Toxicodendron rydbergii

Toxicodendron rydbergii (syn. Rhus rydbergii; Western Poison-ivy) is a species of Toxicodendron native to most of the United States except the Pacific States, where it can be found growing in forests, and other wooded areas, usually near streams and rivers.

It is a shrub that can grow to 1 m (3 ft) tall, rarely up to 3 m (10 ft). The leaves are trifoliate and alternate. The leaflets are variable in size and shape, and are usually 15 cm (6 in) long, turning yellow or orange in autumn. The fruits are small, round, and yellowish.

Caution
All parts of this plant contain Urushiol, which can cause severe dermatitis in some individuals.