Many times I‘ve amused young people by showing them how to identify poison ivy and then thoughtlessly sticking my head under a batch of it growing out from a tree when I saw something interesting below. I do know my poison ivy! Part of my job is to keep kids safe on nature walks, and they always get a poison ivy lesson when we find it.
Poison ivy is a native plant that grows extensively throughout Hampton Roads. Birds and other wildlife eat its berries and leaves. It has gotten a bad rap. It is not an evil people-poisoning plant–it‘s just trying to keep predators off and spread its seeds, like most other plants.
Poison ivy can be identified with the help of the old saying, ―Leaves of three, let them be. Look for three leaflets at the end of a leaf stalk, with the leaflet at the top of the ―triangle having a longer stem than the two on the sides, and the ―side leaflets having about a 45- to 90-degree angle. The leaves will be entire or slightly lobed, somewhat like the pattern your fingers make when you hold them tightly together. Other plants have ―leaves of three, but they have toothed edges or have different angles. Another clue is clusters of berries that change from green to white to slightly tan with time. Its flowers are tiny, greenish-white, and five-petaled.
Poison ivy can be suspected when you see plants that have similar habitat requirements—edge environments with partial sun combined with higher places like fences or trees where birds and other animals rest. Among the plants that call for a poison-ivy alert are greenbriar, honeysuckle, Virginia creeper, trumpet vine, wild blackberry, and English ivy. When you see them, you should sharpen your eyes for those leaves of three. And although it seems to prefer partial sun, it also seems like any little patch of sunlight will do, so I have seen it in the forest. But I have rarely seen it in full sun or deep shade.
Remember to look in four different ―altitudes – ankle-high plant-lets that are easy to miss until you‘re in the middle of them, stereo-typical ―hairy vines growing up trees, fences, and other platforms, shrubby patches that look like average everyday bushes, and branches that stick out from trees and masquerade as innocent tree branches. All four are poison ivy, and all four can affect you.
Poison ivy is something of an exaggerated name. The plant DOES cause an allergic reaction in most people, but a significant proportion of people (around 15 percent) have no reaction at all to it. The people who do react to it can have symptoms ranging from a few bumps that look like mosquito bites but are clustered in one area to a serious rash that can be painful and seep. Poison ivy causes an itch like no other allergen—persistent and maddening.
The allergenic part of poison ivy is an oil on its leaves and stems called urushiol. This oil is a ―persistent oil, meaning it is some-what sticky and clings to skin, clothing, pets, and solid objects upon contact.
Poison ivy does not ―spread by itself, like some diseases do. You can‘t ―catch it by walking past it. Poison ivy affects only the area that the oil comes into contact with. People DO spread the oil by touching the affected area while it still has the urushiol and then touching themselves elsewhere. The one time that it will seem like you ―caught it will be if you burn poison ivy along with other brush – then you get the full treatment inside and out! And for the highly allergic, poison-ivy-laden smoke inhalation will send you to the hospital.
The poison ivy oil does not cause an allergic reaction for 12 to 24 hours. If someone who comes into contact with it washes it off
within a few hours, most likely they will have no reaction at all. Most experts recommend removal within 30 minutes just to be safe.
People who come into contact with poison ivy should wash the affected area as soon as possible with soap and lukewarm water. Any clothing, shoes, tools, sporting equipment, or other implements that come into contact with poison ivy should also be washed off with soap and warm water or with rubbing alcohol or another solvent. Pets exposed to poison ivy should also be washed, since they can spread the oil to you! Persistent relapses of poison ivy rash may be due to contact with objects, clothing, or pets that have the oil from previous exposure.
If a rash develops from contact, any topical antihistamine should be effective in relieving symptoms in light cases. Benedryl and Caladryl are two readily available brand name topical antihistamines. Severe reactions require a doctor‘s care.
Once a person develops the poison ivy rash, it is NOT contagious to other people. By the time the rash develops, the oil is gone. The fluid from blisters that may develop is basically blood serum, and does not contain the oil.
Susceptibility to urushiol can change over time—sometimes people who seemingly ―never get it can develop a rash after exposure. So it is always best to be safe and avoid exposure when possible.
I like poison ivy. It is beautiful year-round, from its stark wintry lines and berries hulls to its brilliant autumn foliage. You have to admire something that is so successful and so beautiful, even if you have to be wary of it.
By the way, I read in Science News in the not-too-distant past that increasing levels of atmospheric carbon dioxide are benefiting poison ivy by encouraging its growth, thus guaranteeing that more of us will become acquainted with it as time goes by!
The information for this article was gleaned from personal experience and observation, numerous books, and countless internet re-sources.
- Debbie Blanton