Winged Sumac and Smooth Sumac (Rhus copallinum and R. glabra)

Winged Sumac (left) with drooping panicle branches and Smooth Sumac (right) with erect panicle branches

Characteristics:  Winged sumac and smooth sumac are two common and closely related woody plants in Oklahoma. They are members of the family Anacardiaceae, which also includes cashews, pistachios, mango, poison ivy and poison sumac. Each has compound leaves that turn bright red or orange in the fall. Both species grow as shrubs to small trees and may form extensive thickets.

The leaves of smooth sumac have a round rachis and leaflets with serrate (toothed) edges. The buds are covered by the petiole base so they appear to be missing. This species is a favorite of botany professors for this reason, as bud characteristics are one of the first things to look for when they hand you an unknown woody plant and ask you to identify it. The sap is milky and sticky. You’re likely to discover this right after finding the bud and getting sap all over everything. The flowers for both species are tiny and clustered into large panicles. Once the fruit matures, a useful field character is the panicle branches remain erect rather than drooping.

Winged sumac has leaves with a “winged” rachis that appears flat on top and leaflets with smooth margins or with very few teeth. The small buds are visible at the petiole bases. Once the fruit matures, the panicle branches tend to droop to one side.

Area of Importance:  

Smooth sumac occurs throughout the state. Winged sumac overlaps the range of smooth sumac but doesn’t extend as far to the northwest. Pastures, fence rows and overgrown fields are likely habitats for either species. Smooth sumac is the only tree species known to occur in each of the lower 48 states.