Fraxinus excelsior L. | Plants of the World Online

Fraxinus excelsior L. | Plants of the World Online

Geography and distribution

European ash is native to Europe and Iran.

Description

Overview: Deciduous tree as much as 40 m tall with gray, hairless branches. Dormant buds are black.

Leaves: 20-25 cm lengthy, divided into 9-13 toothed leaflets, darkish inexperienced above and paler beneath. Leaves are in opposing pairs.

Flowers: Unisexual or bisexual (on the identical or separate bushes), in dense clusters, showing earlier than leaves. Particular person flowers are small, inconspicuous, with no petals or sepals, and wind-pollinated.

Fruits: Dry, one-seeded, winged fruits as much as four cm lengthy. Borne in bunches and also known as ‘keys’.

Threats and conservation

European ash is beneath menace from ‘chalara ash dieback’, which is brought on by the fungus Hymenoscyphus fraxineus (also known as Chalara fraxinea within the fashionable literature). The illness causes dieback of the crown and lack of leaves and might result in loss of life of the tree if the fungal mycelia progress into the woody tissues. A variety of Fraxinus species have reportedly been contaminated with this illness, though F. excelsior is among the most severely affected species.

Bushes had been reported dying again in giant numbers in Poland in 1992 at the moment are believed to have been contaminated with this newly recognized pathogen. It has since unfold throughout northern, western and southern Europe, inflicting widespread harm to ash populations, and infecting an estimated 60-90% of Denmark’s ash bushes since 2007.

Younger contaminated ash bushes typically die rapidly, whereas older bushes have a tendency to withstand the pathogen for longer. A low share of bushes seem to have heritable low susceptibility to the illness, resulting in hopes that pure choice or breeding could end in populations of resistant bushes sooner or later. Frequent fungicides comparable to triazoles, and strobilurins have important efficacy in opposition to Hymenoscyphus fraxineus , however are inappropriate to be used in treating giant areas of pure woodland. Controlling imports and exports of ash crops and seeds is just efficient in stopping the unfold of the illness over distances such because the Atlantic ocean.

Fraxinus excelsior can also be threatened by the Emerald Ash Borer (Agrilus planipennis) which is discovered round Moscow in Russia and appears to be spreading westwards. The Emerald Ash Borer has induced widespread devastation of F. americana and F. pennsylvanica populations in North America over the previous 15 years.

Makes use of

Extensively used for its timber, European ash produces wooden that’s each sturdy and elastic. It’s significantly good at withstanding sudden shocks and has subsequently been used for a variety of sporting items, comparable to tennis racquets, hockey sticks, cricket stumps, hurley sticks and billiard cues, in addition to for software handles and strolling sticks.

It was previously used for wheel-making and remains to be used to make the frames of Morgan vehicles. European ash has lengthy been coppiced (repeatedly reduce to a brief stump with a purpose to harvest the various new shoots that sprout from it). In Suffolk (UK) there’s a still-productive, coppiced tree estimated to be over 1,000 years outdated.

Cultivated as a decorative in parks and enormous gardens, European ash is a helpful shade tree that tolerates air pollution and uncovered websites. Cultivars accessible embody:

Fraxinus excelsior ‘Aurea’ (golden ash) – slow-growing with yellow leaves
F. excelsior ‘Crispa’ – darkish leaves with ruffled margins
F. excelsior ‘Jaspidea’ – as much as about 20 m tall with yellow leaves and yellow winter shoots (awarded the Royal Horticultural Society’s AGM)
F. excelsior ‘Pendula’ – with an umbrella-shaped crown of pendulous branches (awarded the Royal Horticultural Society’s AGM)

European ash has been utilized in conventional medication. Its bark was as soon as used to deal with fevers, its buds had been used as a slimming assist within the UK, its leaves had been used to deal with gout, and its sap was used as a treatment for earache and warts.

In 18th century England, ash leaves had been used to adulterate tea. Ash leaves have been used as cattle-fodder in Scandinavia.

Mythology and superstition

In Scandinavian mythology, the tree of the world was an ash known as Yggdrasil. It was stated that its roots reached down into hell whereas its crown touched the heavens, its big trunk connecting the 2. Odin, thought of to be the best of the gods, was stated to have carved the primary man from its wooden.

European ash was thought to be a therapeutic tree in Britain up till the top of the 18th century. In Hampshire (UK), it was believed {that a} little one with damaged or weak limbs might be healed by passing the kid bare by means of the break up trunk of an ash, which might then be plastered with loam and sure again collectively. If the break up trunk then grew again collectively it was believed that the kid can be cured.

Previously, burning of ash logs was thought to drive evil spirits from the room. There was a long-standing perception courting again to the writings of historic Roman writer, Pliny the Elder, that ash-sticks can be utilized to repel snakes or to guard in opposition to snake-bite. Some thought a single blow with an ash-stick would kill a snake, whereas others believed that merely drawing a circle round it, or simply carrying an ash-stick, would shield the consumer.

Millennium Seed Financial institution: Seed storage

The Millennium Seed Financial institution Partnership goals to avoid wasting plants worldwide, specializing in crops beneath menace and people of most use sooner or later. Seeds are dried, packaged and saved at a sub-zero temperature in our seed financial institution vault.

The UK Nationwide Tree Seed venture has collected Fraxinus excelsior seeds from all UK native Seed Zones the place ash exists, and these collections are held in Kew’s Millennium Seed Financial institution primarily based at Wakehurst in West Sussex.

This species at Kew

There are over 200 specimens of Fraxinus excelsior within the collections at Kew and Wakehurst. These embody a variety of cultivars grown for his or her horticultural benefit. The principle ash assortment is grown alongside both aspect of Princess Stroll at Kew. European ash can be seen rising in Kew’s Conservation Space.

Dried and alcohol-preserved specimens of Fraxinus excelsior are held in Kew’s Herbarium, the place they’re accessible to researchers by appointment. Particulars of a few of these could be seen on-line in Kew’s Herbarium Catalogue.

Specimens of wooden, bark and sap of European ash, along with a wood backyard dibber and boomerangs made out of it, are held in Kew’s Financial Botany Assortment, the place they’re accessible to researchers by appointment.

Scientists at Kew have sequenced the genome of Fraxinus excelsior (see www.ashgenome.org) and are utilizing this to develop genomic sources for wholesome ash bushes.

‘Chalara ash dieback’ and Kew

No signs of ‘chalara ash dieback’ have thus far been discovered within the ash bushes at Kew, however the illness was present in August 2017 on younger ash bushes rising alongside the Thames path a couple of metres from the Kew Gardens boundary

Kew workers are inspired to be vigilant while working within the Gardens and look out for the signs on ash bushes. A professional-active monitoring programme will monitor any results that it has on the collections.

Ash dieback is now widespread at Wakehurst Place and plenty of bushes are closely affected.

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