Citron
The citron ("Citrus medica") is a large fragrant citrus fruit with a thick rind. It is one of the original citrus fruits from which all other citrus types developed through natural hybrid speciation or artificial hybridization. Though citron cultivars take on a wide variety of physical forms, they are all closely related genetically. It is used widely in Asian cuisine, and also in traditional medicines, perfume, and for religious rituals and offerings. Hybrids of citrons with other citrus are commercially prominent, notably lemons and many limes.
Diamante citron
The Diamante citron ("Citrus medica" var. "vulgaris" or cv. "diamante" − , or גינובה) is a variety of citron named after the town of Diamante, located in the province of Cosenza, Calabria, on the south-western coast of Italy, which is its most known cultivation point. This is why this variety is sometimes called the "Calabria Esrog". ""Esrog"" is the Ashkenazi transliteration of the Hebrew name for citron.
The Diamante citron was one of the most important varieties candied by the largest factories at Livorno, Italy; it was gathered from Liguria, Naples, Calabria & Sicily and then shipped into England and the United States.