Both indoor and outdoor garden plants can cause problems. For example, the foliage of the bird-of-paradise and philodendron plants is toxic. A poinsettia leaf can kill a young child. Outdoor plants such as castor beans are highly dangerous. All parts of the potato and tomato plant are poisonous, except the potato and tomato themselves. Large amounts of rhubarb's leaf blade can be fatal by causing convulsions, coma, and death. These statements, though true, are surprising to many people. Science teachers need to be knowledgeable about the plants they plan on using in the classroom. Most often, alternatives can and should be used for investigations by students in the science laboratory. Before venturing into the great outdoors with for class activities, review plant safety tips. This article provides a list of some of the more popular and accessible plants that are in some ways poisonous and a list of related Internet resources.