San Francisco State University
Department of Geography

Geography 316:  Biogeography

Biogeography of  Bigleaf Maple (Acer macrophyllum)

by  Alicia Mariscal, student in Geography 316, Fall 2001

Kingdom: Plantae
Division: Anthophyta
Class: Dicotyledoneae
Order: Sapindales
Family: Aceraceae
Genus: Acer
Species: Acer macrophyllum
(Hickman 1933)

Figure 1: Maple Tree 
(McClellan & McClellan 1999)

Description of Species


Natural History



Other Interesting Issues

Description of Species:

The bigleaf maple is a commercial hardwood, small to medium sized tree on the Pacific Coast. It grows from 25 to 100 feet tall and 1 to 9 feet in diameter. These larger size dimensions occur when it grows in the rich, alluvial river bottomlands (Sudworth 1908). It is also found in mountain valleys, as the border of low mountain streams and foothill areas; and on rocky slopes (Harlow et al. 1979; Peattie 1991).

The bigleaf maples’ name derived from foliar attributes, mature leaves are from 7 to 14 inches in diameter (van Gelderen et al. 1994); deeply 5-lobed; and shiny on top with a glabrous (smooth, not hairy) surface, paler green underneath (Sargent 1905; Sudworth 1908). The leaves turn a clear, reddish yellow just before falling. The leave stems are from 6 to 12 inches long.

When the tree is about twenty years old and the leaves are grown for that season, drooping clusters of fragrant yellow flowers (a polygamous species) appear. The flowers are about 1/4 inch long on a stalk that is about 1/2-3/4 inch long; these together form racemes 4 to 6 inches long (Sargent 1905; van Gelderen et al. 1994).  

 Figure 2: Maple Leaf (TreeGuide Inc. 2001)

These flowers produce the trees’ tawny or yellowish brown fruit, their seeds (Figure 3), which in large quantities appear in autumn. The seeds usually remain on the branches until winter or longer. This tree is deciduous and sheds all of its leaves (Peattie 1991). The wings of the seeds, or samaras, are slightly divergent and about 1˝ inches long (Crittenden 1997). The outer portion of the seed is covered with stout and sharp pale brown hair (Sudworth 1908). The wings spread out at <90° angle (Hickman, 1993).

The bark of bigleaf maples is checkered or with narrow grooves (Crittenden 1997). Characteristic of old trunks are rough bark with pale gray to reddish-brown colored hard, scaly ridges. The wood is finely grained and hard, with a light brown color and a very light reddish tint (Sudworth 1908). Large burls occasionally develop along the boles of older trees, which are frequently defective (Harlow et al. 1979).  

Figure 3: Maple Seed 
(Puget Sound Shorelines 2001)

In dense forest conditions it develops a narrow crown, and a bole (or stem of the tree) usually without limbs for a half to two-thirds of its height (Preston 1976). When the tree grows in an open area the short tree trunk generally separates into several ascending, stout branches that form a compact ovate to subglobose crown (Sudworth 1908). In all of its habitats it has a shallow and far-reaching root system (Preston 1976).

A. macrophyllum has been identified for 200 years (van Gelderen et al. 1994). The first scientist to collect specimens of this tree was Archibald Menzies, a botanist with the Vancouver Expedition. The first Americans to collect specimens were Lewis and Clark. Thomas Nuttall, a botany professor at Harvard provided us with the first visual illustration and written description of the bigleaf maple in his work, The North American Sylva. Pursh wrote a full description of the tree in 1814 (van Gelderen et al. 1994). This tree also grows in England, its seeds brought over by David Douglas (Peattie 1991).

The bigleaf maple is the largest maple tree in the Pacific region (Sudworth 1908). It is also called broadleaf, Oregon, Canyon, or White maple (Crittenden 1997; Peattie 1991).

This tree is found primarily in cool habitats (Crittenden 1997). The bigleaf maple grows on a variety of soils, but usually it is found in rich humus soils that are moist and gravelly (Sudworth 1908). Frequent fires (Rundel & Parsons 1977) aid the growth of the trees in these areas.

The maple is also the principal forest species in areas where the land is burned or logged, such as in some sections of southwestern Oregon (Harlow et al. 1979).

The trees grow in dense stands over large areas of land, in small groves, or scattered. It is usually found in proximity to other evergreen broad-leaved species or coniferous trees, such as lowland Douglas firs, red alder, Pacific madrone, cypress, California redwood, and California laurel (Axelrod 1977; Harlow et al. 1979; Sudworth 1908).

Natural History:

The bigleaf maple tree begins to flower (Figure 4) at about twenty years of age. Insects and bees pollinate the tree and produce about 1000 pollen grains (55µm each) for an individual flower. This is a low number of pollen grains when compared to wind-pollinated oaks, birches, ashes, poplars, and elms that produce about 10,000 pollen grains per flower. Characteristic of the Acer genus to have a low pollen yield, it is one reason why microfossils of Acer pollen are infrequently found (van Gelderen et al. 1994).

This tree effectively naturally regenerates each year, due to the abundance of seed it produces, especially in the open areas. Stump sprouts are full of vitality (Harlow et al. 1979).

