Definition - What does Vitis Rupestris mean?
The Vitis Rupestris is a rare species of grape that grows in North American forests and wild environments and is not cultivated for winemaking as a standalone grape, but it is used to make hybrid grape varieties because it is a resilient species of grape that is resistant to disease, specifically downy mildew, phylloxera and other pests, which makes it great for crossbreeding with other grape species that are used to make wine.
WineFrog explains Vitis Rupestris
American and French viticulturists have used this grape to make hybrid vines with hardier root stocks that can endure harsher climate conditions if necessary. This was especially important during the Great French Wine Blight in the 1800's where 40% of vines were devastated following a phylloxera infestation that damaged thousands of hectares of rootstock. French botanists and viticulturists consulted with Thomas Munson, who suggested grafting Vitis rupestris to French vine rootstock to make them more resistant to phylloxera.
The grafting was a success, prevented diseases and is still the only known prevention method for phylloxera. Without the intervention/cross breeding of this grape, the French wine industry would have significantly declined.
The grape fruit from this vine grows naturally in the states of Arkansas, Missouri, Kentucky, Texas, Oklahoma and New Mexico. Some vines from this species can be found on the eastern coast of the United States, but it grows there by propagation. This hardy species of grape ripens early and grows in clusters of 12-24 small dark purple berries usually 6-12 mm in diameter.