It seems that the red midrib is pretty prominent and there is also some red coloration on the pseudo stem (just a little, but noticeable). I've noticed that there are several varieties of banana that have this coloration including Basjoo. Could it possibly be a dwarf red, green red or mona lisa as well? I'll have uploaded a new pic to my gallery:
Banana Gallery - Mystery BananaThe petioles seem to be pretty green, only the top and bottom (underside of leaf) of the midrib and blotches on the pseudo stem have that purplish red coloration. I know it's really early to tell, I'm just throwing around some ideas. Thanks!