What Is Poison Sumac?

Sumac has stems with rows of 7 to 13 smooth edged leaflets. It doesn't look anything like poison oak or poison ivy. The same kind of thing is going on from what I can tell it's like a mistaken response. To something that shouldn't give you a rash. That's why you see animals eating it like crazy and rolling around in it. Because they're not dumb humans with dumb immune systems. They're like this stuff really is no big deal.