Poinsettias are a common holiday decoration, but they are poisonous. Keep them out of reach of children (and pets). The same applies to holly, which also has poisonous red berries. “Symptoms of ingesting poinsettia plants include rashes, vomiting, and other allergic reactions,” warns Dr. Elliott. “If poinsettias and other toxic plants are in the home, make sure to have them out of reach of children and it is a good idea to have the number for poison control on hand.”