Indigofera hendecaphylla and Indigofera spicata Forssk., used to be considered as the same species and were then named Indigofera spicata. They are now considered to be different species. The literature is therefore confusing, and references to toxicity most probably refer to Indigofera hendecaphylla[
Indigofera anceps Vahl ex Poir.
Indigofera bolusii N.E.Br.
Indigofera endecaphylla Jacq.
Indigofera endecaphylla P. Beauv.
Indigofera endecaphylla Poir.
Indigofera kleinii Wight & Arn.
Indigofera onobrychioides Boivin ex Baill.
Indigofera pectinata Baker
Indigofera stricata Forssk.
Flowering plant, being grown as a green manure ground cover in a macadamia nut orchard in Hawaii
Photograph by: Forest and Kim Starr
Indigofera hendecaphylla is a sub-erect shrublet that grows 40 - 100cm tall and gradually becomes prostrate as it grows larger. The stems become creeping, up to 2 metres long and rooting at the nodes, with branches that are ascending. The main root can be 50 - 100cm long and 5 - 10mm wide[
The plan is used locally as a source of the blue dye indigo. Itt is a commonly grown and very popular green manure crop within its native range, especially in Asia, but also in Africa. It is also often cultivated outside its native range, in areas such as Australia and the Americas[
Some strains of this species have leaves and seeds that are highly hepatotoxic[
The leaves of Indigofera hendecaphylla, possibly only of tetraploid forms originally from Sri Lanka, contain per 100 g dry matter 0.1 - 0.5 g indospicine (2,7-diamino-7-amino-heptanoic acid) while the seeds contain 0.1 - 2 g. Indospicine is a specific antagonist of arginine, interfering with its synthesis and incorporation into proteins and with the synthesis of DNA. Indospicine is highly toxic to chicken, rabbits, pigs, goats, sheep, cattle and horses. In small doses it causes loss of vitality and abortion in cattle and goats. Indospicine is especially dangerous to horses, which relish plants containing it and eat them preferentially[
Tropical Africa - widely distributed, including Madagascar; through tropical Asia to New Guinea.
Disturbed grassland; cultivated areas and waste places; at elevations up to 2,700 metres, but most commonly below 700 metres, in Africa[
|Other Uses Rating||
|Cultivation Status||Cultivated, Wild
Indigofera hendecaphylla is a plant mainly of the tropical lowlands, where it thrives at elevations below 700 metres, though can also be found ascending to about 2,500 metres. It grows best in areas with a mean annual temperature of 16 - 27°c and a mean annual rainfall in the range 600 - 1,500mm, but may also be found in wetter locations receiving up to 4,000mm[
In cultivation, the plant is fairly resistant to drought and shade[
]. Under heavy shade however, such as in old rubber plantations, growth is poor[
]. It performs best on clay soils, but grows on various soil types, including sandy soils, with a pH of 5.0 - 7.7. It is tolerant of poor, moderately acid, phosphorus-deficient soils[
Soil covers of Indigofera hendecaphylla are notorious for harbouring snakes and leeches[
Seedlings develop a strong taproot which assists in loosening the soil[
When cuttings are used plant growth remains very low, the cover rarely exceeding 12 cm in height. A fair cover can be formed in 6 months and a continuous even cover in a year from planting[
The plants send out trailing stems which, under favourable conditions, may attain a length of 2 metres, producing numerous adventitious roots at the nodes. As the plants mature they become taller and at 2 years of age they are usually about 30 - 40cm tall. Vigorous regrowth occurs at the start of the rainy season[
Once established, Indigofera hendecaphylla is self-sowing[
This species has 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[
Indigofera hendecaphylla provides a good soil cover and smothers weeds. In tea estates in Sri Lanka it was the most popular green manure and cover crop. In Indonesia and Peninsular Malaysia it is used as a cover crop in rubber, sisal, oil palm and tea plantations; in Africa in coffee plantations[
Its maximum effect as a green manure is reached when the cover crop is incorporated in the soil when still green and flowering has started. Green manure crops produce 4.5 - 25 tonnes per hectare of green material. In trials in Indonesia Indigofera hendecaphylla has produced a green matter yield of 3.0 tonnes per hectare 3 months after planting, containing 10 kg nitrogen and 3 kg phosphorus. After 6 months the green matter yield was 18 tonnes, containing 86 kg nitrogen and 21 kg phosphorus[
A cover crop of Indigofera hendecaphylla controls erosion effectively on hilly and undulating land even under heavy rainfall, and is considered more effective than Clitoria ternatea. Few weeds, except some grasses, can grow through this cover and, once established, a reduction in weeding costs may be anticipated. Weeds such as Mikania spp. and Convolvulus spp. can cause some trouble[
The foliage has sometimes been used as a source of indigo, a much-used blue dye obtained commercially from species such as Indigofera arrecta and Indigofera tinctoria[
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. To obtain a good distribution of the seed it is mixed with sand or filtered dry soil at a ratio of seed to sand of 1 : 4 before sowing. If planted in rows 60cm apart the seed rate is about 3.3 kg/ha[
]. Cuttings of about 20cm long are planted at a spacing of 60cm x 60cm with 5 cuttings per hole[