Grape varieties, Groups and families: Over time, grape varieties bearing the same name, or at least a part of it that is the same, have been mistakenly lumped together, blurring their identities. This practice is understandable yet incorrect. For instance, all the people with the same family name of Smith are not all related. Some may be, not all. The same holds true for grape varieties. For example, the extensive Malvasia group has 17 members, linked together for having the word Malvasia in their names. In reality, only a few are genetically related, yet they carry the same name because Malvasia was a highly popular name given to many grapes. We refer to this as a group rather than a family. Conversely, Lambrusco is just that, a family of native grapes bearing the same name giving similar yet distinct wines. When varieties share the same basic name and close enough genetic ties, they are called a family; when they share the same name but are not related, they are called a group.
Italian Wine Unplugged (Positive Press, 2017), p.43-44.