Sweet flag was used as a strewing herb to hide the odorous consequences
of poor sanitation during the middle ages in Europe. In North America,
natives chewed on the root as a stimulant much like coffee or cocoa, a
practice later adopted by Canadian trappers employed by the Hudson Bay
Company.
Although calamus root has been used as a flavoring agent for various
beverages, tooth powders and candies, and still is in some parts of
the world, use of the root or essential oil as flavoring or food has
been banned in the United States since 1968.