Fraxinus (/ˈfræksɪnəs/), commonly calledash, is agenus of plants in the olive and lilac family,Oleaceae,[4] and comprises 45–65 species of usually medium-to-largetrees, most of which aredeciduous (dropping their leaves in autumn), although somesubtropical species areevergreen. The genus is widespread throughout much of Europe, Asia, and North America.[3]
The leaves are usuallyopposite, and mostlypinnately compound (divided into leaflets in a feather-like arrangement). The seeds, known as "keys", are botanically fruits of the type calledsamara. Some species aredioecious, having male and female flowers on separate plants.
The tree's common English name, "ash", derives from theOld Englishæsc, from theProto-Indo-European name for the tree, while the name of the genus originated inLatinfrāxinus, from a Proto-Indo-European word forbirch. Both words also meant "spear", as ash wood was used for shafts.[5]
The leaves of ash trees are usuallyopposite (rarely inwhorls), and mostlypinnate. The seeds, known as "keys", are botanically single-winged fruits of the type calledsamara. MostFraxinus species aredioecious, having male and female flowers on separate plants. The male flowers have two stamens. If acalyx is present, it has four lobes; if there is acorolla, it has four lobes or four petals, which are white or pale yellow.[6]
The oldest fossils that are clearlyFraxinus are from theMiddle Eocene (49–39 million years ago) of southeast North America, including the extinct speciesF. wilcoxiana.[7][8] Fossil pollen ofF. angustifolia is known from theUpper Miocene (12 million years ago) of Europe.[7]F. oishii winged fruits have been found in theMiddle Miocene of Korea.[9]
The genusFraxinus was described byCarl Linnaeus in 1753. The name remains accepted by taxonomists.[10] Multiple authors have described other tree genera that are synonymous withFraxinus:Ornus by the German botanist and physicianGeorg Rudolf Boehmer in 1760;Fraxinoides by the German physicianFriedrich Kasimir Medikus in 1791;Mannaphorus by the French polymathConstantine Samuel Rafinesque in 1818;Calycomelia by the CzechVincenz Franz Kosteletzky [de] in 1834;Leptalix,Ornanthes,Samarpsea (misspelt) andSamarpses,Apilia andAplilia by Rafinesque, all in 1838;Meliopsis by the German botanistLudwig Reichenbach in 1841; andPetlomelia by the Belgian priestJulius Nieuwland in 1914.[10]
The genusFraxinus is widespread throughout much of Europe, Asia, and North America.[3] The genus is primarily temperate or subtropical; 22 of the species occur in China,[16] while for example Italy has 4 species.[17] Both native and introducedFraxinus species occur in almost every contiguous state of the United States and all the southern provinces of Canada.[18]
Theemerald ash borer (Agrilus planipennis), is a wood-boringbeetle 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[23] and neighbouringOntario andQuebec in Canada. It threatens some seven billion ash trees in North America. Three native Asian wasp species, natural predators of the beetle, have been evaluated as possiblebiological controls. The public was cautioned to avoid transporting unfinished wood products, such as firewood, to slow the spread of the pest.[24] Damage occurs when emerald ash borer larvae feed on the inner bark,phloem of ash trees, preventing nutrient and water transportation.[25][26]
The European ash,Fraxinus excelsior, has been affected by thefungusHymenoscyphus fraxineus, causing chalaraash dieback[27] in a large number of trees since the mid-1990s, particularly in eastern and northern Europe.[28][29] The disease has infected about 90% of Denmark's ash trees.[30] In 2012 in the UK, ash dieback was found in mature woodland.[31] The combination of emerald ash borer and ash dieback has threatened ash populations in Europe,[32] but trees in mixed landscapes appear to have some resistance to the disease.[33]
TheFender musical instrument company has used ash as atonewood for itselectric guitars since 1950.[37] Species used for guitar building includeswamp ash.[38] Ash is in addition used for makingdrum shells. It has been described as resonant, providing a balanced tone for both high and low notes.[39] Ash wood can be used for furniture, agricultural tools, and household objects such as bowls, candlesticks, and spoons.[40] TheMorgan Motor Company of Great Britain still manufactures sports cars with frames made from ash.[41]
The green ash (F. pennsylvanica) is widely planted as a street tree in the United States.[42] The inner bark of the blue ash (F. quadrangulata) has been used as a source for bluedye.[43] In Sicily, Italy, a sugarymanna is obtained from the resinous sap of themanna ash, extracted by making cuts in the bark.[44] The young seedpods of the European ash, known as "keys", are edible; in Britain, they are traditionally pickled with vinegar, sugar and spices.[45] A range of pharmacologically active compounds exist inFraxinus species, with for exampleanti-inflammatory,antihypertensive, andantihyperglycaemic properties which might find practical applications.[46]
The Welshfolk songLlwyn Onn, "The Ash Grove", sings in the English version byJohn Oxenford "The ash grove, how graceful, how plainly 'tis speaking; The lark through its branches is gazing on me".[52]
^Caldwell, Richard,Hesiod's Theogony, Focus Publishing/R. Pullins Company (June 1, 1987).ISBN978-0-941051-00-2. p. 38 n. 178–187: "The nymphs calledMeliai are properly "ash-tree" nymphs; the Greek word for ash-trees ismeliai also".
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![Ash is widely used for tool handles.[36]](/mt/?noimg=&dark=on&url=http%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aShovel_24cm_(cropped).jpg)
