Different varieties of indigos are found to exist like the white wild indigo, the blue wild indigo and the dwarf indigo. Depending on the different species, the plant bears flowers with colours like yellow, white and dark blue. The flowers are in the shape of peas arranged on a long vertical spike and look like the flowers of the genus ‘Lupin’. The white indigo blooms in May and June while the blue indigo flowers in the later part of summer. The flowers attract the bumblebees and butterflies which help in the pollination.

The plant is a member of the bean family and is a perennial herb. The leaf structure is known as trifoliate. The greyish green leaves bear small, oval leaflets which look like cloves. The blue-black fruit is also oval shaped with a tapering end. The yellow-brown seeds are shaped like a kidney and are used to produce a dye.

Indigos grow well in soils that are dry, stony and devoid of lime. They prefer bright sunlight.

The genus of indigo, ‘baptisia’, derives its name from the Greek word ‘baptizein’ which means ‘to dye’. It is often acts as a substitute of the true indigo. It is also found to be a good antiseptic and a purgative.