Rhizome
In botany, a rhizome is a horizontal, usually underground stem of a plant that often sends out roots and shoots from its nodes. Also called a creeping rootstalk or rootstock. Many plants have rhizomes that serve to spread the plant by vegetative reproduction. Examples are asparagus and lily of the valley.A tuber is a thickened part of the rhizome or underground stem of certain plants, enlarged as a starch storage organ. Some tubers are edible, such as those of potato, Jerusalem artichoke and jicama.
A corm is a short, thickened, vertical rhizome that stores starch.
