Description

Indigofera tinctoria, true indigo, is an annual or perennial shrub of the family Fabaceae, native to tropical Asia and now cultivated across South Asia, tropical Africa, and the Americas. The plant is the world’s oldest commercial dye crop and one of the most historically significant cultivated plants in global trade history — documented in ancient Mesopotamian, Egyptian, Greek, and Indian texts as a prized blue colorant. The leaves contain the glucoside indican, which upon fermentation yields the brilliant blue pigment indigotin. The British colonial indigo trade — centred in Bengal — was one of the most economically consequential botanical industries in Indian history, leading to the Indigo Revolt of 1859. In Ayurvedic medicine, the leaves are referenced as Nili and incorporated in formulations for liver conditions, skin disorders, and anti-parasitic preparations.