Hi,
In Musaceae taxonomy is commonly only used sectional status, species, subspecies and variety.
I studied over 800 publication on Musa for my article:
"Typification and check-list of Musa L. names (Musaceae) with nomenclatural notes"
at:
http://www.mnhn.fr/museum/front/medi...95_a08n1a7.pdf
and I can't remember any forms of Musa was used.
Markku.