My knowledge of banana morphology is tiny, but in English,
the stringy stuff are phloem bundles,
the edible part is starchy parenchyma,
of course the fruit itself is a berry,
and so forth,
but there's no satisfactory term I can find for the "spike" or "banana pill" at the base of the edible part.
I would be happy to be shown a term outside of English (portmanteau, online, or from a book) that does the job, perhaps from a region where bananas are indigenous, as opposed to only store-bought. A friend suggested fructus fructus pravus, which is clever but inadequate.
I regret that if one is unfamiliar with this fruit (Ltn. Musa acuminata or the hybrid Musa × paradisiaca), my description will be incomprehensible. But it will be immediately recognizable (I hope) for those who have eaten one.
Thanks in advance.