Now that I think about it, my unknown fern was sitting by my front door during that nasty winter. Unprotected. The pot it was in was too heavy so it sat as far as I could carry it when I got it. In the spring I threw the remains in a small pot and forgot about it. Months later I noticed it and was shocked that it was still alive. Moved it once more and it's still growing as y'all can see from the pics. Now that my memory is returning I'm even more curious as to its identity.