Fraxinus

Fraxinus (/ˈfræksnəs/) is a genus of flowering plants in the olive and lilac family, Oleaceae. It contains 45–65 species of usually medium to large trees, mostly deciduous though a few subtropical species are evergreen. The tree's common English name, ash, goes back to the Old English æsc, while the generic name originated in Latin. Both words also meant "spear" in their respective languages. The leaves are opposite (rarely in whorls of three), and mostly pinnately compound, simple in a few species. The seeds, popularly known as keys or helicopter seeds, are a type of fruit known as a samara. Rowans or Mountain Ashes are unrelated to true ashes and belong to the Genus Sorbus though the leaves and buds are superficially similar.

Fraxinus
Fraxinus ornus
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Lamiales
Family:	Oleaceae
Tribe:	Oleeae
Genus:	Fraxinus L.
Species
See text

European Ash in flower

Narrow-leafed Ash (Fraxinus angustifolia) shoot with leaves

Selected species

Eastern North America

• Fraxinus americana L. – White Ash or Autumn Purple Ash
• Fraxinus caroliniana Mill. – Carolina Ash
• Fraxinus nigra Marshall – Ash
• Fraxinus pennsylvanica Marshall Green Ash
• Fraxinus profunda (Bush) Bush – Pumpkin Ash
• Fraxinus quadrangulata Michx. – Blue Ash

Western and southwestern North America

• Fraxinus anomala Torr. ex S.Watson – Singleleaf Ash
• Fraxinus berlandieriana DC. – Mexican Ash
• Fraxinus cuspidata Torr. – Fragrant Ash
• Fraxinus dipetala Hook. & Arn. – California Ash or Two-petal Ash
• Fraxinus dubia
• Fraxinus gooddingii – Goodding's Ash
• Fraxinus greggii A.Gray – Gregg's Ash
• Fraxinus latifolia Benth. – Oregon Ash
• Fraxinus lowellii – Lowell Ash
• Fraxinus papillosa Lingelsh. – Chihuahua Ash
• Fraxinus purpusii
• Fraxinus rufescens
• Fraxinus texensis (A.Gray) Sarg. – Texas Ash
• Fraxinus uhdei (Wenz.) Lingelsh. – Shamel Ash or Tropical Ash
• Fraxinus velutina Torr. – Velvet Ash or Arizona Ash

Western Palearctic (Europe, north Africa and southwest Asia)

• Fraxinus angustifolia Vahl – Narrow-leafed Ash
  • Fraxinus angustifolia subsp. oxycarpa – Caucasian Ash
• Fraxinus dimorpha
• Fraxinus excelsior L. – European Ash
• Fraxinus holotricha Koehne
• Fraxinus ornus L. – Manna Ash or Flowering Ash
• Fraxinus syriaca
• Fraxinus pallisiae Wilmott – Pallis' Ash

Eastern Palearctic (central and east Asia)

• Fraxinus apertisquamifera
• Fraxinus baroniana
• Fraxinus bungeana DC. – Bunge's Ash
• Fraxinus chinensis Roxb. – Chinese Ash or Korean Ash
• Fraxinus chiisanensis
• Fraxinus floribunda Wall. – Himalayan Manna Ash
• Fraxinus griffithii C.B.Clarke – Griffith's Ash
• Fraxinus hubeiensis Ch'u & Shang & Su – 湖北梣 hu bei qin
• Fraxinus japonica – Japanese Ash
• Fraxinus lanuginosa
• Fraxinus longicuspis
• Fraxinus malacophylla
• Fraxinus mandschurica Rupr. – Manchurian Ash
• Fraxinus mariesii – Maries' Ash
• Fraxinus micrantha Lingelsh.
• Fraxinus paxiana Lingelsh.
• Fraxinus platypoda
• Fraxinus raibocarpa Regel
• Fraxinus sieboldiana Blume – Japanese Flowering Ash
• Fraxinus sogdiana Bge
• Fraxinus spaethiana Lingelsh. – Späth's Ash
• Fraxinus trifoliata
• Fraxinus xanthoxyloides (G.Don) Wall. ex DC. – Afghan Ash

• 
  Closeup of European Ash seeds
• 
  Fraxinus ornus
• 
  Unusual "treelets" growing from a fallen ash tree in Lawthorn wood, Ayrshire, Scotland

Ecology

Ash is used as a food plant by the larvae of some Lepidoptera species (butterflies and moths)—see list of Lepidoptera that feed on ashes.

