Acer platanoides
commonly known as the Norway Maple
Intro and Distribution
Acer platanoides is a species of maple native to continental Europe and western Asia and has recently become a widely invasive plant species in North America. The Norway Maple is commonly found at an elevation around 6,500 ft but no higher than 7,500 ft. It is a large deciduous shade tree with a rounded crown, dense branching and usually grows between 40’ to 60’ tall.
Characteristics
A. platanoides is in the plant family Aceraceae and is distinguished from the other maples by flattened, disc-shaped seeds; milky sap in petiole and leaf veins; large, green-maroon buds and large and broad leaves. Another characteristic of Norway maple is a noticeable tendency for its leaves and samaras to be afflicted with tar spots caused by a fungus known as Rhytisma acerinum. This causes the infected leaves to turn brown, and drop prematurely from the tree. However the disease is only damaging aesthetically and has little effect on the long-term health because the infected leaves are able to still keep most of their photosynthetic capabilities and the leaf drop is late enough in the season that e-foliation doesn’t happen. This means that the energy reserves already stored will be enough to allow the tree to develop the following spring.
Ecological Information
Its aesthetics and tolerance of shade, poor soils, and urban pollution have caused it to be commonly used for cultivation. However, these same characteristics have allowed it to become an aggressive invader to North American forests. An interesting characteristic that has enabled it to become an invasive plant is its ability to prevent the production of native trees. The tree does this by first establishing itself through allelopathy and then leaching substances called phytoxins into the soil to prevent native seeds from germinating near it. Unlike trees native to Europe, the trees in North America have not co-evolved with the Norway maple and very few are immune to its toxins. This causes the understory of the invaded woodland to lose plant diversity and the soils to become bare.
