# Striga

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Striga
> Markdown URL: https://mediated.wiki/source/Striga.md
> Source: https://en.wikipedia.org/wiki/Striga
> Source revision: 1352933579
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{Short description|Genus of flowering plants in the broomrape family}}
{{Distinguish|Strzyga|Strigoi|Shtriga}}
{{Automatic taxobox
|image = Striga bilabiata MS4167.jpg
|taxon = Striga
|authority = [Lour.](/source/Jo%C3%A3o_de_Loureiro)
| synonyms = 
* ''Campuleia'' <small>Thouars</small>
* ''Microsyphus'' <small>C.Presl</small>
* ''Psammostachys'' <small>C.Presl</small>
* ''Camphyleia'' <small>Spreng.</small>
}}

'''''Striga''''', commonly known as '''witchweed''',<ref>{{PLANTS|id=STRIG|taxon=Striga|accessdate=4 December 2015}}</ref> is a [genus](/source/genus) of [parasitic plant](/source/parasitic_plant)s that occur naturally in parts of Africa, Asia, and Australia. It is currently classified in the family [Orobanchaceae](/source/Orobanchaceae),<ref>{{cite journal |title=The Evolution of Parasitism in Scrophulariaceae/Orobanchaceae: Plastid Gene Sequences Refute an Evolutionary Transition Series |first1=Nelson D. |last1=Young |first2=Kim E. |last2=Steiner |first3=Claude W. |last3=dePamphilis |journal=Annals of the Missouri Botanical Garden |volume=86 |issue=4 |date=Autumn 1999 |pages=876–93 |doi=10.2307/2666173 |jstor=2666173 |bibcode=1999AnMBG..86..876Y |url=https://www.biodiversitylibrary.org/pdf3/007556000014018.pdf}}</ref> although older classifications place it in the [Scrophulariaceae](/source/Scrophulariaceae).<ref>For example, [Integrated Taxonomic Information System](/source/Integrated_Taxonomic_Information_System) as of 16 Sep 2007</ref> Some species are serious [pathogen](/source/pathogen)s 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. The generic name derives from [Latin](/source/Latin) ''strī̆ga'', "witch".<ref>{{Cite web|url=https://latin-dictionary.net/definition/35801/striga-strigae |title=Latin Definition for: striga, strigae (ID: 35801) - Latin Dictionary and Grammar Resources |publisher=Latdict}}</ref>

Witchweeds are characterized by bright-green stems and leaves and small, brightly colored and attractive flowers.<ref name="Sand">Sand, Paul, Robert Eplee, and Randy Westbrooks. ''Witchweed Research and Control in the United States''. Champaign, IL: [Weed Science Society of America](/source/Weed_Science_Society_of_America), 1990.{{page needed|date=December 2013}}</ref> They are [obligate hemiparasite](/source/obligate_parasite)s of roots and require a living host for germination and initial development, though they can then survive on their own.<ref name=Wainwright />

The number of species is uncertain, but may exceed 40 by some counts.<ref name="Wainwright">"Witchweeds - beautiful but deadly", ''The Horticulturalist'', Vol. 21-4, October 2012{{page needed|date=December 2013}}</ref><ref>{{cite journal |first1=Kamal I. |last1=Mohamed |first2=Lytton John |last2=Musselman |first3=Charles R. |last3=Riches |date=Winter 2001 |title=The Genus ''Striga'' (Scrophulariaceae) in Africa |journal=Annals of the Missouri Botanical Garden |volume=88 |issue=1 |pages=60–103 |jstor=2666132 |doi=10.2307/2666132 |bibcode=2001AnMBG..88...60M |url=https://digitalcommons.odu.edu/cgi/viewcontent.cgi?article=1221&context=biology_fac_pubs}}</ref>

==Hosts and symptoms==
Although most species of ''Striga'' are not pathogens that affect agriculture, some species have devastating effects upon crops, particularly those planted by [subsistence farm](/source/subsistence_farm)ers.<ref>{{cite journal |doi=10.1094/PHI-I-2004-0330-01 |title=Introduction to Parasitic Flowering Plants |year=2004 |last1=Nickrent |first1=D. L. |last2=Musselman |first2=L. J. |journal=The Plant Health Instructor}}</ref> Crops most commonly affected are [maize](/source/maize), [sorghum](/source/sorghum), [rice](/source/rice) and [sugarcane](/source/sugarcane).<ref name="Sand" /><ref>{{cite journal |title=Addressing current and future problems of parasitic weeds in rice |year=2010 |last1=Rodenburg |first1=Jonne |last2=Riches |first2=Charles R. |last3=Kayeke |first3=Juma M. |journal=Crop Protection |volume=29 |issue=3 |pages=210–221 |doi=10.1016/j.cropro.2009.10.015 |bibcode=2010CrPro..29..210R }}</ref> Three species cause the most damage: ''[Striga asiatica](/source/Striga_asiatica)'', ''[S.&nbsp;gesnerioides](/source/Striga_gesnerioides)'', and ''[S.&nbsp;hermonthica](/source/Striga_hermonthica)''.

