I don't remember just where the roots
and shoots sprout from -- if not from eyes, where?

On a true tuber, leafy shoots spring from the eyes all over. On a tuberous
root, the leafy shoot would only come from the top, where it was joined to the
stem. Try it & tell me if that is correct.
All I know about these things is what happens in the refrigerator. White
potatoes sprout from the eyes; sweet potatoes eventually rot.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"When you come to a fork in the road, take it." Yogi Berra