By Abigail Rumsey: The flowers might look pretty but Striga has affected millions of hectares of crops in Africa.
Striga hermonthica, or witchweed, is the main weed affecting many cereals including rice, maize, sorghum and millet. It is responsible for more crop loss in Africa than any other individual species of weed. Striga is a hemi-parasitic weed; its roots latch onto the roots of its host (e.g. a crop plant such as rice) and take water and nutrients from the host plant.