Indigofera tinctoria L.

Global description
 
Indigofera tinctoria is an herbaceous, annual, biennial or perennial plant, with a small bushy shrub, 60 to 120 cm tall. The young branches are covered with a white pubescence, consisting of appressed hairs. The leaves are alternate, compound imparipinnate, with (3) 4-6 pairs of leaflets. The leaflets are opposite, obovate to elliptical. The petiole and rachis of about 7 cm long, are covered with appressed hairs and dug with a furrow on the upper side. The flowers of papilionaceae type, with pink or white corolla, are grouped in axillary sessile racemes, 3 to 6 cm long. The fruit is a linear pod, 20 to 35 mm long and 2 mm wide, containing 7 to 12 seeds.
 
General habit
 
Indigofera tinctoria is an annual herb or small bushy perennial shrub, 60 to 120 cm tall.
 
Underground system
 
Taproot.
 
Stem
 
The stem is cylindrical, full, erect, more less woody at the base, abundantly branched, the young parts and the twigs are covered with bifid, appressed, whitish hairs.
 
Leaf
 
The leaves are compound imparipinnate and alternate. They comprise of (7) -9 to 13 leaflets. At the base of the petiole, the stipules are narrowly triangular, 1.5 to 3 mm long. The leaflets are opposite, obovate to elliptic, 5 to 23 mm long by 3 to 12 mm wide, with sparse navicular hairs on the underside. The upper side is glabrous. The apex is rounded and mucronate, the base is wedged or rounded. The margin is entire. Petiole and rachis are up to 7 cm long; they are covered with appressed hairs and sagging with a groove on the upper side.
 
Inflorescence
 
The inflorescences are sessile axillary racemes, 3 to 6 cm, with numerous flowers. The bracts are narrowly triangular, about 1 mm long, more or less persistent.
 
Flower
 
The flowers are small, about 5 mm long, bisexual, papilionaceae type, with pedicel 1 to 1.5 mm long; they include:
- A calyx of 1.5 mm, fused into a slanting cut at the base and the upper half divided into 5 triangular lobes, with white appressed hairs;
- A corolla of about 4 mm long, formed from an oval standard of about 4 mm by 3.5 mm, whitish pink with reddish veins, two wings with very short claw, pink, and a keel with 'lateral spurs, pink to red;
- 10 stamens, 4 to 5 mm long, the free upper stamen, the other 9 fused together around the ovary.
- Superior Ovary pubescent, with single carpel, surmounted by a long style.
 
Fruit
 
The fruit is a linear pod of 20 to 35 mm long and 2 mm wide, straight or slightly curved towards the apex, brown when ripe, indehiscent, containing 7-12 seeds, with a slight constriction between seeds .
 
Seed
 
The seeds are shortly oblong, about 2 mm long and 1.5 mm wide, rhombic in cross section.
 

Origin
 
Indigofera tinctoria is native to southern Asia, probably India.
 
World distribution
 
Widely introduced and naturalized species in many tropical countries and southern tropical Africa, South-west islands of the Indian Ocean, India and Pakistan, China, Southeast Asia, Indonesia, Australia and the Pacific Islands; naturalized in Central and South America.

https://www.gbif.org/fr/species/2972043