Difference between revisions of "Ash tree"

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Ash
European Ash (Fraxinus excelsior)
European Ash (Fraxinus excelsior)
Plant Info
Scientific classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Lamiales
Family: Oleaceae
Genus: Fraxinus
Tourn. ex L.

Species
See text
European Ash in flower
Narrow-leafed Ash (Fraxinus angustifolia) shoot with leaves
Closeup of European Ash seeds
19th century illustration of Manna Ash (Fraxinus ornus)

An ash can be any of four different tree genera from four very distinct families (see end of page for disambiguation), but originally and most commonly refers to trees of the genus Fraxinus in the olive family Oleaceae. The ashes are usually medium to large trees, mostly deciduous though a few subtropical species are evergreen. The leaves are opposite (rarely in whorls of three), and mostly pinnately-compound, simple in a few species. The seeds, popularly known as keys, are a type of fruit known as a samara. The tree's common English name goes back to the Old English æsc.

Selected species

Ashes of eastern North America
Ashes of western and southwestern North America
Ashes of the Western Palearctic (Europe, north Africa and southwest Asia)
Ashes of the Eastern Palearctic (central & eastern Asia)

Threats

The emerald ash borer Agrilus planipennis, a wood-boring beetle accidentally introduced to North America from eastern Asia with ash wood products in about 1998, has killed millions of trees in southeast Michigan, adjacent Ontario, and some isolated smaller areas on eastern North America. It threatens some 7 billion ash trees in North America. Ash is also used as a food plant by the larvae of some Lepidoptera species - see list of Lepidoptera which feed on Ashes.

Uses

The wood is hard (a hardwood), tough and very strong but elastic, extensively used for making bows, tool handles, quality wooden baseball bats, hurley sticks and other uses demanding high strength and resilience. It is also used as material for the bodies of guitars, known for its bright, cutting tone and sustaining quality. It also makes excellent firewood. The two most economically important species for wood production are White Ash in eastern North America, and European Ash in Europe. The Green Ash is widely planted as a street tree in the United States. The inner bark of the Blue Ash has been used as a source for a blue dye. The cortex (bark) of Fraxinus rhynchophylla HANCE (Chinese: Ku li bai la shu), Fraxinus chinensis ROXB. (Chinese: Bai la shu), Fraxinus szaboana English (Chinese: Jian ye bai la shu) and Fraxinus stylosa English (Chinese: su zhu bai la shu)are used in Traditional Chinese Medicine (TCM) for diarrhea, dysenteric disorder, and vaginal discharge. It is also good for the eyes where there is symptoms of redness, swelling, and pain. The dosage is 6-12 grams.

Cultural aspects

In Norse mythology, the World Tree Yggdrasil is commonly held to be an ash tree, and the first man, Ask, was formed from an ash tree (the first woman was made from elm). Elsewhere in Europe, snakes were said to be repelled by ash leaves or a circle drawn by an ash branch. Irish folklore claims that shadows from an ash tree damage crops. In Cheshire, it is said that ash could be used to cure warts or rickets. See also the letter ash.

In Greek mythology, the Meliai were nymphs of the ash, perhaps specifically of the Manna Ash (Fraxinus ornus), as dryads were nymphs of the oak. Many echoes of archaic Hellene rites and myth involve ash trees.

Other name uses (Green Tree)

In North America, the name "Mountain ash" is applied to species of the genus Sorbus, more commonly known in the UK as Rowans and Whitebeams, and the name "Prickly ash" is applied to Zanthoxylum americanum. In Australia, many common eucalyptus species are called ash because they too produce hard, fine-grained timber. The best known of these is the Mountain Ash, the tallest broadleaf tree in the world..