Differences Between Fibers and Sclereids

INTRODUCTION

Sclerenchyma is a type of simple permanent tissue. It forms the main strengthening tissue of the plant. It consists of long, narrow, thick-walled and lignified dead cells. They are fibre like in appearance due to their pointed structure at both ends. For this, the tissue is called sclerenchymatous fibres or simple fibres.

They also have simple, often oblique pits in their walls. The middle lamellae is conspicuous in sclerenchyma. They are found abundantly in plants, and occur in patches or in definite layers.

WHAT ARE THE FUNCTIONS OF SCLERENCHYMA?

They serve purely mechanical function, i.e., they give strength and rigidity to plant body and thus enable it to withstand mechanical strains.

TYPES OF SCLERENCHYMA

Sclerenchyma is of two types. They are:

• Fibers
• Sclereids or stone cells

WHAT ARE FIBRES AND SCLEREIDS?

Fibres are type of sclerenchyma that are long, thick-walled and are dead cells that provide support to the internal structure of plants.

Image source: articlebazar

Fibers are of three types, which is on the basis of their origin. They are:

• Surface fibers

These fibers are found in the testa of various seeds or form the covering on the fruit. For e.g. cotton fibres, mesocarp fibre of coconut.

• Wood fibers

Mostly present in the xylem of stem and roots. They are also known as xylary fibres. They originate from the derivatives of the cambium.

• Bast fibers

These are obtained from pericycle and phloem of various plants. These fibres are also known as extra xylary fibres as they occur outside the xylem.

FUNCTIONS OF FIBERS

• Give mechanical strength that is the major function.
• Save the plant from various stresses and strains of the environmental factors such as strong wind based on the position and distribution.

SCLEREIDS AND ITS FUNCTIONS

They are extremely thick walled. They are of various shapes like spherical, oval, cylindrical, T or dumb-bell shaped or even stellate. They are generally found in hard parts of plant body and sometimes in the pulp of fruits. Sclereids can be categorized into four main types on the basis of their shapes. They are:

Imagesource: brainkart

i. Brachysclereids or stone cells (isodiametric)

ii.Macrosclereids or rod cells (elongated rod like)

iii. Osterosclereids or prop cells (rod with dilated ends)

iv. Asteosclereids (stellate or star like form)

FUNCTIONS OF SCLEREIDS 

• They provide local mechanical strength and protection.

COMPARISON BETWEEN FIBERS AND SCLEREIDS  

References: 

i) https://www.brainkart.com/article/Difference-Between-Different-types-of-tissues_33031/

ii) https://pediaa.com/difference-between-fibres-and-sclereids/

Differences Between Fibres and Sclereids