Difference Between Tendrils and Spine

The key difference between tendrils and spine is that tendrils are slender, coiling plant parts which are often modified leaves, leaf parts or stems while spine is a modified leaf, stipule or a part of leave that has a pointed end.

Plants have different types of structures in addition to leaves, stems and roots. Tendrils and spines are two such structures. They can be modified leaves, leaf parts, stipules, petioles or stems. Tendrils are thread-like in shape while spines have pointed ends. Tendrils support climbing plants to twine around a suitable host. Spines fulfil a defensive function as they protect plants from herbivores.

CONTENTS

1. Overview and Key Difference
2. What are Tendrils 
3. What is Spine
4. Similarities Between Tendrils and Spine
5. Side by Side Comparison – Tendrils vs Spine in Tabular Form
6. Summary

What are Tendrils?

Tendril is a modified stem, leaf or petiole that is thread-like in shape. Tendrils help plants to twine around a suitable host. They are also useful in attachment and cellular invasion. They twine around suitable hosts by sensing touch. In other words, when tendrils come into contact with an object for a certain time period, they usually curl around it.  Tendrils do not have a lamina or a blade. But, they are green in colour, and they can photosynthesize. Moreover, tendrils are sensitive to chemicals. This ability helps them to find the direction of growth. Stem tendrils and leaf tendrils are seen in many climbing plants.

Stem tendril is a modified or specialized stem or terminal bud. The growth of stem tendril occurs through the help of axillary bud. Stem tendrils wind themselves around objects in order to stabilize the upward growing plant. Stem tendrils are commonly seen in passion fruits and grape wine. Stem tendrils can be branched or unbranched. There may be scale leaves on the stem tendrils. Moreover, there are four types of stem tendrils as axillary, extra- axillary, leaf opposed and floral bud or inflorescence tendrils.

Figure 01: Tendril

Leaf tendril is a type of tendril that is formed from an entire leaf. They can be formed from modified leaflets, leaf tips, or leaf stipules as well. In some plants such as sweet pea and vicia, leaf axis terminates in a tendril in order to facilitate climbing. In the flame lily, the leaf tip of the blade elongates into a tendril for the support of the plant. Moreover, in garden pea, the terminal leaflet of the compound leaf modifies into a tendril, while in some plants, several leaflets of the compound leaf convert into tendrils. Furthermore, in some other plants, leaf petiole modifies into a tendril for the purpose of clinging.

What is a Spine?

A spine is a hard extension with a pointed end. It is made for defensive purpose. Spines are mainly modifications of leaves. The entire leaf or a part of the leaf modifies into a spine. There are vascular tissues inside the spine.

Figure 02: Spines

In prickly pear, the minute leaves of the axillary bud modify into spines. In date palm, the leaf apex modifies into a spine. In barberry, whole-leaf has modified into a spine. In cacti, spines are wholly transformed leaves that protect the plant from herbivores. Furthermore, spines can develop from the leaf margins as well. Roots and buds also can be modified into spines.

What are the Similarities Between Tendrils and Spine?

• Tendrils and spines are found in plants.
• They may form due to modifications of leaves, roots, stems or buds.
• Both are important structures of plants.

What is the Difference Between Tendrils and Spine?

Tendrils are modified stems, leaves or petioles with a threadlike shape while spine is a modified leaf, stipule or a part of a leaf with a pointed end. So, this is the key difference between tendrils and spine. Functionally, tendrils are useful for climbing plants, mainly for support and attachment, while spines protect the plants from herbivores. Besides, a further difference between tendrils and spine is that tendrils are sensitive to chemicals while spines are not sensitive to chemicals.

Summary – Tendrils vs Spine

Tendrils are modified leaves, leaflets, leaf tips, or leaf stipules that are specialized to anchor and support climbing plants. In contrast, spine is a stiff, rigid structure with a sharp point which provides protection against herbivores. It can be a highly modified leaf, scale, or stipule. Structurally, tendrils are thread-like structures while spines are sharp thorns like. So, this summarizes the difference between tendrils and spine.

Reference:

1. “Thorns, Spines, and Prickles.” Wikipedia, Wikimedia Foundation, 25 Sept. 2019, Available here.
2. “Tendril.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 23 Aug. 2016, Available here.

Image Courtesy:

1. “Vine” By Jon Sullivan –  (Public Domain) via Commons Wikimedia
2. “3573574” (CC0) via Pixabay

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