Oak and Poison Oak in Photos: Can You Tell the Difference?
Oaks and Poison Oaks Are Often Found Together
Oak and Poison Oak are Friends
As in the case of the tree in the photo above, you will very often find them together. On the tree above, it's fairly easy to tell what part is oak and which part is poison oak. But it's not always that easy. If you live in North San Luis Obispo County, where all these pictures were taken, you need to know the many habitats poison oak will choose and the many forms it takes. But it looks and behaves much the same way anywhere in the West.
Comparing Baby Poison Oak and White Oak Plants
Poison Oak Flower and Berries
The Many Forms of Poison Oak Through the Seasons
Poison oak is a great survivor, and it spreads rapidly. It is planted by birds who eat its berries. It then spreads through its roots, which creep along the ground and grow new stems. For this reason, young plants are often found near trees where the birds have dropped the seeds. I've found it under nut and fruit trees, as well as in oak forests. If it's in an area and producing berries, the birds will eat the berries and drop the seeds.
The young plants sprout and old ones spread and leaf out in the early spring and may have new leaves which are tinged with red. Later in the spring, they will turn dark green, and female plants will produce clusters of white flowers, which will then turn into white or yellowish berries by summer or fall. The birds then eat the berries and continue to spread the seeds in their droppings. In the fall, the leaves turn a bright red as they prepare to leave the plant. In winter, the bare stems will stand up or stay wherever they were. Sometimes in a dry summer, the leaves will turn red earlier because there's not enough water to support them.
Although the above is supposed to help you identify the plant through the seasons, take it with a grain of salt. Most of the pictures you see here were taken in the last week of October unless otherwise noted. You will see that some are new leaves, some are bright green, some are deep green, and some are turning red. Some have flowers and no berries, and others have berries.
I found most of my specimens with berries in the plant in the large picture at the top where it lives at the base of the large oak. I discovered flowers on one poison oak plant at home a couple of weeks ago, and only today did I see them turning into little reddish berries, which I assume will turn pale white or yellow. You will see them in the videos. Most of the plants I'm seeing now have neither flowers nor berries.
As far as identification goes, the old adage, "Leaves of Three, Let it Be," is probably the safest course. Poison oak leaves are divided into three leaflets on the same stem. But some wild berries are, too. Poison oak leaves will be shiny, though, whereas berry leaves won't be.
Also, poison oak has a smooth stem, and a wild berry will have thorny stems. If you are in doubt, don't take chances, since touching poison oak, which has a resin on all its plant parts, will cause dermatitis in most people that can be very unpleasant. Since the two plants often grow near each other, be careful about picking berries unless you're sure you can do it without touching any poison oak.
It's much easier to tell the difference between oak leaves and poison oak. Live oaks only have a single simple leaf on each stem. They will be dark green and will sometimes have a holly-like edge. They stay on the trees all year and are evergreen. But the deciduous white oaks found throughout the West, and other deciduous oaks, have lobed leaves that might seem similar to poison oak.
Each oak leaf has its own stem, whereas the threefold leaf of poison oak has a single stem. It's one leaf that looks like three. In the videos, I will show you two white oak babies and then some poison oak babies. I think you will find it easy to tell the difference. I also have examples in the pictures above.
If in spite of your best efforts you cannot avoid getting poison oak (your dog brings it home, you fall into a clump of it, etc.), you might try one of the products below. I'm thinking I should get something to have here just in case since as you see, I am surrounded by the plant, and I'm always afraid I might step on some leaves that have blown into a trail, thus getting it on my shoe.
Beautiful Poison OakClick thumbnail to view full-size
Experience Is the Best Teacher
Although I have lots of poison oak pictures, it's easier to show you poison oak in the field in its many forms. Most books I have only show you the leaves of three, and maybe a plant in bloom or with berries. You might see a young plant or a plant in fall with flaming leaves. But the weather in your region will largely determine how poison oak will appear in any given season.
I live in a mild climate where the primary crop is grapes. It's very often hot and always dry in the summer months. Even today on Halloween, my tomatoes are still blooming and ripening fruit. Farther north and closer to the coast poison oak might match the field guide descriptions much better than it does here. In my videos, I will attempt to show you all four seasons in one piece of property in the same hour.
The more experience you have in seeing poison oak in its various forms and understanding where it likes to grow, the better you will get at identifying it. Different plants may have the same shape leaves, but the plants themselves may appear as mounds in the distance, short weeds if they are young, or large or small shrubs if they are older.
