Snow!! Snow in the southern UK in late April, when will summer finally turn up?! Hopefully very soon, and in that vein I’d like to wish everyone a happy Arbour Day! I’m pretty sure last week’s issue, the cruel Carnotaurus cares not one iota for trees unlike me and hopefully yew. Wait Yew? Yep we’re off the beaten track with an Impurest’s Guide to Not Animals. Hope you all enjoy.
Issue #171 - European Yew
Kingdom – Plantae
Division – Pinophyta
Class – Pinopsida
Order – Pinales
Family – Taxaceae
Genus – Taxus
Species – baccata
Related Species - The European Yew is one of over twenty species in the genus Taxus (1).
Range - The native range of the European Yew covers the majority of Europe, Northwest Africa, Southern Asia and parts of Iran.
The Graveyard Tree
The European Yew is a medium sized evergreen tree that grows to an adult height of 10 to 20m in height, and can easily be recognised by the flaky brown bark and the bright red berries it produces in autumn. The leaves of this tree are flattened soft needle like structures that are dark green in colouration and are anywhere between 1 to 4cm in length. Relatively slow growing, the European Yew is hard to age due to its boughs and trunk hollowing with age, thus making ring counts impossible to accomplish in mature trees (2). That being said, an average lifespan of 400-600 years seems like a reasonable estimate, although there are many specimens that are potentially far older then this estimate, with the oldest specimen the Fortingall Yew from Fortingall, Perthshire in Scotland, being estimated at being over 2000 years old.
Yew trees, unlike the vast majority of plants, are dioecious and have defined genders in regards to their flowers. Male flowers are small pale green orb like structures, while those of female plants resemble small scaly buds (3). Only male Yew trees produce pollen, which is dispersed on the wind to the flowers found on female trees. From there the female tree produces bright red berry like structures known as arils, unlike many other conifers which produce cones, which are consumed and dispersed by birds.
The European Yew tree is a plant steeped in myth and folklore across Europe, featuring in Norse, Gallic, Germanic and Pre Christian British mythology, and would later play a big part in Christian iconography. Due to their toxicity, it was believed that Yew trees were deliberately planted in burial grounds to deter farmers and drovers from letting their animals graze in these sacred spaces. The Yew was also adopted by Christianity as a symbol of transcendence over death, and was commonly planted in graveyards. There is even some suggestions that Yggdrasil of Norse Mythologhy may not be an Ash Tree (Fraxus excelsior) but rather a Yew Tree from the translation of words related to it, such as barraskar and vetgrønster vida as ‘needle ash’ and ‘forever green tree’ respectively, names that support the World Tree being a Yew and not an Ash.
Terrors of Toxicology #6 - Taxine
An old man hangs from a European Yew Tree for a week, never moving yet alive, before finally overcoming his lethargically and moving. Said old man is Odin, and the tree is Yggdrasil, and is likely a reaction to the alkaloid Taxine, a chemical that, on warm days is exuded from the bark of tree and causes, among other things hallucinations and a lethargic state. This reaction is just the tip of the iceberg when it comes to the Yew Tree, all parts with the exception of the aril are toxic, both in living specimens and dead wood. The poison is so potent that, during Ceaser’s invasion of Gaul, defeated chieftains would commit ritual suicide by chewing yew leaves rather then be taken prisoner, with only around 50g of material required to kill a healthy adult human.
Taxine is an alkaloid compound featuring a number of toxic compounds, all of whom attack the core cardiac and respiratory muscles by increasing the flow of ions through the calcium channels in the cardiac cells, effectively causing the heart to beat irregularly before eventually stalling it altogether (4). As mentioned above almost all parts of the European Yew are toxic, and even shavings of the bark accidently inhaled are enough to cause convulsions, as is contact with leaves that have dried up and smoke from wood gathered from trees many months previously.
For all its toxicity, mankind has long realised the danger this tree possess and as such deaths, despite no anti-toxin being available, are quite rare. In fact the compound Paclitaxel (5) found within the Taxine alkaloid may even save your life due to its ability to combat certain cancers when used in chemotherapy by binding to the compound Tubulin, the compound that when unbalanced causes rapid cell division. While first extracted from the bark of the Pacific Yew (Taxus brevifolia), the European Yew’s more resistant nature towards harvesting provides a far more reliable source of this chemical, since unlike its American relative, the tree doesn’t need to be killed to obtain the bark and timber.
2 - Kinmonth, F. (2006). Ageing the yew – no core, no curve? International Dendrology Society Yearbook 2005: 41–46.
3 - https://www.woodlandtrust.org.uk/visiting-woods/trees-woods-and-wildlife/british-trees/native-trees/yew/
4 - G. Barceloux, Donald (2008). Medical Toxicology of Natural Substances: Foods, Fungi, Medicinal Herbs, Plants, and Venomous Animals. p. 900
5 - https://www.drugs.com/monograph/paclitaxel.html
1 - https://bigrab.files.wordpress.com/2012/05/000_0012.jpg
2 - http://gallery.nen.gov.uk/assets/0603/0000/0109/yew007_mid.jpg
4 - https://ofthegoodtree.files.wordpress.com/2014/06/odintree.jpg?w=665
So it seems what doesn’t kill you can make you stronger. Next week we have an issue that is infernal and vampire in nature, but until then though make sure to critic, comment and suggest future issues as well as making sure you check out past issues in Impurest’s Bestiary
Happy Arbour Day