How Do Tendrils Help Plants Survive?
It is a kind of plant organ that is used for anchoring and supporting the vining system. It can be a modified structure of leaves, leaflets, leaf tips, or leaf stipules. They may also be derived from modified stem branches like in grapes. They are thin, thread-like growths present on the stem or leaves of climbing plants. Based on growth tendril are of two types they are: stem tendril and leaf tendril. And their growth is mainly towards the support with which they can attach themself for the support and this phenomenon is known as thigmotropism.
Function of Tendril
Some of the common function of tendril are discussed below:
They are known to be modified portions of leaf, stem or petiole.
Their main function is to provide support to the plant as it climbs up a structure. By doing so they allow a plant to find a more suitable area to grow due to more light.
When stems are modified into tendril they help plants to climb.
The positions of tendril are different in different plants like in leaf, stem or even branches in few plants.
What is Stem Tendril?
When stems are modified into threadlike leafless structure then they are known as stem tendril. Their major role is for climbing purposes, they don't necessarily contain a branch.
Further Stem Tendril is classified into different types. They are as follows:
Axillary: E.g., Passiflora
Extra-Axillary: E.g., Luffa
Apical Bud: E.g., Grapevine
Floral Bud: E.g., Antigonon
What is Thigmotropism?
It is a kind of curvature movement shown by a plant in response to a unilateral touch stimulus and can be observed in many climbers. In tendril climbers, the tendrils first show mutation, and as soon as their apices touch support, they move thigmotropic ally to turn around it.
Some of the common examples of tendril-producing plants are the grape, members of the squash or melon family (Cucurbitaceae), the sweet pea (Lathyrus odoratus), and the passion flowers (Passiflora species).
Explain the Role of Auxin in the Growth of Tendril
It is a kind of growth hormone which is generally synthesized at the shoot tip. It enhances the growth of cells so that plants can increase their length. As soon as the tendril comes in contact with any support system, auxin stimulates the cell to grow faster on the opposite side that’s why the tendril forms a coil around the support.
Common Examples of Auxin based on their Synthesis
Naturally occurring auxins: Indole acetic acid, indole ethanol, indole acetaldehyde.
Synthetic auxins: Naphthalene acetic acid, indole butyric acid, 2, 4 - dichlorophenoxyacetic acid.
Tendrils
In Botany, tendrils are defined as the plant organ which is specialised for anchorage and supporting the vining stems. They can be defined as the modified leaves, leaf tips, leaflets or stipules. They can also be derived from modified stem branches like in grapes. Tendrils are distinct and are specialised structures which strongly possess a tendency to the leaf which then encircles any object it encounters. It is thus, slender and whip-like strand which is produced from the node of the stem which is a vine or plants that climb on objects or other plants. The anatomy of the tendrils may be like that of a leafstalk tissue or a stem tissue. Examples of plants having tendrils are grapes, melon family, squash family and peas. Tendrils are sensitive to contact and when it is bent towards the ground it actually bends towards the ground. When it encounters an object, it encircles the object and clings to it for a long time as long as the stimulation is persisted. Eventually, sclerenchyma which is a strong mechanical tissue develops in tendrils and supports the vining system which makes them strong enough to carry the weight of the plant.
Some of the tendrils produce terminal enlargements which come in contact with firm surfaces that flatten and secrete an adhesive which actually glues the tendril to the substrate. Based on the growth of the tendril, there are two types of them which are namely the stem tendril and leaf tendril. The difference between the stem tendril and the modified tendril is that the stem tendril is a modified stem but the leaf tendril is a modified leaflet, leaf or its part. Both their growth mainly supports the part to which they are attached to and gives support to them. This process is called thigmotropism.
FAQs on Tendril: Definition, Functions, and Examples
1. What is a tendril and what is its main function in plants?
A tendril is a specialised slender, thread-like structure that is used by climbing plants for support, attachment, and cellular invasion. Its primary function is to help a plant with a weak stem, like a grapevine or pea plant, to climb upwards towards a support structure, ensuring it gets adequate sunlight for photosynthesis. This movement is a key survival adaptation for many vining plants.
2. What parts of a plant can be modified to form a tendril? Provide some examples.
Tendrils are fascinating examples of plant adaptation and can be formed from the modification of various plant organs. Common modifications include:
Stem Tendrils: The entire axillary or terminal bud modifies into a tendril. Example: Grapevine and passionflower.
Leaf Tendrils: The entire leaf transforms into a tendril. Example: Wild pea (Lathyrus aphaca).
Leaflet Tendrils: One or more of the leaflets of a compound leaf become tendrils. Example: Garden pea (Pisum sativum).
Petiole Tendrils: The petiole (leaf stalk) becomes elongated and coils like a tendril. Example: Clematis.
3. What is the key difference between a stem tendril and a leaf tendril?
The primary difference lies in their origin. A stem tendril develops from a modified axillary or terminal bud of a stem, as seen in grapevines and cucumbers. In contrast, a leaf tendril originates from a modified leaf or a part of a leaf (like a leaflet or petiole), as observed in pea plants. While both perform the same function of climbing, their anatomical origin is the main distinguishing factor. You can learn more about the Difference Between Stem Tendril and Leaf Tendril on our detailed page.
4. How do tendrils coil around a support? Explain the mechanism involved.
Tendrils coil around a support through a process called thigmotropism, which is a plant's directional growth in response to touch. When a tendril comes into contact with an object, the side touching the support grows slower, while the opposite side grows faster. This differential growth is regulated by the plant hormone auxin, which moves away from the point of contact, accelerating cell elongation on the outer side. This causes the tendril to bend and coil tightly around the support structure. For more information, you can explore the topic of Tropism in plants.
5. Are the thorns of Bougainvillea and the tendrils of Cucurbita related in terms of evolution?
Yes, they are related. The thorns of Bougainvillea and the tendrils of Cucurbita (cucumber family) are classic examples of homologous structures. This means they share a common evolutionary origin—both are modifications of the axillary bud. However, they have evolved to perform different functions. The thorn provides protection against herbivores, while the tendril provides support for climbing. This phenomenon, where related structures adapt for different purposes, is known as divergent evolution.
6. How does the climbing mechanism of a plant with tendrils differ from a plant that is a twiner?
The key difference is the structure used for climbing.
Tendril climbers, like pea plants and grapevines, use specialised, sensitive organs (tendrils) to grasp and coil around a support. The main stem remains relatively straight.
Twiners, like morning glory or beans, use their entire main stem or its growing tip to wrap around a support in a helical or spiral manner. They do not possess specialised tendrils for this purpose. You can learn about different plant habits on our page covering the difference between creepers and climbers.
7. Do tendrils perform photosynthesis?
Generally, the primary function of a tendril is support, not photosynthesis. Most tendrils are non-leafy, slender structures that lack a significant amount of chlorophyll. However, some tendrils, especially when young, may appear green and can perform a limited amount of photosynthesis. But this contribution is negligible compared to the plant's main leaves, and their energy is primarily directed towards the mechanical function of climbing.
