Which archaic or historical designation arose from comparing the tuber to a fruit grown in soil?

Answer

earth apple

The designation 'earth apple' is an evocative, though now rare, name that likely arose from a descriptive observation comparing the subterranean, round shape of the vegetable to an apple grown in the soil.

Which archaic or historical designation arose from comparing the tuber to a fruit grown in soil?
foodpotatovegetabletuber