Sclerenkymän

Sclerenchyma is a type of supporting tissue in plants, characterized by cells with uniformly thickened, lignified secondary cell walls. These cells are typically dead at maturity, providing mechanical strength and rigidity to plant organs. Sclerenchyma is found throughout the plant body, including in stems, roots, leaves, and the hard parts of fruits and seeds.

There are two main types of sclerenchyma cells: fibers and sclereids. Fibers are elongated, often spindle-shaped cells that are usually found in bundles. They contribute significantly to the tensile strength of plant tissues. Examples include the fibers in flax, hemp, and cotton. Sclereids, on the other hand, are variable in shape and size, and often occur singly or in small groups. They are responsible for the hardness of structures like nut shells, seed coats, and the gritty texture of pears.

The thick, lignified secondary walls of sclerenchyma cells are a key feature. Lignin is a complex polymer that makes the cell walls rigid and resistant to compression and decay. This structural integrity is crucial for supporting the plant against gravity and wind, and for protecting it from herbivores and pathogens. The presence of sclerenchyma contributes to the overall structural support of the plant, allowing it to grow upright and maintain its form.