| Acer macrophyllum | |
|---|---|
 | |
| Bigleaf maple foliage | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Sapindales |
| Family: | Sapindaceae |
| Genus: | Acer |
| Section: | Acersect. Macrophylla |
| Species: | A. macrophyllum |
| Binomial name | |
| Acer macrophyllum Pursh 1813 | |
 | |
| Natural range | |
| Synonyms | |
List
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Acer macrophyllum, thebigleaf maple[2] orOregon maple,[3] is a largedeciduoustree in the genusAcer. It is native to westernNorth America. In addition to uses by animals, it is of some culinary and woodworking interest.
Bigleaf maple can grow up to 48 metres (158 feet) tall,[4][5] but more commonly reaches 15–20 m (50–65 ft) tall and 90–120 centimetres (35–47 inches).[6] The species' currentnational champion for size is located inLane County, Oregon. It is 36 m (119 ft) tall with a crown spread of 28 m (91 ft), with an averagediameter at breast height (dbh) of about 3.7 m (12 ft).[7] The previous national champion is located inMarion, Oregon, and is 27 m (88 ft) tall with a crown spread of 32 m (104 ft), with an average dbh of about 2.5 m (8 ft). Thebark is gray brown, darkening and developing ridges with age.[6]
The bigleaf maple has the largestleaves of any maple, typically 15–30 cm (6–12 in) across with five deeply incised palmate lobes, with the largest running to 61 cm (24 in).[8][9] The stems are 15–30 cm (6–12 in) long and contain milky sap.[6] In autumn, the leaves turn gold and yellow, contrasting against backdrops ofevergreenconifers.In spring, the tree producesflowers in pendulousracemes 10–15 cm (4–6 in) long, greenish-yellow with inconspicuous petals. It ishermaphroditic, bearing both male and female flowers in each raceme. The flowers appear in early spring, before the leaves.[10]Thefruit is a paired wingedsamara, eachseed 1–1.5 cm (3⁄8–5⁄8 in) in diameter with a4–5 cm (1+5⁄8–2 in) wing.[11][9][8] Bigleaf maple begins bearing seed at about ten years of age.[10]
Unofficial world's largest maple leaf found Circa 1990 at Shawnigan Lake, Vancouver Island, British Columbia, Canada - measuring 63.4 cm W by 52.3 cm H (without stem).
In May 2018 the oldest two Oregon maples in Europe, 175 years old, were removed fromTrinity College Dublin (TCD), Ireland. The first had an interior which was beginning to rot, and it fell after inclement windy weather. The second, also infected, was cut down as the same fate was expected. Both were in the adjoining grassy area which was originally the cemetery of All Hallows and is now the Front Square of TCD.[12]
The fallen leaves, blossoms, and seeds are concentrated withpotassium,calcium, and other nutrients.[6]
Bigleaf maple mostly occurs near North America'sPacific coast, west ofBritish Columbia'sCoast Ranges and theCascade Range, from southernmostAlaska to southernCalifornia. Some stands are also found inland in the foothills of theSierra Nevada of central California, and a tiny population occurs in centralIdaho.[2][11][13]
It usually grows from sea level to elevations of 450 m (1,480 ft), and more exceptionally 1,200 m (3,900 ft).[6] It can form pure stands on moist soils in proximity to streams, but is generally found withinriparianhardwood forests or dispersed, (under or within), relatively opencanopies of conifers, mixed evergreens, oroaks (Quercus spp.)[14][13] In cool and moist temperatemixed woods they are one of the dominant species.[15] Though very rare north ofVancouver Island, it is cultivated inPrince Rupert,[16] nearKetchikan, and inJuneau.[17]
The tree can live in a wide range of habitats, but thrives in fairly well-hydrated hardwood forests, occurring withred alder,black cottonwood, andwillows. It is fairlyshade tolerant, but not as much so asvine maple, and benefits fromdisturbances.[6]It is not considered to befire-resistant due to its thin bark, but large trees with thick bark may survive moderate fires. Along with red alder, bigleaf maple often dominates early postfiresuccession inDouglas-fir forests, and fire can increase its forest presence.[18] It spreads and growsvegetatively from cuttings and stumps of any size in a prolific manner.[10]
Insects fertilize the tree's flowers.[6] The winged fruits are eaten by squirrels, and bygrosbeaks in the winter.[19]Deer mice have been observed consuming bigleaf maple seeds in the spring in the Sierra Nevada. The foliage is browsed byungulates such asblack-tailed deer,mule deer,elk, and horses, as well as by mountain beavers and other rodents.[20][21]A western Oregon study found that 60% of bigleaf maple seedlings over 25 cm (10 in) tall had been browsed by deer, most several times.[22]
Bigleaf maple is preferred as habitat by thebarred owl, an invasive species to coast range habitat, and the presence of the tree is positively associated withHammond's flycatchers.[20]
In the wetter parts of its range, such as in theOlympic National Park and lowland forest around Puget Sound, the bark is often covered withepiphytes such asclub moss andlicorice fern.[10]
Older trees suffer fromheart rot.[6]
Cultivars are plants sourced and/or bred for specific characteristics that are deemed to be attractive and/or commercializable to the mainstream public. Given the opportunity, cultivars will near-universally cross with their native counterparts, which brings a risk of contamination to local genetic stock that can be a challenge to identify. Examples of cultivars include:
Native Americans grew sprouts from the seeds for consumption,wove baskets from the inner bark, and used the leaves to cover food incooking pits. They also carved the wood into dishes, utensils, and canoe paddles.[6][26]
Maple syrup has been made from the sap of bigleaf maple trees.[27] While the sugar concentration is about the same as inAcer saccharum (sugar maple), the flavor is somewhat different. Interest in commercially producing syrup from bigleaf maple sap has been limited.[28] Although not traditionally used for syrup production, it takes about 40 volumes of sap to produce 1 volume of maple syrup.
The buds of the tree are also considered edible.[29] They are often fried and made into fritters.
The bigleaf maple is the only commercially important maple of the Pacific Coast region.[14]
The wood is primarily used inveneer production for furniture, but is also used in musical instrument production (including piano frames), interior paneling, and other hardwood products; theheartwood is light reddish-brown, fine-grained, moderately heavy, and fairly robust.[6] It sometimes shows aquilted figure.
In California, land managers do not highly value bigleaf maples, and they are often intentionally knocked over and left unharvested during harvests forDouglas fir andredwood stands.[30]
