Is it too late to add to the controversy? My humungous Webster's Third
New International Dictionary gives BRASSavola as the 1st pronunciation
& BrasSAvola as the 2nd. It's an American dictionary; maybe the 2nd
pronunciation is British? Sometimes they put different accents on
syllables than we do in North America. I've heard "conTROVersy", for
example. I was trying to think of others but my brain is blank.
It also says A.M. Brassavola lived in the 1500s.
I too was going to suggest maybe someone here who speaks Italian could
say what the most likely pronunciation is.
I just thought BrassaVOla sounds better, but what do I know

Alison