Glad the advice I offered helped!
That is definitely NOT musa zebrina
Looks like you scored yourself the number one commerical variety of banana!
From my understanding... gran nain is the variety that chiquita bananas are!
now you know.. bananas make great houseplants.. their huge leaves allow them to get sufficient light even in low light conditions.. I'd put that baby in a large pot and keep it indoors this winter.. and then put it out next spring