Artworks ready to go…Yew tree

Yew ready to go lo res

The Yew Tree artwork ready for some additional work before installation on the 29th of September 2017.

Materials – Fluorescent yellow perspex, clear tubing and yellow paint.

Finished artwork will be installed on the railings of the triangular section of the physic garden behind the Science Gallery.

Opening night – Guided exhibition walk

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As part of the opening event for the Trinity College Trees Exhibition there will be a guided walk to all the exhibits by one of the project team.   The walk will take place on Friday 29th September between 5.15-5.45.  There will be a limited number of spaces.  Details on how to sign up for the guided walk will be posted nearer the time.  

If you are unable to book a slot on the guided walk don’t worry the team are also in the process of developing a sound piece that will accompany those wishing to take a self guided walk from Saturday the 30th of September until the end of the exhibition.  Once the walker brings their own headphones they can visit the works at their leisure.   In front of each of the chosen trees the team also plan to have an A4 stand with a brief description of the project and the positioning of each tree on a campus map.

There will be two versions of sound piece depending on which end of the campus you are starting will determine the listing of the trees and which sound piece you click on.  One version of the sound piece covers the walk if you are starting in the main square at the Oregon Maple.  The other version if you are starting at the Science Gallery.  

Included in the audio piece is a brief introduction to the Trinity Trees Project, the trees involved and the artworks commissioned in response to these trees.

Yew the sacred and the mystical

 

close up berry-Taxus_baccata_MHNT

The evergreen yew with dark green, needle-like leaves and red berries has commonly symbolized immortality in the Indo-European imagination as it is the longest-lived entity, often lasting more than 1,000 years, to be found in the European environment.

-yew-Harlington-1000 years
Yew tree believed to be more than 1,000 years old in the churchyard of St Peter & Paul Harlington, near Heathrow Airport

The yew tree has been found near chapels, churches and cemeteries since ancient times as a symbol of the transcendence of death, and is usually found in the main squares of the villages where people celebrated the open councils that served as a way of general assembly to rule the village affairs. It has been suggested that the Sacred Tree at the Temple at Uppsala was an ancient yew tree.

The Christian church commonly found it expedient to take over existing pre-Christian sacred sites for churches. It has also been suggested that yews were planted at religious sites as their long life was suggestive of eternity, or because being toxic they were seen as trees of death. Another suggested explanation is that yews were planted to discourage farmers and drovers from letting animals wander onto the burial grounds, the poisonous foliage being the disincentive. A further possible reason is that fronds and branches of yew were often used as a substitute for palms on Palm Sunday. It is still commonly planted in Christian churchyards and cemeteries.

Conifers were in the past often seen as sacred, because they never lose their green. In addition, the tree of life was not only an object from the stories, but also believers often gathered around an existing tree. The yew releases gaseous toxins (taxine) on hot days. Taxine is in some instances capable of causing hallucinations. This has some similarities with the story that Odin had a revelation (the wisdom of the runes) after having been hanging from the tree for nine days.

druids yew wand

The druids preferred yew for wand-making over their other favourite woods, apple and oak. Several Irish and Scottish place-names allude to the yew, notably Youghall [Eochaill, yew wood] in County Cork. The Irish personal name Eógan means ‘born of the yew’, so that the great Munster dynasty could be glossed as ‘people of the yew’.

Yew and Chemotherapy drug Taxol

 

Peeling-Pacific-Yew-Taxus-007

Certain compounds found in the bark of yew trees were discovered by Wall and Wani in 1967 to have efficacy as anti-cancer agents. The precursors of the chemotherapy drug paclitaxel (taxol) was later shown to be synthesized easily from extracts of the leaves of European yew, which is a much more renewable source than the bark of the Pacific yew (Taxus brevifolia) from which they were initially isolated. This ended a point of conflict in the early 1990s; many environmentalists, including Al Gore, had opposed the destructive harvesting of Pacific yew for paclitaxel cancer treatments. Docetaxel can then be obtained by semi-synthetic conversion from the precursors.

Paclitaxel chemotherapy drug from yew

Paclitaxel is in the taxane family of medications. (PTX), sold under the brand name Taxol among others, is a chemotherapy medication used to treat a number of types of cancer. This includes ovarian cancer, breast cancer, lung cancer, Kaposi sarcoma, cervical cancer and panc cancer. It works by interference with the normal function of microtubules during cell division. It is given by injection into a vein. There is also an albumin bound formulation.

