Anacardiaceae Angiosperms Main Menu FOR 21 . Toxicodendron contains about 22 species which contain an oily substance that causes a painful skin irritation. Poison Ivy (T. radicans) Poison Oak (T. pubescens) Poison Sumac (T. vernix)
Poison Ivy (T. radicans) Poison Oak (T. pubescens) Poison Sumac (T. vernix)