#yew /PLANTS, berries & FUNGI, PLANT VARIETIES /Yew (Taxus baccata) Leaves & seeds are poisonous. $2 SYMPTOMS: {Vomiting}, {diarrhea}, abdominal pain, {delirium}, {convulsions}, slow {pulse}, {coma}. Transfer to hospital urgently. The poisonous nature of the tree was what originally encouraged churchwardens to plant Yews in graveyards, thus preventing people from grazing their animals on holy ground. The tree has since taken on a religious significance, its berries symbolising Christ's blood (it is also reputed to avert witches).