Dipsacus fullonum ssp fullonum. Historically teasels have been used to bring up a lustrous polished nap or pile on certain woollen cloths before the final finishing process. This image was taken from the bas-relief on the Cloth Worker's Court Building at the University of Leeds.
And here they are ready for action at Armley Mills, apparently no mechanical invention has been found to match the teasel.
The image was manipulated in photoshop, printed on cloth and stitched by Elizabeth Thackrah.