How do bulbs, tubers, rhizomes, and tuberous roots differ?

Bulbs, tubers, rhizomes, and tuberous roots are specialized plant structures that function in food and water storage, often enabling plants to survive dormancy or harsh conditions. While they share similar roles, they differ significantly in their botanical origin and structure:12

• Bulbs: These consist of a greatly reduced, short stem (a basal plate) surrounded by thick, fleshy, compressed leaf bases or scales that store food. Examples include onions and lilies.345
• Tubers: These are thickened, fleshy portions of underground stems. Unlike bulbs, they lack specialized leaf coverings and are often irregular in shape. They bear buds (often called "eyes") that can develop into new plants. The potato is a classic example.1432
• Rhizomes: These are elongated, horizontal stems that grow within or upon the soil. They are distinguished from roots by the presence of nodes, internodes, and scale leaves. They serve as both storage organs and a means of vegetative reproduction. Ginger and iris are common examples.524
• Tuberous roots: Unlike the others, these are modified roots rather than stems. They are fleshy, swollen structures that store nutrients and can produce adventitious shoots. Dahlias and sweet potatoes are propagated by tuberous roots.25