A wine plague spread by lice destroyed vines in France in the 19th century but a small area in the Pyrenees, which contains plants up to 200 years old, was spared and is being classified as a national heritage monument.
Like other national treasures such as the Palace of Versailles and Notre Dame cathedral, the vines in the Ardour valley will be protected.
They contain the ancient DNA of local grape varieties. Some grapes are still being used with grapes from younger generation vines to make Saint-Mont wine.
"It is an exceptional plot," said Olivier Bourdet-Pees, director of the Plaimont wine making firm. "The vines go back 200 years. They were planted in 1800 and 1810. There are 29 different grape varieties of which seven were unknown," he said.
The vine disaster forced many vintners from regions such as Bordeaux and Burgundy to seek grafts, or entire vines, from as far away as America.
The vines of Bordeaux were ravaged by the phylloxera outbreak from 1865, a decade after the famous classification of great wines in 1855, and had to be replanted with imported grafts on remaining stems.
In Burgundy, vintners pulled up their old French vines and replanted them with American pinot noir until they discovered that grafting was the best method.
SAFEGUARDING A NATIONAL HERITAGE
Scientists have been researching the plants and the grapes as part of a mission to safeguard the national heritage. On June 1, the local heritage and sites commission of the Midi Pyrenees region included the vines on the list of national historical monuments.
"This plot of 40 acres contains very old and non-grafted stocks and offers a remarkable example of biodiversity and of genetic heritage: 600 vines in 12 rows, some 20 different varieties of which seven have not previously been recorded," the regional authorities said in a statement.
The plot also showed traces of ancient methods of agriculture, with double rows of vines planted in squares. Although the production is too small for a special wine, the vegetal material can be used to make younger vines.
For eight generations the plot has been in the hands of the family of vintner Jean-Pascal Pedebernade. About 20 years ago, scientists started to study the vines. It took them until 2008 to completely map the genetic make-up of the plants in a study that helped sway the commission in its decision.
The sandy soil plot lies near the village of Sarragchies near Saint-Mont in the Gers, in southwest France. The vines are planted wide apart, which may explain why it resisted the attacks by the phylloxera aphids that travelled to Europe from their original habitat in the United States.
Saint-Mont has its own AOC wine denomination. It is a sturdy wine like the Madiran, which is also produced by the vintners associated in the Plaimont cooperative group. Its headquarters is in the former Benedictine monastery whose monks planted vines around the year 1050 in the Middle Ages. The group also makes the sweet golden Pacherenc du Vic-Bilh and the Cotes de Gascogne wines.
The Saint-Mont AOC area has 46 villages and uses the Tanat, Pinenc, Cabernet France and Cabernet Sauvignon grapes for red and rose wines as well as Gros Manseng, Arrufiac and Petit Courbu for the whites.
While the cabernets are widely used elsewhere, the other grape varieties are typical for the region. Its producers are proud of the biodiversity of the area, which is helpful in the ultra competitive market for inexpensive wines.
Production is about 8 million bottles, half in red, 30 percent in whites and the rest in rosé. Two-thirds of the production is consumed in France with exports mainly to other European countries, the United States, Canada, Australia, Japan and China. They sell in the range of seven to 14 euro per bottle.
Other parcels of vines have also resisted phylloxera.
The Bollinger champagne firm has two walled pre-phylloxera vineyards, which it uses in its rare Vieilles Vignes Francaises. The 2000 vintage sold for 600 euro a bottle.
Other old plots include Romorantin in the centre of France, where Henry and Jean-Sebastien Marionnet claim to own a vineyard planted in 1850. The oldest vines they use for their La Pucelle de Romorantin are 160 years old, mixed with grapes from younger vines grown from the sprouts of the old vines from 2007.
The Stara Trta vines at Maribor in Slovenia are reputed to be more than 400 years old, while the oldest in France, in the city of Reims, are believed to be at least 344 years old.