The Positive Benefits of Iris Versicolor (Blue Flag)

Other Common Names: Amerikan Suseni, Dagger Flower, Dragon Flower, Flag, Flag Lily, Harlequin Blueflag, Iris, Larger Blue Flag, Liver Lily, Poison Flag, Snake Lily, Water Flag, Iris versicolor

Range: Eastern N. America - Newfoundland to Manitoba, south to Florida and Arkansas.

Habitat: Swamps, wet meadows, scrub and by lakes and rivers. Wetlands.

Owing to the similarity of name, and the appearance before blooming, this flag is sometimes mistaken by American children for Sweet Flag or Calamus, which grows in the same localities, often with disastrous results.

Of the 100 species of true Iris, twenty-two inhabit the United States, but only one, Iris Missouriensis, much resembles this species (the rhizome of which yields an official American drug), or has a rhizome likely to be mistaken for it.

The root is an official drug of the United States Pharmacopoeia and is the source of the Iridin or Irisin of commerce, a powdered extractive, bitter, nauseous and acrid, with diuretic and aperient properties.

Blue flag was one of the most popular medicinal plants amongst various native North American Indian tribes. In modern herbalism it is mainly employed to detoxify the body - it increases urination and bile production and has a mild laxative effect. Some caution should be exercised in its use, however, since there are reports that it is poisonous.

The fresh root is quite acrid and when taken internally causes nausea, vomiting, colic and purging. The dried root is much less acrid. This remedy should not be prescribed for pregnant women.

The root is alterative, anti-inflammatory, cathartic, cholagogue, diaphoretic, diuretic, emetic and sialagogue. Taken internally as a tea, the root has been used as a strong laxative or emetic that also acts strongly on the liver and promotes the excretion of excess body fluids. It is also stimulant for the circulatory and lymphatic system. Its detoxifying effect make it useful in the treatment of psoriasis, acne, herpes, arthritis, swollen glands, pelvic inflammatory disease etc.



Externally, it is applied to skin diseases, wounds and rheumatic joints. The roots are harvested in late summer and early autumn and are usually dried for later use. The roots were boiled in water and then mashed to make a poultice which was used to relieve the pain and swelling associated with sores and bruises.

A fine blue infusion is obtained from the flowers and this can be used as a litmus substitute to test for acids and alkalis.

Some native North American Indian tribes used the root as a protection against rattlesnakes. It was believed that, so long as the root was handled occasionally to ensure the scent permeated the person and their clothes, rattlesnakes would not bite them. Some tribes even used to chew the root and then hold rattlesnakes with their teeth and were not bitten so long as the scent persisted.

Known Hazards: Many plants in this genus are thought to be poisonous if ingested, so caution is advised. The roots are especially likely to be toxic. Plants can cause skin irritations and allergies in some people.