Blue dye plant neel of British India times Indigofera tinctoria Linn. has medicinal properties also.
Indigofera tinctoria Linn. Vernacular Names :- Arabic : Nilaj ; Bengal : Nil ; Bombay : Guli , Nila ; Central provinces : Nil ; English : Common Indigo, Indigo ; Gujrat : Gari ; Hindi : Gouli ; Punjab : jil, Nil ; Sanskrit : Gandhapushpi ; Tamil : Attipurashadam ; Telgu : Karunili. Family :- Papilionaceae. Distribution :- It is found in tropical Africa, Ceylon, Phillipines, Burma, Malaya, Pakistan and throughout India. Morphology :- An extensively branched high shrub. Stem terete or sulcate, thinly silky with short medifixed with white hairs. Leaves 5-8 cm long, bear 9-13 leaflets which are glabrous or hairy, rounded or apiculate at apex and acute at base , leaflets are oblong or oblanceolate. Flowers 4-6 cm long, many flowered, lax, axillary racemes, pedicels 2-3 mm long. Calyx hairy outside and 1-2 mm long. Corolla reddish pink and upto 5 mm long. Pods are long, linear, straight or curved, glabrous when matured and bear brown coloured, wide, truncate on sides and more or less quadrate 8-12 seeds (Bhandari, 1978). Chemical composition :- A blue dye stuff obtained from various species of Indigofera. This is called Indocan and is yellow, amorphous, of a nauseous bitter taste with an acid reaction ; readily soluble in water, alcohol and in ether (Trease and Evans, 1973). Part used :- Leaves, root and whole plant. Uses :- Root powder macerated in water is taken in urinary complaints. It is used for inflammation of liver. It is a valuable nervine tonic. Juice of leaves is used as a cure for hydrophobia, being administered both internally and externally. Leaves are made into an ointment which is applied to contused, inflamed or itchy parts. Extract of it is given in epilepsy and nervous disorders. It is also used in bronchitis and as an ointment in sores, old ulcers, haemorrhoides. It is given as an emetocathartic for convulsion in children.