Ask Mr. Smarty Plants

We will certainly give you lists of poisonous plants from several resources. Mostly, of course, the Lady Bird Johnson Wildflower deals only with plants native not only to North America but to the area in which the plant is growing. Non-native plants do slip into gardens or are deliberately planted there, but even those would be listed on the websites we will give you.

However, we are not so sure that a plant is the cause of your problem. Those spots sound more like spider bites. We are neither doctors nor entomologists (scientific study of insects) nor arachnologists (spiders), but we do have experience. This particular member of the Mr. Smarty Plants Team has had lots of close personal contacts with things to which there is a reaction in humans. The venom of a mosquito bite, bee, etc. causes hives all over my body. Poison ivy is practically a hospital matter. But swollen, feverish spots don't even sound like insects, but spiders. We could be very wrong, and spiders, of course, aren't even insects but arachnids, more usually found in dark corners than out in the garden. Since, as we said, this is not our specialty, we are going to find some websites that might help you in your own diagnosis.

WebMD Insect Bites and Stings and Spider Bites

Mayo Clinic Spider Bites: First Aid

Now, on to links with sites listing poisonous plants in North America:

And, finally, Mr. Smarty Plants advice (and remember our disclaimers, above):

In a rephrasing of an old football coach's advice - a good defense is the best offense. No matter which thing is causing your problems, you want it to stop. Begin by covering up any skin that might come in contact with plant or animal. This includes closed shoes, long socks, long pants, long sleeves and gloves, preferably leather gloves. Okay, okay, we know that's all hot, but at least you are in Michigan. You ought to hear the comments we get when we recommend that in Texas! Or maybe, no, you shouldn't. Anyway, eliminate contact of your skin with whatever it is. You should probably launder whatever you have been wearing immediately, lest some beasties be laying low in the folds or cuffs. In your suit of armor, examine the areas where you work, look for nests (ants? bees?), spider webs (they like insects, too), or even a stray plant you hadn't noticed before. Anything suspect should be pulled out and disposed of in a plastic garbage bag. If you suspect spiders, never mind spraying-they are arachnids and are not harmed by insect sprays.

You know at about what height to look, because of the location of the spots on your legs. You could consider thinning out some of the plants you have been going through, checking for bugs and spiders as you go. Not being exposed is a whole lot easier and cheaper than the treatment after the fact.