The bigleaf maple grows the most during its first forty- to sixty years, after which time growth decreases considerably. A mature tree is between two and three hundred years old. The forest trees live a range of fifty to eighty-five years (Sudworth 1908).

Figure 4: Maple Tree Flower
(© Brousseau 1995)

An angiosperm, the earliest known Acer (A. amboyense) was found in eastern North America from the fossil remains of the late Cretaceous period about 67 MYA. All maple fossils have been located exclusively in the Northern Hemisphere and the trees seem most abundant during the Miocene (Oterdoom 1994).

The closest fossil relative to A. macrophyllum appears to be A. merriamii Knowlton (or A. oregonianum Knowlton) from the Late Miocene around 5 MYA (Macginitie 1969; Oliver 1934). Macginitie (1969) notes the potential for a taxonomic problem with assigning the name of a fossil species to a living species, for although they may be morphologically similar it is difficult to determine if the species are genetically identical.

The flowering and sexual mating of Acer have ranged from wind-pollinated to insect-pollinated and monoecy to dioecy. A. macrophyllum is an insect-pollinated dicot in which female flowers occur before male flowers (Oterdoom 1994).

The form of the leaves in the Acer genus has changed over time. From the Late Oligocene to the Early Pliocene (from around 23 to 5 MYA, including the Miocene) the leaf form evolved from the originally more common 3-lobed maples to 5-lobed maples, as evidenced in the paleobotanical studies of the broadening of the A. tricuspidatum leaf base (Oterdoom 1994).  

A. macrophyllum belongs to the deciduous maple Aceraceae family, which has 200 species distributed among 2 genera (van Gelderen et al. 1994). Acer species is believed to have originated in central and western China although no fossils have been located in this area (Oterdoom 1994).

Cladistic analysis has concluded that the Aceraceae family was formed by earlier members of the Sapindaceae like Bohlenia, which was characterized by loss of a stipule and a locule, as well as a change to opposite from alternate leaves. The Dipteronia line of the Aceraceae seems to be more closely related to the Sapindaceae ancestor Bohlenia, except for a change in the secondary venation of its pinnately compound leaves. The A. arcticum line resulted in an actinodromous maple leaf after the fusion of a minimum of three leaflets (Stewart & Rothwell 1993; van Gelderen et al. 1994).  

Figure 5 illustrates the phylogeny of the Acer genus divided into five groups, relating them to Acer’s most prehistoric ancestor (de Jong 1994).    

Figure 5: Maple Evolutionary Tree  (de Jong 1994) 

Figure 6 highlights thirty-seven counties in California that contain native groves of the bigleaf maple within them. A. macrophyllum has a continuous distribution on the Pacific coast of California, and is native to the west coast of North America (Harlow et al. 1979).

Fossil records reveal that the bigleaf maple is a descendant to the associates of the Miocene floras of the central Great Basin (Axelrod 1977). It is also a member of the Blue Mountains flora in Oregon. It has been found in the Miocene of western Nevada. This tree is a contributor to the San Francisco Bay region savanna and oak woodland sites. In southern Humboldt County it was seen as a riparian species in the forest. It has been located on the mesic slopes of the Shasta fir closed forests; and six small to medium-sized stands of the bigleaf maple are on the northern portion of Santa Cruz Island.

The maple tree is found in numerous locations in the western states, as illustrated in Figure 7. Among these include the area south of 55şN latitude on the coast of Alaska (Sargent 1905; Sudworth 1908); in British Columbia and its islands up to 1,000 feet above sea level (Crittenden 1997; Harlow et al. 1979); west of the Cascade Mountains in Washington and Oregon (Peattie 1991); and throughout California, especially the Coast Ranges and Sierra, and including areas from 3,000 to 7,000 feet in Southern California (Crittenden 1997; Harlow et al. 1979).  

Maps of Distribution:

Figure 6: Map of bigleaf maple tree distribution in California 
(CalFlora 2001)

Figure 7: Map of bigleaf maple tree distribution in North America (TreeGuide Inc. 2001)

Other Interesting Issues:
A. macrophyllum is a shade tree, mostly because of its very long and broad leaves. Since it is lobed it allows some light to pass through. A walk through a mixed evergreen or conifer forest would find these trees growing in the light gaps of the forest. The light yielded through this tree when its reddish yellow leaves are just about to fall is spectacular. My favorite place locally where this occurs is in Muir Woods National Monument in Marin County, California.

Pseudomonas acris, a bacterial agent, sometimes causes a leaf spot on the leaves of this tree in California. An aphid, Drepanosiphum oregonensis, was first discovered on this tree in North America. Unknown until its discovery on the bigleaf maple, this aphid is native to the eastern Mediterranean (van Gelderen et al. 1994).

The commercialization of this species has increased due to the demand for western maple burls and fancy grained logs. It is one of the main hardwood lumbers of the west, and is used for similar purposes as the eastern maple. The main uses of the wood are for furniture, flooring, interior veneers, and boat building (Peattie 1991; Preston 1979). In the past it has also been used for making gun stocks, canoe paddles, and sugar made from its sap (Peattie 1991).

