The Zinfandel grape has long been promoted as the only native American grape.  Zinfandel is grown in most of the wine regions of California and is the the grape variety from which the most popular North American rose or blush (another story) wines are made.  A DNA study announced in December has proven otherwise.

DNA testing last month revealed that Zin is identical with a native Croatian grape called
Crljenik Kasteljanski (pronounced "kurlyenik kastelyansky"), said Dr. Carole Meredith of the University of California at Davis.

Meredith, a professor of enology and viticulture who has made previous discoveries tracing the heritage of Cabernet Sauvignon, Chardonnay and other grapes using DNA technology, worked with Croatian scientists Edi Maletic and Ivan Pejic on the Zinfandel quest. She credits her Croatian fellows with the discovery, saying it took five years to track down the elusive parent grape even after the research trail led them to Croatia.