Witchweed parasitizes maize, millet, sorghum, sugarcane, rice, legumes, and a range of weedy grasses.<ref name="Wales">Johnson, Annie. New South Wales. Witchweed. 2005. http://www.wyong.nsw.gov.au/environment/Weeds_category_one_Witchweed.pdf {{Webarchive |url=https://web.archive.org/web/20070831213931/http://www.wyong.nsw.gov.au/environment/Weeds_category_one_Witchweed.pdf |date=2007-08-31 }}</ref> It is capable of significantly reducing yields, in some cases wiping out the entire crop.<ref name="Sand" />

Host plant symptoms, such as [stunting](/source/Stunt_(botany)), [wilting](/source/wilting), and [chlorosis](/source/chlorosis), are similar to those seen from severe drought damage, nutrient deficiency, and vascular disease.<ref name="Sand" /><ref name="Wales" /><ref name="text">Agrios, George N. Plant Pathology. 5th ed. London: Elsevier Academic Press, 2005.{{page needed|date=December 2013}}</ref>

==Lifecycle==
thumb|upright|Plant roots with connected ''Striga'' plant

Each plant is capable of producing between 90,000<ref name="bebawi"/> and 500,000 seeds, which may remain viable in the soil for over 10 years.<ref name="Pest">United States. Witchweed: A Parasitic Pest. District of Columbia: USDA, 2011. [https://web.archive.org/web/20131204065250/http://www.aphis.usda.gov/publications/plant_health/2011/witchweed_parasitic_pest.pdf]{{page needed|date=December 2013}}</ref> Most seeds produced are not viable.<ref name="bebawi">{{cite journal |author1=Faiz F. Bebawi |author2=Robert E. Eplee |author3=Rebecca S. Norris |title=Effects of Seed Size and Weight on Witchweed (S''triga asiatica'') Seed Germination, Emergence, and Host-Parasitization |jstor=4043831 |journal=Weed Science |volume=32 |issue=2 |pages=202–205 |date=March 1984 |doi=10.1017/S0043174500058811|bibcode=1984WeedS..32..202B |s2cid=89078686 }}</ref> An annual plant, witchweed overwinters in the seed stage.<ref name="Sand" /> Its seeds germinate in the presence of host root [exudate](/source/exudate), and develop [haustoria](/source/haustoria) which penetrate host root cells.<ref name="Sand" /> Host root exudate contain [strigolactone](/source/strigolactone)s, signaling molecules that promote ''Striga'' seed germination.<ref name="Strigalactone">{{cite journal |doi=10.1104/pp.105.061382 |title=The Strigolactone Germination Stimulants of the Plant-Parasitic ''Striga'' and ''Orobanche'' spp. Are Derived from the Carotenoid Pathway |year=2005 |last1=Matusova |first1=Radoslava |journal=Plant Physiology |volume=139 |issue=2 |pages=920–34 |pmid=16183851 |last2=Rani |first2=Kumkum |last3=Verstappen |first3=Francel W.A. |last4=Franssen |first4=Maurice C.R. |last5=Beale |first5=Michael H. |last6=Bouwmeester |first6=Harro J. |pmc=1256006}}</ref> A bell-like swelling forms where the parasitic roots attach to the roots of the host.<ref name="Wales" /> The pathogen develops underground, where it may spend the next four to seven weeks before emergence, when it rapidly flowers and produces seeds.<ref name="Wales" /> Witchweed seeds spread readily via wind and water, and in soil via animal vectors.<ref name="Wales" /> The chief means of dispersal, however, is through human activity, by means of machinery, tools, and clothing.<ref name="Wales" /><ref name="Pest" />

