According to the EU Regulation, Member States must classify the wine grape varieties that may be planted or grafted in their territory for the purpose of wine production. These must belong to the European species Vitis vinifera or come from a cross of this species with other species of the genus Vitis (e.g. the Asian Vitis amurensis or the American Vitis labrusca). However, six grape varieties are banned even though they fulfil these conditions. These are Clinton, Herbemont, Isabella, Jacquez, Noah and Othello. Why these six in particular has historical reasons that no one knows or can explain today, even from the official side (one of the mysteries of EU laws). They are American hybrids, but there are also many others that are allowed for cultivation. If varieties are deleted from the classification, the areas concerned must be grubbed up within 15 years of their deletion (with the exception of areas for the vintner's own use).