Fraxinus

Fraxinus (/ˈfræksɪnəs/), commonly called ash, is a genus of plants in the olive and lilac family, Oleaceae,^[4] and comprises 45–65 species of usually medium-to-large trees, most of which are deciduous trees, although some subtropical species are evergreen trees. The genus is widespread throughout much of Europe, Asia, and North America.^{[3][5][6][7][8]}

Fraxinus
Fraxinus ornus 1862 illustration[1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Lamiales
Family:	Oleaceae
Tribe:	Oleeae
Subtribe:	Fraxininae
Genus:	Fraxinus L.[2]
Synonyms[3]
Ornus Boehm. Fraxinoides Medik. Mannaphorus Raf. Calycomelia Kostel. Leptalix Raf. Ornanthes Raf. Samarpses Raf. Aplilia Raf. Meliopsis Rchb. Petlomelia Nieuwl.

European ash in flower

Narrow-leafed ash (Fraxinus angustifolia) shoot with leaves

The leaves are opposite (rarely in whorls of three), and mostly pinnately compound, though simple in a few species. The seeds, known as "keys", are botanically fruits of the type called samara. Some Fraxinus species are dioecious, having male and female flowers on separate plants.

Ash wood is strong and elastic, and used for the handles of tools. Musical instrument makers use it for electric guitars and for drum shells. The Morgan Motor Company makes the frames of sports cars from ash wood. In Greek mythology, the Meliae were the nymphs of ash trees.

Etymology

The tree's common English name, "ash", derives from the Old English æsc, from the Proto-Indo-European name for the tree, while the name of the genus originated in Latin frāxinus, from a Proto-Indo-European word for birch. Both words are also used to mean "spear," as its wood is good for shafts.^[9]

Evolution

Taxonomy

The genus Fraxinus was described by Carl Linnaeus in 1753. The name remains accepted by taxonomists.^[10] Multiple authors have described other tree genera that are synonymous with Fraxinus: Ornus by the German botanist and physician Georg Rudolf Boehmer in 1760; Fraxinoides by the German physician Friedrich Kasimir Medikus in 1791; Mannaphorus by the French polymath Constantine Samuel Rafinesque in 1818; Calycomelia by the Czech Vincenz Franz Kosteletzky [de] in 1834; Leptalix, Ornanthes, Samarpsea (misspelt) and Samarpses, Apilia and Aplilia by Rafinesque, all in 1838; Meliopsis by the German botanist Ludwig Reichenbach in 1841; and Petlomelia by the Belgian priest Julius Nieuwland in 1914.^[10]

Phylogeny

Species are arranged into sections identified by phylogenetic analysis of clades within the Fraxinus genus:^[11][12]

Fraxinus	section Dipetalae section Melioides section Pauciflorae section Ornus section Fraxinus section Sciadanthus

Section Dipetalae

• Fraxinus anomala Torr. ex S.Watson – singleleaf ash
• Fraxinus dipetala Hook. & Arn. – California ash or two-petal ash
• Fraxinus parryi Moran – Chaparral ash
• Fraxinus quadrangulata Michx. – blue ash
• Fraxinus trifoliolata

Section Fraxinus

• Fraxinus angustifolia Vahl – narrow-leaved ash
  • Fraxinus angustifolia subsp. oxycarpa – Caucasian ash
  • Fraxinus angustifolia subsp. syriaca
• Fraxinus excelsior L. – European ash
• Fraxinus mandschurica Rupr. – Manchurian ash
• Fraxinus nigra Marshall – black ash
• Fraxinus pallisiae Wilmott – Pallis' ash
• Fraxinus sogdiana Bunge – Tianshan ash

Section Melioides sensu lato

• Fraxinus chiisanensis Nakai – Jirisan ash
• Fraxinus cuspidata Torr. – fragrant ash
• Fraxinus platypoda Oliv. – Chinese red ash
• Fraxinus spaethiana Lingelsh. – Späth's ash

Section Melioides sensu stricto

• Fraxinus albicans Buckley – Texas ash
• Fraxinus americana L. – white ash or American ash
• Fraxinus berlandieriana DC. – Mexican ash
• Fraxinus caroliniana Mill. – Carolina ash
• Fraxinus latifolia Benth. – Oregon ash
• Fraxinus papillosa Lingelsh. – Chihuahua ash
• Fraxinus pennsylvanica Marshall – green ash
• Fraxinus profunda (Bush) Bush – pumpkin ash
• Fraxinus uhdei (Wenz.) Lingelsh. – Shamel ash or Tropical ash
• Fraxinus velutina Torr. – velvet ash or Arizona ash

Section Ornus

• Fraxinus apertisquamifera
• Fraxinus baroniana
• Fraxinus bungeana DC. – Bunge's ash
• Fraxinus chinensis Roxb. – Chinese ash or Korean ash
• Fraxinus floribunda Wall. – Himalayan manna ash
• Fraxinus griffithii C.B.Clarke – Griffith's ash
• Fraxinus insularis Hemsl. – Chinese flowering ash
• Fraxinus japonica – Japanese ash
• Fraxinus lanuginosa – Japanese ash
• Fraxinus longicuspis
• Fraxinus malacophylla
• Fraxinus micrantha Lingelsh.
• Fraxinus ornus L. – manna ash or flowering ash
• Fraxinus paxiana Lingelsh.
• Fraxinus sieboldiana Blume – Japanese flowering ash