The bigleaf maple has only four known rare cultivars which are only occasionally, if still, available: ‘Kimballiae’ and ‘Seattle Sentinel’ from Washington, ‘Rubrum’ from the U.C. Berkeley Blake Gardens, and ‘Tricolor’ from Germany which is no longer in cultivation (van Gelderen et al. 1994).

Interesting Websites: 

CalFlora: Information on California plants for education, research and conservation. 2000. Acer macrophyllum Pursh (Aceraceae). Berkeley,
        California: The CalFlora Database
[a non-profit organization]. [Online]. Available: 

Fire Effects Information Service. 2001. Index of Species Information. Species: Acer macrophyllum. [Online]. 

Government of British Columbia, Ministry of Forests. 2001. Treebook: Bigleaf Maple. [Online]. 

National Park Service. 2001. The Bigleaf Maples of English Camp. [Online]. Available:

Phommosaysy, Chan. 2001. CSU Fullerton, Biological Sciences. Bigleaf Maple – Acer
macrophyllum. [Online].

TreeGuide Inc. 2001. Bigleaf Maple: Acer Macrophyllum Pursh. [Online].

Puget Sound Shorelines, Washington State Department of Ecology. 2001. Bigleaf Maple – Acer macrophyllum. [Online].


Axelrod, D.I. 1977. Outline History of California Vegetation. In Terrestrial Vegetation of California, eds. M.G. Barbour and J. Major, 141.
        New York: John Wiley & Sons. 

© Brousseau, Br. A., Saint Mary's College. 1995. CalFlora: Information on California plants for education, research and conservation. 2000.
        Berkeley, California: The CalFlora Database [a non-profit
organization]. [Online]. Available: [September
        27, 2001].

CalFlora: Information on California plants for education, research and conservation. 2000. Berkeley, California: The CalFlora Database [a non-
organization]. [Online]. Available: [September 27, 2001].

Crittenden, M. 1997. Trees of the West. Millbrae: Celestial Arts.

de Jong, P.C. 1994. Taxonomy and Reproductive Biology of Maples. In Maples of the World, eds. D.M. van Gelderen, P.C. de Jong, and H.J.
        Oterdoom, 69-103. Portland: Timber Press, Inc. 

Harlow, W.M., E.S. Harrar, and F.M. White, eds. 1979. Textbook of Dendrology. San Francisco: McGraw-Hill Book Company. 

Hickman, J.C., ed. 1993. The Jepson Manual: Higher Plants of California. Berkeley: University of California Press.

Macginitie, H.D. 1969. The Eocene Green River Flora of Northwestern Colorado and Northeastern Utah. In Paleobotany Part II: Triassic
        Through Pliocene
, eds. T.N. Taylor and E.L. Smoot, 266-267. New York: Van Nostrand Reinhold Company Inc.

McClellan, J.E., and B. McClellan, California Academy of Sciences. 1999. Maple Tree.
CalFlora: Information on California plants for education,
        research and conservation.
2000. Berkeley, California: The CalFlora Database [a non-profit organization]. [Online]. Available:
. [September 27, 2001].  

NatureServe; Comprehensive report – Acer macrophyllum. [Online]. Available: [October 3, 2001].

Oliver, E. 1934. A Miocene Flora from the Blue Mountains, Oregon. In Contributions to Paleontology: Middle Cenozoic Floras of Western
        North America
, Carnegie Institution of Washington, 24-25. New York: Johnson Reprint Corporation.

Oterdoom, H.J. 1994. Paleobotany and Evolution of Maples. In Maples of the World, eds. D.M. van Gelderen, P.C. de Jong, and H.J.
        Oterdoom, 63-68. Portland: Timber Press, Inc. 

Peattie, C.D. 1991. A Natural History of Western Trees. Boston: Houghton Mifflin Company.

Preston Jr., R.J. 1976. North American Trees – Third Edition. Ames: The Iowa State University Press.  

Puget Sound Shorelines, Washington State Department of Ecology. 2001. Bigleaf Maple – Acer macrophyllum. [Online].
        Available: [Permission Granted October 31, 2001].

Rundel, P.W., and D.J. Parsons. 1977. Montane and Subalpine Vegetation of the Sierra Nevada and Cascade Ranges. In Terrestrial Vegetation
        of California, eds. M.G. Barbour, and J. Major, 565. New York: John Wiley & Sons.  

Sargent, C.S. 1905. Manual of the Trees of North America. Cambridge: The Riverside Press.

Stewart, W.N., and G.W. Rothwell. 1993. Paleobotany and the Evolution of Plants – Second Edition. Cambridge: Cambridge University

Sudworth, G.B. 1908. Forest Trees of the Pacific Slope. Washington: U.S. Government Printing Office.

TreeGuide Inc.; Bigleaf Maple: Acer Macrophyllum Pursh. [Online]. Available: [Permission Granted October 23, 2001].

van Gelderen, D.M., P.C. de Jong, and H.J. Oterdoom. 1994. Maples of the World. Portland: Timber Press, Inc. 


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