Crotalaria juncea

Crotalaria juncea, known as brown hemp, Indian hemp, Madras hemp, or Sunn hemp, is a tropical Asian plant of the legume family (Fabaceae). It is generally considered to have originated in India.

It is now widely grown in the Indian subcontinent and Brazil for its fiber, which makes it especially useful in the manufacturing of twine, rug yarn and fish nets. This plant is also used as forage for cattle and goats as they have a significant percentage of protein (34.6%). Additionally, according to new research from the Agricultural Research Service (ARS), Sunn hemp is being looked at as a possible bio-fuel. After being put under experimental research the Sunn hemp was found to have produced 82.4 gigajoules of energy per acre, equivalent to 620 gallons of gas. Although it is a useful plant it can be an invasive weed and has been listed as a noxious weed in some jurisdictions.