Fraxinus excelsior

Fraxinus excelsior
Foliage and immature fruit
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Lamiales
Family:	Oleaceae
Genus:	Fraxinus
Species:	F. excelsior
Binomial name
Fraxinus excelsior L.
Range

Fraxinus excelsior (Ash; also European Ash or Common Ash on occasion to distinguish it from other ash species), is a species of Fraxinus native to most of Europe with the exception of northern Scandinavia and southern Iberia, and also southwestern Asia from northern Turkey east to the Caucasus and Alborz mountains. The northernmost location is in the Trondheimsfjord region of Norway.^[1][2]

Description

Male flowers

It is a large deciduous tree growing to 20–35 m (exceptionally to 46 m) tall with a trunk up to 2 m (exceptionally to 3.5 m) diameter, with a tall, domed crown. The bark is smooth and pale grey on young trees, becoming thick and vertically fissured on old trees. The shoots are stout, greenish-grey, with jet black buds (which distinguish it from most other ash species, which have grey or brown buds). The leaves are 20–35 cm long, pinnate compound, with 7-13 leaflets, the leaflets 3–12 cm long and 0.8–3 cm broad, sessile on the leaf rachis, and with a serrated margin. The leaves are often among the last to open in spring, and the first to fall in autumn if an early frost strikes; they have no marked autumn colour, often falling dull green. The flowers open before the leaves, the female flowers being somewhat longer than the male flowers; they are dark purple, and without petals, and are wind-pollinated. Both male and female flowers can occur on the same tree, but it is more common to find all male and all female trees; a tree that is all male one year can produce female flowers the next, and similarly a female tree can become male. The fruit is a samara 2.5-4.5 cm long and 5–8 mm broad, often hanging in bunches through the winter; they are often called 'ash keys'.^[1][3][4] If the fruit is gathered and planted when it is still green and not fully ripe, it will germinate straightaway, however once the fruit is brown and fully ripe, it will not germinate until 18 months after sowing (i.e. not until two winters have passed).^[5]

European Ash rarely exceeds 250 years of age. However there are numerous ones estimated between 200 and 250 years old and there are a couple over 250. The largest is in Clapton Court, England and is 9 m (29 ft) in girth. There are several examples over 4.5 metres (15 feet) in Derbyshire alone.

Ecology

Ash occurs on a wide range of soil types, but is particularly associated with basic soils on calcareous substrates. The most northerly ashwood in Britain is on limestone at Rassal, Wester Ross, latitude 57.4278 N.

A number of Lepidoptera use the species as a food source. See Lepidoptera which feed on ashes.

Ash dieback

Ash dieback caused by the fungus Chalara fraxinea^[6] has affected large numbers of trees since the mid-1990s, particularly in eastern and northern Europe (though the disease has been observed across much of its range).^[7][8]

Uses

Replica of the body frame from the Volvo ÖV 4 car, made primarily from ash wood

The resilience and rapid growth made it an important resource for smallholders and farmers. It was probably the most versatile wood in the countryside with wide-ranging uses. Until World War II the trees were often coppiced on a ten year cycle to provide a sustainable source of timber for fuel and poles for building and woodworking.^[9]

Wood

The colour of the wood ranges from creamy white through light brown, and the heart wood may be darker olive-brown. Ash timber is hard, tough and very hard-wearing, with a coarse open grain with a density of 710 kg per cubic meter.^[10] It lacks oak's natural resistance to decay, and is not as suitable for posts buried in the ground. Because of its high flexibility, shock-resistance and resistance to splitting Ash wood is the traditional material for bows, tool handles, especially for hammers and axes, tennis rackets and snooker cue sticks^{[citation needed]} Ash is valuable as firewood because it burns well even when 'green' (freshly cut).^[11] Ash was coppiced, often in hedgerows, and evidence in the form of some huge boles with multiple trunks emerging at head height can still be see in parts of Britain. In Northumberland, crab and lobster pots (traps) sometimes known as 'creeves' by local people are still made from ash sticks.^{[citation needed]} Because of its elasticity European Ash wood was commonly used for walking sticks. Poles were cut from a coppice and the ends heated in steam. The wood could then be bent in a curved vise to form the handle of the walking stick. The light colour and attractive grain of ash wood make it popular in modern furniture such as chairs, dining tables, doors and other architectural features and wood flooring, although the wood is often popularly stained jet black.^{[citation needed]}

