Crotalaria juncea, known as sunn or sunn hemp, is a tropical Asian plant of the legume family (Fabaceae). It is generally considered to have originated in India and has been grown since the dawn of agriculture. It is now widely grown throughout the tropics and subtropics as a source of green manure, fodder and lignified fiber obtained from its stem. There are millions of acres of this crop grown in other countries. Brazil calls it their number one soil builder. Crotalaria ochroleuca is grown in Africa and South America as a popular multipurpose green manure crop.