I have battled this plant for years and just happened to catch it in Dave's new left side photo feature and recognized it. Glad to finally know what it really is. Never let it get started unless you want it for the rest of your life.

Thanks for the identification. This grows in my yard and my daughter's 'back 40' (really only one acre).
Now that I know the tubers are edible, I will eat faster hoping to get ahead of it.