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.
Moroccan citron
As to the Diamante citron (Yanova) and the Greek citron (Corfu), he argued based on the booklet from the Salant partners, that since some of them are proven to be grafted, no certification may be granted to the rest, since it is impossible to determine if the non-grafted citrons are not descendants of the grafted ones.
As to the Moroccan and Yemenite citrons he argued, that although there were no grafted trees ever discovered among those kinds, they should be unfit, in light of the differentiation from the Ashkenazi types. The Moroccan citron is allegedly noted for its seedlessness, and the Yemenite for its pulplessness, both are too much different in morphology from the traditional Yanova and Israeli esrogs.