In biological classification, family (Latin: familia, plural familiae) is a taxonomic rank. Exact details of formal nomenclature depend on the Nomenclature Code which applies. » Example: "Walnuts and Hickories belong to the Walnut family" is a brief way of saying: the Walnuts (genus Juglans) and the Hickories (genus Carya) belong to the Walnut family (family Juglandaceae). History of the concept Family, as a rank intermediate between order and genus, is a relatively recent invention. The term… (More on Superfamily)