Acer negundo - WikiHQ

thumb|Female flowers

thumb|Male flowers

Acer negundo, also known as the box elder, boxelder maple, Manitoba maple or ash-leaved maple, is a species of maple native to North America from Canada to Honduras. It is a fast-growing, short-lived tree with opposite, ash-like compound leaves. It is sometimes considered a weedy or invasive species, and has been naturalized throughout much of the world, including South America, Australia, New Zealand, South Africa, much of Europe, and parts of Asia. The typical lifespan of box elder is 60 - 75 years. Under exceptionally favorable conditions, it may live to 100 years.

The shoots are green, often with a whitish to pink or violet waxy coating when young. Branches are smooth, somewhat brittle, and tend to retain a fresh green color rather than forming a bark of dead, protective tissue. The bark on its trunks is pale gray or light brown, deeply cleft into broad ridges, and scaly.

Unlike most other maples (which usually have simple, palmately lobed leaves), Acer negundo has pinnately compound leaves that usually have three to seven leaflets. Simple leaves are also occasionally present; technically, these are single-leaflet compound leaves. Although some other maples (such as Acer griseum, Acer mandshuricum and the closely related A. cissifolium) have trifoliate leaves, only A. negundo regularly displays more than three leaflets. The leaflets are about long and wide with slightly serrate margins. Leaves have a translucent light green color and turn yellow in the fall.

The yellow-green flowers are small and appear in early spring, with staminate flowers in clusters on slender pedicels and pistillate flowers on drooping racemes long.

The fruit is a schizocarp of two single-seeded, winged samaras on drooping racemes. Each seed is slender, long, with a incurved wing; they drop in autumn or they may persist through winter. Seeds are usually both prolific and fertile. The male and female flowers appear on separate plants, with males featuring clusters that generally have four flowers together, while females appear as a raceme.

Boxelder (Acer negudo) with young fruit - Flickr - Jay Sturner.jpg|Leaves and fruit

2014-10-11 12 48 07 Box Elder Maple foliage during autumn in Elko, Nevada.JPG|Autumn leaf color

Acer negundo 31026528.jpg|Retained seeds in winter

Acer negundo 2018-05-01 9940.jpg|Seedling

Acer negundo 60052613.jpg|Sprawling, multi-stemmed growth form

2020 year. Herbarium. Acer negundo. img-010.jpg|Fruit

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Taxonomy

The Box elder is not in the Elder genus Sambucus in the family Adoxaceae. A few botanists treat boxelder maple in its own distinct genus (Negundo aceroides) but this is not widely accepted.

Common names

Indicative of its familiarity to many people over a large geographic range, A. negundo has numerous common names. The names "box elder" and "boxelder maple" are based upon the similarity of its whitish wood to that of boxwood and the similarity of its pinnately compound leaves to those of some species of elder.

Other common names are based upon this maple's similarity to ash, its preferred environment, its sugary sap, a description of its leaves, its binomial name, and so on. These names include "Manitoba maple", "ash-leaf maple", "cut-leaved maple", "three-leaf maple", "ash maple", "sugar maple", "negundo maple", and "river maple".

Names vary regionally. Box elder, boxelder maple, ash-leaved maple, and maple ash are among its common names in the United States. In Canada it is commonly known as Manitoba maple and occasionally as elf maple. In the British Isles it is known as box elder or ashleaf maple. In Russia it is known as American maple () as well as ash-leaf maple ().

Because of its leaflets' superficial similarity to those of poison ivy, Acer negundo saplings are often mistaken for the allergenic plant. While both poison ivy and Acer negundo have compound leaves composed of three leaflets with ragged edges, Acer negundo exhibits an opposite branching pattern, as opposed to the alternating pattern of poison ivy. Like poison ivy, Acer negundo is also a noted riparian species, and can often be found growing along riverbeds and in wet soils generally. For all these reasons, and despite their obvious differences, Acer negundo is sometimes referred to informally as the poison ivy tree.

Subspecies

Acer negundo is often divided into three or more subspecies, some of which were originally described as separate species. These are:

Acer negundo subsp. negundo, native from the Atlantic Coast to the Rocky Mountains. as is the town of Box Elder, South Dakota

Although native to North America, it is considered a weedy species in some areas, such as in parts of the Northeastern United States, and has increased greatly in these areas. In 1928, Joseph Illick, chief forester for the state of Pennsylvania, wrote in Pennsylvania Trees that box elder was "rare and localized" in the state. After World War II, box elder's rapid growth made it a popular landscaping tree in suburban housing developments despite its poor form, vulnerability to storm damage, and tendency to attract large numbers of box elder bugs. Intentional cultivation has thus made the tree far more abundant than it once was.

It can quickly colonize both cultivated and uncultivated areas and the range is therefore expanding both in North America and elsewhere. In Europe where it was introduced in 1688 as a park tree it is able to spread quickly and is considered an invasive species in parts of Central Europe, including Germany, the Czech Republic, Hungary, Slovenia, Poland and Russia where it can form mass growth in lowlands, disturbed areas, and riparian biomes on calcareous soils. It has also become naturalized in eastern China,

This species prefers bright sunlight. It often grows on flood plains and other disturbed areas with ample water supply, such as riparian habitats. Human influence has greatly favored this species; it grows around houses and in hedges, as well as on disturbed ground and vacant lots.

Ecology

thumb|Boxelder bugs (Boisea trivittata) feed on Acer negundo

Several birds and some squirrels feed on the seeds. The evening grosbeak uses them extensively.

The boxelder bug (Boisea trivittata) lays its eggs on all maples, but prefers this species, clustering the eggs in bark crevices.

Small galls are formed on the leaves by a bladder mite, Aceria negundi. A gall midge, Contarinia negundinis joins and enlarges the galls of Aceria negundi. The midge sometimes creates a separate, tubular gall on the midrib or veins of the undersides of the leaves. Many cultivars have been developed, such as: It is analogous to Jamaican vomiting sickness in humans, also caused by hypoglycin A.

Acer negundo pollen, which is released in winter or spring (varying with latitude and elevation) is a severe allergen. There is also some commercial use of the tree for various decorative applications, such as turned items (bowls, stem-ware, pens). Such purposes generally use burl or injured wood, as the injured wood develops a red stain.

The wood has been used for a variety of purposes by Native Americans, such as by the Navajo to make tubes for bellows, by the Cheyenne to make bowls, and by the native peoples of Montana who use the large trunk burls or knots to make bowls, dishes, drums, and pipe stems. and the Keres make the twigs into prayer sticks.

The Dakota people and the Omaha people make the wood into charcoal, which is used in ceremonial painting and tattooing.

Acer negundo was identified as the material used in the oldest extant wood flutes from the Americas. The flutes, excavated by Earl H. Morris in 1931 in Northeastern Arizona, have been dated to 620–670 CE.

Medicinal use

Acer negundo has been used by Native Americans for several medicinal purposes. The Cheyenne burn the wood as incense for making spiritual medicines, and during Sun Dance ceremonies. and the Ojibwe use an infusion of the inner bark for the same purpose.

As food

The sap has been used to make syrup by Native Americans, including the Dakota, Omaha, Pawnee, Ponca, Winnebago, Sioux, and the indigenous people of Montana. The Cheyenne mix the boiled sap with shavings from the inner sides of animal hides and eat them as candy. The Ojibwe mix the sap with that of the sugar maple and drink it as a beverage.

Citations

General and cited references

Philips, Roger. Trees of North America and Europe. New York: Random House. , 1979.

External links

Acer negundo facts and diagnostic traits
Interactive Distribution Map of Acer negundo
Acer negundo images at bioimages.vanderbilt.edu