Acer is a genus of trees or shrubs commonly known as Maple.
Maples are variously classified in a family of their own, the Aceraceae, or together with the Hippocastanaceae included in the family Sapindaceae. Modern classifications, including the Angiosperm Phylogeny Group system, favour inclusion in Sapindaceae. The type species of the genus is Acer pseudoplatanus (Sycamore Maple).
There are approximately 125 species, most of which are native to Asia,], with a number also appearing in Europe, northern Africa, and North America.
The word Acer is derived from a Latin word meaning "sharp", referring to the characteristic points on maple leaves. It was first applied to the genus by the French botanist Joseph Pitton de Tournefort in 1700. A red maple leaf is the prominent feature of the flag of Canada.
Maples are mostly trees growing to 10-45 metres (30-145 ft) in height. Others are shrubs less than 10 metres tall with a number of small trunks originating at ground level. Most species are deciduous, but a few in southern Asia and the Mediterranean region are evergreen. Most are shade-tolerant when young, and are often late-successional in ecology; many of the root systems are typically dense and fibrous. A few species, notably Acer cappadocicum, frequently produce root sprouts, which can develop into clonal colonies.
Maples are distinguished by opposite leaf arrangement. The leaves in most species are palmate veined and lobed, with 3-9 (rarely to 13) veins each leading to a lobe, one of which is central or apical. A small number of species differ in having palmate compound, pinnate compound, pinnate veined or unlobed leaves. Several species, including Acer griseum (Paperbark Maple), Acer mandshuricum (Manchurian Maple), Acer maximowiczianum (Nikko Maple), and Acer triflorum (Three-flowered Maple), have trifoliate leaves. One species, Acer negundo (Box-elder), has pinnately compound leaves that may be simply trifoliate or may have five, seven, or rarely nine leaflets. A few, such as Acer laevigatum (Nepal Maple) and Acer carpinifolium (Hornbeam Maple), have pinnately-veined simple leaves.
The flowers are regular, pentamerous, and borne in racemes, corymbs, or umbels. They have four or five sepals, four or five petals about 1–6 mm long (absent in some species), four to ten stamens about 6-10 mm long, and two pistils or a pistil with two styles. The ovary is superior and has two carpels, whose wings elongate the flowers, making it easy to tell which flowers are female. Maples flower in late winter or early spring, in most species with or just after the leaves appear, but in some before them.
Maple flowers are green, yellow, orange or red. Though individually small, the effect of an entire tree in flower can be striking in several species. Some maples are an early spring source of pollen and nectar for bees.
The distinctive fruit are called samaras or "maple keys". These seeds, or 'whirlybirds,' occur in distinctive pairs each containing one seed enclosed in a "nutlet" attached to a flattened wing of fibrous, papery tissue. They are shaped to spin as they fall and to carry the seeds a considerable distance on the wind. Children often call them "helicopters" due to the way that they spin as they fall. Seed maturation is usually in a few weeks to six months after flowering, with seed dispersal shortly after maturity. However, one tree can release hundreds of the seeds at a time. Depending on the species, the seeds can be small and green to orange and big with thicker seed pods. The green seeds are released in pairs, sometimes with the stems still connected. The yellow seeds are released individually and almost always without the stems. Most species require stratification in order to germinate, and some seeds can remain dormant in the soil for several years before germinating.
The genus is subdivided by its morphology into a multitude of sections and subsections
The leaves are used as a food plant for the larvae of a number of Lepidoptera species (see List of Lepidoptera that feed on maples). Aphids are also very common sap-feeders on maples. In horticultural applications a dimethoate spray will solve this.
Maples are affected by a number of fungal diseases. Several are susceptible to Verticillium wilt caused by Verticillium species, which can cause significant local mortality. Sooty bark disease, caused by Cryptostroma species, can kill trees which are under stress due to drought. Death of maples can rarely be caused by Phytophthora root rot and Ganoderma root decay. Maple leaves in late summer and autumn are commonly disfigured by "tar spot" caused by Rhytisma species and mildew caused by Uncinula species, though these diseases do not usually have an adverse effect on the trees' long-term health
Maples are planted as ornamental trees by homeowners, businesses and municipalities. Acer platanoides (Norway Maple) is especially popular as it is fast-growing and extremely cold-resistant, though it is also an invasive species in some regions. Other maples, especially smaller or more unusual species, are popular as specimen trees.
