Norway Maple

Norway Maple

Acer platanoides L.

Description

Norway maple is a member of the cashew family (Sapindaceae).  It is a tree that usually reaches 50 feet tall ¹, but may reach 100 feet 8.  It is fast-growing and can live up to 200 years 9.  It has opposite leaves that are three to six inches long and are palmately lobed with five lobes resembling sugar maple.  However, it has several points between the lobes and  exudes a milky sap from the broken petiole that distinguishes it from sugar maple ¹.    The leaves turn yellow in the fall rather than the orange and red of sugar maple.  It flowers are yellow-green and produce fruits that are double-winged samaras with oppositely spreading wings ¹, further distinguishing it from sugar maple .

A dense cluster of green, lobed, maple leaves with long petioles set against an unfocused background of dark shadows and green vegetation. The leaves are spotted with raindrops, some leaves wetter than others.

Leaves of Norway maple.  @ Martin Bobka, Wikipedia ³.

Three pairs of light-green winged maple fruits hang from slightly darker green and slender branches, which are themselves attached to thicker branches varying from even darker green to light brown in color. Each pair is made of two, single, oval-shaped and dimpled fruits attached to a wider, oval-shaped and ridged wing. These fruit are set against an unfocused background of dense branch and leaf foliage with dark green leaves, dark brown branches, and darker shadows. Very small bits of white light and light-blue sky peak through the dark background.

Fruits of Norway maple.  Wikimedia Commons 4.

Distribution

Norway maple is an introduced species from Europe 2,10 .  It is widely planted throughout North America ², especially in the Northeast US and Canada and the Pacific Northwest.  It has naturalized in the Northeastern  USA and Midwest and is considered to be an invasive species 10.

A black-and-white map of the United States but county. Current distribution of Norway maple by county designated in green, showing a native range that includes all of Maine, New Hampshire, Massachusetts, Rhode Island, and Connecticut. Green counties also include approximately half of New York and Pennsylvania, most of Maryland, some northern Virginian, and much of West Virginia and Indiana. A few green counties show a sparse native range in portions of Michigan, Illinois, Wisconsin, Minnesota, western Montana, Idaho, Washington, and Oregon. A few counties in northwestern New Mexico are also shaded green.

Distribution of Norway maple in USA 8.

A yellowish map of Europe showing the native range of Acer platanoides, designated in green and tan, encompassing almost all of the central European continent in green, with some tan portion extending into northwestern Europe, including the British Isles.

European distribution of Norway maple.  @By Giovanni Caudullo – Caudullo, G., Welk, E., San-Miguel-Ayanz, J., 2017, Wikipedia ³.

Wildlife Importance

Supports larvae of Imperial Moth ¹.

Economic Importance

Widely used in the horticultural trade for urban trees, it poses problems for sidewalks and  walkways 9.  There are numerous cultivars selected for variations in size, leaf color, and hardiness 10.  The deep shade it casts causes inhibits growth of anything beneath the drip line of the canopy 1,2. The wood is used in furniture, flooring and musical instruments 6.

Threats

Norway maple has few threats.  It is susceptible to verticillium wilt.  It is considered an invasive species throughout its North American range 5,8.  It is banned for sale in New Hampshire and Massachusetts and is considered invasive by Maryland.

Interesting Facts

  • Norway maple was probably the wood to make Stradivari violins 5.
  • Norway maple leafs out earlier in the spring and holds its leaves longer in the fall than most other deciduous trees 6.
  • The Maryland champion Norway maple is in Carroll County and is 70 feet tall 7.
  • Introduced to North American by John Bartram in 1756 8.
  • Its common name, Norway maple, is ironic as it occurs only in a small part of Norway, but throughout much of the rest of Europe 10.

References

  1. North Carolina Extension: Acer platanoides
  2. Missouri Botanical Gardens:  Acer platanoides
  3. Wikipedia:  Acer platanoides
  4. Wikemedia Commons:  Acer platanoides fruit
  5. University of Minnesota:  Norway maple
  6. The mystic magic of th Norway maple tree–Acer plantaoindes
  7. Maryland Big Tree Program
  8. University of Maryland Extension–Invasives in your woodland: Norway maple
  9. Gardenia:  Acer platanoides
  10. International Dendrology Society:  Acer platanoides

Contributed by J. Hull

Towson University Glen Arboretum

Towson University