are the roots of the Canadian thistle edible? I have also heard that you can put the open flowers in water and let them steep for about 8-hours, strain the water and use it to make thistle head cheese? also is the fruit of the may apple edible?
Missouri Department of Conservation has a book called Wild Edibles of Missouri that discusses both plants mentioned. The book is no longer in print but available as a pdf online at https://nature.mdc.mo.gov/sites/default/files/downloads/page/WildEdibles.pdf
I always urge extreme caution when looking for wild edibles because lots of plants are easy to miss identify and the consequences could be deadly.