Flax, (Linum usitatissimum), plant of the family Linaceae, cultivated both for its fibre, from which linen yarn and fabric are made, and for its nutritious seeds, called flaxseed or linseed, from which linseed oil is obtained. Though flax has lost some of its value as a commercial fibre crop owing to the availability of synthetic fibres, flaxseed has grown in popularity as a health food, and flax remains economically significant in a number of countries around the world, including China, Russia, and Canada.Linen, Fibre, yarn, and fabric made from the flax plant. Flax is one of the oldest textile fibres used by humans; evidence of its use has been found in Switzerland's prehistoric lake dwellings. Fine linen fabrics have been discovered in ancient Egyptian tombs. The fibre is obtained by subjecting plant stalks to a series of operations, including retting (a fermentation process), drying, crushing, and beating. Linen is stronger than cotton, dries more quickly, and is more slowly affected by exposure to sunlight.