There was a time when it would be considered treason to pick one of these grapes without express permission from the Emperor himself. It is my understanding that although growers in Skyrim were successful in improving the fruit's survivability, it came at the cost of flavor. No longer is it quite the prize it once was. And yet, growing amidst the volcanic tundra of Eastmarch, it is still immensely useful for concocting potions. Mages value it highly as it can be combined with simple garlic to enhance the regeneration of magicka. While no longer against the law, picking these grapes in large amounts is best kept to oneself.