Maddalena,
I don't know about drying bananas of plantain but here's some info. --
Banana (including plantain) belong to the genus Musa of the Musaceae family (monocot). They originate from Southeast Asia. They've been around for a very long time. The Greeks and Romans ate them too. I would think they'd qualify as paleo.
The banana fruit is a berry and it is protected by a cover [peel].
Both the stem and the in florescence are edible.
In South East Asia, the banana leaf is used to wrap food (in the place of plastic bags and cling wraps), providing a unique flavour and aroma to various dishes.
Dedy