Zingiber officinale is an underground modified stem called a rhizome.
Zingiber officinale or ginger is an underground modified stem called a rhizome. Ginger is widely used as a spice and in Ayurveda and traditional medicine. The rhizome is a perennial underground stem. Continuously it produces aerial shoots and new leaves during the favorable season. The stem is differentiated into nodes and internodes. The rhizome in ginger is branched in a cymose fashion. The ginger rhizomes are fleshy and juicy with a mild taste. Upon mature, the rhizomes become fibrous and nearly dry.
Corm, tuber and bulb are also modified stems. A corm is usually short, thick and unbranced underground stem (Colocasia), tuber is an oval or spherical underground stem and does not bear adventatious roots (potato) and bulb is an pyriform-spherical underground stem with several fleshy scales enclosing the terminal bud (onion).