Blue Flag, Harlequin blueflag

Iris versicolor

Physical Characteristics

Iris versicolor is a PERENNIAL growing to 0.6 m (2ft) by 1 m (3ft 3in). See above for USDA hardiness. It is hardy to UK zone 5. It is in flower from May to June. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. The plant is self-fertile. Suitable for: light (sandy) and medium (loamy) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist or wet soil.

Distribution

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

Habitats

Bog Garden;

Edible Uses

None known

Medicinal Uses

Alterative Antiinflammatory Cathartic Cholagogue Diuretic Emetic Sialagogue Stimulant Blue flag was one of the most popular medicinal plants amongst various native North American Indian tribes[213]. In modern herbalism it is mainly employed to detoxify the body - it increases urination and bile production and has a mild laxative effect[254]. Some caution should be exercised in its use, however, since there are reports that it is poisonous[222]. The fresh root is quite acrid and when taken internally causes nausea, vomiting, colic and purging[4, 238]. The dried root is much less acrid[4]. This remedy should not be prescribed for pregnant women[238]. The root is alterative, anti-inflammatory, cathartic, cholagogue, diaphoretic, diuretic, emetic and sialagogue[21, 46, 165, 238]. 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[4, 213]. It is also stimulant for the circulatory and lymphatic system[165]. Its detoxifying effect make it useful in the treatment of psoriasis, acne, herpes, arthritis, swollen glands, pelvic inflammatory disease etc[238, 254]. Externally, it is applied to skin diseases, wounds and rheumatic joints[238]. The roots are harvested in late summer and early autumn and are usually dried for later use[4, 238]. 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[213].

Known Hazards

Many plants in this genus are thought to be poisonous if ingested, so caution is advised[65]. The roots are especially likely to be toxic[238]. Plants can cause skin irritations and allergies in some people[238]. Fresh root can cause nausea and vomiting. The volatile oil furfural is irritant to mucous membranes and causes larchrymation (tears) and inflammation of the eyes. Irritation of the throat and headache also reported. The sap can cause dermatitis. Should not be used internally except in small doses. Should not be used by people with allergies or sensitivities [301].