Numerous maple cultivars which have been selected for particular characteristics can be propagated only by asexual reproduction such as cuttings, tissue culture, budding or grafting. Acer palmatum (Japanese Maple) alone has over 1,000 cultivars, most selected in Japan, and many of them no longer propagated or not in cultivation in the western world. Some delicate cultivars are usually grown in pots and rarely reach heights of more than 50-100 cm. Maple is also a key wood in the construction of percussion instruments like drum kits. Some of the best drum building companies like DW (Drum Workshop) use maple extensively throughout their mid-pro range
Maples are a popular choice for the art of bonsai. Acer palmatum (Japanese Maple), Acer buergerianum (Trident Maple), Acer ginnala (Amur Maple), Acer campestre (Field Maple) and Montpellier Maple (A. monspessulanum) are popular choices and respond well to techniques that encourage leaf reduction and ramification, but most species can be used
Maple collections, sometimes called aceretums, occupy space in many gardens and arboreta around the world including the "five great W's" in England: Wakehurst Place Garden, Westonbirt Arboretum, Windsor Great Park, Winkworth Arboretum and Wisley Garden. In the United States, the aceretum at the Harvard-owned Arnold Arboretum in Boston is especially notable. In the number of species and cultivars, the Esveld Aceretum in Boskoop, Netherlands is the largest in the world.
Many maples have bright autumn foliage, and many countries have leaf-watching traditions. In Japan, the custom of viewing the changing colour of maples in the autumn is called "momijigari". Nikko and Kyoto are particularly favoured destinations for this activity. In addition, in Korea, the same viewing activity is called "Danpung-Nori" and Seoraksan and Naejang-san mountains are very famous places for it.
The particularly spectacular fall colours of the Acer saccharum (Sugar Maple) are a major contributor to the seasonal landscape in southeastern Canada and in New England. Fall tourism is a boon to the economy of this region, especially in Quebec, Vermont, New Hampshire and Western Massachusetts. In the American Pacific Northwest and British Columbia it is the spectacular fall colours of Acer circinatum (Vine Maple) that draw tourists and photographers.
Maples are important as source of syrup and wood. Dried wood is often used for the smoking of food. They are also cultivated as ornamental plants and have benefits for tourism and agriculture.
The Sugar Maple (Acer saccharum) is tapped for sap, which is then boiled to produce maple syrup or made into maple sugar or maple taffy. It takes about 40 litres of Sugar Maple sap to make a litre of syrup. Syrup can be made from closely-related species as well, but their output is inferior.
The seeds are sometimes consumed after they are boiled in water to remove bitter tasting compounds and are ground up in some varieties of exotic coffee
Some of the larger maple species have valuable timber, particularly Sugar Maple in North America, and Sycamore Maple in Europe. Sugar Maple wood, often known as "hard maple", is the wood of choice for bowling pins, bowling alley lanes, pool cue shafts, and butcher's blocks. Maple wood is also used for the production of wooden baseball bats, though less often than ash or hickory due to the tendency of maple bats to shatter when broken. The maple bat was introduced to Major League Baseball (MLB) in 1998 by Sam Holman of Sam Bats. Today it is the standard maple bat most in use by professional baseball.
Maple wood is often graded based on physical and aesthetic characteristics. The most common terminology includes the grading scale from common #2 which is unselected, and often used for craft woods, common #1 used for commercial and residential buildings, Clear, and select grade which saught out for fine woodworking.
Some maple wood has a highly decorative wood grain, known as flame maple , quilt maple, birdseye maple and burl wood. This condition occurs randomly in individual trees of several species, and often cannot be detected until the wood has been sawn, though it is sometimes visible in the standing tree as a rippled pattern in the bark.
These select decorative wood pieces also have subcategories which further filter the aesthetic looks. Crotch Wood, Bees Wing, Cats Paw, Old Growth and Mottled are some terms used to describe the look of these decorative woods.
Maple is considered a tonewood, or a wood that carries sound waves well, and is used in numerous musical instruments. Maple is harder and has a brighter sound than Mahogany, which is the other major tonewood used in instrument manufacture.
The back, sides, and neck of most violins, violas, cellos, double basses and many guitars are made from maple.
Electric guitar necks are commonly made from maple. The necks of the Fender Stratocaster and Telecaster were originally an entirely maple one piece neck, but later were also available with rosewood fingerboards. Maple fingerboards have a brighter sound than rosewood. The tops of Gibson's Les Paul guitars are made from carved maple. Many Les Pauls have quilted or flamed maple tops, and these models are particularly prized by players and collectors. Very few solid body guitars are made entirely from maple, as it is considered too heavy. Many guitars do, however, have maple tops or veneers. Gibson uses laminated maple in the manufacture of many of its semi-hollowbody guitars.
