Common burdock (Arctium minus) (Compositae family). The thistle-like burs or flower heads, particularly the hooked, bristly bracts, of this bushy plant served as a model for the hook-and-loop fastener such as Velcro. The seeds attach themselves to passing animals to spread into a greater distance. Thus the hooks serve seed dispersion. Enhanced SEM. Image width: 965 micrometers. Magnification: 104x if the image is printed 10 cm wide. Bar: 200 micrometers.