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.
Kitron
Kitron is a citron liqueur produced on the Greek island of Naxos. It is made from the fruit and leaves of the citron tree, which is similar to the lemon tree but stronger and slightly different in taste.