You have to give poison ivy points for autumn color…but better not give Miss Ivy a congratulatory pat for donning such a dazzling red dress. If you do, she'll likely respond by thanking you with an itchy, blistering rash. Photo taking is perfectly safe, however, so long as you keep your hands off the leaves and don't brush against the plant with your clothing—which could pick up some of the chemical irritant and later get transferred to your skin.
It doesn't take much.
The problematic substance is an oily resin called urushiol. Something like 90% of the population is susceptible to the stuff, through their reactions vary—from so mild as to be scarcely felt or noticed, to scary-awful, possibly requiring hospitalization. For most folks it's usually just a patch of itchy red rash, maybe a few blisters, which torments for a couple of weeks. However, urushiol is so potent that only a few molecules of the toxic oil will do you in—a mere quarter-once would be sufficient to cause an allergic skin reaction in every human on earth!
I'm not much bothered by poison ivy. I've regularly waded through half-acre patches—it's prevalent along streams and the edges of fields and woods—and now and then will react with a dime-sized itchy rash. But as is the case with most allergic reactions, personal sensitivity can change dramatically—so I may not always remain immune.
Here in this corner of Ohio we have three urushiol-laden plants—poison ivy, poison oak, and poison sumac. The latter is pretty much restricted to bogs, swamps, marshes, and fens and most people never come close to exposure…a good thing, since the urushiol in poison sumac is said to be far more potent than in either poison ivy or poison oak.
Like most outdoorsy kids, I learned to recognize the distinctive leaf patterns early on, and just pay attention (sorta) when rambling afield. I made the photo above yesterday when, after finishing grocery shopping, I decided to take the roundabout way home and see how autumn was coming along away from the riverbank. I saw the scarlet clump blazing along a fence.
It's practically impossible to resist a pretty lass in a red dress!