=== Haustoria development ===
Once germination is stimulated, the ''Striga ''seed sends out an initial root to probe the soil for the host root. The initial root secretes an oxidizing enzyme that digests the host root surface, releasing [quinone](/source/quinone)s.<ref>{{Cite journal |title=The haustorium and the chemistry of host recognition in parasitic angiosperms |last=Chang |first=M |date=1986 |journal=Journal of Chemical Ecology |doi=10.1007/bf01020572 |pmid=24306796 |volume=12 |issue=2 |pages=561–579 |bibcode=1986JCEco..12..561C |s2cid=30452898}}</ref> If the quinone product is at the appropriate concentrations, a [haustorium](/source/haustorium) will develop from the initial root. The haustorium grows toward the host root until it makes contact with the root surface, establishing parasitic contact in relatively short order. Within 12 hours of initial haustorium growth, the haustorium recognizes the host root and begins rapid cell division and elongation.<ref name=":0">{{Cite journal |title=Primary haustorial development and ''Striga asiatica'' on host and nonhost species |last=Hood |first=M.E. |date=1997 |journal=Phytopathology |volume=88 |issue=1 |pages=70–75 |doi=10.1094/PHYTO.1998.88.1.70 |pmid=18945002 |doi-access = }}</ref> The haustorium forms a wedge shape and uses mechanical force and chemical digestion to penetrate the host root, pushing the host cells out of the way.<ref name=":0" /><ref name=":1">{{Cite journal |title=How ''Striga'' parasitizes its host: a TEM and SEM study |last=Dorr |first=Inge |date=1996 |journal=Annals of Botany |volume=79 |issue=5 |pages=463–472 |doi=10.1006/anbo.1996.0385 |doi-access = }}</ref> Within 48–72 hours, the haustorium has penetrated the host root [cortex](/source/Cortex_(botany)).<ref name=":0" /> Finger-like structures on the haustorium, called oscula (from Latin {{Lang|la|osculum}}, "little mouth") penetrate the host xylem through pits in the membrane.<ref name=":1" /> The oscula then swell to secure their position within the xylem membrane. ''Striga'' [sieve tubes](/source/sieve_tubes) develop along with the oscula. Shortly after the host xylem is penetrated, ''Striga ''sieve tubes develop and approach the host phloem within eight cells.<ref name=":2">{{Cite book |title=Sieve elements: comparative structure, induction, and development |publisher=Springer-Verlag Berline Heidelberg |year=1990 |pages=239–256}}</ref><ref name=":3">{{Cite journal |title=Symplastic sieve element continuity between Orobanche and its host |last=Dorr |first=Inge |date=1995 |journal=Botanica Acta |volume=108 |issue=1 |pages=47–55 |doi=10.1111/j.1438-8677.1995.tb00830.x|bibcode=1995BotAc.108...47D }}</ref> This eight cell layer allows for nonspecific nutrient transport from the host to the ''Striga'' seedling.<ref name=":2" /><ref name=":3" /> Within 24 hours after tapping the host xylem and phloem, the ''Striga'' cotyledons emerge from the seed.<ref name=":0" />

==Environment==
Temperatures ranging from {{cvt|30|to|35|C|F}} in a moist environment are ideal for germination.<ref name="Wales" /> Witchweed will not develop in temperatures below {{cvt|20|C|F}}. Agricultural soils with a light texture and low nitrogen levels tend to favor development.<ref name="Cali">California Department of Food and Agriculture. Witchweed. http://www.cdfa.ca.gov/phpps/ipc/weedinfo/striga.htm</ref> Still, witchweed has demonstrated a wide tolerance for soil types if soil temperatures are favorably high.<ref name="Sand" /> Seeds have been shown to survive in frozen soil of temperatures as low as {{cvt|-15|C|F}}, attesting to their aptitude as [overwintering](/source/overwintering) structures.<ref name="Sand" />

Soil temperature, air temperature, [photoperiod](/source/photoperiod), soil type, and soil nutrient and moisture levels do not greatly deter the development of witchweed.<ref name="Sand" /> These findings, while limited to the Carolinas in the United States, seem to suggest that the pathogen could successfully infect the massive corn crops of the American Midwest.<ref name="Sand" />

==Management==
Management of witchweed is difficult because the majority of its life cycle takes place below ground. If it is not detected before emergence, it is too late to reduce crop losses.<ref name="Wales" /> To prevent witchweed from spreading it is necessary to plant uncontaminated seeds and to clean soil and plant debris off of machinery, shoes, clothing, and tools before entering fields.<ref name="Wales" /><ref name="Cali" /> If populations are low, hand weeding before seeds are produced is an option.

''Striga'' in the United States has been controlled through the use of several management strategies, including quarantines imposed on affected areas, control of movement of farm equipment between infected and uninfected areas, herbicide application, and imposed "suicidal germination". For the latter, in fields not yet planted in crops, seeds present in the soil are induced to germinate by injecting [ethylene](/source/ethylene) gas, which mimics the natural physiological response tied to host recognition. Because no host roots are available, the seedlings die. However, each mature ''Striga'' plant can produce tens of thousands of tiny seeds, which may remain dormant in the soil for many years.<ref>{{cite book |last1=van Mourik |first1=Thomas A |year=2007 |title=''Striga hermonthica'' seed bank dynamics process quantification and modelling |type=PhD thesis |publisher=Wageningen University |isbn=978-90-8504-692-9}}{{page needed|date=December 2013}}</ref> Thus, such treatments do not remove all seeds from the soil. Moreover, this method is expensive and not generally available to farmers in developing nations of Africa and Asia.