Section Pauciflorae

• Fraxinus dubia
• Fraxinus gooddingii – Goodding's ash
• Fraxinus greggii A.Gray – Gregg's ash
• Fraxinus purpusii
• Fraxinus rufescens

Section Sciadanthus

• Fraxinus dimorpha
• Fraxinus hubeiensis Ch'u & Shang & Su – 湖北梣, Hubei qin
• Fraxinus xanthoxyloides (G.Don) Wall. ex DC. – Afghan ash^[13][14]

• 
  Fraxinus excelsior, European ash "keys", winged fruits (samaras)
• 
  Fraxinus ornus, the manna ash

Ecology

Ash species native to North America provide habitat and food for the larvae of multiple long-horn beetles, as well as Tropidosteptes plant bugs, lace bugs, aphids, larvae of gall flies, and caterpillars. The black ash supports wood ducks, wild turkey, cardinals, pine grosbeaks, cedar waxwings, and yellow-bellied sapsuckers, with habitat and food. Many mammalian species from meadow voles eating the seeds to white-tailed deer eating the foliage to silver-haired bats nesting will also make use of ash trees.^{[15][16][17][18]} They are a critical food source for frogs, as their fallen leaves, lacking tannins, are particularly suitable for tadpoles to feed upon in water bodies.^[19] The lack of tannins reduces the trees' resistance to the ash borer.^[19]

Threats

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 22 states in the United States^[20] and neighbouring Ontario and Quebec in Canada. It threatens some seven billion ash trees in North America. Research is being conducted to determine whether three native Asian wasps that are natural predators of the beetle could be used as a biological controls to manage pest populations in the United States. The public was cautioned to avoid transporting unfinished wood products, such as firewood, to slow the spread of the pest.^[21]

Damage occurs when emerald ash borer larvae feed on the inner bark, phloem, inside branches and tree trunks. Feeding on the phloem prevents nutrients and water transportation. If the ash is attacked, the branches can die and eventually the whole tree can as well.^[22] Ways to detect emerald ash borer infestation include seeing bark peeling off, vertical cracks in the bark, seeing galleries within the tree that contain powdery substance, and D-shaped exit holes on the branches or trunk. Not all of these may be present, but any of these warning signs could be an indication of possible infestation.^[23]

The European ash, Fraxinus excelsior, has been affected by the fungus Hymenoscyphus fraxineus, causing chalara ash dieback^[24] in a large number of trees since the mid-1990s, particularly in eastern and northern Europe.^[25][26] The disease has infected about 90% of Denmark's ash trees.^[27] In 2012 in the UK, ash dieback was found in mature woodland.^[28] The combination of emerald ash borer and ash dieback has threatened ash populations in Europe,^[29] but trees in mixed landscapes appear to have some resistance to the disease.^[30]

• 
  Emerald ash borer
  adult
• 
  Emerald ash borer larva
• 
  Chalara ash dieback
• 
  Canker on an ash tree

Uses

Ash is a hardwood and is dense, around 670 kg/m³ for Fraxinus americana, the white ash,^[31] and 710 kg/m³ for Fraxinus excelsior, the European ash.^[32] The wood of the European ash is strong and elastic, making it suitable for uses such as the handles of tools.^[33] It is a good firewood.^[33]

The Fender musical instrument company has used ash as a tonewood for its electric guitars since 1956.^[34] Species used for guitar building include swamp ash.^[35] Ash is in addition used for making drum shells. It has been described as resonant, providing a balanced tone for both high and low notes.^[36] Ash wood can be used for furniture, agricultural tools, and household objects such as bowls, candlesticks, and spoons.^[37] The Morgan Motor Company of Great Britain still manufactures sports cars with frames made from ash.^[38]

The green ash (F. pennsylvanica) is widely planted as a street tree in the United States.^[39] The inner bark of the blue ash (F. quadrangulata) has been used as a source for blue dye.^[40] In Sicily, Italy, a sugary manna is obtained from the resinous sap of the manna ash, extracted by making cuts in the bark.^[41] The young seedpods of the European ash, known as "keys", are edible; in Britain, they are traditionally pickled with vinegar, sugar and spices.^[42]

• 
  Ash headstock of a Fender Telecaster
  electric guitar
• 
  Ash is widely used for tool handles.^[33]

• 
  5/16" thick flame figure quartersawn ash guitar top, unmilled
• 
  Ash coffee table
• 
  Ash frame of a
  Morgan Motor Company car

Mythology and folklore

In Greek mythology, the Meliae, their name meaning "ash trees", are nymphs associated with the ash, perhaps specifically of the manna ash (Fraxinus ornus), as dryads were nymphs associated with the oak. They appear in Hesiod's Theogony, which states that they were born when drops of Ouranos's blood fell on the earth (Gaia).^[43] In Norse mythology, a vast, evergreen ash tree Yggdrasil ("the steed (gallows) of Odin"), watered by three magical springs, serves as axis mundi, sustaining the nine worlds of the cosmos in its roots and branches. Askr, the first man in Norse myth, literally means 'ash'.^[44] In Slavic folklore, an ash stake could be used to kill a vampire.^[45] In the Old English Latin alphabet, Æ was the letter æsc, "ash tree".^[46] This transliterated the Anglo-Saxon futhorc rune ᚫ.^[47]