They're not "Tree of Heaven," which is another Chinese invasive import. Neither are they poisonous or cause any allergic reaction. What you see is Staghorn Sumac, a non-invasive shrub, native to the midwestern United States. It's an aggressive shrub, but not in any way invasive, and although it looks similar to the Tree of Heaven, [ sometimes referred to as "tree of hell" ] it's not related to it. It's a beautiful shrub in the fall [as you can see] and is easy to control if you keep an eye on it. The problem arises when it's left alone, it spreads out. Kinda like our bike collections. The name "Pink Lemonade" was derived from the use of this shrub's red berries to make a lemonade-like drink. I'll send you some small plants, and you'll thank me.