What's Up With That?!
Weird Stuff and Fun Facts from the Gardening World: by Nancy Rose
Ever eat a pear and feel a bit of grittiness between your teeth? What you were chewing on were stone cells, a rather unique type of cell found in the fruits of pears and quince.
Stone cells are one example of the cell types found in sclerenchyma. Sclerenchyma (pronounced sklahr-ING-ke-mah, more or less) is an important type of plant tissue that provides support in various plant parts. Sclerenchyma cells have extremely thick cell walls - in fact, this thickened wall comprises nearly the entire cell.
The two main types of sclerenchyma are sclereids and fibers. Stone cells are one type of sclereid. Sclereids come in a range of shapes but are generally short and chunky. In addition to those gritty bits in pears, sclereids are also responsible for the hard outer layer of plant parts like walnut shells and cherry pits.
The other type of sclerenchyma, fiber cells, also have thick walls but fibers are generally long and thin. In some plants these fibers are so fine and flexible that they can be extracted and used for making fabrics or rope. Prime examples are flax, hemp, and jute.