The white grape is one open blownseedling from Cabernet Sauvignon, The name means "white swan". The vine was discovered in 1989 by the wife of Australian winemaker Dorham Mann in her garden in the Western Australian community of Baskerville (in the eponymous Swan Valley). The garden is located near a vineyard planted with Cabernet Sauvignon, so the vine is likely to be the result of a selfing It is Blanc is a separate variety, which was officially registered in 1997. It is cultivated as Keltertraube in the area Mount Benson on the Limestone Coast in South Australia. In 2010, however, no stock was reported (Kym Anderson ).
Source: Wine Grapes / J. Robinson, J. Harding, J. Vouillamoz / Penguin Books Ltd. 2012