Big Leaf Maple (Acer Macrophyllum)

Identifying Features:

For Maples:
Opposite leaves
-Palmately lobed
-Long leafstalks
-Bundle scars are 3
-Fruit in two winged keys.

For Big Leaf Maples:
-Leaves are very large.

(All of these images come from the CalFlora Website)

A Big Leaf Maple in a riparian habitat.

Photographer: Charles
Thoreau Townsend



Newly formed two winged "keys" coming from a drooping flower stalk.

Photographer: Charles Webber






The deep palmately arranged lobes of the Maple leaf.


Photographer: Brother Alfred Brousseau

Where are they found?

Big Leaf Maples are found along the Pacific Coast west of the Sierras. They can be found as far north as British Colombia and as far south as Southern California. They are limited by cold temperatures to the north and limited humidity and moisture to the south.

If you find a group of this tree, also look for:

In old growth temperate rainforst:
Sitka Spruce (Picea sitchensis), and Western Hemlock (Tsuga heterophylla)

Coniferous forests:
Douglas-fir (Pseudotsuga menziesii), Grand Fir (Abies grandis)
Redwood (Sequoia sempervirens)

Mixed evergreen forests:
Douglas-fir (Pseudotsuga menziesii)
Tanoak (Lithocarpus densiflora)
Pacific Madrone (Arbutus menziesii)
Chinkapin (Castanopsis chrysophylla)
Coast Live Oak (Quercus agrifolia)
Canyon Live Oak (Q. chrysolepis)
Jeffrey Pine (Pinus jeffreyi)
Sugar Pine (P. lambertiana)
Ponderosa Pine (P. ponderosa)

Oregon White Oak (Quercus garryana).

Deciduous or mixed deciduous/coniferous riparian forests:
Red Alder (Alnus rubra)
White Alder (A. rhombifolia)
Oregon Ash (Fraxinus latifolia)
Quaking Aspen (Populus tremuloides)
Black Cottonwood (Populus tricocarpa)
Willows (Salix spp.)

Succession Status

Big Leaf Maple plays many roles in the succession of forest environments. In low elevations along rivers it was found living in environments most recently produced by river erosion, but in interior valleys in Oregon it was found to be a late or even climax species along with Douglas Fir.

Ecological Use

Big Leaf Maple trees are abundant "shoot growers". These young sprouts provide good browse for mule deer and black-tailed deer. Some rodents have been known to pull small seedlings down directly into burrows from below. These trees also provide forage in the form of seeds which feed many species including: squirrels, chipmunks, finches and grosbeaks. Several species of small birds nest in these trees.

Yearly Timeline
Big Leaf Maple (Acer macrophyllum)