Difference Between Corm and Bulb

Plants modify their stems in a variety of ways to meet the demands of adaptation. Rhizomes, bulbs, corms, and tubers are underground stems that resemble plant roots, but they are distinguished by nodes and internodes, leaves, and buds. Nature has adapted stems to perform functions such as food storage, plant support, protection, and vegetative growth. Geophytes are plants that belong to this group. Corms and bulbs both require a period of rest after a period of vigorous growth. Garlic is an example of a bulb, whereas crocus, gladiolus, autumn crocus, and so on are examples of corms.

What is a corm?

A corm is a swelling subterranean plant stem modification found in many plants. Corms are designed to store nutrients and food for the plant to use later during one growing season. They help the plant produce various plant parts such as roots, leaves, and flowers in preparation for the next growing season. Corms are reproduced using cormlets or individual corms. Cormlets can be split from the parent plant to make exact replicas. Corms have a flattened or spherical appearance. Roots can sprout from the corm base underground. Typically, the parent corm dies back, and the corm allows it to become the plant’s source the following year. The corm is a nutrient collector with membranous to scaly leaves. It keeps them fresh for the next season. The corm can be separated and moved to different areas of the garden for vegetative multiplication. Gladiolus, crocus, and crocosmia are examples of classic corms.

What is a bulb?

Another stem variation is bulb. Most perennial monocotyledons have this type of stem, which serves as a resting place for their seeds. A bulb is distinguished by a massive central bud that grows underground and is typically shaped like a globe. A bud grows from the centre of the bulb, producing leaves and flowers. 

It also has fleshy or membrane leaves on a short stem. A clump of adventitious roots sprouts from the bulb base. The branches of the bulb emerge from the lateral buds. All of the plant’s food is stored in the leaves. As the bulbs age, they are replaced with new bulbs. The onion, aside from garlic, is the best example of a bulb. Lilies, tulips, and hyacinths are examples of bulb plants. Some bulbs, such as lilies, tulips, and iris, are grown for their ornamental blossoms.

What is a Rhizome?

This is a thickened underground stem that grows horizontally. Rhizomes are equipped with eyes (some call them buttons). The eyes open, forming the above-ground plant. They can be multiplied by severing them into pieces. Because they have no skin, they dry out quickly. The calla is a rhizome, but it is often referred to as a stem tuber because stem tubers are often formed from thickened stolons or rhizomes. As you can see, there is some overlap here.

What is a Tuber?

The tuber is very similar to the flower bulb, but there are a few differences. For one thing, its appearance. Tubers do not have this ball shape, but rather something that resembles a swollen stem, the ‘tube.’ As a result, tubers store their reserve food in the fleshy root (root tubers) or the stem rather than the bulb (stem tubers). The dahlia is a type of root tuber, whereas the begonia is a type of stem tuber. Did you know that regular potatoes are stem tubers, whereas sweet potatoes are root tubers (also known as tuberous roots).

Tubers lack scales and are typically covered with a skin that allows them to be well preserved. The tuber is completely depleted during growth, and all of the reserve food is absorbed. As a result, most tubers are annuals. The crocus and gladiolus then form a new tuber on top of the old tuber, as well as a number of small nodules known as beads. The beads are used as a starting material once more (young tubers that can be grown).

Difference between corm and bulb

The terms “bulbs,” “tubers,” “rhizomes,” and “corms” all have different meanings to horticulturists. Gardeners, on the other hand, frequently fail to distinguish between them when speaking casually. Instead, they collectively refer to all of these swollen, underground plant parts as “bulbs.” 

If you want to group them all together, the correct umbrella term is geophytes. The term “geophyte” is derived from the Greek words for earth and plant. Perennial plants with underground food storage organs are included. Shoots emerge from these organs, crack the surface, and develop the part of the plant visible above ground.

Corm and bulb types

A true bulb is a storage structure beneath the ground. It includes a food supply to get it started as well as the genetic material to produce more plants. There are many different types of bulbs, but only one true bulb. Many people incorrectly refer to all plants with fleshy underground storage as bulbs, which is incorrect. The various flower bulb types – bulbs, corms, rhizomes, tubers, and tuberous roots – are better described as geophytes than as bulbs.

Conclusion

Typically, the parent corm dies back, and the corm allows it to become the plant’s source the following year. A bulb is distinguished by a massive central bud that grows underground and is typically shaped like a globe. A bud grows from the centre of the bulb, producing leaves and flowers. The onion, aside from garlic, is the best example of a bulb. The calla is a rhizome, but it is often referred to as a stem tuber because stem tubers are often formed from thickened stolons or rhizomes. The tuber is very similar to the flower bulb, but there are a few differences. The dahlia is a type of root tuber, whereas the begonia is a type of stem tuber.