 To further add to the mystery, there is some belief that the extremely close genetic similarities between Sangiovese and Nielluccio could mean that they are exactly the same grape (or rather a clone given Sangiovese's propensity for mutation).Indeed, the German Vitis International Variety Catalogue data base of known grape cultivars does not even give Nielluccio a separate entry, rather grouping it in as a synonym of Sangiovese.Still many French and English wine texts, such as the "Oxford Companion to Wine", list the grape as a separate entry but with a note describing its close similarities to Sangiovese.