Norway Maple
Acer platanoides L. (Aceraceae)
This species of maple is native to eastern and central Europe and western Asia and was introduced to North America in the mid-1700s. Its popularity is due to its tall trunk and tolerance of poor, compacted soils.
Acer platanoides is a deciduous tree, growing to 20–30 m (65–100 ft) tall with a trunk up to 1.5 m (5 ft) in diameter, and a broad, rounded crown. The bark is grey-brown and shallowly grooved. Unlike many other maples, mature trees do not tend to develop a shaggy bark. The shoots are green at first, soon becoming pale brown. The winter buds are shiny red-brown.
The leaves are opposite, palmately lobed with five lobes, 7–14 cm (2+3⁄4–5+1⁄2 in) long and 8–25 cm (3+1⁄4–9+3⁄4 in) across; the lobes each bear one to three side teeth, and an otherwise smooth margin.[ The leaf petiole is 8–20 cm (3+1⁄4–7+3⁄4 in) long, and secretes a milky juice when broken. The autumn color is usually yellow, occasionally orange-red.[1],[2]
The flowers are in corymbs of 15–30 together, yellow to yellow-green with five sepals and five petals 3–4 mm (1⁄8–3⁄16 in) long; flowering occurs in early spring before the new leaves emerge. The fruit is a double samara with two winged seeds. the seeds are disc-shaped, strongly flattened, 10–15 mm (3⁄8–5⁄8 in) across and 3 mm (1⁄8 in) thick. The wings are 3–5 cm (1+1⁄4–2 in) long, widely spread, approaching a 180° angle. It typically produces a large quantity of viable seeds.
Under ideal conditions in its native range, Norway maple may live up to 250 years, but often has a much shorter life expectancy; in North America, for example, sometimes only 60 years. Especially when used on streets, it can have insufficient space for its root network and is prone to the roots wrapping around themselves, girdling and killing the tree. In addition, their roots tend to be quite shallow and thereby they easily out-compete nearby plants for nutrient uptake.[3] Norway maples often cause significant damage and cleanup costs for municipalities and homeowners when branches break off in storms as it does not have strong wood.[4],[5]
Introduced to the United States in the mid- to late 1700s in eastern Pennsylvania. A popular tree planted along urban streets and in yards. In many areas it escapes into surrounding forest and woodlands, where it may become invasive.
[1] "Introduced Species Summary Project: Norway Maple (Acer platanoides)". Retrieved September 30, 2018.
[2] "Acer platanoides". Retrieved September 30, 2018.
[3] "Norway Maple (Acer platanoides)".
[4] Rushforth, K (1999). Trees of Britain and Europe. Collins. ISBN 978-0-00-220013-4.
[5] Mitchell, AF (1974). A Field Guide to the Trees of Britain and Northern Europe. Collins. ISBN 978-0-00-212035-7.