oh wow.
Good news! You
do have something different!
Bad news...what is it?
Ok. Lets start with what we know. The tuber looks
a lot like a potato. It has smooth skin, a large connecting root like structure (stolon) but is has these weird secondary fine root hairs coming off of them close to the stolon. It has a white inner flesh and a taste that was unimpressive.
Do you remember anything about the top part of the plant? Did it have square stems? did it smell minty? (Mints are notorious for their bad behavior).