Another method called [trap crop](/source/trap_crop)ping involves planting a species in an infested field that will induce the ''Striga'' seeds to germinate but will not support attachment of the parasite. This method has been used in sorghum plantations by planting ''[Celosia argentea](/source/Celosia_argentea)'' between the sorghum rows.<ref>{{cite journal |doi=10.1016/S0261-2194(02)00181-3 |title=The effectiveness of ''Celosia argentia'' (''Striga'' 'chaser') to control ''Striga'' on Sorghum in Uganda |year=2003 |last1=Olupot |first1=J.R |last2=Osiru |first2=D.S.O |last3=Oryokot |first3=J |last4=Gebrekidan |first4=B |journal=Crop Protection |volume=22 |issue=3 |pages=463–8 |citeseerx=10.1.1.503.8991}}</ref> Cotton, sunflower and linseed are also effective trap crops.<ref name="Wales" /> Planting silverleaf desmodium (''[Desmodium uncinatum](/source/Desmodium_uncinatum)''), as is done in [push-pull intercropping](/source/Push%E2%80%93pull_agricultural_pest_management), inhibits ''Striga'' seed germination and has worked effectively intercropped with maize.<ref>{{cite journal |doi=10.1023/A:1020525521180 |year=2002 |last1=Khan |first1=Zeyaur R. |last2=Hassanali |first2=Ahmed |last3=Overholt |first3=William |last4=Khamis |first4=Tsanuo M. |last5=Hooper |first5=Antony M. |last6=Pickett |first6=John A. |last7=Wadhams |first7=Lester J. |last8=Woodcock |first8=Christine M. |journal=Journal of Chemical Ecology |volume=28 |issue=9 |pages=1871–85 |pmid=12449513 |title=Control of witchweed ''Striga hermonthica'' by intercropping with Desmodium spp., and the mechanism defined as allelopathic |bibcode=2002JCEco..28.1871K |s2cid=21834435}}</ref><ref>{{cite news |date=September 18, 2003 |work=The Guardian |title=Perfect maize, in three simple steps |url=https://www.theguardian.com/education/2003/sep/18/research.highereducation1 |location=London |first=Tim |last=Radford |access-date=May 24, 2010}}</ref>

Increasing nitrogen levels in the soil, growing ''Striga''-tolerant varieties, trap-cropping, and planting susceptible crops harvested before witchweed seed is produced, are proven tactics.<ref name="Cali" /> Coating maize seeds with fungi or a herbicide also appears to be a promising approach. An example is TAN222, the "''Striga''-resistant" maize variety which is coated with the systemic herbicide [imazapyr](/source/imazapyr), to which it is resistant. Any witchweed seeds sprouting when this maize is in the seedling stage are poisoned when their haustoria embed in the seedling's roots.<ref>{{cite web |last1=Communications |first1=Corporate |title=New maize brings hope to farmers in ''Striga''-infested regions in Tanzania and Uganda |url=http://blog.cimmyt.org/new-maize-brings-hope-to-farmers-in-striga-infested-regions-in-tanzania-and-uganda/ |website=CIMMYT: International Maize and Wheat Improvement Center |publisher=CIMMYT |access-date=2 December 2016}}{{Dead link|date=April 2019 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref name="Africa">"Controlling Witchweed in Sub-saharan Africa." Web. 7 Dec 2010. <http://www.aatf-africa.org/UserFiles/File/Controlling%20witchweed%20in%20SSA_AATF_Annual-Report_2005.pdf></ref>

