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Common Name: Wild Indigo, Horsefly weed, Shoofly, American indigo, Yellow indigo, False indigo, Indigo weed, Indigo broom - The constituent parts of the plant yield a blue dye when dried, crushed and hydrated that is similar to but not as deep as the blue from the true indigo plants (genus Indigofera)


Scientific Name: Baptisia tinctoria - The generic name is from baptizein, the Greek verb 'to dye' in reference to their use in this application. Similarly the nomem trivialum or trivial name is from tinctura, the Latin verb for the act or instance of dying.


The use of colored dyes for artistic, ritualistic and practical applications is one of the defining attributes of Homo sapiens. Red ochre has been found in burial sites dating to 15,000 years BCE.  Indigo is one of the most ancient colorants, imparting a cyanic hue to contrast with the ocherous tones of the cave habitat. Based on cultural etiology, indigo and madder, a red dye made from the root of the madder herb (Rubia tinctorum), have been in use on the Indian subcontinent since 2500 BCE.  The etymology of the word indigo indicates the provenance of the blue dyes of the Greco-Roman Western Civilization; it is derived from indikon, the Greek name for India. The primary sources of indigo dye  are plants of the genus Indigofera, notably I. tinctoria,  which is native to the tropics in both the Old World of Eurasia and Africa and the New World of the Americas and to the woad plant (Isatis tinctoria), a biennial herb native to Europe. Blue dyes have been in use for millennia in civilizations from Mesopotamia to Mesoamerica; Egyptian mummies dating from 2000 BCE have been found wrapped with strips of indigo-dyed cloth and the Romans used indigo pigments for painting and cosmetics.


The collapse of commerce that attended the cultural vacuum of the so-called Dark Ages in  Europe rendered Indian indigo a rare commodity, the native woad serving as the blue dye surrogate. The Age of Discovery and the concomitant colonization by the European powers engendered a resurgence of indigo as a dye; by the late 19th Century, over 3,000 square miles of cropland was dedicated to the cultivation of 19,000 tons of I. tinctoria, primarily in India but also in South Carolina and Jamaica. The conversion of the indigo plant to indigo dye is a fairly involved process that involves the hydrolyzing of indican, which comprises only about 0.5 percent of the leaves, into indoxyl, which is oxidized by the air into the dye indigo. When the synthetic dye industry was founded in 1857 by the English chemist William Perkin, the search for an artificial colorant to replace indigo began in earnest. The German chemist Adolf von Baeyer first  synthesized an alternative chemical (C16H10N2O2) to indoxyl in 1883 but it was not until 1897 that a commercially viable chemical blue dye was formulated (a fusion of sodium phenylglycinate in a mixture of caustic soda and sodamide). By the First World War, the cultivation of I. tinctoria for blue indigo dye had largely ceased.


Wild or American  indigo was never widely used as a substitute for the far more esthetic blues of the true indigo, though they are closely related members of the Pea Family (Fabaceae) as evidenced by the characteristic 'pea-like' flowers. The North American variant was, however, widely used by Native Americans  as a medicinal. The Mohegan Tribe of  Connecticut boiled wild indigo roots to formulate a decoction used as a vulnerary, easing the pain of an open wound. The Cherokee and Iroquois both used the plant  as a palliative for hepatic problems and venereal disease. The Native Americans of the west used it as a more general all-purpose herb, and, when joined in admixture with juniper, as a treatment for influenza and pneumonia. Wild indigo made the transition to the colonial population and was for a time included in the U. S. Pharmacopoeia as a treatment for typhoid fever and for dysentery.


Wild indigo contains a number of constituent chemicals that can have a palliative or toxic effect according to the concentration of the dosage, notably estrogenic and antioxidant isoflavones common to the Pea Family in addition to the more ubiquitous alkaloids and polysaccharides. The alternative common names Horsefly weed and Shoofly attest to its use as an insect repellant. Though it has been used for many years as  an herbal remedy for a variety of ailments, most references caution against direct ingestion with added invectives against its use in treating children, pregnant women and people with liver and kidney problems, though there are no recorded fatalities involving the plant. Baptisia tinctoria combined with Echinacea purpurea and Thuja occidentalis (Northern White Cedar) has been demonstrated in double blind tests with  over 250 participants to improve recovery from the symptoms of the common cold. Under the aegis of the "rational phytotherapy" of the German Commission E, it is used by about two thirds of Germans for treatment of colds and the flu.

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