Poison Ivy
A toxic plant with three glossy, pointed leaflets, commonly found in forests, fields, and along trails. Contact with its oil, urushiol, causes itchy rashes and skin irritation. If touched, wash the affected area with soap and water immediately.

Closely related to poison oak and poison sumac, which are also skin irritants.

https://en.m.wikipedia.org/wiki/Toxicodendron_radicans
