| Fraxinus ornus |
|Genus:|| Fraxinus |
Fraxinus // , English name ash, 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 number of subtropical species are evergreen. The genus is widespread across much of Europe, Asia, and North America.
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. Some Fraxinus species are dioecious, having male and female flowers on separate plants but sex in ash is expressed as a continuum between male and female individuals, dominated by unisexual trees. With age, ash may change their sexual function from predominantly male and hermaphrodite towards femaleness;if grown as an ornamental and both sexes are present, ashes can cause a considerable litter problem with their seeds. Rowans or mountain ashes have leaves and buds superficially similar to those of true ashes, but belong to the unrelated genus Sorbus in the rose family.
The tree's common English name, "ash", traces back to the Old English æsc, which relates to the proto-Indo-European for the tree, while the generic name originated in Latin from a proto-Indo-European word for birch. Both words are also used to mean "spear" in their respective languages, as the wood is good for shafts.
Species are arranged into sections supported by phylogenetic analysis:
North American native ash tree species are a critical food source for North American frogs, as their fallen leaves are particularly suitable for tadpoles to feed upon in ponds (both temporary and permanent), large puddles, and other water bodies.Lack of tannins in the American ash makes their leaves a good food source for the frogs, but also reduces its resistance to the ash borer. Species with higher leaf tannin levels (including maples and non-native ash species) are taking the place of native ash, thanks to their greater resistance to the ash borer. They produce much less suitable food for the tadpoles, resulting in poor survival rates and small frog sizes.
Ash species native to North America also provide important habit and food for various other creatures native to North America. This includes the larvae of multiple long-horn beetles, as well as other insects including those in the genus Tropidosteptes, lace bugs, aphids, larvae of gall flies, and caterpillars. Birds are also interested in black, green, and white ash trees. The black ash alone supports wood ducks, wild turkey, cardinals, pine grosbeaks, cedar waxwings, and yellow-bellied sapsuckers, with habitat and food (such as the sap being of interest to the sapsucker) among others. Many mammalian species from meadow voles eating the seeds, white-tailed deer eating the foliage, to silver-haired bats nesting, will also make use of ash trees.
Ash is used as a food plant by the larvae of some Lepidoptera species (butterflies and moths).
The emerald ash borer (Agrilus planipennis, EAB) 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 Statesand adjacent Ontario and Quebec in Canada. It threatens some seven billion ash trees in North America. Research is being conducted to determine if three native Asian wasps that 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.
Damage occurs when emerald ash borer larvae feed on the inner bark, phloem, inside brands 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.Ways to detect emerald ash borer infestation include seeing bark peeling off, vertical strips 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 these warning signs could be a good indication of possible infestation.
The European ash, Fraxinus excelsior , has been affected by the fungus Hymenoscyphus fraxineus , causing ash diebackin 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 Department for Environment, Food and Rural Affairs (Defra) reported that ash dieback had been discovered in mature woodland in Suffolk; previous occurrences had been on young trees imported from Europe. In 2016, the ash tree was reported as in danger of extinction in Europe.
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.
Ash, particularly Swamp ash because of its figure, is a choice of material for electric guitar bodiesand, less commonly, for acoustic guitar bodies, known for its bright, cutting edge and sustaining quality. Some Fender Stratocasters and Telecasters are made of ash, (such as Bruce Springsteen's Telecaster on the Born to Run album cover), as an alternative to alder. They are also used for making drum shells.
Woodworkers generally consider ash a "poor cousin" to the other major open pore wood, oak, but it is useful in any furniture application. Ash veneers are extensively used in office furniture. Ash is not used much outdoors due to the heartwood having a low durability to ground contact, meaning it will typically perish within five years. The F. japonica species is favored as a material for making baseball bats by Japanese sporting-goods manufacturers.
