Linen fibers are found in the stalk of the flax plant. Flax is a fast and easy growing annual herb that requires a cool and relatively humid climate. The plants are sown densely and uniformly so the stalks grow straight and resist wind in order to get the best quality long fibers. The long fibers used in textiles are on the outer part of the stalk covering a woody core.
Flax has been cultivated for millennia and, together with wool, was one of the most important fibers before the industrial revolution.