Across the road fro our home are two trees that bear fruit this time of year. Shown above, you might recognize a black walnut. The green outer casing rots way, revealing the walnut inside. I like walnuts, but even with a source near by, I prefer to buy them. The rotted casing stains your hands and is difficult to wash away.
You are forgiven if you don't recognize this one. Say hello to a hedgeapple. In my home, we call them brain fruit. They are also called osage oranges (go figure, they are all green). In Arkansas or Texas, they are also called horse apples though, to be honest I think of horse apples as something else entirely.
As far as I know, hedgeapples have no real purpose other than as an insect repellent. They are not poisonous or toxic, but are said to taste terrible. If I ever come a cross a recipe for hedgeapple pie, I'll be sure to share it with you.