Its robust structure, good looks, and flexibility combine to make ash ideal for staircases. Ash stairs are extremely hard-wearing, which is particularly important for treads. Due to its elasticity, ash can also be steamed and bent to produce curved stair parts such as volutes (curled sections of handrail) and intricately shaped balusters. However, a reduction in the supply of healthy trees, especially in Europe, is making ash an increasingly expensive option.
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 to simplify construction. The Morgan Motor Company of Great Britain still manufactures sports cars with frames made from ash. It was also widely used by early aviation pioneers for aircraft construction.
It lights and burns easily, so is used for starting fires and barbecues, and is usable for maintaining a fire, though it produces only a moderate heat. 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 blue dye.
In Sicily, Italy, sugars are obtained by evaporating the sap of the manna ash, extracted by making small cuts in the bark.The manna ash, native to southern Europe and southwest Asia, produces a blue-green sap, which has medicinal value as a mild laxative, demulcent, and weak expectorant.
In Greek mythology, the Meliae 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.
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'.
Fraxinus quadrangulata, the blue ash, is a species of ash native primarily to the Midwestern United States from Oklahoma to Michigan, as well as the Bluegrass region of Kentucky and the Nashville Basin region of Tennessee. Isolated populations exist in Alabama, Southern Ontario, and small sections of the Appalachian Mountains. It is typically found over calcareous substrates such as limestone, growing on limestone slopes and in moist valley soils, at elevations of 120–600 m.
Fraxinus americana, the white ash or American ash, is a species of ash tree native to eastern and central North America.
Fraxinus excelsior, known as the ash, or European ash or common ash to distinguish it from other types of ash, is a flowering plant species in the olive family Oleaceae. It is native throughout mainland Europe east to the Caucasus and Alborz mountains, and the British Isles which determine its western boundary. The northernmost location is in the Trondheimsfjord region of Norway. The species is widely cultivated and reportedly naturalised in New Zealand and in scattered locales in the United States and Canada.
The emerald ash borer, also known by the acronym EAB, is a green buprestid or jewel beetle native to north-eastern Asia that feeds on ash species. Females lay eggs in bark crevices on ash trees, and larvae feed underneath the bark of ash trees to emerge as adults in one to two years. In its native range, it is typically found at low densities and does not cause significant damage to trees native to the area. Outside its native range, it is an invasive species and is highly destructive to ash trees native to Europe and North America. Before it was found in North America, very little was known about emerald ash borer in its native range; this has resulted in much of the research on its biology being focused in North America. Local governments in North America are attempting to control it by monitoring its spread, diversifying tree species, insecticides, and biological control.
Fraxinus pennsylvanica, the green ash or red ash, is a species of ash native to eastern and central North America, from Nova Scotia west to southeastern Alberta and eastern Colorado, south to northern Florida, and southwest to Oklahoma and eastern Texas. It has spread and become naturalized in much of the western United States and also in Europe from Spain to Russia.
Fraxinus albicans, commonly called the Texas ash, is a species of tree in the olive family (Oleaceae). It is native to North America, where it is found from eastern Texas and southern Oklahoma in the United States, to the state of Durango in Mexico. Its natural habitat is in dry, rocky slopes, often over limestone.
Fraxinus nigra, the black ash, is a species of ash native to much of eastern Canada and the northeastern United States, from western Newfoundland west to southeastern Manitoba, and south to Illinois and northern Virginia. Formerly abundant, as of 2014 the species is threatened with near total extirpation throughout its range, as a result of infestation by a parasitic insect known as the emerald ash borer.
Fraxinus angustifolia, the narrow-leaved ash, is a species of Fraxinus native to central and southern Europe, northwest Africa, and southwest Asia.
Fraxinus ornus, the manna ash or South European flowering ash, is a species of Fraxinus native to southern Europe and southwestern Asia, from Spain and Italy north to Austria and the Czech Republic, and east through the Balkans, Turkey, and western Syria to Lebanon and Armenia.
Chionanthus virginicus is a tree native to the savannas and lowlands of the southeastern United States, from New Jersey south to Florida, and west to Oklahoma and Texas.
