I have had a number of potato tubers form tiny potatoes on the side of them. Kinda like the potato had baby's attached. Sometimes it is caused by the tuber being old. Yet, this one was never dug up from growing new. I have heard a potato can do this if it is stressed also.
Dry potato with small micro tubers attached
I was never able to harvest this plant. The top died back like it was time to harvest. Yet, new growth was forming from the new potatoes. With all the rain and temperature up and down. I think this broke the dormancy of the new tuber. Or it had no dormancy in it. I do not have a name for this potato. It was part of an exotic variety pack I ordered to grow this year. It did have a dark purple to brown woody stem and purple flowers.
wet potato tuber to show more color
It seems the loner I leave these micro tubers attached the more they grow and the parent potato shrinks from feeding it. I have them sitting out of soil now. Yet they continue to enlarge. Adding water to the parent helps it to survive and re-hydrate a bit. If I were to put it in moist cocoa coir it would help to re-hydrate it more. Yet it could create roots to get the get plant process going again.