1 Taro (purple) called hairy yam grows in the dry field

Hairy potato (Rhizome of Winged Yam) is also known as ginseng yam, Li-dong yam, big yam, yam, etc., for the Dioscoreaceae plant ginseng yam tubers. Pseudo yam, sweet taste, flat, non-toxic. Its form is: ginseng potato, perennial twining herb. Tubers fleshy, up to 60 cm long, a variety of shapes and colors.

2 Possibly purple potatoes

Purple potatoes (Ipomoea batatas (L.) Poir. Cyclophyllaceae Convolvulaceae sweet potatoes genus), also known as black potatoes, the flesh of the potatoes is purple to dark purple.