Threats

Canker on an Ash tree in North Ayrshire, Scotland

Emerald ash borer

The emerald ash borer (Agrilus planipennis) is a wood-boring beetle accidentally introduced to North America from eastern Asia via solid wood packing material in the late 1980s to early 1990s. It has killed tens of millions of trees in 15 states in the United States and adjacent Ontario in Canada. It threatens some 7 billion ash trees in North America. Research is being conducted to determine if three native Asian wasps, who are natural predators of EAB could be used as a biological control for the management of EAB populations in the United States. The public is being cautioned not to transport unfinished wood products, such as firewood, to slow the spread of this insect pest.

The European ash, Fraxinus excelsior, has been affected by the fungus Hymenoscyphus pseudoalbidus, causing ash dieback in a large number of trees since the mid-1990s, particularly in eastern and northern Europe. The disease has infected about 90% of Denmark's ash trees. At the end of October 2012 in the UK the Food and Environment Research Agency (Fera) reported that ash dieback had been discovered in mature woodland in Suffolk, previous occurrences had been on young trees imported from Europe.

Uses

Ash is a hardwood and is hard, dense (within 20% of 670 kg/m³ for Fraxinus americana, and higher at 710 kg/m³ for Fraxinus excelsior), tough and very strong but elastic, extensively used for making bows, tool handles, baseball bats, hurleys and other uses demanding high strength and resilience.

It is also often used as material for electric guitar bodies and, less commonly, for acoustic guitar bodies, known for its bright, cutting tone and sustaining quality. Some Fender Stratocasters and Telecasters are made of ash, as an alternative to the darker sounding alder. They are also used for making drum shells. Interior joinery is another common user of both European Ash and White Ash. Ash veneers are extensively used in office furniture. Ash is not used extensively outdoors due to the heartwood having a low durability to ground contact, meaning it will typically perish within five years.

Woodworkers generally like the timber for its great finishing qualities. It also has good machining qualities, and is quite easy to use with nails, screws and glue. Ash was commonly used for the structural members of the bodies of cars made by carriage builders. Early cars had frames which were intended to flex as part of the suspension system in order to simplify construction. The Morgan Motor Company of Great Britain still manufacture sports cars with frames made from ash. It was also widely used by early aviation pioneers for the aircraft.

It makes excellent firewood and barbecue or smoking wood. The two most economically important species for wood production are White Ash in eastern North America, and European Ash in Europe. The Green Ash (F. pennsylvanica) is widely planted as a street tree in the United States. The inner bark of the Blue Ash (F. quadrangulata) has been used as a source for a blue dye.

The leaves of ash are appreciated by cows, goats and rabbits. Cut off in the autumn the branches can be a valuable winter supply for domestic animals.

Cultural aspects

In Greek mythology, the Meliae were nymphs of the ash, perhaps specifically of the Manna Ash (Fraxinus ornus), as dryads were nymphs of the oak. They appear in Hesiod's Theogony.

The ash exudes a sugary substance that, it has been suggested, was fermented to create the Norse Mead of Inspiration. 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. 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 would damage crops. In Cheshire, it was said that ash could be used to cure warts or rickets. In Sussex the ash and elm tree were known as the Widow Maker because the large boughs would often drop without warning.

See also

• List of Lepidoptera that feed on ashes
• Æ, the letter ash

Bibliography

• Philips, Roger (1979). Trees of North America and Europe: A Guide to Field Identification, Revised and Updated. New York: Random House. ISBN 0-394-50259-0. OCLC 4036251.