Source
The root of Isatis indigotica Fort. (Fam. Cruciferae).

Distribution
Mainly in Chinese provinces such as Hebei and Jiangsu. Introduced to and cultivated in most regions of China.

Harvest & Processing
Dig out roots in autumn; remove stemsand leaves; wash clean and dry under the sun; store in cool, dry places.

Description
Cylindrical, slightly twisted; 10-20 cm long, 0.5-1 cm in diameter. Outer surface pale greyish-yellow or pale brownish-yellow, marked with longitudinal wrinkles, transverse lenticels and branch roots or branch root scars; top part slightly bulgy, with verticillate (arranged in whorls) dull green or dull brown remnants of petiole base, petiole scars and dense verruciform (wart-shaped) protuberances. Solid and slightly brittle. When broken, surface fairly even; bark yellowish-white, occupying about 1/2-3/4 of radius; xylem yellow.

Indications
1. Seasonal febrile diseases, pestilence
2. Mumps and other eruptive exanthem
3. Aphthous ulcer, sore throat

Chemical Composition
Mainly contains indigotin and indirubin.

Photos