Vitis ×sullivaniana (Vitaceae), a name for the hybrid between V. acerifolia and V. riparia

A name, Vitis ×sullivaniana, is assigned to the cultigen hybrid between North American V. acerifolia and V. riparia, selected in France as a grape phylloxera-resistant rootstock in 1881 and currently naturalized in different European countries. A detailed morphological description of the nothospecies, accompanied by original and historical illustrations, is provided, along with a comparison with similar taxa and nothotaxa found in the wild in Europe. The history of the most widespread rootstock belonging to this nothospecies, ‘Couderc 1616’, is reconstructed in the context of the vineyard reconstitution of the 19th and 20th centuries.