Indigo Dye is obtained from the processing of the plant's leaves. They are soaked in water and fermented in order to convert the glycoside indican naturally present in the plant to the blue dye indigotin. The precipitate from the fermented leaf solution is mixed with a stron... 

Most natural indigo dye is obtained from indigo leaves in the genus Indigofera, which are native to the tropics. In Europe, indigo can be obtained from woad (Isatis tinctoria) and dyer's knotweed (Polygonum tinctorum). The primary commercial indigo species in Asia is true in... 

Indigofera tinctoria bears the common name true indigo. The plant was one of the original sources of indigo dye. It has been naturalized to tropical and temperate Asia, as well as parts of Africa, but its native habitat is unknown since it has been in cultivation worldwide f...