poison ivy

/P OY1 Z AH0 N AY1 V IY0/
noun
  1. 1

    Any of three ivy-like species of Toxicodendron, known for their ability to cause an itching rash and blistering for most people, through urushiol, an oil that is a skin irritant.

Source: https://en.wiktionary.org/wiki/poison%20ivy