An example of fibre obtained from stem of the plant is:

Question

Accepted Answer

The correct option is 4: Flax

Flax fibre is a classic example of what is scientifically classified as a **bast fibre**, meaning it is obtained directly from the phloem or inner bark of the plant's stem. The fibre is harvested from the flax plant, *Linum usitatissimum*. To extract the long, strong, and highly valued fibres, the stems must undergo a process called retting, which involves soaking the stems to allow microbial action to break down the cellular tissues binding the fibre bundles together. The raw fibre is then separated from the woody core of the stem through scutching and hackling. These stem fibres are the raw material used to produce the luxurious and durable fabric known as linen, distinguishing flax as a key agricultural product derived specifically from the stem of the plant.

The incorrect option is 1: Kapok

Kapok fibre is obtained from the seeds contained within the large pods or fruits of the Kapok tree, *Ceiba pentandra*. This fibre is essentially a seed fibre, much like cotton, as it grows inside the fruit surrounding the seeds. It is a light, buoyant, and water-resistant fibre that is known for its silky feel but is too brittle and smooth to be easily spun into yarn. Because it is harvested from the interior of the plant's fruit, and not from the structural tissue of the stem, it does not fit the description of a stem-derived fibre. Therefore, despite its general classification as a natural fibre, its botanical origin disqualifies it as a correct answer.

The incorrect option is 2: Coir

Coir is a coarse, hard fibre that is extracted from the outer husk (the mesocarp) of the coconut fruit, which is a large drupe. The purpose of the coir layer is to provide buoyancy and protection for the seed during its waterborne dispersal in the wild. Its strength, resistance to salt water, and durability make it ideal for products like doormats, brushes, and ropes. Since coir is structurally part of the fruit's protective layer, it is botanically classified as a fruit fibre. This is a distinct category from the bast fibres that are found in the inner bark or stem of a plant.

The incorrect option is 3: Cotton

Cotton is, without a doubt, the world's most important natural fibre, but it is not derived from the stem. The fluffy white material we recognize as cotton fibre is technically a seed hair: long, single-celled epidermal hairs that grow from the surface of the cotton plant's seeds, which are enclosed in a structure called a boll. When the boll matures and bursts open, the fibre becomes visible and ready for harvesting. Because the fibre originates directly from the seed coat as an outgrowth, cotton is categorized strictly as a seed fibre, making it an incorrect example of a fibre obtained from the stem of the plant.