Corms

A corm is a stem in an herbaceous vascular plant that has been modified to store food. In plants that possess a corm, the stem is modified into a large, fleshy, and bulbous sheath that wraps around the food.

Like bulbs, corms occur in underground biennials, and they are used to protect food over time as they develop and hibernate; however, corms are distinguished via the presence of circular, horizontal nodes. These nodes are typical of monocots: accordingly, only monocots are known to modify their stems into corms. Examples of these monocots include bananas, gladiolus, and taro roots.