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Western poison oak in flower. The scalloped leaflets usually have no sharp points. Flower clusters hang down. only female plants will continue on to produce fruit. Male flowers are needed for pollination only. photo: Sandra J. Baker

As spring progresses, the bronze color changes to green in the new leaves. photo: Sandra J. Baker

In this western poison oak photo, these two mature leaves are from one plant. (One botanical leaf consists of 3 leaflets). I am not allergic any more, but I always sccrub my hands with dry dirt (clay) after touching the plant just in case. If you are allergic, don't touch the plants on purpose. photo: Sandra J. Baker

Since it lives in swampy areas, folks are not as likely to come across poison sumac. The leaflets are said to resemble rabbit ears. What looks like a stem with 9 leaves on it is actually one leaf. The midrib is always red, as seen in the photo to the right.

Eastern poison ivy (Toxicodendron radicans). The leaflets of eastern poison ivy have sharper tips than those of most western and eastern poison oak plants. This is a young vine with few aerial roots. (the roots that hold the plant to the post or tree). With no climbing support like the tree, this plant would grow as a shrub. photo: John Paine

This mature eastern poison ivy vine has more aerial roots than the younger vine on the left. Old poison ivy trunks are sometimes so covered with aerial roots, they resemble old frayed roots. photo: Judy Feller

Western poison oak has sparse aerial roots when compared to those of eastern poison ivy. It grows way up into the crown of huge trees by nestling into cracks in the bark here and there. photo: Sandra J. Baker

In the spring and summer this bush looks alive. When the western poison oak leaves turn red in the fall, we realize it is using a dead bush as a support system.

The color of the leaves can be bright or just a dull yellow or tan. Amounts of sun and water can affect fall leaf color. photo: Sandra J. Baker

This is a good example of how various plants can become jumbled together. You might be unaware that poison ivy is right in front of you. Did you notice the poison ivy leaf (consisting of three leaflets) near the bottom left corner?

The middle leaflet, hanging down toward the corner has a longer leaflet stem than the side leaflets. This is one of the identifying clues. photo: permission by

The branch in the foreground is a great example of how a western poison oak or eastern poison ivy branch, without support, will reach toward the sun. The upward curve at the end of the branch is a dead giveway.

Also, notice how simple the growth is—one branch, short side shoots. No masses of offshoots going here and there. photo: Sandtra J. Baker

Looking like a sumac, poison sumac (Toxicodendron vernix) is actually closely related to poison oak and poison ivy. It has the same allergenic oil, urishiol. Some folks insist the allergen in poison sumac is stronger than the other two, but there apparently have been no clinical studies on the subject of which is the stronger of the three, except for a casual test by a researcher who rubbed the bruised leaves on volunteers. No differences were seen. photo: Ted Bodner. Plants database/James H. Miller and Karl V. Miller. 2005. Forest Plants of the Southeast and Their Wildlife Uses.

The fruit of poison oak, ivy and poison sumac (called drupes) are small and about the size of a pea. When young, the skin is smooth with a green tint. At maturity, the outer skin falls off. As you can see above, the fruit resembles tiny peeled oranges. photo: Sandra J. Baker

Poison oak & Poison Ivy

Identification System

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Western poison oak (Toxicodendron diversiloba). In spring, emerging leaflets are reddish bronze. The three leaflets clumped together are botanically one leaf. photo:Sandra J. Baker

These red growths on the eastern poison ivy leaf are galls. Gall mites have laid eggs in the plant tissue. photo: Sandra J. Baker

This western poison oak leaflet (they are not always lobed) shows the distinctive veining that poison oak and poison ivy have. See the mid vein? The smaller veins going off to the side are alternating, instead of being directly across from each other. photo: Sandra J. Baker

This eastern poison ivy is growing among cactus. It is impossible to remove without digging everything up. The roots are  that sgrow laterally just under the soil. Leave a little bit, and it keeps growing. photo: John Paine

Western poison oak easily climbs a redwood tree and disappears into the canopy. Allergenic resin leaking from a bark wound soon hardens pitch black. With sun exposure, it might turn a chalky grey over time. photo: Sandra J. Baker

This powerful allergenic oil in the resin of poison oak/ivy and poison sumac is almost identical to that in the Japanese Lacquer tree, Toxicodendron vernicifluum. The famous lacquerware of Japan, China and Korea is created with this oil that's part of the resin that flows out of the trees. It creates one of the strongest membranes known when painted on objects. Its only failing is that the sun degrades it.

There is a slight difference in the allergenic oil of poison oak and poison ivy that keeps it from having the strength of the Asian plants. photo: Sandra J. Baker

This beautiful eastern poison ivy vine is obviously loved and pruned as it hugs a garden shed. photo: Judy Feller

Western poison oak grows up a pine tree by creeping under pieces of bark. Note the golden tree resin on the left. Poison oak/ivy/sumac resin turns pitch black upon exposure to air. photo: Sandra J. Baker

The leafless branch hanging over the path is a western poison oak plant in wintertime.

This is very typical for these plants, because they are always leaning toward the sunnier areas in paths. An unsuspecting hiker is likely to face-plant into this branch. I have an unconscious warning system that stopped me two inches short of this branch. photo: Sandra J. Baker

Toxicodendron rydbgerii. Western poison ivy. Once considered a subspecies of eastern poison ivy, T. rydbergii now has a spot as a separate species, although some botanists disagree.

This plant is a shrub, not a vine, and leaflets fold up like butterfly wings. photo: Sandra J. Baker

Eastern Poison oak is sometimes called atlantic poison oak. (Toxicodendron pubescens). With the classic "oak leaf" shaped leaflets, this plant is not as prevalent as eastern poison ivy. The short scrubby shrub lives in sandy soil. It prefers oaks and pine barrens.

photos of poison oak, poison ivy & poison sumac

the pictures will help you identify the plants,

but follow the identification system described below to know for sure