Is it ensure, insure, or assure?
(Crotalaria juncea), plant of the pea family (Fabaceae, or Leguminosae) or its fibre, one of the bast fibre group. The plant is also cultivated in many tropical countries as a green manure crop that is plowed under to fertilize soil. The sunn plant is not a true hemp. It is probably native to the Indian subcontinent, where it has been cultivated since prehistoric times. It was introduced to the Western Hemisphere early in the 19th century.