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.