Lignin is a complex organic compound that provides rigidity and strength to plant cell walls. In sclerenchyma tissue, lignin deposition in the cell walls increases their thickness, making them rigid and resistant to bending, thus providing strength to plant parts.

Sclerenchyma cells are dead and have long, narrow shapes with thickened walls due to lignin deposition, often leaving no internal space within the cell. In contrast, collenchyma cells are living, elongated, and irregularly thickened at the corners.

Sclerenchyma tissue contributes to the hardness and stiffness of plants. It is commonly found in structures such as the husk of a coconut, stems around vascular bundles, veins of leaves, and the hard covering of seeds and nuts.

Collenchyma cells are living, elongated, and irregularly thickened at the corners. Their arrangement with thickened cell walls provides strength and support while allowing flexibility, making them suitable for structures requiring bending in plants.

Collenchyma tissue provides flexibility and mechanical support to various parts of a plant, such as tendrils and stems of climbers, by allowing bending without breaking. It is typically found in leaf stalks below the epidermis.