This species is closely related to Indigofera flavicans, having a more northerly range than that species[
Indigofera diphylla is a semi-woody, spreading, perennial herb growing 30 - 60cm tall[
The plant is harvested from the wild for local use as a dye and medicine, it is also sometimes grown to help stabilize sand dunes.
Sub-Saharan tropical Africa - Mauritania and Senegal east to Sudan.
Fixed sand dunes in dry sandy areas[
|Other Uses Rating||
|Cultivation Status||Cultivated, Wild
Indigoera species generally grow best in a sunny position, preferring a well-drained but moist soil[
]. Many of the species will also succeed in drier conditions and in poor soils.
We have seen no specific information for this species, but most members of the genus have a symbiotic relationship with certain soil bacteria; these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby.
The plant is used medicinally[
Plants can be used to help stabilize sand dunes[
The plant is the source of a blue dye[
The leaves and twigs of Indigofera species do not actually contain indigo, but rather they contain colourless precursors that must be extracted and then processed in order to produce the indigo dye[
The harvested leafy branches are placed in a tank containing water to which some lime has been added, and are weighted down with planks[
]. After some hours of fermentation, during which enzymic hydrolysis leads to the formation of indoxyl, the liquid is drained off and then stirred continuously for several hours to stimulate oxidation of the indoxyl[
]. Afterwards the solution is left to rest and the insoluble indigo settles to the bottom as a bluish sludge[
]. The water is drained and after the indigo has dried, it is cut into cubes or made into balls[
To dye textiles, indigo is reduced to a soluble form by a fermentation process under alkaline conditions. In traditional preparations of the dye, various reducing agents such as molasses are used, together with coconut-milk, bananas and the leaves of Psidium guajava[
]. The alkalinity is maintained by adding lime. After the textile has been dipped into solution it turns blue when exposed to the air[
Seed - it has a hard seedcoat and may benefit from scarification before sowing in order to speed up and improve germination. This can usually be done by pouring a small amount of nearly boiling water on the seeds (being careful not to cook them!) and then soaking them for 12 - 24 hours in warm water. By this time they should have imbibed moisture and swollen - if they have not, then carefully make a nick in the seedcoat (being careful not to damage the embryo) and soak for a further 12 hours before sowing.
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