I thought I would take a look today at that old favourite- the Yew Tree. Many legends surround this unusual specimen of plant life so I decided a closer look was needed in order to dispel a couple of the myths that surround it, and explain a bit more.
The Yew tree is slightly unusual as it is able to reproduce through both epicormics and basal shoots, in the trunk, from branches and through roots. Once the tree reaches a certain size, it will send out basal shoots which will grow upwards wrapping themselves around the trunk to form a new outer layer. The Yew will be decomposing interiorly whilst the outer layer of the tree continues to grow. These shoots often form a buttress effect for the decaying tree inside, providing support. Eventually this new growth becomes the tree. It is, as a result very difficult to date a Yew through dendrochronology as a result of this decomposition, removing rings from the flesh of the tree inside the bark. The Yew is an evergreen, with spiral-shaped “needle” foliage and red berries. The interior dead wood is white whilst the decomposed heart wood is red.
A popular myth is that Yews are typically found within churchyards, with a number of equally legendary explanations. It is often said they were planted there to grow wood for longbows during the medieval period, which by virtue of being on consecrated land, prevented anybody felling the wood for their own use, or to prevent livestock from eating parts of the tree, spoiling it for longbow provision. Both these stories are in fact untrue. Most of the Yew tree is in fact toxic in natural form, and when “dried”, both to animals and humans, producing a range of symptoms from simple pollen allergies, through Asthma to cardiac arrest in extreme cases. However, that being said, in a fairly recent study, there were found to be just short of 11200 cases of Yew poisoning in the surveyed period, 96.4% being suffered by children under the age of 12. None of the cases were fatal.
Due to the continuous decomposition of the tree interior, there would simply not be, nor ever was enough viable wood contained within the trunk or branches of the churchyard yews of Britain and Ireland to sustain the production numbers of bows required for the period. Yews were fairly common outside of churchyards and burial grounds, but again not a viable source of enough quantities of the wood required to keep up with demand. Once the bark has been stripped away little wood remains below the surface; Waste is high. The wood of a Yew tree is one of the harder softwoods, similar to pine. The white wood is used to shape the exterior of the bow being more durable and working better under tension, whilst the heartwood, forms the interior as it works better under compression.
As a result, from around the 13th to 15th Centuries contracts were signed with other countries, to supply a high quantity of material each year as stocks in Britain and Ireland were depleted to the point of inviable quantity. Spain was the first country to supply the required staves, followed by Bavaria. In the first half of the 15th Century, the amount of Yew staves imported reached an estimated 1million. By 1568 Elizabeth I issued a decree to replace all military longbows with firearms. One popular myth has it that this was because guns were considered the better weapon, however, far from being superior, early firearms were slower and less accurate than the favoured longbow. The truth of the matter was that there was not a viable Yew tree left in Europe with which to make the bows.
Going back to the association of yew trees and burial grounds, the most likely explanation for this is contrary to popular belief that Yews were planted in churchyards. As many of these existing trees are thought to be between 1000 and 3000 years old, many of them pre-date Christianity and were most likely planted on sacred sites, as a symbol of the Tree of Life, being as its practically impossible to kill a Yew completely, and that later Christian Churches were built on the same sites, incorporating the trees. Yew trees are known to thrive in most conditions, weather and soil, with few exceptions. It is accepted that they also draw valuable nutrients from the bodies buried nearby, and in return assist with the decomposition process.
The tree of life is a symbol repeated in various rites of worship, the great Sacred Tree at the Temple of Uppsala mentioned in the Ynglinga Saga is thought to have been a Yew tree, likewise the Germanic Yggdrasill, despite earlier acceptance as an Ash, is now felt to have been mis-translated and was in fact a Yew. (This from the description of its evergreen foliage, which an Ash is not.) links with Christianity determine the Yew as a metaphor for resurrection with the body and blood of Christ represented by the white and the red woods within. As Yews are seemingly difficult to destroy, providing one small living part remains connected to the earth, it will regenerate, the association with eternal life seems straight-forward and further reasoning for their place within holy ground, is not such a stretch of the imagination. They also thrive better in open conditions found in most burial grounds, with good sunlight exposure, although can be found growing quite densely, although not as magnificently in wooded areas.
It is felt that the majority of veteran or ancient Yews are now sited in Britain, although strangely, they have maintained a notable absence along the South and East regions from Cornwall to Suffolk, up towards Cambridge and Lincolnshire. In several European countries, examples of noteworthy Yews, the older specimens, have achieved various levels of protection. Sadly in Britain, such measures have not been introduced. There are however examples of several sub-types of Yew which have been transplanted to the National Botanical Gardens at Kew for further development and species preservation.
In the early 11th century, venerated Polymath and author Avicenna (Ibn-Sina) of the ‘Canon of Medicine’, which was still in use in modern times, promoted the use of a Taxis Baccata derived herbal drug for the treatment of hypertension, as a calcium channel blocking agent. He called it Zarnab. Similar synthetic or derivative drugs were not introduced into modern medicine until over 940 years later. In the Himilayas the bark of the Yew is used as a treatment for female cancers. In the Western world, the process of extraction has been found to be easier and more viable from the leaves of the European (English) Yew than the previously favoured bark of the Pacific Yew which had led to its mass-destruction. The precursors are then converted to produce chemotherapy drugs Paclitaxel and Docetaxel.
So in summary, some myths dispelled surrounding the magnificent Yew tree… more than just a big green plant in a churchyard.