An oil called urushiol causes skin irritation when you brush up against this 3-leafed plant, Rhus radicans
[DOC] [TLE] Top tips for poison ivy, oak and sumac | Earth | EarthSky [PAR] Jun 15, 2016 ... Master of disguise poison ivy (Toxicodendron radicans) can be a shrub ... by 
urushiol, that they can eat the poisonous plants that cause our ...