Rhizome

Scheme of the rhizome Polygonatum verticillatum. I and II indicate the growth of the previous two years, III points to the current growth. Arabic numerals (1, 2, 3...) indicate the node or place where each catufil or modified leaf was found, the spaces between the numbers are the nudes. K1, k2, indicate the position of the axillary yolks that are inactive (dormides).

rhizome Phragmites australis.

rhizome Zingiber officinale ("jerk").

In biology, a rhizome is an underground stem with several buds that grow horizontally, emitting roots and herbaceous shoots from their nodes, which serve as a nutrient-reserving organ.

Rhizomes grow indefinitely. Over the years the older parts die off, but each year they produce new shoots, thus they can cover large areas of land. Its thickened branches usually present short internodes, have colorless and membranaceous cataphylls, adventitious roots and buds.

Classification

Based on their growth and branching, rhizomes can be classified into 2 groups or sympodial or monopodial ramifications. The sympodial rhizomes are those in which each portion corresponds to the development of successive axillary buds. The terminal bud of each portion produces the epigeal bud. Examples of this type of rhizome are Sansevieria thyrsiflora and Paspalum nicorae.

In monopodial rhizomes, on the other hand, the terminal bud continues the indefinite growth of the rhizome, while the axillary buds originate the epigeal shoots. This type of rhizomes is characteristic of many invasive species or weeds, such as Sorghum halepense.

It is a vegetative reproduction system common to many plants, such as Achimenes, Canna, Zantedeschia, lily and ginger (Zingiber officinale).

Rhizomes can be divided into pieces containing at least one bud each and planted separately. Plants with rhizomes are perennial, losing their aerial parts in cold climates, keeping only the underground organ that stores nutrients for the following season.