Maple is also often used to make bassoons and sometimes for other woodwind instruments.
Most drums are made from maple. From the 70s to the 90s, maple drum kits were a vast majority of all drum kits made. In recent years, Birch has become popular for drums once again.
As they are a major source of pollen in early spring before many other plants have flowered, maples are important to the survival of honeybees that play a commercially-important role later in the spring and summer.
Acer palmatum, called Japanese Maple or Smooth Japanese Maple (Japanese: irohamomiji; ) is a species of woody plant native to Japan, Korea and China. Many different cultivars of this maple have been selected and they are commonly grown in other parts of the world too, for their attractive leaf shapes and colors. They are highly sought after and are relatively costly trees given the size.
Acer palmatum is a deciduous shrub or small tree reaching heights of 6–10 m, rarely 16 m, often growing as an understory plant in shady woodlands. It may have multiple trunks joining close to the ground. In habit, it is often shaped like an upside-down circle (especially when younger) or takes on a dome-like form, especially when mature.The leaves are 4–12 cm long and wide, palmately lobed with five, seven, or nine acutely pointed lobes. The flowers are produced in small cymes, the individual flowers with five red or purple sepals and five whitish petals. The fruit is a pair of winged samaras, each samara 2–3 cm long with a 6–8 mm seed. The seeds of Japanese maple and similar species require stratification in order to germinate.
Even in nature, Acer palmatum displays considerable genetic variation. As such, even seedlings with the same parent tree can show difference in such aspects as leaf size and shape, and colour.
Three subspecies are recognised:
Acer palmatum subsp. palmatum. Leaves small, 4–7 cm wide, with five or seven lobes and double-serrate margins; seed wings 10–15 mm. Lower altitudes throughout central and southern Japan (not Hokkaido).
Acer palmatum subsp. amoenum (Carrière) H.Hara. Leaves larger, 6–12 cm wide, with seven or nine lobes and single-serrate margins; seed wings 20–25 mm. Higher altitudes throughout Japan and South Korea.
Acer palmatum subsp. matsumurae Koidz. Leaves larger, 6–12 cm wide, with seven (rarely five or nine) lobes and double-serrate margins; seed wings 15–25 mm. Higher altitudes throughout Japan.
Japanese Maple has been grown in temperate areas around the world since the 1800s and has been cultivated in Japan for centuries.
History of Japanese Red Maple When Swedish doctor-botanist Carl Thunberg was privileged to travel in the mysterious land of Japan late in the eighteenth century, he secreted out drawings of a small tree that would eventually become synonymous with the high art of oriental gardens. The first specimen of the tree reached England in 1820 and was named Acer palmatum after the hand like shape of its leaves. This would hardly surprise the Japanese who for centuries referred to their group of maples as kaede and momiji, references to the 'hands' of frogs and babies, respectively.
For centuries Japanese horticulturalists have developed cultivars of maples found in their country and nearby Korea and China. Today there are hundreds of Japanese Maples on the market, and Acer palmatum 'Atropurpureum' (meaning "dark purple") is one of the most popular
Today Numerous cultivars are readily available commercially and are a popular item at garden centres and other retail stores in Europe and North America. Red-leafed cultivars are the most popular, followed by cascading green shrubs with deeply dissected leaves. It is also a popular and appropriate choice for bonsai enthusiasts and has been used throughout the history of the art.
Acer palmatum includes hundreds of named cultivars with countless forms, colors, leaf types, sizes, and preferred growing conditions. Heights of mature specimens can range from 0.5 m to 25 m, depending on type. Some tolerate sun, and others like shade. Almost all are adaptable and blend well with companion plants. The trees are particularly suitable for borders and ornamental paths because the root systems are compact and not invasive. Well drained soil is preferred, and the trees grow strongest when not over-fertilized. Many varieties of Acer palmatum are successfully grown in containers.
