The conifer known as European Yew, Common Yew or English Yew is endemic to Western, Central and Southern Europe, Northwest Africa, Northern Iran and Southwest Asia.
All parts of the small evergreen tree are highly toxic, except the bright red aril surrounding the seed. Nowadays using laboratory methods detecting its highly toxic alkaloide (taxin) is not really a poblem anymore, however taxin was undetectable over millennia, since it was used as a secret poison.
Death due ultimately to heart failure may occur so rapidly that the early symptoms of poisoning may go unnoticeable and hence, missed.
Horses may die in 15 minutes following consuming an about 30 cm long branch and toxicity is retained even in dried leaves or wood. The wood is beautifully structured and colored. Small wonder, it is resistant to woodworm and other insect attacks, too.