Several sorghum varieties have high levels of resistance in local conditions, including 'N-13', 'Framida', and 'Serena'.<ref>{{cite journal |doi=10.1016/j.fcr.2004.09.004 |title=How can field selection for ''Striga'' resistance and tolerance in sorghum be improved? |year=2005 |last1=Rodenburg |first1=J. |last2=Bastiaans |first2=L. |last3=Weltzien |first3=E. |last4=Hess |first4=D.E. |journal=Field Crops Research |volume=93 |issue=1 |pages=34–50 |bibcode=2005FCrRe..93...34R |url=http://oar.icrisat.org/3601/1/FieldCropsResearch_93_1_34-50_2005.pdf}}</ref><ref name="Bio">"Purple Witchweed." Infonet-biovision. N.p., 14 Sep 2009. Web. 7 Dec 2010. <{{cite web |url=http://www.infonet-biovision.org/default/ct/112/pests |title=www.infonet-biovision.org - Purple witchweed |access-date=2010-12-08 |url-status=dead |archive-url=https://web.archive.org/web/20101124132706/http://infonet-biovision.org/default/ct/112/pests |archive-date=2010-11-24}}>.</ref> 'Buruma', 'Shibe', 'Okoa' and 'Serere 17' millet cultivars are considered to be resistant in Tanzania.<ref name="Bio" /> Some maize varieties show partial resistance to witchweed, including 'Katumani' in Kenya.<ref name="Bio" /> In a number of rice cultivars, including some cultivars of NERICA (New Rice for Africa), effective pre- and post- attachment resistance mechanisms have been identified.<ref>{{cite journal |doi=10.1111/j.1469-8137.2011.03850.x |title=Pre-attachment ''Striga hermonthica'' resistance of New Rice for Africa (NERICA) cultivars based on low strigolactone production |year=2011 |last1=Jamil |first1=Muhammad |last2=Rodenburg |first2=Jonne |last3=Charnikhova |first3=Tatsiana |last4=Bouwmeester |first4=Harro J. |journal=New Phytologist |volume=192 |issue=4 |pages=964–75 |pmid=21883233|doi-access=free |bibcode=2011NewPh.192..964J }}</ref><ref>{{cite journal |doi=10.1111/j.1469-8137.2011.03846.x |title=New Rice for Africa (NERICA) cultivars exhibit different levels of post-attachment resistance against the parasitic weeds ''Striga hermonthica'' and ''Striga asiatica'' |year=2011 |last1=Cissoko |first1=Mamadou |last2=Boisnard |first2=Arnaud |last3=Rodenburg |first3=Jonne |last4=Press |first4=Malcolm C. |last5=Scholes |first5=Julie D. |journal=New Phytologist |volume=192 |issue=4 |pages=952–63 |pmid=21883232|doi-access=free|bibcode=2011NewPh.192..952C }}</ref><ref name="Africa"/> 'StrigAway' herbicide-resistant, herbicide-impregnated maize has been shown to reduce the seed bank by 30% in two seasons.<ref name="Africa" />

== Importance ==

Maize, sorghum, and sugarcane crops affected by witchweed in the United States have an estimated value well over $20 billion.<ref name="Sand" /> Furthermore, witchweed is capable of wiping out an entire crop.<ref name="Wales" /> It is so prolific that in 1957 the US Congress allocated money in an attempt to eradicate witchweed. Because of ''Striga'', the Animal and Plant Health Inspection Service ([APHIS](/source/APHIS)) of the U.S. Department of Agriculture established a research station and control methods.<ref name="Pest" /> Through infestation mapping, quarantine, and control activities such as contaminated seed destruction, the acreage parasitized by witchweed has been reduced by 99% since its discovery in the United States.<ref name="Pest" /> APHIS has even offered cash rewards those who identify and report the weed, and encourages landowners to check their own acreage.<ref name="Pest" />

Parasitizing important economic plants, witchweed is one of the most destructive pathogens in Africa.<ref name="text" /> Witchweed affects 40% of Africa's arable savanna region, resulting in up to $13 billion lost every year.<ref name="Bio" /> ''Striga'' affects 40 million hectares (98,842,153 acres) of crops in sub-Saharan Africa alone.<ref name="Africa" /> In parts of Africa, the witchweed infestation is so severe that some farmers must relocate every few years.<ref name="Gene">Samarrai, Fariss. "U.Va. Scientists Identify Gene for Resistance to Parasitic 'Witchweed'." UVaToday. N.p., 27 Aug 2009. Web. 7 Dec 2010. <[https://archive.today/20121212191250/http://www.virginia.edu/uvatoday/newsRelease.php?id=9543]></ref> The majority of crops in Africa are grown by subsistence farmers who cannot afford expensive witchweed controls, who therefore suffer much as a result of this pathogen.<ref name="Gene" />

==Species==
===Common crop parasites===
[[File:Striga plant.jpg|thumb|upright|''[Striga asiatica](/source/Striga_asiatica)'']]
[[File:Striga bilabiata at Kadavoor.jpg|thumb|upright|''[Striga bilabiata](/source/Striga_bilabiata)'']]
*''[Striga asiatica](/source/Striga_asiatica)'' has a very wide geographic distribution, from Africa through southern and eastern Asia to Australia. Since the 1950s, it is also known from the United States. This introduction, likely a result of human activity, resulted in an infestation on corn ([maize](/source/maize)) across many counties in North and South Carolina. The United States Department of Agriculture and state agencies imposed a quarantine on this area to control its spread—a process that was apparently successful.
*''[Striga gesnerioides](/source/Striga_gesnerioides)'', cowpea witchweed, as its name implies, is a parasite of [cowpea](/source/cowpea) (''[Vigna unguiculata](/source/Vigna_unguiculata)''), which is not a grass, but a member of the legume family ([Fabaceae](/source/Fabaceae) or [Leguminosae](/source/Leguminosae)). This species was also accidentally introduced into Florida in the United States, where it was found parasitizing ''[Indigofera hirsuta](/source/Indigofera_hirsuta)'' (hairy indigo, another legume).
*''[Striga hermonthica](/source/Striga_hermonthica)'' (purple witchweed) is also a parasite that affects grasses, particularly [sorghum](/source/sorghum) and [pearl millet](/source/pearl_millet) in sub-Saharan Africa (Senegal to Ethiopia, Democratic Republic of Congo and Tanzania, Angola, Namibia).

