In botany
Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...

 and dendrology
Dendrology or xylology is the science and study of wooded plants . There is no sharp boundary between plant taxonomy and dendrology. However, woody plants not only belong to many different plant families, but these families may be made up of both woody and non-woody members. Some families include...

, a rhizome (from "mass of roots", from "cause to strike root") is a characteristically horizontal stem
Plant stem
A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...

 of a plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

 that is usually found underground, often sending out root
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...

s and shoot
Shoots are new plant growth, they can include stems, flowering stems with flower buds, and leaves. The new growth from seed germination that grows upward is a shoot where leaves will develop...

s from its nodes. Rhizomes may also be referred to as creeping rootstalks or rootstocks.

If a rhizome is separated into pieces, each piece may be able to give rise to a new plant.