What is "versoaln"

Versoaln (or Versailler) is a white Italian wine grape variety that is grown in the Trentino-Alto Adige/Südtirol wine region of northeast Italy. In the commune of Tisens, in South Tyrol, one of the world's oldest vines is a Versoaln vine planted at Castle Katzenzungen that has been dated to be at least 350 years old by the viticulturists at the University of Göttingen.