If space is not a constraint, no pruning is necessary except to remove any dead branches. If space is a constraint or you want to do some artistic pruning use these 5 helpful tips
Some growers prefer to shape their trees artistically or to thin out interior branches to better expose the graceful main branches, especially in winter. If you must prune keep your Japanese red maple tree
Acer grandidentatum (Bigtooth Maple) is a species of maple native to interior western North America, occurring in scattered populations from western Montana in the United States south to Coahuila in northern Mexico. It is closely related to Acer saccharum (Sugar Maple), and is treated as a subspecies of it by some botanists, as Acer saccharum subsp. grandidentatum (Nutt.) Desmarais
It is a small to medium-sized deciduous tree growing to 10–15 m tall and a trunk of 20–35 cm diameter. The bark is dark brown to gray, with narrow fissures and flat ridges creating plate-like scales; it is thin and easily damaged. The leaves are opposite, simple, 6–12 cm long and broad, with three to five deep, bluntly-pointed lobes, three of the lobes large and two small ones (not always present) at the leaf base; the three major lobes each have 3–5 small subsidiary lobules. The leaves turn golden yellow to red in fall (this trait is less reliable in warmer areas).
The flowers appear with the leaves in mid spring; they are produced in corymbs of 5–15 together, each flower yellow-green, about 4–5 mm diameter, with no petals. The fruit is a paired samara (two winged seeds joined at the base), green to reddish-pink in color, maturing brown in early fall; each seed is globose, 7–10 mm diameter, with a single wing 2–3 cm
long.
It commonly grows in limestone soils but can adapt to a wide range of well-drained soils, from sand to clays to even white limestone areas. It prefers valleys, canyons, and the banks of mountain streams, primarily at higher elevations such as the sheltered canyons of the Edwards Plateau in Texas (where a population is protected in the Lost Maples State Natural Area). Although continental climates prevail over all of its natural range, it grows well in the maritime climate of Vancouver. It is slow growing when young, and does not have many pests.
It is occasionally planted as an ornamental tree, valued for its drought tolerance and ability to grow in rocky landscapes.
Other vernacular names occasionally used include Lost Maple, Sabinal Maple, Western Sugar Maple, Uvalde Big Tooth Maple, Canyon Maple, Southwestern Big Tooth Maple, Plateau Big Tooth Maple, Limerock Maple, Wasatch Maple and Rocky Mountain Sugar Maple.
Acer platanoides (Norway Maple) is a species of maple native to eastern and central Europe and southwest Asia, from France east to Russia, north to southern Scandinavia and southeast to northern Iran.
It is a deciduous tree growing to 20–30 m tall with a trunk up to 1.5 m diameter, and a broad, rounded crown. The bark is grey-brown and shallowly grooved; unlike many other maples, mature trees do not tend to develop a shaggy bark. The shoots are green at first, soon becoming pale brown; the winter buds are shiny red-brown. The leaves are opposite, palmately lobed with five lobes, 7–14 cm long and 8–20 cm (rarely 25 cm) across; the lobes each bear one to three side teeth, and an otherwise smooth margin. The leaf petiole is 8–20 cm long, and secretes a milky juice when broken. The autumn colour is usually yellow, occasionally orange-red. The flowers are in corymbs of 15–30 together, yellow to yellow-green with five sepals and five petals 3–4 mm long; flowering occurs in early spring before the new leaves emerge. The fruit is a double samara with two winged seeds; the seeds are disc-shaped, strongly flattened, 10–15 mm across and 3 mm thick. The wings are 3–5 cm long, widely spread, approaching a 180° angle. It typically produces a large quantity of viable seeds. It is not particularly a long-lived tree, with a maximum age of around 250 years.
Norway Maple is a member (and is the type species) of the section Platanoidea Pax, characterised by flattened, disc-shaped seeds and the shoots and leaves containing milky sap. Other related species in this section include Acer campestre (Field Maple), Acer cappadocicum (Cappadocian Maple), Acer lobelii (Lobel's Maple), and Acer truncatum (Shandong Maple). From Field Maple, Norway Maple is distinguished by its larger leaves with pointed, not blunt, lobes, and from the other species by the presence of one or more teeth on all of the lobes.
It is also frequently confused with the more distantly related Acer saccharum (Sugar Maple). Sugar Maple is easy to identify by clear sap in the petiole (Norway Maple has white sap). The tips of the points on Norway Maple leaves reduce to a fine "hair", while the tips of the points on Sugar Maple leaves are on close inspection rounded. On mature trees, Sugar Maple bark is more shaggy, while Norway Maple bark has small, often criss-crossing grooves. While the shape and angle of leaf lobes vary somewhat within all Maple species, the leaf lobes of Norway Maple tend to have a more triangular shape, in contrast to the more squarish lobes often seen on Sugar Maples. The seeds of Sugar Maple are globose, while Norway Maple seeds are flattened. Sugar Maple usually has a brighter orange autumn color, where Norway Maple is usually yellow, although some of the red-leaved cultivars appear more orange. The tree tends to leaf out earlier than most maples and holds its leaves
The wood is hard, yellowish-white to pale reddish, with the heartwood not distinct; it is used for furniture and turnery.
