This article gives some examples of plants that are sometimes thought to look like poison oak. Some plants simply appear similar out of coincidence. Others have actually evolved to be similar in appearance to their poisonous neighbors. Herbivores can’t see clearly enough to tell the mimic from the actual poison oak, so the mimic lives long enough to flower and germinate.
Poison oak, like poison ivy, is a wild plant that can cause severe skin reactions in people and animals. Unlike other plants, which have physical defense mechanisms like thorns or sharp leaves, poison oak (Toxicodendron toxicarium) contains compounds that irritate mammals’ skin. These compounds are a type of resin called urushiol.
In the wild, a deer or other herbivore would taste the poison oak but quickly avoid it because the compounds irritate the inside of their mouth. Poison oak can be easy to miss if you’re not watching carefully. It grows near high disturbance areas like trails and open woodlands.
Keep reading to learn about the plant species that look like poison oak. We’ll discuss their scientific and common names, where they grow, and what traits set them apart from poison oak.
7 Plants that Look Like Poison Oak
Before we dive into poison oak mimics, let’s discuss some of the main characteristics of poison oak.
You’ve probably heard this classic rhyme before: “Leaves of three, let it be.” This ditty is true with poison oak. You can identify the plant by way of its ground-dwelling habit, clusters of oak-like leaves, and where it grows.
This shrub prefers drier climates. It grows best in sandy soils with minimal to moderate rainfall.
The most common places it lives in North America are along the coasts and in the western United States. It’s so common in California that there is a subspecies of poison oak native to the state!
One more important detail about poison oak: its leaves can be lobed or non-lobed. Lobed leaves appear more similar to those of an oak tree.
That’s actually what gives poison oak its name. Non-lobed leaves have smooth sides and slightly bumpy centers. Leaves vary in shape and size depending on what environment the plant’s growing in.
Poison oak’s flowers are yellow and its fruits are white. During the fall, the leaves turn bright red while the foliage dies. Even though the leaves are dying or dead, they still contain urushiol resin. Don’t touch!
1. Virginia Creeper
Scientific name: Parthenocissus quinquefolia
Virginia creeper is native to the eastern United States. That doesn’t mean it won’t be spotted in areas where poison oak is abundant. Tell a vine of Virginia creeper apart from poison oak thanks to the edges of its leaves.
They are ‘toothed,’ the botanist’s term for jagged. There are five leaflets in each group of Virginia creeper, not three like in poison oak.
If you’re still unsure, look at the leaf shape. Poison oak gets its name from having oak-shaped leaves even though it’s not related to oak trees. Virginia creeper leaves are oval shaped with a pointed tip.
2. Fragrant Sumac
Scientific name: Rhus aromatica
Fragrant sumac, a relative of the infamous poison sumac, is a non-threatening and non-irritating species of sumac. It can be easy to mistake for poison oak due to the shape of its leaves. Most cases of confusion occur in environments where they grow nearby each other.
Fall is the best time to identify the plant you suspect might be fragrant sumac. Look at the color of its berries.
If they are red, this plant is definitely not poison oak. Poison oak berries are white and waxy colored.
3. Skunkbush Sumac
Scientific name: Rhus trilobata
Skunkbush sumac and its close relative fragrant sumac are more similar to each other than either is to poison oak. However, skunkbush sumac is on this list because of their coloration and growing pattern.
Leaves on a skunkbush sumac grow in groups of three. They are also lobed similarly to oak trees.
You can tell skunkbush sumac apart from poison oak by looking at its fruit. Sumac berries are red and covered in downy hairs. They strike a dramatic color difference in comparison with poison oak, which has white berries.
4. Box elder
Scientific name: Acer negundo
The box elder is a fast-growing hardwood tree. It is most common in the Great Plains and Eastern regions of the United States.
Because the habitats for poison oak and the box elder have minimal overlap, it is less common to confuse the plants for each other. However, they have enough similarities that it is useful to be able to tell the differences between plants.
Box elders are small ornamental maple trees that have compound leaves. Their leaves can be in groups of 3, 5, or 7 leaflets. The leaflet edges are toothed, not smooth. Look for different numbers of leaflets when trying to tell it apart from poison oak.
Autumn shows off the differences between box elder and poison oak. Box elders spread seeds via samaras, wind-borne seed pods that twirl like tiny helicopters as they fall. Poison oak grows small white berries.
5. Poison Ivy
Scientific name: Toxicodendron radicans
You might be surprised to see poison ivy on a list of plants that look like poison oak. It’s here for good reason. Poison ivy is a climbing vine.
When it’s young, it creeps across the ground in search of optimal tree trunks and surfaces to climb. It is easily mistaken for poison oak at this age.
Unlike the innocuous mimics of poison oak, poison ivy is dangerous in its own right. It contains the same inflammatory resin that poison oak does.
Its range isn’t limited to within a few feet of the ground, either. Keep your eye out for this irritating mimic.
6. Climbing Hydrangea
Scientific name: Decumaria barbara
Climbing hydrangea’s natural growing habit is to climb as a vine, while poison oak almost always grows as a shrub. Despite the disparity of growth forms, the climbing hydrangea vine can look similar enough to poison oak that it alarms people. If there aren’t vertical surfaces to grow up, climbing hydrangea will grow on the ground.
Look closely at the vine to tell it apart from poison oak. Poison oak leaves are usually shaped like oak leaves, not heart-shaped like climbing hydrangea leaves.
The edges are highly toothed, not smoothed. They are also matte, while most poison oak leaves have a shine to them.
7. Blackberry Bush
Scientific name: Rubus spp.
Blackberries are a popular and delicious fruit. Did you know that their parent plant can be confused with poison oak?
It’s usually a glance from far away that leads to people mistaking blackberry bushes as poison oak. The presence of berries, thorns, and five leaves signifies that the plant is a blackberry bush.
If you’re still not sure, look at the leaf’s edge. Blackberry bush leaves have jagged edges. Poison oak leaf edges are smooth.
You’ll still need to take precautions if you are rambling through a blackberry thicket. Poison oak and poison ivy are known to grow amid the tangled stems of blackberry bushes. Add in the sharp thorns on blackberry vines and you’ve got a recipe for a very itchy hike!