Poisonous Plants
Posion Ivy
(Toxicodendron radicans)
“Leaves of three, let it be!”
Poison ivy is one of the most common plants hikers encounter in the Smokies. It grows as a vine or small shrub and has clusters of three pointed leaflets. The leaves may appear shiny or slightly dull, and they often turn red or orange in the fall.
Where you’ll see it: Along trail edges, tree trunks, and fence posts.
Danger: Contains urushiol, an oil that causes itchy, blistering rashes. It can be spread by skin contact or through clothes, gear, or even pets.
Poison Oak
(Toxicodendron pubescens)
Often mistaken for poison ivy, poison oak grows more like a shrub here in the southeastern U.S. It also features three leaflets, but the leaves are often lobed or wavy, resembling oak leaves.
Where you’ll see it: Sunny clearings and forest edges.
Danger: Also carries urushiol. Contact may lead to red, itchy skin and painful blisters.
Poison Sumac
Toxicodendron vernix)
Less common but more potent, poison sumac is a small tree or tall shrub with smooth-edged, pointed leaves arranged in clusters of 7 to 13. Its reddish stems and white berries make it stand out.
Where you’ll see it: In wet, swampy areas or along creek beds.
Danger: Contains the highest concentration of urushiol. Even light contact can cause severe skin reactions.
Virginia Creeper
(Parthenocissus quinquefolia)
Often confused with poison ivy, Virginia creeper has five leaflets (not three!) and turns a stunning red in the fall. While not poisonous to the touch for most people, it does have a few hidden risks.
Where you’ll see it: Climbing trees, fences, and rocks.
Danger: Its berries are toxic if eaten, especially to children and pets. Some sensitive hikers may also react mildly to its sap.