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.
Citrus limetta
It is native to southern regions of Iran and also cultivated in the Mediterranean Basin.It is a different fruit from the Palestinian sweet lime and from familiar sour limes such as the Key lime and the Persian lime. However, genomic analysis revealed it to be highly similar to the Rhobs el Arsa, and the two likely shared a common origin.