Wikipedia
The Bizzaria of Florence (citrus medica + citrus 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 to plant sexuality; its offspring is intermediate showing influences of both parents. But the Florentine Bizzaria, named after its origin, shows an unusual fruit which has both characteristics distinctly expressed in close proximity.
The plant's name has a number of different spellings, e.g. Bizaria,Traite des Plantes