This variety is believed to be a Sicilian spontaneous mutation of the Femminello Comune lemon.
Its name is derived from carrubo, the Italian name for the carob plant (Ceratonia siliqua L.), which is fairly common in Sicily and which it resembles in its characteristic clusters of fruit and flowers and the bright purplish colour of its young shoots.
The plant is very vigorous with assurgent growth and an irregular canopy. It is remontant and highly productive. The leaves are deep green, while the buds and fruit are bright purple when young.