The grainy taste of pear flesh

Sclerenchyma cells are derived from parenchymal cells, which form secondary thickening edges in the cell wall. These are rich in lignin, which practically does not allow any substances getting through, which finally leads to dying of the cell content. Sclerenchyma is thus usually a dead support tissue, whose task is mainly to provide support an mechanical strength. Depending on the shape of the cells, stone cells (sclereids) and sclerenchyma fibers are distinguished.

Stone cells are approximately isodiametric in shape and completely changed into wood like structures. Branched pit channels are usually found in their walls. They are responsible for the grainy taste of the pear flesh. They are also found in the kernels of stone fruit  

Sclerenchyma fibers are elongated, pointed cells. In groups they form long, tight structures. Such fibers are economically very important, we think of the wood fibers which are the main constituent of wood or the less wood-like and more flexible fibers, which are found in flax, coconut palm fibers, jute and the like.