rhizome

Ginger (Zingiber officinale). Commonly called ginger root, the edible portion is actually a rhizome, or underground stem.

rhizome, horizontal underground plant stem capable of producing the shoot and root systems of a new plant. Rhizomes are used to store starches and proteins and enable plants to perennate (survive an annual unfavourable season) underground. In addition, those modified stems allow the parent plant to propagate vegetatively (asexually), and some plants, such as poplars and various bamboos, rely heavily on rhizomes for that purpose. In plants such as water lilies and many ferns, the rhizome is the only stem of the plant. In such cases, only the leaves and flowers are readily visible. Notably, the rhizomes of some species—including ginger, turmeric, and lotus—are edible and valued for their culinary applications.