Striga pusilla Hochst. Striga parvula Miq. Noxious annual semiparasite of tropical and subtropical annual grasses.
Plants are capable of parasitizing numerous grass species.
A heavy infestation can severely damage crops and is difficult to control. Symptoms in host plants include stunting, chlorosis, and wilting. Witchweed is native to semi-arid and tropical grassland regions of Africa and Asia, but can also flourish in temperate regions outside its natural range. Populations are highly variable, and flower color varies regionally, from red, orange, or yellow in Africa to pink, white, yellow, or purple in Asia. In the U.S., infestations currently exist only on agricultural lands near the eastern border between North and South Carolina.