Wednesday, July 7, 2010

Adirondack Outdoor Hazards: Poison Ivy

Lately I’ve been enjoying a close, personal relationship with a plant we all know by reputation if not from direct experience. It is the plant version of the skunk – the name alone conjures reactions that may or may not be deserved. It is reviled and feared. And yet, it fills a vital link in the ecosystems around us. Today, I give you poison ivy, Toxicodenron radicans.

Even if they’ve never seen it, children can describe poison ivy: it has three red leaves! As we all know, reputations, while usually founded on some morsel of truth, often become wildly exaggerated and the truth left behind in the dust. So, let’s start off on the right foot with a correct description of this plant.

First, its leaves are composed of three leaflets. A leaflet can look like a full-fledged leaf to the untrained eye. The key is that a leaf has a stem (petiole) that attaches directly to the twig of the tree/shrub/plant. Think of your fingers. Together they make up a hand, but you wouldn’t call each finger a hand, would you?

When these leaflets first emerge, they might have a reddish tinge to them, and in the fall they can turn red, too. But to claim that year-round they are red would be misleading. Look for green, for this is the dominant color. You also want to look for teeth (jagged edges). And bilateral symmetry. Bilateral what? Bilateral symmetry means that if you were to hold a poison ivy leaf (with its three leaflets all intact) in front of you, with the center leaflet pointing upwards, you could fold it right in half, down the middle of that middle leaflet, so that the left leaflet lies right on top of the right leaflet, and it would match up almost perfectly. The left side is a mirror image of the right side.

Poison ivy is a native plant. It likes wooded understories, but also does well in rocky, disturbed areas. This is not a plant that seems to be too choosy about where it puts down roots. Sometimes it grows as a dense ground cover. Other times it grows as a vine, using hairy rootlets to attach itself a tree or fence post. Where it becomes established, it can be difficult to eradicate.

In the spring, PI blossoms right along with other early bloomers. Its flowers are white, grow in clusters, and are probably missed by most passersby since they are neither large nor showy. As summer progresses, the flowers that were successfully fertilized become white berries, which are an important food source, especially in winter, for lots of wildlife, namely birds.

And here is where the men are separated from the boys. Or the wildlife from the humans. Y’see, most wildlife, be they birds or mammals, are immune to the effects of urushiol, the oil that is the cause of all the problems we associate with this plant.

Urushiol can be dreadful stuff if you are allergic to it, and most of us have some level of sensitivity. All parts of the plant (the leaves, stem, flowers, fruit, bark, roots) contain this oil. Sometimes just brushing against the plant is enough contact to cause distress, while other times one needs to really crush it to get a reaction. I don’t recommend the latter.

I always prided myself on not being sensitive to PI, but I also kept in mind that this could be simply because I know what the plant looks like and have done well to avoid contact. Until recently.

Some of my readers may recall that about three weeks ago I was down at the Ice Meadows and simply had to try and photograph the flowering partridge berries. They were, of course, nestled down below a robust growth of PI. Throwing caution to the wind, I lay down on the very narrow herdpath and snapped away with the camera. I never got a good shot of the flowers, but about a week later the itching began.

At first I thought it was a bug bite – I’d been gardening and the ants have been known to crawl up my pant legs and nip away. A few days later, the “bite” had turned into three or four bites, and they really were beginning to itch. Then the area was the size of a quarter. By the time it became palm-sized, I was beginning to think “um, these aren’t ant bites…I think I have poison ivy.”

Sure enough, the local medical staff confirmed that I had a healthy rash going on my leg. Calamine lotion wasn’t helping much, so I invested in an industrial strength version, and started taking Prednisone and Benedryl. Another week has passed and I think the worst is over, although random individual blisters are appearing in other locations.

Here are some PI facts:

• Urushiol is water resistant. In other words, it doesn’t just rinse away. Soap and water, these are important. Wash well as soon as you come into contact. Get that stuff off as fast as you can.

• Once you have removed the oil, it cannot spread.

• The blisters, when they form, are filled with your own body’s fluids – not more urushiol. If
they burst or ooze, the liquid is not going to spread the rash.

• If the rash seems to be spreading, there are a couple rational explanations. One, you are getting more of the oil on you from a source (like your pants, or boots, or the dog, or the furniture you sat on while wearing your contaminated clothes). Two, the newer eruptions are occurring on parts of your skin that are either less sensitive or received a smaller dose of the oil and simply took longer to react.

• The oil can linger for years. I read on one website that people got reactions from contaminated artifacts that had been in a museum for over a hundred years.

When I teach people to go out and enjoy the outdoors, one of the things that I cover right up front is “know your local hazards.” This may seem like common sense, but as a society we have become so disassociated from the outdoors that we often need these reminders. The “wild” can be dangerous, but if you know what to look for, it is no more dangerous than your basement. Hazards can be cliffs, raging waters, nests of bees. They can also be the weather, plants and animals. Learn to identify what’s in your neighborhood, and you won’t have to worry so much about unplanned encounters.

That said, wild clematis and box elder are often confused with poison ivy. These are harmless native plants that grow around much of the Adirondack Park. Knowing how to tell them apart from PI is useful. If in doubt, however, treat the unknown as unfriendly and don’t risk unnecessary contact. Better safe than sorry, eh?

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Ellen Rathbone

Ellen Rathbone is by her own admission a "certified nature nut." She began contributing to the Adirondack Almanack while living in Newcomb, when she was an environmental educator for the Adirondack Park Agency's Visitor Interpretive Centers for nearly ten years.

Ellen graduated from SUNY ESF in 1988 with a BS in forestry and biology and has worked as a naturalist in New York, New Jersey, and Vermont.

In 2010 her work took her to Michigan, where she currently resides and serves as Education Director of the Dahlem Conservancy just outside Jackson, Michigan.

She also writes her own blog about her Michigan adventures.



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