Toxicodendron radicans, commonly known as eastern poison ivy or poison ivy, is a poisonous Asian and Eastern North American flowering plant that is well-known for causing Urushiol-induced contact dermatitis, an itchy, irritating, and sometimes painful rash in most people who touch it. It is caused by urushiol, a clear liquid compound in the plant's sap. The species is variable in its appearance and habit, and despite its common name it is not a true ivy (Hedera)