Corm facts for kids

Taro corms for sale in a Réunion market

A corm is a special kind of underground plant stem that looks swollen and round. It acts like a storage room for plants, holding food and water. This helps plants survive difficult times, such as cold winters or hot, dry summers. It's how they stay alive year after year!

When we talk about plants that grow from corms, we call them cormous plants. This is similar to how we say "bulbous" for plants that grow from bulbs, or "tuberous" for plants that grow from tubers.

What is a Corm?

A corm is often confused with a bulb or a tuber, but it's different. While a bulb (like an onion) is made of fleshy leaves, and a tuber (like a potato) is a swollen stem, a corm is a solid, short, and vertical underground stem. It has a flat bottom and a rounded top.

Corms are covered by dry, papery leaves called a "tunic," which helps protect the corm. Inside, the corm is mostly solid storage tissue. This tissue is packed with nutrients that the plant can use to grow new leaves and flowers when the weather is right.

How Do Corms Help Plants Survive?

Corms are amazing because they allow plants to go dormant, or "sleep," during harsh conditions. When it gets too cold, too hot, or too dry, the plant's leaves and flowers might die back. But the corm stays alive underground.

It uses the stored food to survive until conditions improve. When spring arrives or the rains return, the corm sprouts new shoots, and the plant starts growing again. This ability to survive and regrow makes corms very important for many plants, especially those in areas with changing seasons.

Growing New Plants from Corms

Corms are also very useful for growing new plants. Many plants that have corms can be grown by taking the corms out of the ground. For example, you might have seen taro corms for sale, which are used to grow new taro plants.

Gardeners often cut larger corms into smaller pieces. Each piece needs to have at least one "bud" (a tiny bump that can grow into a new shoot). If these pieces are planted carefully, each one can grow into a brand new corm and eventually a new plant. This is a great way to make more of your favorite cormous plants, like Gladiolus or Crocosmia.

New corms, sometimes called "cormels," can also form naturally around the base of the main corm. These smaller cormels can also be separated and planted to grow new plants.

Images for kids

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  A Crocosmia corm with its protective outer layer partly removed. You can see where the corm started growing from different points on its surface.

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  Inside a Crocosmia corm, showing its outer layer, the main storage part, and a new corm beginning to grow from a bud near the top.

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  A Crocosmia corm with new shoots, called stolons, growing out. These stolons often form new corms at their ends.

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  A Gladiolus corm, showing how small new corms (cormels) are forming at the ends of short shoots.

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  A corm from the Alocasia macrorrhizos plant.

See also

In Spanish: Cormo para niños