Rhobs el Arsa
The Rhobs al Arsa has long been viewed as a citron hybrid, though a different cultivars have been suggested for the parent, for example, Moroccan citron as a male parent and sour orange as the female parent, citron or lemon and a mandarin., or citron and the lime. Detailed genomic analysis has shown Rhobs al Arsa to be highly similar to several cultivars of "Citrus limetta", the limetta or Persian sweet lime, and likely shared a common origin with them, arising from a cross between citron ("Citrus medica") and sour orange ("Citrus" × "aurantium"). The common lemon arose from a distinct hybridization event involving the same two species.
Buddha's hand
The different cultivars and variations of this citron variety form a gradient from "open-hand" types with outward-splayed segments to "closed-hand" types, in which the fingers are kept together. There are also half-fingered fruits, in which the basal side is united and the apical side fingered. The origin of this kind of citron is commonly traced back to the Far East, probably northeastern India or China, where most domesticated citrus fruits originate.