Isatis tinctoria (syn. I. indigotica)

Family

Brassicaceae (Cabbage Family)

Etymology

Isatis the genus and common name is a Greek term denoting a plant producing a dark dye. Tinctoria, the species name, derives from the Latin tingere, "to tinge," in reference to this plant being a source of a blue dye.  

Range of Appearance

Isatis is a biennial or perennial native to Eurasia that grows in moist, alkaline soil in full sun to partial shade. The first year it bears a rosette of leaves; in its second year it produces a stem of about 2 feet in height bearing small, four-petaled, hermaphroditic yellow flowers. The leaves are pointed and oblong. The seed capsules turn black when ripe. Isatis is widely naturalized in North America and is considered a noxious weed in many regions.

Parts Used

Root (primarily), leaf

Physiological Effects

Alterative, antibiotic, anti-inflammatory, antimicrobial, antiseptic, antiviral, astringent, febrifuge

Medicinal Uses

Isatis was once used in war paint during the Roman Empire, where it served the double purpose of stopping bleeding and healing wounds. The root is most commonly used, though the leaves are used as well. The leaves are said to be best for the upper portions of the body, such as the throat and lungs. Isatis diminishes the activity of bacteria, fungi, and viruses; it exhibits in vitro activity against E. coli, salmonella, shigella, neissera, staph, and strep bacteria. It clears heat, reduces inflammation, and increases the number and activity of phagocytes. It is used to treat AIDS, blood poisoning, boils, bronchitis, cancer, chicken pox, conjunctivitis, cough, encephalitis, fever, hepatitis, herpes, HIV, infection, jaundice, laryngitis, leukopenia (low white-bloodcell count), measles, meningitis (viral), mononucleosis, mumps, pneumonia, scarlet fever, shingles, sore throat, tonsillitis, and typhoid. Topically, isatis can be used as a poultice to prevent infection in wounds.

Culinary Uses

The root is not generally considered edible. The leaves can be consumed but are very bitter; they are best if soaked first and rinsed.

Other Uses

After a double-fermentation process, the aboveground portions of the plant produce a blue dye, which was used in ancient times, among other purposes, by peoples of Britain to dye their bodies blue in order to present a terrifying appearance to their enemies in battle. The dye is still in use today, though for tamer purposes, such as to enhance indigo dyes and to dye cotton a dark blue.

Constituents

Arginine, glutamine, proline, tyrosine, polysaccharides, sitosterol, isatin, pigments (indirubin), resin

Contraindications

Do not use isatis for more than three weeks at a time. Long-term use can deplete the body of friendly intestinal flora, weaken digestion, and cause internal coldness. There are some reports of isatis causing nausea. Do not use in cases of general weakness.

Plant details were provided by iPlant by Brigitte Mars.

Hyperlink it to https://brigittemars.com/iplant-app/