Paclitaxel was first isolated in 1971 from the Pacific Yew and approved for medical use in 1993. It is on the World Health Organisation’s List of Essential Medicines, the most effective and safe medicines needed in a health system. The wholesale cost in the developing world is about 7.06 to 13.48 USD per 100 mg vial. This amount in the United Kingdom costs the NHS about 66.85 pounds. It is now manufactured by cell culture.

Tree Spotlight no.6 – the Yew

pacific yew overview image

Taxus baccata is a conifer native to western, central and southern Europe, northwest Africa, northern Iran and southwest Asia. It is the tree originally known as yew, though with other related trees becoming known, it may now be known as English yew, or European yew.

yew bark image

Description: It is a small to medium-sized evergreen tree, growing 10–20 metres (33–66 ft) (exceptionally up to 28 metres (92 ft)) tall, with a trunk up to 2 metres (6 ft 7 in) (exceptionally 4 metres (13ft)) diameter. The bark is thin, scaly brown, coming off in small flakes aligned with the stem. The leaves are flat, dark green, 1–4 centimetres (0.39–1.57 in) long and 2–3 millimetres (0.079–0.118 in) broad, arranged spirally on the stem, but with the leaf bases twisted to align the leaves in two flat rows either side of the stem, except on erect leading shoots where the spiral arrangement is more obvious. The leaves are poisonous.

The seed cones are modified, each cone containing a single seed, which is 4–7 millimetres (0.16–0.28 in) long, and partly surrounded by a fleshy scale which develops into a soft, bright red berry-like structure called an aril. The aril is 8–15 millimetres (0.31–0.59 in) long and wide and open at the end. The arils mature 6 to 9 months after pollination, and with the seed contained, are eaten by thrushes, waxwings and other birds, which disperse the hard seeds undamaged in their droppings. Maturation of the arils is spread over 2 to 3 months, increasing the chances of successful seed dispersal.

Yew trees do not need rich soil but they do need a well drained site, preferably not too exposed to wind or frost. Many yews are single sex, but most Irish yews are female and so bear fruit. Even if the flesh is removed, these may be slow to germinate. The best seeds are those that have been eaten by birds and have passed through them; such bare seeds may be collected from under yew trees. The Yew tree is in fact a good tree for wildlife as birds roost and nest in it.

Longeivity: Taxus baccata can reach 400 to 600 years of age. Some specimens live longer but the age of yews is often overestimated. Ten yews in Britain are believed to predate the 10th century. The potential age of yews is impossible to determine accurately and is subject to much dispute. There is rarely any wood as old as the entire tree, while the boughs themselves often become hollow with age, making ring counts impossible. Evidence based on growth rates and archaeological work of surrounding structures suggests the oldest yews, such as the  may be in the range of 2,000 years, placing them among the oldest plants in Europe. One characteristic contributing to yew’s longevity is that it is able to split under the weight of advanced growth without succumbing to disease in the fracture, as do most other trees. Another is its ability to give rise to new epicormic and basal shoots from cut surfaces and low on its trunk, even at an old age.

fortingall-2000 year old yew

The Fortingall Yew in Perthshire, Scotland, has the largest recorded trunk girth in Britain and experts estimate it to be 2,000 to 3,000 years old, although it may be a remnant of a post-Roman Christian site and around 1,500 years old.

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The Yew arch in the Golden bridge Cemetery, Dublin


In Ireland the yew is native and may be found in old woods although it is often seen in the artificial surroundings of estates or churchyards. An evergreen conifer (although an unusual one), yew is a dramatic tree with its dark foliage and red berries encasing a single seed. Reenadina wood on the Muckross Peninsula, Co. Kerry is Ireland’s only native yew wood.

yew red berries

Toxicity: All parts of a yew plant are toxic to humans with the exception of the yew berries (however, their seeds are toxic); additionally, male and monoecious yews in this genus release cytotoxic pollen, which can cause headaches, lethargy, aching joints, itching, and skin rashes; it is also a trigger for asthma. These pollen grains are only 15 microns in size, and can easily pass through most window screens.

The foliage itself remains toxic even when wilted, and toxicity increases in potency when dried. The major toxin within the yew is the alkaloid taxine. Horses have a relatively low tolerance to taxine, with a lethal dose of 200–400 mg/kg body weight; cattle, pigs, and other livestock are only slightly less vulnerable. Several studies have found taxine LD50 values under 20 mg/kg in mice and rats.

