What Christmas plant is poisonous to humans?

After the Christmas tree, the pretty scarlet poinsettia (Euphorbia pulcherrima) is the most traditional Christmas plant. The poinsettia has long been considered poisonous, but Ohio State University recently conducted research that showed poinsettias are not poisonous. Ingestion of leaves or stems may cause upset tummies and diarrhea in your furry friends, however. For people with latex Allergies, the white sap may cause allergic reactions