what is sclerenchyma

Sclerenchyma is a type of supportive tissue found in plants. It is composed of dead cells that have heavily thickened walls containing lignin and a high cellulose content. The cells are rigid and non-stretchable, and are usually found in non-growing regions of plant bodies, such as the bark or mature stems. Sclerenchyma is one of the three types of ground, or fundamental, tissue in plants; the other two types are parenchyma (living thin-walled tissue) and collenchyma (living support tissue with irregular walls) . Sclerenchyma cells occur in many different shapes and sizes, but two main types occur: fibers and sclereids. Fibers are greatly elongated cells whose long, tapering ends interlock, thus providing maximum support to a plant. They often occur in bundles or strands and can be found almost anywhere in the plant body, including the stem, the roots, and the vascular tissue.