poison oak

''Toxicodendron diversilobum'', commonly named Pacific poison oak or western poison oak , is a woody vine or shrub in the Anacardiaceae family. It is widely distributed in western North America, inhabiting conifer and mixed broadleaf forests, woodlands, grasslands, and chaparral biomes. It is known for causing itching and allergic rashes in many humans, after contact by touch or smoke inhalation.