Rhizomi

Rhizomi, the plural form of rhizome, refer to a type of underground stem that grows horizontally and functions in storage and vegetative propagation for many plants. A rhizome typically lies beneath the soil or just at the surface, with nodes along its length that produce roots downward and shoots upward. The segments between nodes are called internodes. Rhizomes store carbohydrates and other nutrients, helping plants survive adverse seasons and providing a means to spread laterally.

Rhizomi vary in form. Some are slender and spreading (leptomorph), forming extensive networks that quickly occupy space; others are thick and compact (pachymorph) and stay more clumped around the parent. Many familiar plants are rhizomatous, including ginger and turmeric, which form culinary rhizomes; iris and many grasses; bamboo and canna lilies; as well as various ferns. In horticulture and agriculture, rhizomes can enable rapid clonal propagation and resilient perennial growth, and they may be cultivated for ornamental or edible purposes.

Rhizomi are distinct from related structures. They differ from stolons (aboveground runners that produce new plants at their tips) and from roots, which generally lack buds that generate shoots. Tubers can be storage organs that arise from the tips of stolons or rhizomes, such as the potato, but tubers are not themselves rhizomes.

Ecologically and economically, rhizomi support perennial life, enable vegetative spread, and can influence ecosystem dynamics. In cultivation, propagation is often achieved by dividing rhizomes or transplanting sections with buds.