The Bizzaria of Florence (Citrus medica + C. aurantium), which is probably the first graft chimera obtained, is a graft between the Florentine citron and sour orange.
It produces branches of regular Florentine citron including such leaves, and from the other side branches of sour orange. The most interesting part of it is the middle shoot, which mixes characteristics of both. The fruit contains characteristics of both citron and orange.
This is not like a regular somatic hybrid which is due ...