Fibers, fiber products, and forage fiber

Many species of plants yield natural fibers that are interwoven to manufacture a variety of valuable products including fabrics, cordage, paper, and brushes. Plant fibers are also incorporated into various composite materials in which a matrix phase is reinforced with fibers. At maturity, fibers typically lose their protoplasts, and thus play no role in metabolism. Fibers lend strength and resilience to the materials made with them. Fibers positioned in the phloem or cortical regions of the stem and leaf fibers of monocotyledons include a number of commercially important cells that are very strong and flexible and which are used in the manufacture of various products. In response to being naturally or experimentally displaced from their normal growth orientation, the main axis or lateral branches of actively growing stems are stimulated to form wood with an eccentric growth pattern that is composed of cells having both an atypical structure and a chemical composition. This secondary xylem is known as reaction wood. The reaction wood of gymnosperms forms on the lower side of the woody cylinder and is known as compression wood. Tracheids of compression wood possess walls with visible discontinuities and abnormal microfibril angles.