sclereid

A relatively short *sclerenchyma cell, usually formed when the wall of a parenchyma cell undergoes secondary thickening and, often, lignification. The simple pits of sclereids are often more conspicuous than those of *fibres. Sclereids are often present as idioblasts in other tissues. They may however be present in large numbers, as, for example, in those plants where they form the testa of the seed. See also astrosclereid , brachysclereid , macrosclereid.