With its fern-like green leaves and slight stature, poison sumac (Toxicodendron vernix) is an innocuous-looking deciduous shrub or small tree that can cause serious skin irritation if touched. A native of North America, poison sumac can be found in the eastern United States in United States Department of Agriculture plant hardiness zones 3 to 8, where it thrives in wet, swampy conditions. Though poison sumac resembles other species in the Toxicodendron genus, it can be identified with careful observation.

Fall in Steamboat Springs Colorado
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Close-up of poison sumac

Foliage Facts

Posion sumac produces pairs of seven to 13 leaflets, with a single leaflet at the end of each stem. The long, oval-shaped leaflets have smooth edges and a soft, fine texture. They are 2 to 4 inches long and 1 to 2 inches wide. Stems, petioles and leaf veins are red. Leaflets change colors throughout the year, appearing bright orange in the spring, glossy green in the summer and reddish orange in the fall.

Fruits, Flowers and Features

Poison sumac generally reaches an average height of 5 or 6 feet, though it may grow as tall as 25 feet. The shrub tends to lean to one side. The shrub flowers from May to July, producing clusters of tiny, yellowish-green blooms, which sit on thin stems at the leaf axils, where the leaf petiole and stem meet. Flowers give way to 10- to 12-inch clusters of grayish or white berries. A deciduous plant, poison sumac drops its foliage in the winter, though berries may persist.

Lookout for Lookalikes

Also known as winged sumac, flameleaf sumac (Rhus copallinum) may be mistaken for poison sumac. Flameleaf sumac grows in USDA zones 4 to 9, reaching an average height of 10 feet and producing smooth green leaves that turn bright red in the fall. Flowers are also greenish yellow. Flameleaf sumac, however, has 9 to 23 leaflets and red berries. The U.S. Army Public Health Command notes that harmless sumac species produce red berries, whereas poison sumac berries are white or gray.

Considerations and Concerns

With the exception of the pollen, all parts of poison sumac contain a toxin called urushiol that can cause painful, itchy rashes and blisters. If you touch poison sumac with your bare skin, immediately apply rubbing alcohol to the affected skin and wash the affected area with warm water and soap. Consider removing poison sumac from your property by cutting down the shrub with a handsaw and applying an herbicide containing glyphosate to the stump. Protect yourself with rubber gloves, long sleeves and pants, and use a foam paintbrush to paint a pint of undiluted, 20 percent glyphosate onto the stump. Follow all label instructions exactly. Dispose of all dropped foliage, wash your clothes in hot water and wipe your shoes down with rubbing alcohol.