Underground stems are specialized plant structures that grow beneath the soil surface. They serve various functions, including storage of nutrients and energy, as well as vegetative reproduction. Common types of underground stems include rhizomes, tubers, and bulbs. These adaptations help plants survive adverse conditions and spread to new areas. Rhizomes are horizontal stems that can produce new shoots and roots, while tubers, like potatoes, store starches for energy. Bulbs, such as onions, consist of a short stem surrounded by fleshy leaves that store nutrients. Together, these structures play a crucial role in plant growth and survival.