Citron
There are also a number of citron hybrids; for example, ponderosa lemon, the lumia and rhobs el Arsa are known citron hybrids, some are claiming that even the Florentine citron is not pure citron, but a citron hybrid.
Diamante citron
Genoa was known to supply citron for the Jews since the times of the Tosafists, along with surrounding municipalities Sanremo, Bordighera, and the rest of Liguria. The city is located in the region of Liguria, which itself has a long history of citron cultivation, thanks to the massive mountain chain (Apennines) which protects it from turbulent winds.