Several species, including Toxicodendron radicans (commonly known as poison ivy), Toxicodendron diversilobum (commonly known as poison-oak), and Toxicodendron vernix (commonly known as poison sumac). All parts of these plants contain a highly irritating oil with urushiol. Skin reactions can include blisters and rashes. It spreads readily to clothes and back again, and has a very long life. Infections can follow scratching.