Leaves of Three, Let Them Be

This is the rhyme about poison ivy. When I saw this new vine growing up a tree, I thought it may be poison oak or ivy. I'll be honest, I'm horrible at identifying either one. It may just be a vine and nothing very dangerous :) I always hear more about poison oak, but either one is a painful nuisance sometimes. I'm rather fortunate not to be highly allergic to it. (I'll knock on wood for that and hope I don't break out by morning) I've had one episode of it when I crawled under the magnolia tree to cut down weeds and must have sat in quite a lot of poison oak..(Like I said, I'm terrible at identifying it) I wound up at the doctor in a few days needing a bit of help in getting rid of it.

I'm not sure it's range worldwide, if it isn't in your neck of the woods, be glad. If you have it you know what it is and what it does.....

ps. if anyone can identify this, be sure and let me know :)