The dark foliage symbolises sorrow.
Yew trees can grow to be very, very old and have
therefore become a symbol of immortality.
The thorns and seeds of the yew tree are poisonous,
and so the tree represents death and resurrection (the life
after death promised by the Christian church).
The yew tree has associations not only with Christian
ideas but also with magical beliefs, and in the Middle Ages
people thought that the tree could protect you from enchantment.