Mucuna pruriens is a legume, found in Africa, India and the Caribbean. It is an annual, climbing shrub which grows over 13 – 15 m height. The young plant is completely covered by hair where as older plants are free of it. The leaves are tripinnate . Flowers are white, lavender, or purple. The fruits are leguminous. The husk is very hairy and carries up to seven seeds. Its seed pods are about 10 cm long and are covered in loose, orange hairs that cause a severe itch if they come in contact with skin. The chemical compounds responsible for the itch are a protein, mucunain, and serotonin
This plant is also known as cowhage, cowitch , Velvet Bean , Itchy bean, Buffalo bean etc. In India it is known as Kevancha, kavach or kevach (Hindi).
Ayurveda acharyas have grouped this plant under Balya (body strengthening herbs), Madhura skanda (herbs with sweet taste) and Vatasamshamana (Herbs which normalize vata dosha).