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Acer rubrum (red maple)

Acer rubrum

Red maple, Acer rubrum, is particularly fond of low-lying, wet areas, but also appears in drier forests. In our area (central Illinois) it is uncommon in natural settings, but we see it frequently in Michigan, southern Ohio, and Kentucky. Red maple is aptly named; its leaves turn red in the fall, its spring flowers are red, and its leaf-stems are red.

The leaves of red maple are arranged in opposing pairs and have three (rarely five) main lobes which are "cut" less than half of the distance to the base of the leaf. The upper side is green, but the underleaf is silvery-whitish. The leaf-stems (petioles) are long, naked, and red.

Red maple bark is similar to the bark of silver maple: young bark is pale gray and smooth, while in older trees shallow longitudinal cracks develop. Pale, whitish and hospital-pastel-green lichens are often found all over the bark.

 

Over winter, the flower buds are round and bright red; flowers are produced in the spring, and are also bright red—or sometimes orangish. The fruit is a small "helicopter" produced in spring or early summer (unlike the helicopters produced by sugar maples, which appear in late summer or fall). In fact, the small size of the red maple's helicopters (they are usually less than 3 centimeters long) will distinguish the tree among the naturally occurring maples in the Midwest.

Red maple has several naturally occurring varieties that differ in small ways, and swamp red maple (Acer drummondii) is similar but features much longer helicopters and fuzzy leaf-stems. Cultivated versions of red maple are very popular and can be found in cities and towns throughout the Midwest.

Range of Acer rubrum

midwestern range



Acer rubrum
tall red maples in Kentucky

 

Acer rubrum
summer leaves

Acer rubrum
fall leaves


Acer rubrum
young bark

 

Acer rubrum
maturing bark

 

Acer rubrum
mature bark


Acer rubrum
samaras ("helicopters")


Acer rubrum
fall leaves being attacked by Rhytisma americanum (tar spot of maple), a harmless parasite; see the linked page for more information about the fungus





References: Harlow 1946, Peattie 1948, GN Jones 1971, Miller & Jaques 1978, Kricher & Morrison 1988, Preston 1989, RL Jones 2005, Mohlenbrock 2006, Kershaw 2007, Voss & Reznicek 2012, Mohlenbrock 2014.



Kuo, Michael & Melissa Kuo (September, 2017). Acer rubrum (red maple). Retrieved from the midwestnaturalist.com website: www.midwestnaturalist.com/acer_rubrum.html

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