Colouring material blue violet extracted from the leaves and stems of indigotier, the indigo derives its name from the resulting dark blue coloration. In Africa, the two most used indigo plants are Indigofera Arrecta and Lonchocarpus Cyanescens. The first grows in dry areas and gives a blue called « savannah blue » and the second, more widespread in West Africa, produces an indigo plant colour called « blue forest ». The leaves harvested from these plants are used to prepare the dye, which are used fresh or dried and are compacted into balls or paste, which are then diluted.