Ash is the only wood used for the manufacture of hurleys, referred to as hurls in parts of Leinster and known as a camán in Irish, the timber sticks used in the game of hurling in Ireland. Hurleys are manufactured from the butt log (bottom 1.5 metre of the stem) and from trees ideally of a diameter at breast height of approximately 25-30 centimetres. Only fast grown, straight and branch free ash can be used for this purpose. Due to the lack of available ash in Ireland, over 75% of the timber needed to produce the 350,000 hurleys required for the game annually must be imported, mostly from eastern European countries.^[12] The importance of ash timber to the game of hurling is reflected in the fact that the game is referred to all over Ireland as "The Clash Of The Ash".

Mythology

In the 13th century Edda and other writing relating to Norse mythology, a mythological ash tree called Yggdrasil serves as the center of the world. Its roots were anchored in the abyss of the underworld, and watered by the streams of wisdom and faith. Its trunk was supported by the earth, while its crown touched the arc of heaven.

Cultivars

Ash saplings from a mast year.

There are a number of cultivars including;

• Fraxinus excelsior 'Aurea', see 'Jaspidea'
• Fraxinus excelsior 'Aurea Pendula' (Weeping Golden Ash)
• Fraxinus excelsior 'Autumn Blaze'
• Fraxinus excelsior 'Autumn Purple'
• Fraxinus excelsior 'Crispa'
• Fraxinus excelsior 'Diversifolia' (One-leaved Ash)
• Fraxinus excelsior 'Erosa'
• Fraxinus excelsior 'Jaspidea' (Golden Ash)
• Fraxinus excelsior 'Monophylla'
• Fraxinus excelsior 'Nana'
• Fraxinus excelsior 'Pendula' (Weeping Ash), one of the best known cultivars, widely planted during the Victorian era, it grows vigorously forming an attractive small to medium size tree with mounds of weeping branches.
• Fraxinus excelsior 'Skyline'.

Gallery

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  Two ash trees fused together.

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  Tree 46 m tall, Château des princes de Croÿ, Le Roeulx, Belgium.

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  Old tree, Belgium.

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  Leaf and shoot, showing black bud.

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  Weeping Ash Fraxinus excelsior 'Pendula', Knightshayes Court, England.

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  Seeds.

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  Buds.

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  Bark

References

1. ^ ^{a b} Rushforth, K. (1999). Trees of Britain and Europe. Collins ISBN 0-00-220013-9.
2. ^ Den virtuella floran: Fraxinus excelsior distribution
3. ^ Mitchell, A. F. (1974). A Field Guide to the Trees of Britain and Northern Europe. Collins ISBN 0-00-212035-6
4. ^ Mitchell, A. F. (1982). The Trees of Britain and Northern Europe. Collins ISBN 0-00-219037-0
5. ^ Forestry Commission/ Edlin, H. L. Broadleaves, HMSO, 1985, p36
6. ^ Kowalski T (2006) Chalara fraxinea sp. nov. associated with dieback of ash (Fraxinus excelsior) in Poland. Forest Pathology 36(4), 264-270
7. ^ E. Halmschlager & T. Kirisits (2008). "First report of the ash dieback pathogen Chalara fraxinea on Fraxinus excelsior in Austria". University of Natural Resources and Applied Life Sciences. http://www.bspp.org.uk/publications/new-disease-reports/july2008/2008-25.asp. Retrieved 10 February 2010. 
8. ^ N. Ogris, T. Hauptman & D. Jurc (2009). "Chalara fraxinea causing common ash dieback newly reported in Slovenia". Slovenian Forestry Institute. http://www.bspp.org.uk/publications/new-disease-reports/ndr.php?id=019015. Retrieved 10 February 2010. 
9. ^ Mabey, R. (1996). Flora Britannica. Sinclair-Stevenson Ltd ISBN 1856193772.
10. ^ Ash. Niche Timbers. Accessed 19-08-2009.
11. ^ http://www.scoutbase.org.uk/library/hqdocs/facts/pdfs/fs315001.pdf
12. ^ Teagasc Report - Ash For Hurleys.