Not All Sumac Are the Same
Most people think of irritated skin / dermatitis when the word Sumac is mentioned. Actually, Poison Sumac is a small tree or large shrub with large attractive leaves and white fruits that could be used as an ornamental if it didn’t cause severe skin irritation in most people. Its smaller relatives with 3-parted leaves, Poison Ivy and Poison Oak, have similar irritating properties. Poison Sumac (Rhus vernix) is fairly common in swamp edges and wet woods in the Coastal Plain.
Key features to identify it include large alternate leaves, usually with 9-13 entire (not “tooth” edged) leaflets and a red rachis (the stem connecting the leaflets). The leaflets are smooth and may be shiny above. The red rachis is easy to spot from a distance, once you know to look for it. Poison Sumac is not so prevalent in the Piedmont region of NC and is even less so in the Mountains. The lack of “hair” on the white fruit, or stems, and the smooth-edged leaves on poison sumac are a good way to tell the difference between Poison Sumac and Staghorn Sumac (Rhus typhina). Note that Dwarf Sumac (Rhus copallina) is similar in appearance except its stems have raised dots and its leaflets have smooth edges.
Staghorn Sumac is a native of eastern U.S. with a range extending north to Quebec, south to Georgia, and as far west as Iowa. ‘Staghorn’ refers to the appearance of the branches of this species, which are covered with soft hairs resembling that on a deer’s antlers when ‘in velvet’. Staghorn Sumac establishes on clearings, hillsides, open woods, and disturbed areas such as roadsides and reduced-tillage fields. It was planted as an ornamental but escaped cultivation, so it can also be found growing in lawns and gardens. The plant tolerates unfavorable conditions, thrives in polluted city air, and grows in such inhospitable sites as cracks in pavement. It will grow on any soil type.
This deciduous, woody perennial grows in a colony as a shrub or it may grow alone as a small tree. Staghorn Sumac has compound leaves that can grow 12 to 24 inches long and are made up of many 2- to 5-inch-long leaflets. Leaflets turn bright colors before falling off in the fall. Red fruits form in dense, upright clusters that look like hairy cones located at the tips of branches.
Root systems tend to be shallow and wide-spreading. Young shoots have thin, dark-brown bark and are densely hairy. Trees can grow over 30 feet tall but usually do not exceed 15 feet. Stems are covered with long, soft hairs and exude a milky sap when cut.
You can really tell the difference with the flowers. In Staghorn Sumac, the flowers are small and green and form 8-inch long, pyramid-shaped clusters found at the end of stems. Male and female flowers are located on separate trees. The fruits are red, berry-like, hard, and covered with long hairs. Fruits form in erect, cone-shaped clusters at the tips of branches. Clusters are so compact they look like hairy cones. Fruit may hang on until spring. In Poison Sumac the small, yellowish-green flowers are held in clusters on slender stems starting from the leaf axils. Flowers mature into ivory-white to gray fruits that dangle in loose clusters of up to 10–12 inches in length. Enjoy the flowers and unique fall colors of the Sumacs even more when you know which ones to enjoy from a distance!
Minda Daughtry is Horticulture Agent for North Carolina Cooperative Extension in Lee County.