Sclerenchyma

Sclerenchyma

Sclerenchyma is the tissue which makes the plant hard and stiff. Sclerenchyma is the supporting tissue and contributes to the mechanical behaviour of plants. Two types of sclerenchyma cells exist: cellular fibers and sclereids. Their cell walls consist of cellulose, hemicellulose, and lignin. Sclerenchyma cells are the principal supporting cells in plant tissues that have ceased elongation. In fruit peduncles (stalk), sclereids often develop from cortical parenchyma and form rings or bands together with sclerenchyma fibres. Experiments in apple fruit have shown that fibres maintain stiffness and tensile strength of the peduncle, while sclereids are especially effective in building resistance to bending and in dampingoscillations caused by wind. In this way, sclereids help peduncles to support the growing mass of developing fruits while holding enough flexibility to avoid mechanical failure and preventing them from breaking due to loads caused by the fruit weight and winds. Sclerenchyma fibers are of great economic importance, since they constitute the source material for many fabrics (e.g. flax, hemp, jute, and ramie).