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.
Lemon tart
In the UK, lemon tart (also called tarte au citron) consists of a pastry case (often made in a fluted tart tin) containing a baked lemon custard (usually composed of eggs, sugar, lemon juice and cream). Usually recipes include blind-baking before adding the custard. Sometimes the tart is dusted with icing sugar prior to serving.