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.
Lumia (citrus)
The most known origin for the Lumia is from the Mediterranean basin. The Lumia is also classified as "Citrus limon var. lumia" by Swingle which places it under the taxonomy of lemon, and "Citrus medica L. var. lumia", that suggests it is similar to citron.