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
The tree produces large fruit, ellipsoid to very slightly obovate; basal area slightly depressed and radially furrowed; apical nipple suppressed or indistinct. Color lemon-yellow when ripe. Rind very thick and fleshy, sweet with some bitter after-taste; surface rather rough, bumpy, and commonly somewhat ribbed. Flesh crisp and solid; lacking in juice; flavor sweet without acid. Seeds white yellowish. This giant citron can measure up to 25 cm in length and weigh up to 4 kg.