Which underground stem helps in the storage of food and perennation?

Step-by-step solution

Underground stems are modified plants that grow horizontally under the surface of the stem but are derived from the stem tissue only. They mainly work as a storage for food and nutrients, like tubers and rhizomes, these modified stems also function to propagate new clones and perennation. Few examples of such stems are Colocasia, Zamikand, Turmeric, potatoes, ginger etc.