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An ash can be any of three different tree genera from three 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.

Species

Ashes of eastern North America

• Fraxinus americana White Ash
• Fraxinus caroliniana Water Ash
• Fraxinus nigra Black Ash
• Fraxinus pennsylvanica Green Ash (also includes Red Ash )
• Fraxinus profunda (syn. F. tomentosa) Pumpkin Ash
• Fraxinus quadrangulata Blue Ash

Ashes of western and southwestern North America

• Fraxinus anomala Single-leaf Ash
• Fraxinus cuspidata Fragrant Ash
• Fraxinus dipetala Two-petal Ash
• Fraxinus dubia
• Fraxinus gooddingii Goodding's Ash
• Fraxinus greggii Gregg's Ash
• Fraxinus latifolia Oregon Ash
• Fraxinus papillosa Chihuahua Ash
• Fraxinus purpusii
• Fraxinus rufescens
• Fraxinus texensis Mountain Ash or Texas Ash
• Fraxinus uhdei Shamel Ash
• Fraxinus velutina Velvet Ash

Ashes of the Western Palearctic (Europe, north Africa and southwest Asia)

• Fraxinus angustifolia Narrow-leafed Ash
  • Fraxinus angustifolia var. oxycarpa (F. oxycarpa) Caucasian Ash
• Fraxinus excelsior European Ash
• Fraxinus holotricha
• Fraxinus ornus Manna Ash or Flowering Ash
• Fraxinus pallisiae Pallis' Ash

Ashes of the Eastern Palearctic (central & eastern Asia)

• Fraxinus apertisquamifera
• Fraxinus baroniana
• Fraxinus bungeana Bunge's Ash
• Fraxinus chinensis Chinese Ash or Korean Ash
• Fraxinus chiisanensis
• Fraxinus floribunda Himalayan Manna Ash
• Fraxinus griffithii Griffith's Ash
• Fraxinus hubeiensis
• Fraxinus lanuginosa
• Fraxinus longicuspis Japanese Ash
• Fraxinus malacophylla
• Fraxinus mandshurica Manchurian Ash
• Fraxinus mariesii Chinese Flowering Ash
• Fraxinus micrantha
• Fraxinus paxiana
• Fraxinus platypoda
• Fraxinus raibocarpa
• Fraxinus sieboldiana Japanese Flowering Ash
• Fraxinus spaethiana Späth's Ash
• Fraxinus trifoliata
• Fraxinus xanthoxyloides Afghan Ash

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 including November Moth and Ash Pug.

Uses

The wood is hard, tough and very strong but elastic, extensively used for tool handles, quality wooden baseball bats, hurleys and other uses demanding high strength and resilience. 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.

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 alder). 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.

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 (disambiguation)

In North America, the name ash is also given to species of Sorbus, more accurately known as Rowans and Whitebeams. 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.