(from rune secrets) The needle of the yew is poisonous, containing a toxin that affects the central nervous system. The vapors from the toxin can become concentrated in close proximity to the tree. As a conifer/’evergreen’, it is associated with immortality, and the mysteries of life and death- the Great Initiation into the mysteries of life. To die before you die is to discover what in life is truly important. In psychology, this often happens as a result of near-death experiences.