sclerenkymälle

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 support to the plant. Sclerenchyma cells are classified into two main types: fibers and sclereids. Fibers are elongated, spindle-shaped cells that often occur in bundles, contributing to the tensile strength of stems, leaves, and roots. Examples include the fibers found in flax and hemp. Sclereids are more variable in shape, ranging from isodiametric to irregular or stellate. They are commonly found in the hard, protective layers of seeds and nuts, as well as in the gritty texture of pears and the stony endocarp of some fruits. The thick, rigid cell walls of sclerenchyma are a result of the deposition of lignin, a complex polymer that reinforces the cellulose framework, making the cells strong and resistant to compression. This structural role is crucial for plant growth, allowing them to withstand environmental stresses such as wind and gravity, and for the protection of plant organs.