maples (Acer) — identification, habitat & look-alikes

Maples are trees and shrubs found in U.S. forests, mountain woods, and city streets. Their leaves or buds grow in pairs on sides of a twig, and their winged fruits come in pairs, even when the leaves lack the familiar five-lobed shape. Sugar maple sap is the main source of U.S. maple syrup.

In this group

sugar mapleAcer saccharum

A major eastern forest tree and the leading source of maple syrup; its leaves usually have smooth U-shaped gaps between the lobes.

red mapleAcer rubrum

Widespread across the eastern United States, from wet lowlands to upland woods; red flowers and buds can show before the leaves.

silver mapleAcer saccharinum

Common along rivers and also planted in towns; the deeply cut leaves have silvery undersides.

boxelderAcer negundo

A widespread native maple that often grows near water and in disturbed ground; its can make it look unlike a maple.

bigleaf mapleAcer macrophyllum

A western native of the Pacific Coast, recognizable by exceptionally broad leaves and large flower clusters.

Japanese mapleAcer palmatum

A popular garden tree from East Asia that has escaped cultivation in parts of the eastern United States.

Norway mapleAcer platanoides

A European street tree that has spread into forests in parts of the Northeast; broken leaf stalks release milky sap.

Appearance

Growth form: The genus includes large canopy trees, small understory trees, and shrubs. Most species are deciduous.
Leaves: Leaves may be unlobed, three-lobed, many-lobed, or divided into leaflets. Fall color can be yellow, orange, scarlet, or muted brown depending on the species and conditions.
Flowers: Maple flowers are usually small and appear in clusters, often in spring. Flower structure and the placement of male and female flowers vary among species.
Fruit: The familiar maple fruit is a pair of winged , each side holding one seed.
How to recognize it: Most maples have opposite leaves and buds, plus paired samaras. Boxelder (Acer negundo) is the important exception to the familiar leaf shape: it is a true maple with compound leaves.

Look-alikes

sweetgumsLiquidambar

Sweetgums have alternate leaves and round fruit clusters. Maples have opposite leaves or buds and paired winged fruits.

Why they get mixed upAmerican sweetgum and many maples have lobed leaves and bright fall color.

Where it lives

Typical habitats: deciduous forests
stream valleys
parks and streets
Range: The genus is native across much of the temperate Northern Hemisphere and into some tropical mountains. Native U.S. maples occur from Atlantic forests to western mountains, while several Asian and European species are grown or . Norway maple (Acer platanoides), a nonnative species, has spread into forests in parts of the Northeast.
Preferred conditions: Different species range from moisture-loving forest trees to small maples of dry mountain sites, so site needs cannot be generalized to the whole genus.

Life cycle

Seed dispersal: The wings make the fruit spin or glide away from the parent tree on the wind.

Growing it

Propagation: Wild maples reproduce by seed, while named garden selections are often grafted or propagated from cuttings.

Name and classification

About the name: Maples were formerly placed in their own family, Aceraceae. Current flowering-plant classifications place Acer in the soapberry family, Sapindaceae.
Group name: “Maples” closely matches the botanical genus Acer in everyday U.S. English. Names such as Japanese maple (Acer palmatum) and sugar maple (Acer saccharum) refer to particular species or groups within the genus.
Number of species: About 155 maple species are recognized worldwide.

Culture and stories

Culture and stories: Sugar maple sap is the main source of U.S. maple syrup, especially in the Northeast and upper Great Lakes region.
Indigenous peoples made maple sugar before European settlement, and maple products later became an important regional trade and farm tradition.

22 sources