Fraxinus mandshurica, the Manchurian ash, is a species of Fraxinus native to northeastern Asia in northern China, Korea, Japan and southeastern Russia.
Fraxinus profunda, the pumpkin ash, is a species of Fraxinus (ash) native to eastern North America, primarily in the United States, with a scattered distribution on the Atlantic coastal plain and interior lowland river valleys from southern Maryland northwest to Indiana, southeast to northern Florida, and southwest to southeastern Missouri to Louisiana, and also locally in the extreme south of Canada in Essex County, Ontario. The pumpkin ash tree is native to swampland areas. It is a tree that is very important environmentally and economically. Currently, Fraxinus profunda is threatened by the emerald ash borer which is threatening all species of ash trees in North America. The fruits of the pumpkin ash tree are also the largest of all ash trees in eastern North America.
Fraxinus lanuginosa is a species of ash native to Japan and to the Primorye region of eastern Russia.
Manna is the food produced for the Israelites in the desert, as described in the Biblical book of Exodus.
Fraxinus caroliniana, the pop ash, Florida ash, swamp ash, Carolina ash, or water ash, is a species of ash tree native from Cuba through the subtropical southeastern United States from southern Virginia to Texas. It was originally described by the botanist Philip Miller. It is a small tree about 40 ft. Leaves are compound, opposite, 7–12 in long, leaflets 5–7 in, ovate to oblong, coarsely serrate or entire, 3–6 in long, 2–3 in wide. Fruit is frequently 3-winged (samara) with flat seed portion; seed sometimes a bright violet color. It is the smallest of eastern North American ash species, wood light, soft, weak, 22 lbs./cu.ft. Typical to coastal swamps and subtropical lowlands. Like other species in the section Melioides, Fraxinus caroliniana is dioecious, with male and female flowers produced on separate individuals.
Tetrastichus planipennisi is a parasitic non-stinging wasp of the family Eulophidae which is native to North Asia. It is a parasitoid of the emerald ash borer, an invasive species which has destroyed tens of millions of ash trees in its introduced range in North America. As part of the campaign against the emerald ash borer (EAB), American scientists in conjunction with the Chinese Academy of Forestry searched since 2003 for its natural enemies in the wild leading to the discovery of several parasitoid wasps, including Tetrastichus planipennisi which is a gregarious endoparasitoid of EAB larvae on Manchurian Ash and has been recorded to attack and kill up to 50 percent of EAB larvae.
Spathius agrili is a parasitic non-stinging wasp of family Braconidae which is native to North Asia. It is a parasitoid of the emerald ash borer, an invasive species which has destroyed tens of millions of ash trees in its introduced range in North America. As part of the campaign against the emerald ash borer (EAB), American scientists in conjunction with the Chinese Academy of Forestry began searching in 2003 for its natural enemies in the wild, leading to the discovery of several parasitoid wasp species, including Spathius agrili. S. agrili was discovered in Tianjin, China where it is a prevalent parasitoid of EAB larvae in stands of an introduced ash species, and an endemic ash species. S. agrili has been recorded to attack and kill up to 90 percent of EAB larvae.
Hymenoscyphus fraxineus is an Ascomycete fungus that causes ash dieback, a chronic fungal disease of ash trees in Europe characterised by leaf loss and crown dieback in infected trees. The fungus was first scientifically described in 2006 under the name Chalara fraxinea. Four years later it was discovered that Chalara fraxinea is the asexual (anamorphic) stage of a fungus that was subsequently named Hymenoscyphus pseudoalbidus and then renamed as Hymenoscyphus fraxineus.
Fraxinus uhdei, commonly known as tropical ash or Shamel ash, is a species of tree native to Mexico and Central America. It is commonly planted as a street tree in Mexico and the southwestern United States. It has also been planted and spread from cultivation in Hawaii, where it is now considered an invasive species.
Dasineura acrophila is a gall midge which forms galls on the leaves of ash. It was first described by Johannes Winnertz in 1853 an is found in Europe.
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