===Species list===
The following species are recognised in the genus ''Striga'':<ref>{{Cite web |title=Striga Lour. {{!}} Plants of the World Online {{!}} Kew Science |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:38035-1 |access-date=2024-11-16 |website=Plants of the World Online |language=en}}</ref>
{{div col|colwidth=22em}}
*''[Striga aequinoctialis](/source/Striga_aequinoctialis)'' {{small|A.Chev. ex Hutch. & Dalziel}} – West Africa
*''[Striga alba](/source/Striga_alba)'' {{small|Pennell}}
*''[Striga angolensis](/source/Striga_angolensis)'' {{small|K.I.Mohamed & Musselman}} – Angola
*''[Striga angustifolia](/source/Striga_angustifolia)'' {{small|(D.Don) C.J.Saldanha}} – East Africa, Asia, Indonesia
*''[Striga asiatica](/source/Striga_asiatica)'' {{small|(L.) Kuntze}} – (Asiatic witchweed) Africa, Arabian peninsula, India, Burma, China, Indonesia, the Philippines, Malaysia, New Guinea, Australia (introduced?), USA (introduced)
*''[Striga aspera](/source/Striga_aspera)'' {{small|(Willd.) Benth.}} – Africa
*''[Striga barthlottii](/source/Striga_barthlottii)'' {{small|Eb.Fisch., Lobin & Mutke}}
*''[Striga baumannii](/source/Striga_baumannii)'' {{small|Engl.}}
*''[Striga bilabiata](/source/Striga_bilabiata)'' {{small|(Thunb.) Kuntze}} – Africa
*''[Striga brachycalyx](/source/Striga_brachycalyx)'' {{small|Skan}} – Africa
*''[Striga chrysantha](/source/Striga_chrysantha)'' {{small|A.Raynal}}
*''[Striga crispata](/source/Striga_crispata)'' {{small|Sheng Z.Yang, Zi X.Chen, Chien F.Chen & P.H.Chen}}
*''[Striga curviflora](/source/Striga_curviflora)'' {{small|(R.Br.) Benth.}}
*''[Striga dalzielii](/source/Striga_dalzielii)'' {{small|Hutch.}} – West Africa
*''[Striga densiflora](/source/Striga_densiflora)'' {{small|(Benth.) Benth.}}
*''[Striga dewevrei](/source/Striga_dewevrei)'' {{small|De Wild. & T.Durand}}
*''[Striga diversifolia](/source/Striga_diversifolia)'' {{small|Pires de Lima}}
*''[Striga elegans](/source/Striga_elegans)'' {{small|Benth.}} – Angola, Malawi, South Africa, Zimbabwe
*''[Striga ellenbergeri](/source/Striga_ellenbergeri)'' {{small|A.Raynal}}
*''[Striga flava](/source/Striga_flava)'' {{small|Miq.}}
*''[Striga forbesii](/source/Striga_forbesii)'' {{small|Benth.}} – Africa, Madagascar
*''[Striga fulgens](/source/Striga_fulgens)'' {{small|(Engl.) Hepper}}
*''[Striga gastonii](/source/Striga_gastonii)'' {{small|A.Raynal}}
*''[Striga gesnerioides](/source/Striga_gesnerioides)'' {{small|(Willd.) Vatke}} – (cowpea witchweed) Africa, Arabian peninsula, India, USA (introduced)
*''[Striga glumacea](/source/Striga_glumacea)'' {{small|A.Raynal}}
*''[Striga gracillima](/source/Striga_gracillima)'' {{small|Melch.}}
*''[Striga hallaei](/source/Striga_hallaei)'' {{small|A.Raynal}}
*''[Striga hermonthica](/source/Striga_hermonthica)'' {{small|(Delile) Benth.}} – Senegal to Ethiopia, Democratic Republic of Congo and Tanzania, Angola, Namibia
*''[Striga indica](/source/Striga_indica)'' {{small|K.M.P.Kumar, P.Jayanthi, A.Rajendran & M.Sabu}}
*''[Striga junodii](/source/Striga_junodii)'' {{small|Schinz}} – South Africa, Mozambique
*''[Striga kamalii](/source/Striga_kamalii)'' {{small|Omalsree, K.M.P.Kumar, M.Sabu & Sunojk.}}
*''[Striga klingii](/source/Striga_klingii)'' {{small|(Engl.) Skan}} – West Africa, Nigeria, Ghana, Cameroon, Togo
*''[Striga latericea](/source/Striga_latericea)'' {{small|Vatke}} – East Africa, Ethiopia, Somalia
*''[Striga lepidagathidis](/source/Striga_lepidagathidis)'' {{small|A.Raynal}}
*''[Striga linearifolia](/source/Striga_linearifolia)'' {{small|(Schumach. & Thonn.) Hepper}}
*''[Striga lutea](/source/Striga_lutea)'' {{small|Lour.}}    
*''[Striga macrantha](/source/Striga_macrantha)'' {{small|(Benth.) Benth.}} – West Africa, Nigeria, Ivory Coast, Togo
*''[Striga magnibracteata](/source/Striga_magnibracteata)'' {{small|Eb.Fisch. & I.Darbysh.}}
*''[Striga masuria](/source/Striga_masuria)'' {{small|(Buch.-Ham. ex Benth.) Benth.}}
*''[Striga micrantha](/source/Striga_micrantha)'' {{small|A.Rich.}}
*''[Striga multiflora](/source/Striga_multiflora)'' {{small|Benth.}}
*''[Striga musselmanii](/source/Striga_musselmanii)'' {{small|Omalsree & V.K.Sreenivas}}
*''[Striga parviflora](/source/Striga_parviflora)'' {{small|(R.Br.) Benth.}}
*''[Striga passargei](/source/Striga_passargei)'' {{small|Engl.}} – West and Central Africa, Arabian peninsula
*''[Striga pinnatifida](/source/Striga_pinnatifida)'' {{small|Getachew}}
*''[Striga primuloides](/source/Striga_primuloides)'' {{small|A.Chev.}} – Ivory Coast, Nigeria
*''[Striga pubiflora](/source/Striga_pubiflora)'' {{small|Klotzsch}} – Somalia
*''[Striga schlechteri](/source/Striga_schlechteri)'' {{small|Pennell}}
*''[Striga spanogheana](/source/Striga_spanogheana)'' {{small|Miq.}}
*''[Striga squamigera](/source/Striga_squamigera)'' {{small|W.R.Barker}}
*''[Striga strigosa](/source/Striga_strigosa)'' {{small|R.D.Good}}
*''[Striga sulphurea](/source/Striga_sulphurea)'' {{small|Dalzell}}
*''[Striga yemenica](/source/Striga_yemenica)'' {{small|Musselman & Hepper}}
{{div col end}}

