Grows in the ditches in Iowa. Use to be fun to ride around with some cold brews and gravel travel collecting a big haul of it.
Kansas as well, ditches in certain areas would be full of it.
In my quest to learn more about it, I've read about that. Also grows along some rivers in spots up there. With it being hardy to zone 10, I don't know why it doesn't grow "in the wild" down here. My only guess is because most people down here have never tried growing it. I can understand that though because as a kid I hated Asparagus. We didn't have it often and the only way I ever saw it was from a can. Nasty green snot is all that is.