Solomon's Seal rhizome

A rhizome, found in some vascular plants (e.g., mint, couch grass, iris, and water-lily), is a usually more-or-less horizontal, creeping underground stem that have the appearance (but are not) roots. Rhizomes, also called rootstock, may be enlarged for storage, of accumulated starch, or may function in vegetative reproduction. They last for several years and new shoots appear each spring from the axils of scale leaves. Rhizomes differ from roots in having nodes, buds, and scale-like leaves. See also food storage in plants.