Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Poison Ivy, Oak and Sumac ?
    ### Response:
    If you spend time outdoors, chances are you have been bothered by poison ivy, poison oak or poison sumac at some point. Most people are sensitive to the plants' oily sap. The sap is in the root, stems, leaves and fruit of these plants. If it gets on your skin, it causes a blistering skin rash.
    