Corm, also known as Bulbo-tuber or Bulbotuber, is defined as the short, vertical and swollen stem which is fleshy and solid.
A corm usually serves as a food reserve that helps a plant to survive in adverse climatic conditions like winter and summer drought. A corm consists of one or more distinct nodes and internodes. Corm is more or less rounded in shape with a flattened base. The stem is enclosed by several dry, thin scaly leaves that act as the protective covering to prevent insect attack and water loss. The internal structure of corm is usually made up of starch-containing parenchyma cells present above the circular basal node that grows roots.
Corms generally have presence of two different types of roots: fibrous roots (produced from the basal area as the shoot grow) and layered roots or contractile roots (produced in response to fluctuating soil temperatures and light levels). In case of damage to the main growing points, a corm can form numerous cormlets known as cormels from the basal areas. Some of the examples of plants that have corm include Gladiolus, Crocus, Colocasia, Amorphophallus and Alocasia.