If Flora and Florence have returned full force, Florian, with its trendy Latinate ending, could also have a chance. Popular in Germany, Austria and Switzerland -- he was the venerated patron saint of those in danger from water and of firefighters -- might sound a tad feminine and floral to English speakers. But as a middle name, Florian could be a great way to honor grandma Florence (or any other flower name).
The second century Roman martyr St. Florian appears in Tennyson's poem "The Princess," and also in Gilbert & Sullivan's comic opera "Princess Ida." Sir Florian Eustace is an off-stage character in Trollope's novel The Eustace Diamonds, Florian Fortescue runs an ice cream shop in Harry Potter, and Florian is the real first name of singer Dido.