Who is Florence's patron saint?

Florence is the name of a city in Italy. However, there are a number of saints with a similar name:
Flora Bracaval
Flora of Beaulieux
Flora of Cordoba
Flora of Kildare
Florence, Thomas of
Florent le Vieux
Florentian
Florentino Asensio Barroso
Florentinus Asensio Barroso
Florentius 15 Jul
Florentius 1 Dec
Florentius 14 Dec
Florentius 15 Dec
Florentius, George
Florentius of Carracedo
Florentius of Seville
Florentius of Strasburg
Florentius of Vienne
Florentius of Vienne the Martyr
Florentius the Martyr
Florentius the Venerable