Ncert Exercises & Solutions

Which of the following plants is used to extract the blue dye?

1. Trifolium

2. Indigofera

3. Lupin

4. Cassia

(b) Indigofera tintoria and T suffruticoga are the two plants belonging to the family-Fabaceae that produce blue indigo dye.

The other options are incorrect as

Trifolium is used as fodder.

Lupin is an ornamental plant.

Cassia is a shrub usually grown on the road side as an ornamental plant.