Sometimes parts of them might be confused with dead trees. If they are growing in a shaded forest, they may actually climb the trees, attaching to them with aerial roots, as in the top picture in this hub. The tree itself was so large it provided enough shade without other trees to enable the plant to climb.
To the right you see shots I took on a walk October 15 on Oak View Road in Templeton, a more recent walk than one I wrote about in an earlier hub. There were some lovely fall displays of poison oak we don't see earlier in the year. The top photo shows flaming poison oak climbing up this oak in search of sun. Below it, we see a plant that can't make up its mind what color its leaves should be, as some are yellow and some are red. Or perhaps its more than one plant, since they like to live close together. There is coyote plant in bloom to the right of it and in back, some green leaves on the top left, and maybe we should also be careful about getting to close to those dead looking mossy branches to the lower left and underneath.
The other pictures in this group are pretty well explained in their captions. One plant is "iffy" but very suspicious from a distance. Another shows how poison oak can dominate the roadside, climbing up the trees as well as out toward the road. And watch those leaves on the ground. It's really easy for those falling poison oak leaves to get mixed with the leaves falling from those tall white oaks they are climbing on. And you don't want to step on them, do you?
In the three short videos below, I will walk you around parts of my property where we don't normally walk and where poison oak grows. I will show you enough poison oak up close and even in the distance, to give you enough experience to spot it anywhere near enough to see. Please forgive my shadow. I was too excited with what I was doing to pay attention to it all the time, and at other times if I had changed my position, it would have gotten me too close to poison oak for comfort.
I hope the videos will show you every form of poison oak up close and personal, so you can easily stay away from it. All parts of the poison oak—leaves, stems, roots, berries—have the urushiol oil that will come off on you, your clothes, and your shoes if you get too close. It is my belief that I will treat as fact until I know differently, that even the parts that appear dead are dangerous. So, learn to recognize it and stay safe.
Poison oak is, indeed, beautiful in its scarlet autumn splendor, but please stick to maple, grape or sycamore to color your Thanksgiving centerpiece.
Learning to Recognize Poison Oak Part 1
Poison Oak ID: Flowers and Berries
Poison Oak Field Trip: Conclusion
The Most Dangerous Form of Poison Oak
The most dangerous form of poison oak is that which is most likely not to be recognized—those plants which have few or no leaves showing. You are most likely to encounter these in winter or in early spring before the plants grow their new leaves, but as I showed you in the videos, the dead branches, or those that appear to be dead, that appear under or through the leafy stems, can be present at any time of year. In the videos, you saw some of them even covered with moss and lichens, yet they can still contain urushiol oil and give you a rash.
The pictures below show you some of the disguises you may encounter and not recognize. In the first picture taken in mid-April on a trail near the Salinas River, the bare stems actually stick out into the trail, making it easy for shoes or clothing or bare legs to make contact. At this time of year, many of the trails have not yet been cleaned up and can be dangerous if you don't keep a careful eye out for these bare stems and branches. Even the experienced outdoorsman in the video I have linked to above was fooled by the bare branches.
The man in that video said to watch out for the bare stems standing erect. But as you can see in my examples, they can also be bent down or almost parallel to the ground. So in the leafless months, you need to be especially careful of any bare branches of vines hanging from trees or tangled up in each other, or sticking up or out if they are in a place where poison oak might like to grow. In my county, it grows at the side of trails and roads that have a lot of trees nearby, especially oak trees. In the last example to the right, the oak leaves on the ground almost hide the small poison oak plants growing among them in the middle of February. If you see bare stems in clumps or coming from clumps, it's a danger zone, especially if there are oak trees anywhere near.
I hope you have enjoyed this trek through the various poison oak habitats in videos and photographs and that you are now wise in all the ways of poison oak. Now go and enjoy the outdoors, but if you see those leaves of three, or those bare stems where they used to be, just back away and "leave them be."
The Most Dangerous Form of Poison OakClick thumbnail to view full-size
Recognizing Poison Oak
Do you feel confident enough after reading this and seeing the visual information that you can recognize poison oak?
Links for More Information on Poison Oak
- Poison Ivy, Oak, and Sumac Rash Causes, Symptoms, Treatment and Prevention on eMedicineHealth.com
Read about the causes, symptoms, prevention and treatment of an allergic rash from poison ivy, oak and sumac. Get a poison ivy description to help you recognize and avoid the plant.
- Poison Oak - A Survival Guide - YouTube
This video is designed to help you avoid the toxic poison oak plant. In addition to teaching you avoidance, it will show you what to do to minimize the traum...
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2011 Barbara Radisavljevic