Symptoms of yew poisoning include an accelerated heart rate, muscle tremors, convulsions, collapse, difficulty breathing, circulation impairment and eventually cardiac arrest. However, there may be no symptoms, and if poisoning remains undetected death may occur within hours. Fatal poisoning in humans is very rare, usually occurring after consuming yew foliage. The leaves are more toxic than the seed.

Uses:

Wood from the yew is classified as a closed-pore softwood, similar to cedar and pine. Easy to work, yew is among the hardest of the softwoods; yet it possesses a remarkable elasticity, making it ideal for products that require springiness, such as bows. One of the world’s oldest surviving wooden artifacts is a Clactonian yew spear head, found in 1911 at Clacton-on-Sea, in Essex, UK. Known as the Clacton Spear, it is estimated to be over 400,000 years old.

Yew is also associated with Wales and England because of the longbow, an early weapon of war developed in northern Europe, and as the English longbow the basis for a medieval tactical system. The oldest surviving yew longbow was found at Rotten Bottom in Dumfries and Galloway, Scotland. It has been given a calibrated radiocarbon date of 4040 BC to 3640 BC and is on display in the National Museum of Scotland. Yew is the wood of choice for longbow making; the heartwood is always on the inside of the bow with the sapwood on the outside. This makes most efficient use of their properties as heartwood is best in compression whilst sapwood is superior in tension. However, much yew is knotty and twisted, and therefore unsuitable for bow making; most trunks do not give good staves and even in a good trunk much wood has to be discarded.

TAXUS BACCATA (YEW), TOPIARY, TREE CLOUDYew topiary tree cloud

Today European yew is widely used in landscaping and ornamental horticulture. Due to its dense, dark green, mature foliage, and its tolerance of even very severe pruning, it is used especially for formal hedges and topiary. Its relatively slow growth rate means that in such situations it needs to be clipped only once per year (in late summer).

Recent visit to Goldenbridge Cemetery

general grave stones lo res

I noticed that the Goldenbridge Cemetery in Inchacore in Co. Dublin was reopened to the public on Sunday, almost 150 years after it closed. I was lucky recently to have been given a private tour of the Cemetery prior to this opening and was really taken by the archway created by two very well established Yew trees and the general ambience of the space.

yew arch lo res

From the time of the Reformation, Catholics were not allowed their own cemeteries and buried their dead in old churchyards, monasteries and Protestant churchyards. Daniel O’Connell campaigned for a cemetery to be opened in the wake of the Penal Laws, to “those of all religions and none”, Goldenbridge Cemetery was the first non-denominational Cemetery in Ireland. It was closed following a dispute with the British War Office and has operated as a closed cemetery, locked and visited by appointment only for nearly 150 years. Only occasional burials took place, like that of politician WT Cosgrave. His son, former Taoiseach Liam Cosgrave, was at his father’s graveside today.

Ceremonial events on Sunday included a re-enactment of Daniel O’Connell’s ‘speech of the establishment of the non-denomination cemetery’, musical recitals by St James’s Brass and Reed Band and Comhaltas Ceoltóirí Éireann, a lecture on the history of the cemetery from Professor Maurice Bric, and an ecumenical blessing.

The annual commemoration of O’Connell, whose 170th anniversary was on Saturday was also marked. Wreaths in his honour were laid by a number of people including Minister of State for Communities Catherine Byrne and by the Liberator’s great, great, great grandson John Cunningham.  To follow see an image of a tree, which is thought to be  planted by O’Connell when the Cemetery was first opened.  The image on the right shows that many have carved their initials into the tree.

From today onwards, Goldenbridge Cemetery will be open Monday to Friday from 9am to 3pm for visitors and burial services.

The most important grave in the cemetery is that of WT Cosgrave, first head of government of the Irish Free State.

His son, former Taoiseach Liam Cosgrave (97), attended the rededication and formal reopening of the cemetery that Daniel O’Connell had campaigned for.

Mr Cosgrave, whose wife Vera Cosgrave was buried in Goldenbridge last September, said after the ceremony that “I’m very glad, very pleased to see it reopened. It’s a quiet cemetery.”

Frank Burke, a member of the Irish Volunteers and a step-brother of WT Cosgrave, is also buried there as is Mary Anne Jenkins a member of Cumann na mBan and Eugene Lynch an eight-year-old child killed during the 1916 Rising.