302" /> The Norway maple also suffers less [[herbivory]] than the sugar maple, allowing it to gain a competitive advantage against the latter species.<ref>{{cite journal | title = Testing the enemy release hypothesis: a comparison of foliar insect herbivory of the exotic Norway maple (''Acer platanoides'' L.) and the native sugar maple (''A. saccharum'' L.) | journal = Biological Invasions |author1=C. L. Cincotta |author2=J. M. Adams |author3=C. Holzapfel | year = 2009 | doi = 10.1007/s10530-008-9255-9 | url = http://newarkbioweb.rutgers.edu/Holzapfel%20Lab/Main%20Pages/People/people%20pages/Claus/claus%20pdf/8402%20Cincotta%20Norway%20Maple%20BioInv.%202008.pdf | volume=11 | issue = 2 | pages=379–388| bibcode = 2009BiInv..11..379C | s2cid = 45919084 |archiveurl=https://web.archive.org/web/20100710174850/http://newarkbioweb.rutgers.edu/Holzapfel%20Lab/Main%20Pages/People/people%20pages/Claus/claus%20pdf/8402%20Cincotta%20Norway%20Maple%20BioInv.%202008.pdf| archive-date = 2010-07-10 }}</ref> As a result of these characteristics, it is considered [[invasive species|invasive]] in some states,<ref>{{cite web | title=Norway Maple | url=http://www.nps.gov/plants/alien/pubs/midatlantic/acpl.htm | author=Swearingen, J. |author2=Reshetiloff, K. |author3=Slattery, B. |author4=Zwicker, S. | year=2002 | work=Plant Invaders of Mid-Atlantic Natural Areas | publisher=National Park Service and U.S. Fish & Wildlife Service |archiveurl=https://web.archive.org/web/20030317025056/http://www.nps.gov/plants/alien/pubs/midatlantic/acpl.htm| archive-date=2003-03-17 }}</ref> and has been banned for sale in [[New Hampshire]]<ref>{{cite web|title=Invasive Species|url=http://agriculture.nh.gov/divisions/plant_industry/invasive-species.htm|work=New Hampshire Dept. of Agriculture|access-date=22 October 2013|archive-url=https://web.archive.org/web/20121107052220/http://www.agriculture.nh.gov/divisions/plant_industry/invasive-species.htm|archive-date=7 November 2012|url-status=dead|df=dmy-all}}</ref> and [[Massachusetts]].<ref>{{cite web |url=https://www.mass.gov/service-details/massachusetts-prohibited-plant-list |title=Massachusetts Prohibited Plant List |date=2017 |website=Mass.gov |access-date=28 August 2018}}</ref> The [[state of New York]] has classified it as an invasive plant species.<ref name=InvPlant>{{cite web|title=Interim List of Invasive Plant Species in New York State |url=http://www.dec.ny.gov/animals/65408.html |work=Advisory Invasive Plant List |publisher=New York State Department of Environmental Conservation |access-date=1 June 2013 |url-status=dead |archive-url=https://web.archive.org/web/20130512183352/http://www.dec.ny.gov/animals/65408.html |archive-date=12 May 2013 }}</ref> Despite these steps, the species is still available and widely used for urban plantings in many areas.

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File:Acer platanoides fruit kz.jpg|Fruit (samara): note the flat seed capsule and the angle of the "wings"
File:2014-10-30 10 39 54 Norway Maple foliage during autumn on Durham Avenue in Ewing, New Jersey.JPG|Typical yellow fall foliage
File:2014-10-30 09 32 43 Norway Maple foliage during autumn in Ewing, New Jersey.JPG|Atypical orange-red fall colour
File:Acer Platanoides 'schwedleri' leaf.jpg|Purple leaves of cultivar 'Schwedleri'
File:Acer platanoides twig and buds.jpg|Twig and buds
</gallery>