After asking for information on Valdiguie toward the end of a recent post, I decided not to be lazy and to research it a bit myself.
It turns out that it's also known as Napa Gamay...and is a variety from southern France.
From Beacon Hill Wine & Spirits:
The full name of this French red wine grape is Gamay Noir a'Jus Blanc. Gamay wines have gained prominence in France's beaujolais region where this grape, which represents 98 percent of all vines planted, reigns supreme. They're so associated with Beaujolais that winemakers outside of the region often try to imitate the style of immediately drinkable, light- to medium-weight wines with high acid and low tannins. These light purple, fruity wines suggest flavors of bananas, berries, and peaches. Gamay is grown in other parts of burgundy, such as the côte chalonnaise, where a blend of pinot noir and not more than two-thirds Gamay is known as bourgogne passe-tout-grain. In the loire anjou produces Anjou Gamay, and from touraine comes Gamay de Touraine. There is very little true Gamay cultivated in California. For years California vintners grew what they thought was true Gamay Noir a'Jus Blanc, calling the resulting wines gamay beaujolais. However, this "Gamay" was eventually identified as an unexciting clone of pinot noir. California's napa gamay is another case of mistaken identity. It too was thought to be a true Gamay, but has since been recognized as Valdiguie, a variety from Southern France's languedoc-roussillon region. The wines produced from both these grapes are light- to medium-bodied and made in a style similar to true Gamay from Beajolais. Because of historic practice, both California wines are sometimes still called Gamay Beaujolais. blaufränkisch, a variety grown in Austria is also sometimes mistakenly called Gamay. Other names for Gamay include Bourguignon Noir and Petit Gamai.