Tincture of Green, your pharmacist should know what that is, mine was surprised when I asked for it, not many people know about this stuff he said. I know in 2 paddocks, along the hedgerow adjacent to the county road, its in there, you have to watch out for it when mowing, trimming and repairing fence, also in the winter, break that vine, and get it on you, don't matter what time of year it is.
One of the hired help whom I worked with about a year ago, I warned, he was using a string trimmer, and I completely warned him about the plants, people doubt you and learn harsh lessons, told him about the soap, in the cabinet in the rest room too. Awful rash, dermatitis as the medical world calls it.
Apparently, the Urushiol, which leaches from the plant when you break the stalk or leaves, gets on you, knowing you have been in it, this tincture of green soap can be used within a certain amount of time, to clean it off, before it clings on your skin, followed by the allergic reaction.
This year it will be potent, dry like it is, I can see trees wilting near me, not good.
I hate the stuff, last time I had it was in '04, did not know much about it then, look for that plant now before doing anything in a questionable area, that last one was nasty, left craters and scars for awhile, still cannot believe goats eat it.