Many cultivars have been selected, with distinctive leaf shape or coloration such as the dark purple of 'Crimson King' and 'Schwedleri', the variegated leaves of 'Drummondii' and 'Emerald Queen', and the deeply divided, feathery leaves of 'Dissectum' and 'Lorbergii'. The purple-foliage cultivars have orange to red autumn colour. 'Columnare' is selected for its narrow upright growth.
It has been widely placed into cultivation in other areas, including western Europe northwest of its native range. It grows north of the Arctic Circle at Tromsø, Norway. In North America, it is grown as a street and shade tree. It is favoured due to its tall trunk and tolerance of poor, compacted soils and urban pollution
Unfortunately, despite its good looks and urban hardiness, it releases chemicals to discourage undergrowth[10] which tends to create bare, muddy run-off conditions immediately beneath the tree. A. platanoides has been shown to inhibit the growth of native saplings as a canopy tree or as a sapling. As a result of these characteristics it is considered invasive in some states and has been banned in New Hampshire and Massachusetts.Norway Maple is one of three species that Meijer Garden Centers no longer sell; Meijer made this decision due to the tree's invasive nature. Despite these steps, Norway Maple is still available and widely used for urban plantings in many areas.
Norway Maple itself is threatened in a few areas by the Asian long-horned beetle, which eats through the trunk of trees, often killing them.
A number of species of Lepidoptera feed on Norway Maple foliage; see Lepidoptera that feed on maples. Norway Maple is generally free of serious diseases, though can be attacked by the powdery mildew Uncinula bicornis, and verticillium wilt disease caused by Verticillium spp
Acer rubrum (Red Maple, also known as Swamp or Soft Maple), is one of the most common and widespread deciduous trees of eastern North America. It ranges from the Lake of the Woods on the border between Ontario and Minnesota, east to Newfoundland, south to near Miami, Florida, and southwest to east Texas. Many of its features, especially its leaves, are quite variable in form. At maturity it often attains a height of around 15 m (50 ft). It is aptly named as its flowers, petioles, twigs and seeds are all red to varying degrees. Among these features, however, it is best known for its brilliant deep scarlet foliage in autumn.
Over most of its range, red maple is adaptable to a very wide range of site conditions, perhaps more so than any other tree in eastern North America. It can be found growing in swamps, on poor dry soils, and most anywhere in between. Elevation is also not a limiting factor in its range, as it grows well from sea level to about 900 m (3,000 ft). Due to its attractive fall foliage and pleasing form, it is often used as a shade tree for landscapes. It is used commercially on a small scale for maple syrup production as well as for its medium to high quality lumber. It is also the State Tree of Rhode Island.
Though A. rubrum is usually easy to identify, it is highly changeable in morphological characteristics. It is a medium to large sized tree, reaching heights of 18 to 27 meters (60 to 90 feet) and exceptionally over 35 metres (115 ft).The leaves are usually 9 to 11 cm (3 1/2 in. to 4 3/8 in.) long on a full grown tree. The trunk diameter can range from 46 to 76 cm (18 to 30 inches), depending on the growing conditions.[3] Its spread is about 12 m (40 ft). A 10-year-old sapling will stand about 6 m (20 ft) tall. In forests, the bark will remain free of branches until some distance up the tree. Individuals grown in the open are shorter and thicker with a more rounded crown.[4] Generally speaking, however, the crown is irregularly ovoid with ascending whip-like curved shoots. The bark is a pale grey and smooth when the individual is young. As the tree grows the bark becomes darker and cracks into slightly raised long plates. The largest known living red maple is located near Armada, Michigan, at a height of 38.1 m (125 ft) and a bole circumference, at breast height, of 4.95 m (16.25 ft).
The leaves of the red maple offer the easiest way to distinguish it from its relatives. As with nearly all maple trees, they are deciduous and arranged oppositely on the twig. They are typically 5–10 cm (2-4 inches) long and wide with 3-5 palmate lobes with a serrated margin. The sinuses are typically narrow, but the leaves can exhibit considerable variation. When 5 lobes are present, the three at the terminal end are larger than the other two near the base. In contrast, the leaves of the related silver maple, A. saccharinum, are much more deeply lobed, more sharply toothed and characteristically have 5 lobes. The upper side of A. rubrum's leaf is light green and the underside is whitish and can be either glaucous or hairy. The leaf stalks are usually red and are up to 10 cm (4 inches) long. Furthermore, the leaves turn a brilliant red in autumn.
