Poison Ivy, Oak and Sumac: What are they?
Poison ivy, poison oak and poison sumac are plants that are found in various places throughout North America. They favor wooded and watery areas. They have one feature in common: the presence of a chemical called urushiol that is carried in the sap of the leaves. The old rhyme, “leaves of three, let it be” applies to poison ivy and poison oak, as leaflets often appear in groups of three. Poison sumac can have leaflets numbering five, seven or more. One mark that is sometimes observed on these plants is shiny black spots that look like spatters of tar. This is actually the urushiol on the surface of the leaves. Poison Ivy The leaves of these plants are incredibly delicate, and even very gently brushing against them can allow the transfer of a tiny amount of urushiol, which then binds to cells deep in the epidermis. Symptoms, which include an itchy rash with fluid-filled blisters, typically develop 12-72 hours after contact with the oil. Some areas of the skin appear to react more quickl
