Commonly grown as house plants, Dieffenbachia species are actually tropical evergreen perennials in the arum family. They are distinguished by thick, clustered stems that become woody with age, draped with large, fleshy, spotted leaves. Many people are not aware that the base of the leaf stalks and stems contain a milky or yellowish sap that can cause contact dermatitis in susceptible individuals. To relieve skin irritation, wash the affected area thoroughly with soap and water; if the irritation persists, wear gloves when handling your Dieffenbachia. The plant also contains microscopic, needlelike crystals of calcium oxalate that if ingested by humans or pets can cause burning and swelling of the mouth and throat. People who experience severe reactions are sometimes unable to talk�hence one of the plant�s common names, dumb cane. Before bringing any plant into a home that includes small children or pets, be sure to find out if it is potentially toxic.