The twigs of the red maple are reddish in color and somewhat shiny with small lenticels. Dwarf shoots are present on many branches. The buds are usually blunt and greenish to reddish in color, generally with several loose scales. The lateral buds are slightly stalked, and in addition there may be collateral buds present as well. The buds form in fall and winter and are often visible from a distance due to their reddish tint. The leaf scars on the twig are V-shaped and contain
bundle scars.
The flowers are generally unisexual, with male and female flowers appearing in separate sessile clusters, though they are sometimes also bisexual. They appear in spring from April to May, usually coming before the leaves. The tree itself is considered Polygamodioecious, meaning some individuals are male, some female, and some monoecious. The flowers are red with 5 small petals and a 5-lobed calyx borne in hanging clusters, usually at the twig tips. They are lineal to oblong in shape and are pubescent. The pistillate flowers have one pistil formed from two fused carpels with a glabrous superior ovary and two long styles that protrude beyond the perianth. The staminate flowers contain between 4 and 12 stamens, often with 8.
The fruit is a 15 to 25 millimeter (.5 to .75 inch) long double samara with somewhat divergent wings at an angle of 50 to 60 degrees. They are borne on long slender stems and are variable in color from light brown to reddish. They ripen from April through early June, before even the leaf development is altogether complete. After they reach maturity, the seeds are dispersed for a 1 to 2 week period from April through July
A. rubrum is one of the most abundant and widespread trees in eastern North America. It can be found from the south of Newfoundland, Nova Scotia and southern Quebec to the south west of Ontario, extreme southeastern Manitoba and northern Minnesota; south to Wisconsin, Illinois, Missouri, eastern Oklahoma, and eastern Texas in its western range; and east to Florida. It has the largest continuous range along the North American Atlantic Coast of any tree that occurs in Florida. In total it ranges 2600 km (1,600 miles) from north to south. The species is native to all regions of the United States east of the 95th meridian west, with only three exceptions, namely the Prairie Peninsula of the Midwest, the coastal prairie in southern Louisiana and southeastern Texas and the swamp prairie of the Florida Everglades. In several other locations, the tree is absent from large areas but still present in a few specific habitats. An example is the Bluegrass region of Kentucky, where it is not found in the dominant open plains, but is present along streams. Here the red maple is not present in the bottom land forests of the Grain Belt, despite the fact it is common in similar habitats and species associations both to the north and south of this area.
The tree's range ends where the -40°C (-40°F) mean minimum isotherm begins, namely in southeastern Canada. On the other hand, the western range is limited by the much drier climate of the Great Plains. Nonetheless, it has the widest tolerance to climatic conditions of all the North American species of maple. The absence of red maple in the Prairie Peninsula is due to the species intolerance of fire.
A. rubrum does very well in a wide range of soil types, with varying textures, moisture, pH, and elevation, probably more so than any other forest tree in North America. It grows on glaciated as well as nonglaciated soils derived from the following rocks: granite, gneiss, schist, sandstone, shale, slate, conglomerate, quartzite, and limestone. Chlorosis can occur on very alkaline soils, though otherwise its pH tolerance is quite high. As concerns levels of moisture, the red maple grows everywhere from dry ridges and southwest facing slopes to peat bogs and swamps. It occurs commonly in rather extreme moisture conditions, both very wet and quite dry. While many types of tree prefer a south or north facing aspect, the red maple does not appear to have a preference. Its ideal conditions are in moderately well-drained, moist sites at low or intermediate elevations. However, it is nonetheless common in mountainous areas on relatively dry ridges, as well as on both the south and west sides of upper slopes. Furthermore, it is common in swampy areas, along the banks of slow moving streams, as well as on poorly drained flats and depressions. In northern Michigan and New England, the tree is found on the tops of ridges, sandy or rocky upland and otherwise dry soils, as well as in nearly pure stands on moist soils and the edges of swamps. In the far south of its range, it is almost exclusively associated with swamps.
Interestingly, it is thought that the pre-European forest of eastern North America contained far fewer red maples than at present. Most diversity surveys conducted in eastern forests prior to their large scale exploitation showed the red maple representing under 5% of all tree species and it was furthermore mostly confined to poorly drained areas. The density of the tree in many of these areas has increased 6 to 7 fold and this trend seems to be continuing. A series of disturbances to the oak and pine forests since European arrival, such as the suppression of forest fires and global warming, are most likely responsible for this phenomenon. Concern has been expressed, as the ongoing spread of the red maple is changing the nature of eastern forests by reducing the number of oaks and pines that would otherwise dominate.
