Historical Data
The use of Indigofera tinctoria L. in India dates back to the Indus Valley period between the 4th and the 2nd millennium BC. Indigofera tinctoria is native to India one of the oldest known centres of indigo dye production. The association of India with indigo is revealed in the Greek word for the dye, indikon, meaning 'blue dye from India or more literally Indian substance. The Romans used the term indicum, which passed eventually into English as the word indigo. Many species of the Indigofera genus give blue indigo dye, of these Indigofera tinctoria is believed to give the highest yield (under ideal growing conditions). The name indigo also shows that trade in Indian indigo was already well established during the Greco-Roman period, and by implication that cultivation and processing of indigo were also well established.
