Synthetic fibers are the result of an extensive search by scientists to increase and improve upon the supply of naturally occurring animal and plant fibers that have been used in making cloth.
... Birch, both European[?] and Kamchatkan[?]
(Betula elba and B. Ermani), elder, poplar, elm, wild cherry[?] (Prunus padus), Taxus baccata and several willows are mixed with ...