Here is what I found. Of course I'm not an expert just trying to figure things out
Femminello Zagara Bianca (or Fior d’arancio)
Probably deriving from Femminello comune (through vegetative mutation), this fine cultivar, which tolerates well the Phoma tracheiphila, has a continuous blossoming and a high productivity: it can produce on average the 18% of bianchetti, the 36% of verdelli and the 46% of lemons; the last two, with a good commercial quantification.
Femminello siracusano (or Femminello masculuni)
Probably deriving from Femminello comune (through bud-mutation), this type of lemon is a very vigorous plant, with a rapid growth and a fructification ahead of time compared to that of the other Mediterranean lemon trees. It has a certain spontaneous reflorescence and can produce on average the 85% of lemons (because the Primofiore is earlier), the 4% of bianchetti and the 11% of verdelli. This cultivar is of a fine quality, and so it is very appreciated on the market also for its high productivity and for the early growth of the fruit; anyway, it shows some defects: for example, it can’t tolerate well the Phoma tracheiphila.
http://www.limmi.it/en/national-cultivars/