Red maple seldom lives longer than 150 years, making it short to medium lived. It reaches maturity in 70 to 80 years. Its ability to thrive in a large number of habitats is largely due to its ability to produce roots to suit its site from a young age. In wet locations, red maple seedlings produce short taproots with long and developed lateral roots, while on dry sites, they develop long taproots with significantly shorter laterals. The roots are primarily horizontal, however, forming in the upper 25 cm (10 in) of the ground. Mature trees have woody roots up to 25 m (80 ft) long. They are very tolerant of flooding, with one study showing that 60 days of flooding caused no leaf damage. At the same time, they are tolerant of drought due to their ability to stop growing under dry conditions by then producing a second growth flush when conditions later improve, even if growth has stopped for 2 weeks
A. rubrum is one of the first plants to flower in spring. A crop of seeds is generally produced every year with a bumper crop often occurring every second year. A single tree between 5 and 20 cm (2 and 8 inches) in diameter can produce between 12,000 and 91,000 seeds in a season. A tree 30 cm (1 ft) in diameter was shown to produce nearly a million seeds. Fertilization has also been shown to significantly increase the seed yield for up to two years after application. The seeds are epigeal and tend to germinate in early Summer soon after they are released, assuming a small amount of light, moisture, and sufficient temperatures are present. If the seeds are densely shaded, then germination commonly does not occur until the next Spring. Most seedlings do not survive in closed forest canopy situations. However, one to four year old seedling are common under dense canopy and though they eventually die if no light reaches them, they serve as a reservoir, waiting to fill any open area of the canopy above.
Red maple is able to increase its numbers significantly when associate trees are damaged by disease, cutting, or fire. One study found that 6 years after clearcutting a 3.4 hectare (8.5 acre) Oak-Hickory forest containing no red maples, the plot contained more than 2,200 red maple seedlings per hectare (900 per acre) taller than 1.4 m (4.5 ft). One of its associates, the black cherry (Prunus serotina), contains benzoic acid, which has been shown to be a potential allelopathic inhibitor of red maple growth. Red maple is one of the first species to start stem elongation. In one study, stem elongation was one-half completed in 1 week, after which growth slowed and was 90% completed within only 54 days. In good light and moisture conditions, the seedlings can grow 30 cm (1 ft) in their first year and up to 60 cm (2 ft) each year for the next few years making it a fast grower.
The red maple is a used as a food source by several forms of wildlife. Elk and white-tailed deer in particular use the current season's growth of red maple as an important source of winter food. Several Lepidoptera (butterflies and moths) utilize the leaves as food; see List of Lepidoptera that feed on maples.
Due to A. rubrum's very wide range, there is significant variation in hardiness, size, form, time of flushing, onset of dormancy, and other traits. Generally speaking, individuals from the north flush the earliest, have the most reddish Fall color, set their buds the earliest and take the least winter injury. Seedlings are tallest in the north-central and east-central part of the range. The fruits also vary geographically with northern individuals in areas with brief frost free periods producing fruits that are shorter and heavier than their southern counterparts. As a result of the variation there is much genetic potential for breeding programs with a goal of producing red maples for cultivation. This is especially useful for making urban cultivars that require resistance from verticillium wilt, air pollution, and drought.
Red maple frequently hybridizes with Silver Maple; the hybrid, known as Freeman's Maple Acer x freemanii, is intermediate between the parents.
The leaves of red maple, especially when dead or wilted, are extremely toxic to horses. The toxin is unknown, but believed to be an oxidant because it damages red blood cells, causing acute hemolysis that inhibits the transport of oxygen. The ingestion of 700 grams (1.5 pounds) of leaves is considered toxic and 1.4 kilograms (3 pounds) is lethal. Symptoms occur within one or two days after ingestion and can include depression, lethargy, increased rate and depth of breathing, increased heart rate, jaundice, dark brown urine, coma, and death. Treatment is limited and can include the use of methylene blue or mineral oil and activated carbon in order to stop further absorption of the toxin into the stomach. About 50% to 75% of affected horses die or are euthanized as a result
Red Maple is widely grown as an ornamental tree in parks and large gardens, except where soils are too alkaline or salty. In parts of the Pacific Northwest, it is one of the most common introduced trees. Its popularity in cultivation stems from its vigorous habit, its attractive and early red flowers, and most importantly, its flaming red fall foliage. The tree was introduced into the United Kingdom in 1656 and shortly thereafter entered cultivation. There it is frequently found in many parks and gardens, as well as occasionally in churchyards
Red Maple is a good choice of a tree for urban areas when there is ample room for its root system. The red maple is excellent at withstanding harsh urban conditions, including tolerance of both dry and wet soils, and a higher tolerance of pollution than sugar maple. Like several other maples, its low root system can be invasive and it makes a poor choice for plantings in narrow strips between a sidewalk and a street. It attracts squirrels, who eat its buds in the early spring, although squirrels prefer the larger buds of the silver maple.
