Commercially important cotton fibres are

Cotton fibers are unicellular, epidermal hairs that grow on the outside of seeds contained within the pod of boll of several species of the Gos-sypium genus. When the boll ripens and fibers reach maturity, the boll bursts open, the fibers dehydrate and the wide central lumen in the fiber collapses forming mass of flattened fibers with rod-like side walls and twists along the fiber length.