Learn What Poison Oak Looks Like

Poison oak can be challenging to identify, especially since it is similar to poison ivy and can appear in a few different forms. Learning what it looks like can help you avoid coming in contact with its toxic oil, urushiol, as up to 75 percent of the population is sensitive to this rash-causing substance.

Poison oak can be found in many areas of the United States. Pacific poison oak grows in western states like California and Washington, and Atlantic poison oak can be found in the south and east, from Texas to Florida and north to Illinois and Missouri.

Whether you like to spend time in your yard or local park, frequently hike trails through fields and forests, enjoy sitting by streams, or lose hours watching animals in wetlands, these pictures can help you identify—and stay away from—any poison oak in the area.

1

Leaves of Three, Let It Be

Poison oak growing on street corner in Pacific Grove, California

Wendy Bumgardner

Research reveals that poison oak "generally" appears in a pattern of three leaflets branching from a single, independent stem. This suggests that more leaves may be present and still be poison oak, though this is typically not the case.

When in a three-leaf formation, two leaves are attached directly to the stalk opposite each other. The third juts out from them at a right angle, forming a triangle. There are no additional leaves on the same stalk.

The leaves may be serrated, round, or oak-like depending on what other foliage is around the poison oak plants. They may be shiny—or not. They may have a red tinge—or not. This is where the challenge of identifying these plants comes into play.

Additionally, the plant itself may be seen as single stalks close to the ground with three leaves. Or a bush. Or a vine climbing a tree. You can see poison oak plants growing in all of these ways within a few feet of each other.

This photo is an example of poison oak growing profusely, almost as a hedge. You might think it was just another shrub as you passed by it at the street corner. This poison oak has rounded leaves rather than oak-shaped leaves, so you might not immediately think it is poison oak.

2

Oak-Shaped Leaves on Poison Oak

Oak-Shaped Leaves on Poison Oak

Wendy Bumgardner

This poison oak plant shows oak-shaped leaves. You can tell it apart from non-poisonous oak in that the leaves are smaller than those found on the tree and look more like a vine.

Plus, these leaves are in the characteristic pattern for poison oak, which is groups of three. It should be noted again that while this three-leaf pattern is most often the case, this is not an absolute as many agencies indicate that three leaves is the "usual" pattern.

Some agricultural programs report that poison oak can sometimes appear with patterns of five leaflets, though this is not typical. Others report that they can have seven leaves or more.

3

Round Leaves on Poison Oak

Poison Oak with Rounded Leaves

Wendy Bumgardner

The round-shaped leaves on this poison oak plant can imitate those of the nearby trees. But note that it has the distinctive leaves-of-three pattern.

The actual shape of poison oak's leaves change based on the environment it is growing in, with the lobes able to vary on the same plant. Though, typically, round leaves are more common in Pacific poison oak plants.

4

Shiny Poison Oak Leaves

Poison Oak - Leaves of Three

Wendy Bumgardner

Poison oak may look oily and shiny due to the toxic oil urushiol that can give you the rash when it contacts your skin. But the leaves don't have to look shiny. They can still give you a dose of oil if they have a dull appearance.

The good news is that poison oak isn't contagious, except when spread by the oil remaining on your garments, gear, or skin.

5

Poison Oak Flowers and Berries

Poison Oak in Bloom

Wendy Bumgardner

Poison oak plants can also grow clusters of berries that are white or greenish-yellow, like pictured above. Some also have small white or greenish-white flowers that are roughly 1/4 inch in size.

6

Red Poison Oak Leaves in Autumn

Red Poison Oak in Autumn

Wendy Bumgardner

Poison oak leaves may turn a brilliant red in autumn as the bush dies back. This makes it easier to identify since it doesn't blend in to surrounding foliage as well. However, it still contains urushiol even this late in the year.

7

Poison Oak Is an Imitator

Poison Oak Imitates Nearby Leaves

Wendy Bumgardner

In this picture, you see poison oak leaves that have taken on the round shape of the bush next to it. Yet, one way they are usually different is that they have a hairy underside. The presence of flowers or berries can also differentiate poison oak from another plant.

8

Poison Oak and Blackberry Vines

Poison Oak with Blackberry Vine

Wendy Bumgardner

Blackberry vines may appear to have only three leaves but usually have five. A key point is that wild blackberry vines develop thorns.

Poison oak will only have three leaves on a stem, and the stem will not have any thorns. If it is growing next to blackberries, the shape of the leaves will imitate blackberry.

Poison oak is on the left and blackberry is on the right. Look closely at the stem for thorns on the blackberry vines. Also note that blackberry leaves are serrated, with jagged edges for each small vein. Poison oak leaves may be notched but they are not serrated like a saw.

9

Maple Leaves

Maple Leaves - Not Poison Oak

Wendy Bumgardner

These are maple leaves. They are not poison oak. Poison oak does have three lobes, much like maple leaves, but maple leaves don't grow on vines like poison oak. Poison oak spreads via underground stems and seeds.

10

Oak Leaves

Oak - Not Poison Oak

Wendy Bumgardner

These oak-like leaves are probably not poison oak. This is because they are in groups of five leaves rather than a triangle of three leaves. Plus, it looks like the leaves are coming from a small tree trunk versus from a shrub or vine. The fact that they look alike makes it extra confusing.

11

Oregon Grape Leaves

Red Oregon Grape - Not Poison Oak

Wendy Bumgardner

This is Oregon's state flower, the Oregon grape, Mahonia aquifolium. It's shiny, but the leaf pattern is all wrong for it to be poison oak. It has more than three leaves per stalk. Some people identify poison oak by its red color in autumn. But here, Oregon grape is imitating red poison oak.

12

Poison Oak Close-Up

Poison Oak
Ed Reschke/Creative RF/Getty Images

Just looking at poison oak won't give you a rash, but if you touch it or are exposed to the smoke if it burns, its toxic oils can be transmitted to your skin or lungs.

Between 80 percent and 90 percent of adults will get a rash after touching less than one grain of table salt worth of urushiol in poison oak. And if this allergen is inhaled, it can irritate the lungs. The best prevention is to avoid contact with this plant completely.

Avoid Contact With Poison Oak

To avoid getting a poison oak rash, the first step is not coming into contact with the leaves. Wear long sleeves and long pants and wear impermeable gloves if you are going to be working around poison oak or hiking in an area with poison oak.

If You Are Exposed to Poison Oak

Wash as soon as possible with cool water and a degreasing soap (such as dishwashing soap) if you have had possible contact with poison oak. Be sure to wash under your fingernails. You may also rinse with rubbing alcohol or a specialized poison plant wash.

You need to thoroughly clean your clothing and gear before you wear or use it and you should use gloves when doing so. You may need to wash your dog or cat if your pet has tromped through the poison oak. You can use pet shampoo and cool water. Be sure to wear rubber gloves.

If you manage to get a rash, the next step is to learn how to treat it.

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Article Sources
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