Numerous cultivars have been selected, often for intensity of fall color, with 'October Glory' and 'Red Sunset' among the most popular. Toward its southern limit, 'Fireburst', 'Florida Flame', and 'Gulf Ember' are preferred. Many cultivars of Freeman's Maple are also grown widely. Below is a partial list of cultivars:
'Armstrong' - Columnar to fastigate in shape with silvery bark and modest orange to red fall foliage
'Autumn Blaze' - Rounded oval form with leaves that resemble the silver maple. The fall color is orange red and persists longer than usual
'Autumn Flame' - A fast grower with exceptional bright red fall color developing early. The leaves are also smaller than the species.
'Autumn Radiance' - Dense oval crown with an orange-red fall color
'Autumn Spire' - Broad columnar crown; red fall color; very hardy
'Bowhall' - Conical to upright in form with a yellow-red fall color
'Burgundy Bell' - Compact rounded uniform shape with long lasting, burgundy fall leaves
'Columnare' - An old cultivar growing to 20 metres (70 ft) with a narrow columnar to pyramidal form with dark green leaves turning orange and deep red in fall
'Gerling' - A compact, slow growing selection, this individual only reaches 10 metres (30 ft) and has orange-red fall foliage
'Northwood' - Branches are at a 45 degree angle to the trunk, forming a rounded oval crown. Though the foliage is deep green in summer, its orange-red fall color is not as impressive as other cultivars.
'October Brilliance' - This selection is slow to leaf in spring, but has a tight crown and deep red fall color
'October Glory' - Has a rounded oval crown with late developing intense red fall foliage. Along with 'Red Sunset', it is the most popular selection due to the dependable fall color and vigorous growth.
'Red Sunset' - The other very popular choice, this selection does well in heat due to its drought tolerance and has an upright habit. It has very attractive orange-red fall color and is also a rapid and vigorous grower.
'Scarlet Sentinel' - A columnar to oval selection with 5-lobed leaves resembling the silver maple. The fall color is yellow-orange to orange-red and the tree is a fast grower.
'Schlesingeri' - A tree with a broad crown and early, long lasting fall color that a deep red to reddish purple. Growth is also quite rapid.
'Shade King' - This fast growing cultivar has an upright-oval form with deep green summer leaves that turn red to orange in fall.
'V.J. Drake' - This selection is notable because the edges of the leaves first turn a deep red before the color progresses into the center.
In the lumber industry Acer rubrum is considered a soft maple. The wood is close grained and as such it is similar to that of A. saccharum, but its texture is softer, less dense, and has a poorer figure and machining qualities. High grades of wood from the red maple can nonetheless be substituted for hard maple, particularly when it comes to making furniture. As a soft maple, the wood tends to shrink more during the drying process than with the hard maples.
Red maple is also used for the production of maple syrup, though the hard maples Acer saccharum (sugar maple) and Acer nigrum (black maple) are more commonly utilized. One study compared the sap and syrup from the sugar maple with those of the red maple, as well as those of the Acer saccharinum (silver maple), Acer negundo (boxelder), and Acer platanoides (Norway maple), and all were found to be equal in sweetness, flavor, and quality. However, the buds of red maple and other soft maples emerge much earlier in the spring than the sugar maple, and after sprouting chemical makeup of the sap changes, imparting an undesirable flavor to the syrup. This being the case, red maple can only be tapped for syrup before the buds emerge, making the season very short.
Red maple is a medium quality firewood,possessing lower heat energy, nominally 5.4 MJ/m³ (18.7 million BTU (mbtu) per cord), than other hardwoods such as Ash: 7 MJ/m³ (24 mbtu/cord), Oak: 7 MJ/m³ (24 mbtu/cord), or Birch: 5.8 MJ/m³ (20 mbtu/cord).