Wikipedia
Taradi
Taradi, or Himalayan yam, is a little-studied plant which appears above the ground as a low vine, but underground bears long, convoluted tuber growth stretching sometimes as deep as 2 metres. It is native to Palampur in northern India. It has received very little attention from botanists, and its species has not even been determined or named, although its morphology and life patterns show it to belong in the Dioscorea genus, so it has been referred to as Dioscorea spp..
The tubers are edible, and are eaten during traditional religious festivals. Taradi can be roasted or cooked, and used as a vegetable. Digging and selling taradi is a major source of income in the region.