On a recent backpacking trip in S/E MI, I set up my tarp and spent the night in a field of what I now believe to be Poison Ivy. You can see it growing all around my tarp here, and next to my ground cloth (I also placed the ground cloth directly on some). I must also admit that I "yanked some out" of the ground. Fortunately, my system is not that sensative to this stuff, but my ring fniger has blistered to the point of not being able to wear a ring, and I have random "rash" spots over my body.