One way plants store food and reproduce is with a structure called a corm.
Different types of geophytes
Corms are similar to bulbs, tubers, and rhizomes, in that they are all geophytes. Geophytes are structures that store food and water. If you cut these structures in half, however, they look very different.
Each corm is a segment of underground stem that includes at least one growing bud. Corms are often covered with a papery coating called a tunic. The tunic is made out of dead petiole sheaths that were produced the previous year. The tunic protects the corm against insect and animal feeding, flooding, and drought. The inside of a corm is tissue filled with carbohydrates. The flat bottom is where roots emerge and cormels are produced. In some cases, the parent corm is used up completely and is replaced by the cormels it produced. In other cases, the corm simply becomes larger. In yet other cases, a new corm grows from the top of an old one that withers and flattens. Over time, this type of corm ends up becoming a stack of used up corms.
Many corms produce two different types of roots. Familiar fibrous roots anchor the plant in the soil and absorb water and nutrients. Contractile roots pull corms deeper into the soil, away from animals and extreme temperatures. Contractile roots stop pulling the plant downward as conditions above improve.
Caring for corms
When a plant grows from a corm, it draws moisture and carbohydrates from that underground structure. By the time the plant reaches its mature size, much of those resources have been used up and must be replenished. Use these tips to help your corms stay healthy:
Do you any corms in your garden?
You can grow a surprising amount of food in your own yard. Ask me how!