==Gallery==
<gallery heights="180px" >
Image:Striga densiflora (Agya) in Hyderabad, AP W IMG 9828.jpg|''[Striga densiflora](/source/Striga_densiflora)'' in [Hyderabad, India](/source/Hyderabad%2C_India) 
Image:Striga densiflora (Agya) in Hyderabad, AP W IMG 9826.jpg|''Striga densiflora'' in Hyderabad 
Image:Striga densiflora (Agya) in Hyderabad, AP W IMG 9825.jpg|''Striga densiflora'' in Hyderabad
</gallery>

==See also==
*[Push–pull technology](/source/Push%E2%80%93pull_technology)

==References==
{{Reflist}}

==Further reading==
*{{cite journal |doi=10.1093/jxb/45.2.281 |title=The effect of ''Striga hermonthica'' (Del.) Benth. Infection on gas-exchange characteristics and yield of a sorghum host, measured in the field in Mali |year=1994 |last1=Clark |first1=Lawrence J. |last2=Shawe |first2=Keith G. |last3=Hoffmann |first3=Gŕrard |last4=Stewart |first4=George R. |journal=Journal of Experimental Botany |volume=45 |issue=2 |pages=281–3}}
*{{cite book |first1=Hoffmann |last1=Gérard |first2=Roger |last2=Loisel |year=1994 |title=Contribution à l'étude des Phanérogames parasites du Burkina Faso et du Mali: quelques aspects de leur écologie, biologie et techniques de lutte |trans-title=Contribution to the study of parasitic Phanerogams of Burkina Faso and Mali: some aspects of their ecology, biology and control technics |language=fr |type=PhD Thesis |id={{INIST|163863}} |oclc=489977820}}
*{{cite journal |first1=Hoffmann |last1=Gérard |last2=Diarra |first2=C |last3=Dembele |first3=D |year=1994 |title=Outbreaks and new records: ''Striga asiatica'', new pest of maize in Mali |journal=FAO (Food and Agriculture Organization of the United Nations) Plant Protection Bulletin |volume=42 |pages=214–5 |url=http://hal.archives-ouvertes.fr/hal-00549167 |issue=42}}
*{{cite journal |id={{INIST|2781044}} |first1=Hoffmann |last1=Gérard |last2=Marnotte |first2=P. |last3=Dembélé |first3=D |year=1997 |title=Emploi d'herbicides pour lutter contre ''Striga hermonthica'': ''Striga'' |trans-title=The use of herbicides to control ''Striga hermonthica'' |language=fr |journal=Agriculture et Développement |volume=13 |pages=58–62}}
*{{cite journal |doi=10.1023/A:1020525521180 |year=2002 |last1=Khan |first1=Zeyaur R. |last2=Hassanali |first2=Ahmed |last3=Overholt |first3=William |last4=Khamis |first4=Tsanuo M. |last5=Hooper |first5=Antony M. |last6=Pickett |first6=John A. |last7=Wadhams |first7=Lester J. |last8=Woodcock |first8=Christine M. |journal=Journal of Chemical Ecology |volume=28 |issue=9 |pages=1871–85 |pmid=12449513 |title=Control of witchweed ''Striga hermonthica'' by intercropping with ''Desmodium'' spp., and the mechanism defined as allelopathic |bibcode=2002JCEco..28.1871K |s2cid=21834435}}
*{{cite journal |doi=10.2135/cropsci2006.07.0487 |title=Assessment of Different Legumes for the Control of in Maize and Sorghum |year=2007 |last1=Khan |first1=Zeyaur R. |last2=Midega |first2=Charles A. O. |last3=Hassanali |first3=Ahmed |last4=Pickett |first4=John A. |last5=Wadhams |first5=Lester J. |journal=Crop Science |volume=47 |issue=2 |pages=730–4}}
