Citrus taxonomy
All of these hybrids have in turn been bred back with their parent stocks or with other pure or hybrid citrus to form a broad array of fruits. Naming of these is inconsistent, with some bearing a variant of the name of one of the parents or simply another citrus with superficially-similar fruit, a distinct name, or a portmanteau of ancestral species. The Ponderosa lemon ("Citrus limon" × "medica") and Florentine citron ("Citrus x limonimedica") are both true lemon/citron hybrids, the Bergamot orange is a sweet orange/lemon hybrid and the Oroblanco is a grapefruit/pomelo mix, while tangelos are tangerine (mandarin)/pomelo or mandarin/grapefruit hybrids, orangelos result from grapefruit backcrossed with sweet orange, and a sweet orange backcrossed with a tangerine gives the tangor. One lumia, a member of the sweet lemons, is the product of crossing a lemon with a pomelo/citron hybrid, though another lumia variety, the Pomme d'Adam, is a micrantha/citron cross, like the Key lime. The most common and commercially popular 'limes', the Persian limes, are Key lime/lemon hybrids that combine the genetic lineages of four ancestral citrus species: mandarin, pomelo, citron and micrantha.
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.