Striga is one of the very few flowering plants that are parasitic on other plants. It has been given the common name of "witchweed" because of the various debilitating effects inflicted upon its host in addition to attaching to the roots and robbing the host of water and nutrients. Striga exists as several species, the common economic ones being Striga hermonthica in East and West Africa and Striga asiatica occurring in South Africa, India, and to a small extent Mid-Atlantic United States. Both species attack sorghums, millet, and maize. Depending upon the extent of infestation, reductions in per hectare grain yield of 30-60% are common. Striga is most severe in low moisture, low fertility soils and the thousands of seeds it produces can remain dormant but viable for many years.