Eden Apothecary · Herb Profile
Iris versicolor
Pronounced Blue Flag: bloo flag. Iris versicolor: EYE-ris ver-SIK-uh-ler.
Cool and drying: a stimulating, draining alterative that quickens a torpid liver and sluggish bile, drains congested lymph and swollen glands, and clears damp, toxic, eruptive skin.
No pre-1900 source found for this reading.
Avoid in pregnancy. Modern references advise against use for want of reliable human safety data, and because Blue Flag is a stimulating cholagogue and cathartic with emetic potential and a traditional emmenagogue reputation. WebMD and RxList state that Blue Flag is unsafe in pregnancy, PeaceHealth and Herbal Reality advise avoidance, and Mills and Bone and expert opinion do not recommend it in pregnancy. A Southern Cross University monograph, drawing on Mills and Bone, lists a less restrictive Category B (no documented malformations), but on the weight of modern consumer-safety guidance the prudent verdict is to avoid. The exact AHPA Botanical Safety Handbook class was not confirmed in this pass (see needs_review).
Avoid during lactation. There is no reliable data on Blue Flag's constituents in breast milk, and its acrid, irritant, emetic-cathartic nature and lack of lactation data warrant avoidance. Herbal Reality and expert opinion state it is not recommended in breastfeeding, and WebMD and RxList group lactation with pregnancy as unsafe. A Southern Cross University monograph lists a less restrictive lactation Category C (compatible), but the conservative, consumer-safe verdict on the available data is to avoid. Insufficient data; avoid.
Not recommended for children. WebMD and RxList advise that Blue Flag should not be given to children, and Herbal Reality states it is not suitable for children. There is no established pediatric dosing, and the rhizome is a gastrointestinal irritant that is emetic and cathartic, with a real overdose picture. Reserve any pediatric use to a qualified practitioner, and refer children with skin, glandular, or hepatic complaints for evaluation rather than treating at home. Insufficient data; avoid.
Blue Flag is a low-dose herb and not a casual tea. The fresh rhizome is intensely acrid and is emetic and cathartic; it should not be taken internally, and only the dried, aged rhizome is used. In large or repeated doses even the dried rhizome causes nausea, vomiting, violent purging, colic, salivation, and headache; keep to small, measured, specific-medication doses and do not exceed them. Avoid it in acute inflammation and ulceration of the digestive tract and in irritable, inflamed bowel conditions, which the acrid rhizome aggravates. The fresh plant, its juice, and root dust can irritate the skin, eyes, and mucous membranes. Because its emetic and cathartic action can deplete fluids and potassium, it can heighten the toxicity of cardiac glycosides such as digoxin, and should not be combined with them without supervision. It is not for self-directed use in pregnancy, lactation, or childhood, and must not delay medical evaluation of jaundice, biliary disease, or a hard, enlarging gland.
Pregnancy and lactation (avoid: a stimulating cholagogue and cathartic with emetic potential and a traditional emmenagogue reputation, and insufficient modern safety data). Children (avoid: no pediatric dosing, and a gastrointestinal irritant that is emetic and cathartic). Acute gastrointestinal inflammation or ulceration, gastritis, and inflammatory or irritable bowel disease, which the acrid rhizome inflames. Concurrent cardiac glycoside (digoxin) therapy, without supervision. Dry, cold, deficient, and exhausted constitutions, which its drying, draining, purging character aggravates. Known allergy or sensitivity to Iris. Never take the fresh rhizome internally; use only the dried rhizome in low, measured doses.
Iris versicolor is a common, widely distributed native perennial of eastern North American wetlands, and is also widely grown as an ornamental; it is not listed as at-risk or to-watch by United Plant Savers. The real concerns are habitat and harvest: its marsh, wet-meadow, and streambank habitat is diminished by wetland drainage and development and is being displaced in places by the invasive yellow flag (Iris pseudoacorus), and digging the rhizome kills the plant. Prefer cultivated or responsibly wildcrafted dried rhizome, taken only from abundant stands and never from fragile or shrinking wetland populations.
Not found in the canonical biblical texts nor in the classical Greco-Roman herbals of Dioscorides and Pliny, who describe the Old World Iris (orris, Iris germanica and I. florentina) rather than this species. Iris versicolor is native to eastern North America and was unknown to the ancient Mediterranean world. Its medicinal tradition is Native American (the Anishinaabe/Ojibwe, Iroquois, and other eastern peoples used the rhizome for skin, glandular, and hepatic complaints) and, from that root, nineteenth-century Eclectic and Physiomedical American herbalism. Cited honestly as a herb of North American, not biblical, tradition.
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