seed floss of various trees of the Bombax genus of the Malvaceae family; the plants grow in tropical countries and are cultivated in the West Indies and Brazil. The seed floss's individual fibres, soft and ranging from pale yellow to brown in colour, are about 0.5 to 3.25 cm (0.25 to 1.25 inches) long and 20 to 40 microns (a micron is about 0.00004 inch) in diameter. Unlike the fibres of common commercial cotton (Gossypium), bombax cotton fibres come from hairs that grow from the side of the seedpod instead of from the seed itself. Although sometimes mixed with common-cotton fibres for spinning, bombax cotton is weaker and less elastic and contains the woody plant substance lignin, making it unsatisfactory for use alone as a textile fibre. The floss is used primarily as wadding and upholstery material.
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