The Yew, the Tree of Life and Death
By José Luis Gallego, environmental communicator (@ecogallego)
The tree lovers among us are smitten with the beauty of the yew (Taxus baccata), one of the most gorgeous species of European flora. Groves of yew trees make for some of the continent’s most beautiful woodlands. What we also know is that everything about the yew, from its leaves and bark to its seeds, is poisonous, which is why it’s a good idea to be careful when seeking shelter under its branches. Let’s begin by correctly identifying our protagonist.
The yew has a pyramidal shape and a thick canopy with horizontally extending branches that are particularly wide closer to the base of the trunk. It is robust and dense in appearance. The trunk is thick and compact, often exceeding two metres in diameter (closer to eight in some specimens). The bark is brownish-grey in colour and scaly, peeling off to reveal a reddish-orange hue underneath. Some specimens have very short multiple trunks, but generally the yew grows to a height of 15 metres, although some can reach up to 20.
Detail of a yew branch
The evergreen leaves are flat pointed needles about two to four centimetres in length. They are coloured matte dark green above and yellowish below: somewhat similar to those of a fir tree, which some confuse with the yew. The yew is dioecious, meaning that male and female flowers grow on separate trees. Male flowers are axillary and grow in clusters where the leaves meet the branch. They are small and egg-like in structure and resemble berries. At first they are white, but their colour gradually changes to greyish-brown with an orange tinge.
During the autumn, the fruit develops a fleshy layer (aril) that is a striking crimson red colour. The cup-like shape, round and open at the top, reveals the ligneous seeds within. In appearance the yew is as Christmas-like as the fir, but here we find another of its lethal traps: the fleshy part of the berry is edible, but the seed – like the rest of the tree – is highly toxic, so it’s better not to touch, let alone eat, its fruit, because the consequences could be deadly.
Taxane, one of its primary compounds, is among the most potent poisons in nature. It contains alkaloids that deliver a deadly cocktail to the organism, triggering a series of cardiovascular alterations that can lead to death within half an hour of ingestion. And it is found in every part of the tree, from the roots to the very top of the crown.
Yew branches
The yew is a protected species throughout Europe, and Spain is home to several specimens that are listed as monumental trees. Among the most famous is the Teixu de Bermiego, located in the Asturian village of Quirós. Declared a Natural Monument by the Principality of Asturias, the over 1000-year-old tree is venerated by locals and admired by nature lovers who flock to the Las Ubiñas-La Mesa Nature Park, a Biosphere Reserve.
In 2018, this famous yew was the Spanish candidate for European Tree of the Year, which earned it a moment in the media spotlight. Unfortunately the moment was overshadowed by a tragic event that occurred that same spring: the death of a young Latvian student who was staying with a host family in the area, less than five kilometres from Bermiego, after drinking an infusion of yew leaves, which she had confused with those of another species.
The yew, however, is also a tree of life, because those same toxic taxane alkaloids contain molecules that are used for pharmaceutical purposes in chemotherapy treatments to combat different types of cancer. As a result, the yew tree has become one of our most effective natural allies in the fight against this terrible disease.