Relatively common in Europe, northwest Africa and the Middle East, nearly all parts of this slow-growing tree can be poisonous. The exception is the red fleshy aril that surrounds the toxic seeds. The aril is frequently eaten by birds.
Some people have chosen to commit suicide by ingesting the leaves or the seeds, both of which contain a poison called taxanes. Sometimes there are no symptoms of poisoning and a person or animal can die within a few hours of ingesting yew seeds or leaves. If there are symptoms, they can include a fast heart rate, muscle spams and labored breathing.