Modification Of Stem: Functions, Characteristics, Modifications, Concepts

What Is Modification Of Stem?

Modification of the stem refers to the structural changes that the stem undergoes to undertake particular functions other than its usual functions. Such modifications enable a plant to survive in its environment and may differ considerably in different species.

Types Of Modifications Of Stem

Stems are modified in several manners, and all these modifications have different functions:

Rhizomes

Rhizomes are underground horizontal stems which form below the surface of the soil. They may perform various functions:

Asexual Reproduction: Rhizomes can produce new shoots and roots, therefore vegetative propagation is possible.

Storage: They are storage organs, storing the food and energy that allows a plant to overwinter or survive unfavourable conditions.

Tubers

Tubers are enlarged underground stems mainly acting as storage organs, and are recognized by:

Nutrient Storage: Tubers primarily store food in the form of carbohydrates in the shape of starch, which is energy that can be utilized either when growth resumes or during dormancy.

Examples: Probably one of the best examples of tubers is potatoes.

Corms

Corms are short, swollen underground stems which also act as organs of storage. They differ from tubers by structure :

Structure: They are solid, consisting of fleshy stem tissue.

Function: Likewise, the tubers, store energy and can form new shoots.

Bulbs

Bulbs are modified stems that are covered with fleshy leaves. They are found in plants like onion and tulips. Key features include :

Storage: Bulbs are organs of storage and are made of fleshy leaves which provide food for the development of new plants.

Reproduction: New plants can be vegetatively propagated from bulbs.

Stolons

Stolons also known as runners, are stems that grow horizontally on the ground surface. The stolons do the following:

Asexual Reproduction: From the nodes of stolons, adventitious roots and shoots develop and soon produce a new plant. Thus they aid in rapid colonization.

For example: Strawberries produce stolons which develop new plants.

Functions Of Modified Stem

These modified stems undertake several important functions that increase the survival chances of a plant:

Storage

The primary task for which modified stems are used is storing nutrients and energy reserves to be used when growth is undesirable.

Asexual Reproduction

Different types of stem modifications enable plants to reproduce asexually. This means that its population increases at a high rate, increasing the chances of colonizing new areas.

Survival

It is through the stored energy and water in these modified stems that plants can survive in case of drought or lack of nutrient availability.

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