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.
Corsican citron
For a short period of time Genoese merchants, who always supplied fruit for the Jewish ritual of Etrog, used to ship also some amount of this Corsican variety, while there was not enough available from Diamante. This tradition terminated due to competition with the Greek citron which was considered to be of extraordinary beauty.