Mountain Maple

Acer spicatum Lam.

Description

Mountain maple is a member of the soapberry family (Sapindaceae). It is a multi-stem shrub³ or small tree that seldom exceeds 25 feet tall.¹  The trunk is often crooked and much branched with reddish-brown bark.³ The opposite leaves have 3 to 5 shallow lobes and where 5-lobed, the lower two lobes are obscure.  The leaf blade is 3 to 6 inches long with serrated margins. ¹  The leaf has a heat-shaped base.³ The underside of the leaf has small white hairs.³  The flowering stalk is erect and up to 3 inches long with male flowers towards the end and female flowers at the base. ³  For maples it has the unusual trait of insect pollination. ⁷ The individual flowers are less than one inch wide. ¹  Fruits are pairs of winged seeds (samaras) each about one-inch long and at right angles to one another. ²

Mountain maple with leaves and flowers.  Maryland Biodiversity Project ⁴

Fruits of mountain maple.  Trees of the Adirondacks ³

Distribution

Mountain maple is distributed from Newfoundland to Sasskatchewan, Canada, along the Great Lakes region and south along the Appalachian Mountains to North Carolina and Tennessee.³ It is found in rich, moist soils often along rivers, but also in rocky uplands.³  In Maryland it is restricted to the mountains of Allegheny and Garrett counties.⁴

Native distribution of mountain maple.  USGS ⁵

Wildlife Importance

Mountain maple is browsed by white-tailed deer and moose.²  On Isle Royale, Michigan, mountain maple the second preferred food of moose, especially in winter.⁷  It is also used by American beaver for food and dam construction.  It supports the larvae of Imperial Moth¹ , the Dagger Moth and Banded Tussock Moth. ⁴  Ruffed Grouse consume the buds. ³

Economic Importance

Mountain maple has little economic importance.  It is generally unavailable in commercial trade and difficult to cultivate. ¹

Threats

There are few serious threats to mountain maple. ¹  It is affected by aphids and scale in addition to fungi. ⁶

Interesting Facts

• Mountain maple is easily confused with striped maple.  It may be distinguished by having erect flowers, hairs on the lower leaf surface, no green-striped stems. ³
• Native Americans used mountain maple to make arrows and to treat coughs and wounds.³

References

1. North Carolina State Extension:  Acer spicatum
2. Minnesota Wildflowers:  Acer spicatum
3. Trees of the Adirondacks:  Mountain maple (Acer spicatum)
4. Maryland Biodiversity Project:  Mountain maple
5. USGS:  Mountain maple
6. Iowa State University Extension and Outreach: Mountain maple
7. USDA Fire Effects Information System:  Acer spicatum

Contributed by J. Hull

Towson University Glen Arboretum