Name the two types of cells found in sclerenchymatous tissue

Sclerenchymatous tissue comprises two distinct cell types: fibers and sclereids, each with unique structural characteristics and functional roles in plant support. Fibers are elongated, slender cells with tapering ends that can measure several millimeters in length, arranged in bundles that run parallel to the long axis of plant organs. These cells have thick, heavily lignified walls with a very narrow or obliterated lumen (central cavity), providing tensile strength that prevents breakage when plants bend or sway. Commercial textile fibers like jute, hemp, and flax are actually sclerenchyma fibers extracted from plant stems.

Sclereids, in contrast, are shorter, variably shaped cells—sometimes spherical, branched, or irregularly star-shaped—that are scattered individually or in groups throughout plant tissues. These cells, also called stone cells, have extremely thick, multilayered walls with numerous pits for communication. Sclereids give the characteristic gritty texture to pear fruits, form the hard shells of nuts like walnuts and coconuts, and create the protective seed coats of legumes. While fibers primarily provide flexible support allowing plants to withstand pulling forces, sclereids offer rigid, localized protection against mechanical damage and herbivory. Both cell types are typically dead at functional maturity, having deposited their thick walls before the protoplasm degenerates, leaving behind hollow structures that efficiently combine strength with minimal metabolic cost.