The story goes that when my aunt and uncle were kids, they got into an argument over whether or not a certain plant that they had stumbled upon in the woods was poison ivy or not. My aunt was so convinced that she was right and that it was not poison ivy that she pulled up some of the plant in question and began wiping the leaves on all of her exposed skin. Unfortunately, she was wrong and wound up spending a night or two in the hospital as she dealt with the blisters and itchy rash brought on by poison ivy.

While you might be part of the 15% of the population that has no allergic reaction to urushiol, the toxic oil or resin found in these plants, our philosophy is why take the chance. If you are going to be spending any time outdoors—and we hope that you are—it is important to be able to recognize (and hopefully avoid) the three main types of poisonous plants in the woods that contain urushiol: poison ivy, poison oak, and poison sumac.

Poison Ivy:

  • Leaves. Poison ivy has thin, often shiny, bright-green compound leaves. The edges of the leaves usually have large indentations at irregular intervals. The leaves occur in threes, with one leaf at the end of the stem, and two leaves opposite each other on the stem. Hence the popular saying, “leaves of three, leave it be.” The young leaves may be orange, and in the fall the leaves turn red.

  • Vine. The stem is woody and in its native territory, is the only native vine with aerial roots. Aerial roots are small roots that grow out of the stem and also help the vine to cling to a support. The aerial roots are commonly seen on older plants growing up or over non-soil supports (stones, trees, fences, etc.). They are often reddish. The aerial roots make the main stem appear hairy, hence the saying, “hairy rope, don’t be a dope.”

  • Flowers and berries. Depending on the time of year, poison ivy may have clusters of small, yellowish-green flowers (usually in June) or hard, greenish-white berries (fall). Deer and birds eat the berries, and excrete the seeds, causing new plants to sprout in new places.

Poison Oak:

  • The leaves of poison oak grow in clusters of three, like poison ivy, but each leaf is shaped somewhat like oak leaves.

  • Poison oak is usually more shrub-like than poison ivy and the undersides of the leaves are always a much lighter green than the surface and are covered with hair.

  • Poison oak is more common in the western U.S.

Poison Sumac:

  • Poison sumac grows as a woody shrub, with each stem containing 7 to 13 leaves arranged in pairs.

  • Poison sumac can be distinguished from harmless sumac by its drooping clusters of green berries. Harmless sumac has red, upright berry clusters.

  • Poison sumac is more common in wet, swampy areas.

Myth vs Fact

Here are a few myths and facts concerning poison ivy, poison oak, and poison sumac:

Myth Fact
Poison Ivy rash is contagious. Rubbing the rashes won’t spread poison ivy to other parts of your body (or to another person). You spread the rash only if urushiol oil—the sticky, resinlike substance that causes the rash—has been left on your hands.
You can catch poison ivy simply by being near the plants Direct contact is needed to release urusiol oil. Stay away from forest fires, direct burning, or anything else that can cause the oil to become airborne such as a lawnmower, trimmer, etc.
Leaves of three, let them be Not a bad rule to follow in the woods, but remember that poison sumac has 7 to 13 leaves on a branch.
Do not worry about dead plants Wrong. Urushiol oil stays active on any surface, including dead plants, for up to 5 years.
Breaking the blisters releases urushiol oil that can spread Not true. But your wounds can become infected and you may make the scarring worse. In very extreme cases, excessive fluid may need to be withdrawn by a doctor.
I’ve been in poison ivy many times and never broken out. I’m immune. Not necessarily true. Upwards of 90% of people are allergic to urushiol oil, it’s just a matter of time and exposure. The more times you are exposed to urushiol, the more likely it is that you will break out with an allergic rash. For the first time sufferer, it generally takes longer for the rash to show up—generally in 7 to 10 days.

Urushiol is derived from the Japanese word for lacquer, urushi. When the Japanese restored the gold leaf on the Golden Temple in Kyoto, they painted the urushiol lacquer on it to preserve and maintain the gold. Anyone caught trying to steal this gold leaf would have been literally caught “red-handed”.

So let’s hear your poison ivy, poison oak, and poison sumac stories…