Many plants’ stems have been changed to serve a variety of purposes, including storage, protection, photosynthesis, support, propagation, and perennation.
Adaptation and survival are aided by modifications.
The plumule of the germinating seed develops into stems. It produces leaves, fruits, and flowers, among other things.
Nodes and internodes are the distinguishing characteristics of a stem. The stem’s primary role is to sustain other sections of the plant as well as to conduct food, water, and minerals.
Stems of some plants are transformed in various ways, including aerial, subaerial, and subsurface changes. They’ve been tinkered with to perform functions that aren’t generally connected with the stem.
Examples of Different Types of Modifications
There are three different types of modified stems:
Subaerial – Runner, Sucker, Offsets, Stolon Aerial – Tendrils, Thorn, Bulbils, Cladode, Phylloclade Underground – Rhizome, Bulb, Corm, Tuber
- Modifications to the Underground Stem
These are found underground, as the name implies.
They are used for a variety of functions, including food storage, propagation, and perennation. The existence of nodes and internodes distinguishes them from roots.
They aid in asexual reproduction and assist the plant in surviving a period of hibernation. They offer protection from animal grazing as well as environmental stress.
Rhizome – This root system runs parallel to the ground, with the upper portion producing scaly leaves and the lower portion producing adventitious roots.
Nodes, internodes, and buds are all found in them.
They are used to keep food.
Ginger and turmeric are two examples.
Rootstock, which is a rhizome that grows vertically, is found in bananas.
Bulb – The stem has been shortened and is wrapped by scale leaves, revealing modified bulbs.
Tulips, Lilies, Daffodils, Onion, and Garlic are among examples.
Corm – A corm is a short upright stem with scaly leaves on it. When compared to bulbs, it is difficult. Colocasia, yam, and saffron are some examples.
The fleshy terminal of the stem is called a tuber, and it stores food. The stem has nodes and internodes, however these are difficult to distinguish due to swelling.
Eyes or scars can be visible where scaly leaves are present at nodes. Potatoes and artichokes are two examples.
Modifications to the Subaerial Stem
These stems might be found partially underground or on the ground. They’re generally found in plants that have a short lifespan and a weak, herbaceous stem.
The stem is utilized to speed up the propagation process.
The runner is formed by the extension of the basal internode and runs horizontally across the ground.
With the support of root development at nodes, it transports buds and anchors the soil. It sprouts into a new plant.
Grasses, Cynodon, and Oxalis are some examples.
Stolon – A short, weak aerial branch emerges from the main axis, bends down, and forms roots on the earth. There is a new plant growing there.
Mint and strawberry are two examples.
Sucker – Sucker emerges from the stem’s underground portion, grows horizontally beneath the soil, and finally emerges above ground.
It generates a new plant by developing adventitious roots and shoots with leaves. Chrysanthemum, banana, and pineapple are some examples.
Offsets are typically seen in aquatic plants. A lateral branch with short internodes emerges.
The upper portion of nodes develops rosettes of leaves, while the lower portion develops roots. Pistia and Eichornia are two examples.
Modification of the Aerial Stem
The aerial section of the stem and buds of some plants are changed to serve a variety of activities, including support, climbing, photosynthesis, and vegetative propagation.
Tendrils are coiled and sensitive parts of the plant that are used for climbing. The axillary bud is where they grow.
Grapevines, watermelons, pumpkins, and cucumbers are some examples.
Thorns – These grow from the axillary buds. They are hard, spiky formations that are pointed, woody, and give protection from grazing animals.
Bougainvillea and lemon Bulbils are examples of modified axillary buds that store food and grow meaty.
It splits away from the mother plant and grows into a new one. Dioscorea Cladode and Phylloclade are two examples of modified stems that are green and capable of photosynthesis.
They develop a meaty appearance. Spines have replaced the leaves. To prevent water loss, they are typically found in xerophytic plants. Opuntia, Euphorbia, and Asparagus are some examples.
Conclusion
Many plants’ stems have been changed to serve a variety of purposes, including storage, protection, photosynthesis, support, propagation, and perennation.
Adaptation and survival are aided by modifications.
Nodes and internodes are the distinguishing characteristics of a stem. The stem’s primary role is to sustain other sections of the plant as well as to conduct food, water, and minerals.
Stems of some plants are transformed in various ways, including aerial, subaerial, and subsurface changes.
They’ve been tinkered with to perform functions that aren’t generally connected with the stem.