Any of several flowering plants of the genus Striga, from Africa and Asia, some of which are parasitic to crops.
1968, (U.S.) National Research Council: Committee on Plant and Animal Pests: Subcommittee on Weeds, Principles of Plant and Animal Pest Control, Volume 2: Weed Control, National Academy of Sciences Publication 1597, page 43,
The witchweed-suppression program is a classic example of a systems approach to weed management and represents one of the finest organized efforts in the United States to eradicate a weed.