I live in Bucks County Pa, (Zone 6a), and this stuff is all over the hill in my back yard. A day ago, I was pulling vines out of me beds and got a nasty rash on the underside of my forearms. I pulled littel versions of these along with some vines. The vine leaflets don't have the "notch" that poison ivy has and they are longer, like trumpet vines, and are not waxy. So, I think sumac is the culprit. However, these stems are hairy, indicative of non-urushional varitey. True? And what about the vines I see?

SumacPatch.JPG