Fibers from the stems of flax plants are used to make linen. Flax fibers are up to three times stronger than cotton, so they are very durable. Flax flourishes in cooler climates and is primarily grown in France, Netherlands, and Belgium. Traditionally, linen has been used for bedding and upholstery, but today, it is frequently used in fashion.

Linen fabric is made from the cellulose fibers that grow inside the stalks of the flax plant. Flax, also known as common flax or linseed, is a flowering plant, 'Linum usitatissimum', one of the oldest cultivated plants in human history.

More Info: en.wikipedia.org