*{{cite journal |doi=10.1007/BF01681808 |title=New sources of resistance of cowpea (''Vigna unguiculata'') to ''Striga gesnerioides'', a parasitic angiosperm |year=1995 |last1=Moore |first1=T. H. M. |last2=Lane |first2=J. A. |last3=Child |first3=D. V. |last4=Arnold |first4=G. M. |last5=Bailey |first5=J. A. |last6=Hoffmann |first6=G. |journal=Euphytica |volume=84 |issue=3 |pages=165–74 |bibcode=1995Euphy..84..165M |s2cid=30202739}}

==External links==
*[https://parasiticplants.siu.edu/Orobanchaceae/Striga.Gallery.html The Parasitic Plant Connection: ''Striga'' Photo Gallery]
*[https://parasiticplants.siu.edu/Orobanchaceae/Striga.asiatica.html The Parasitic Plant Connection: ''Striga asiatica'' in the USA]
*[http://www.cdfa.ca.gov/phpps/ipc/weedinfo/striga.htm Witchweed]
*[http://www.africa.upenn.edu/eue_web/striga.htm UN Development Programme]
*[https://web.archive.org/web/20100923104758/http://iita.org/cms/details/research_summary.aspx?a=86&z=63 ''Striga'' research at the International Institute of Tropical Agriculture (IITA)]
*[https://web.archive.org/web/20070217235643/http://www.dpw.wageningen-ur.nl/cwe/Weed_Research/nature-problem.html Parasitic Plants as Weeds]
*[https://web.archive.org/web/20020902175236/http://www.cimmyt.cgiar.org/Research/Maize/results/striga/control.htm ''Striga'' weed control with herbicide-coated maize seed, CIMMYT]
*[https://web.archive.org/web/20060303154450/http://www.idrc.ca/en/ev-5575-201-1-DO_TOPIC.html A recipe for ''Striga'' control in sub-saharan Africa]
*{{cite journal |doi=10.1007/BF01681808 |title=New sources of resistance of cowpea (''Vigna unguiculata'') to ''Striga gesnerioides'', a parasitic angiosperm |year=1995 |last1=Moore |first1=T. H. M. |last2=Lane |first2=J. A. |last3=Child |first3=D. V. |last4=Arnold |first4=G. M. |last5=Bailey |first5=J. A. |last6=Hoffmann |first6=G. |journal=Euphytica |volume=84 |issue=3 |pages=165–74 |bibcode=1995Euphy..84..165M |s2cid=30202739}}
*[http://www.facebook.com/media/set/fbx/?set=a.220085194674814.72657.205932102756790&saved#!/pages/Striga-research-and-control/205932102756790 Facebook community page "''Striga'' Research and Control"]
*{{cite web |title=DP 30: ''Striga'' spp. |website=[International Plant Protection Convention](/source/International_Plant_Protection_Convention) |url=http://www.ippc.int/en/publications/90164/ |access-date=2021-10-25}}

{{Taxonbar|from=Q135029}}

Category:Orobanchaceae
Category:Parasitic plants
Category:Orobanchaceae genera
Category:Taxa named by João de Loureiro

---
Adapted from the Wikipedia article [Striga](https://en.wikipedia.org/wiki/Striga) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Striga?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.