includes a framework 12 for supporting sets of roller assemblies 14 and their associated drives 16 referring to fig2 4 the method in accordance with the invention includes arranging the roller assemblies 14 in sets so that they define the woody material bending regions 18 between upper and lower rollers 14a and 14b in a set the plant material 20 is then fed through these bending regions 18 as best seen in fig3 the method herein utilizing the machine 10 is ideally suited for decorticating flax straw to yield flax fibers although it will be recognized that other plant material from which it is desired to separate woody material from the plant fibers can also be processed by way of the method of the present invention to separate the woody material from the plant fibers the roller assemblies 14 are provided with bending or pulling surfaces or flutes 22 thereon the rollers 14 in a set are arranged so that the bending and pulling surfaces 22 move through the bending regions 18 in an overlapping manner thereby bending the plant material 20 in the bending region 18 the bending and pulling surfaces 22 are caused to move through their respective bending regions 18 at different predetermined operating speeds so.