rizomi

Rizomi are modified plant stems that grow horizontally, typically underground or just beneath the soil surface. As a key organ for storage and vegetative propagation, rizomi enable a plant to spread laterally and survive adverse conditions. New roots grow from the lower side of the stem, while new shoots emerge from the upper side at nodes along the rizom.

Structure and growth: Rizomi have nodes and internodes. At each node, adventitious roots may form and a shoot can appear, creating a new shoot–root system connected to the original plant. They can be thick and fleshy, as in culinary ginger and turmeric, or slender and creeping as in iris rhizomes and many grasses.

Ecological and horticultural role: Rizomi store carbohydrates and nutrients, helping plants endure drought, cold, or fire. They allow clonal reproduction, rapid colonization of spaces, and resilience after disturbance. In gardening and agriculture, rizomi can be propagated by division, enabling rapid multiplication. Because they can spread, some rhizomatous species are considered invasive in certain habitats.

Taxonomy and related structures: Rizomi are distinguished from tubers, which are swollen storage tips of stolons or roots, and from bulbs, which are short stems with layered leaves. They are also contrasted with stolons, which grow above ground and form new plants at their tips. The term rhizome comes from Greek rhis, meaning root, and in some contexts is discussed in philosophy as a metaphor for non-hierarchical networks of knowledge.