page_title: Striga
section_title: Lifecycle
hierarchical_section_title: Striga / Lifecycle
caption_attribution_description: English: Photo of plant roots with Striga plant connected
context_page_description: Striga, commonly known as witchweed, is a genus of parasitic plants that occur naturally in parts of Africa, Asia, and Australia. It is in the family Orobanchaceae. Some species are serious pathogens of cereal crops, with the greatest effects being in savanna agriculture in Africa. It also causes considerable crop losses in other regions, including other tropical and subtropical crops in its native range and in the Americas.
context_section_description: Each plant is capable of producing between 90,000 and 500,000 seeds, which may remain viable in the soil for over 10 years. Most seeds produced are not viable.  An annual plant, witchweed overwinters in the seed stage.  Its seeds germinate in the presence of host root exudate, and develop haustoria which penetrate host root cells.  Host root exudate contain strigolactones, signaling molecules that promote striga seed germination.  A bell-like swelling forms where the parasitic roots attach to the roots of the host.  The pathogen develops underground, where it may spend the next four to seven weeks before emergence, when it rapidly flowers and produces seeds.  Witchweed seeds spread readily via wind and water, and in soil via animal vectors.  The chief means of dispersal, however, is through human activity, by means of machinery, tools, and clothing.
caption: Photo of plant roots with connected Striga plant
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