How can I identify a poison sumac tree?

You can identify a poison sumac tree by looking for clusters of smooth, oval-shaped leaves arranged in rows of 7-13 leaflets. The leaves are shiny and have a white or pale yellow color on the underside. The tree also produces small greenish-white berries that hang in loose clusters. Be cautious as contact with the leaves or any part of the tree can cause a rash or skin irritation.