Background
- Blue flag is a species of iris, which commonly grows in moist meadows, marshes, and along stream banks in northern North America. The root or rhizome is the part most often used and is the source of the iridin, also known as irisin. Iridin is usually used as a powdered extract that is bitter and nauseating and has diuretic and laxative properties.
- The blue flag rhizome has a very slight but peculiar odor, and a pungent, unpleasant taste. When used internally, fresh blue flag produces nausea, vomiting, purging, and gastrointestinal cramping. The dried root is less acrid and is traditionally employed as an emetic, diuretic, and cathartic. It has also been used for syphilis, some scrofula (tuberculosis infection of the neck lymph glands), skin disorders, and dropsy (edema).
- Currently, blue flag is frequently used topically for skin conditions, such as impetigo, eczema, and psoriasis. It is also used for detoxification by increasing urination, stimulating bile production, and acting as a laxative. Various Native American tribes have had many uses for blue flag including for lymphatic or kidney cancer.
- There are currently no high quality studies on the medicinal applications of blue flag. Clinical trials are needed to define the efficacy and safety of blue flag.
References
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to . Selected references are listed below.