Orobanche minor

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|image = (MHNT) Orobanche minor.jpg

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|genus = Orobanche

|species = minor

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Orobanche minor, the hellroot,{{PLANTS|id=ORMI|taxon=Orobanche minor|accessdate=25 July 2015}} common broomrape, lesser broomrape, small broomrape, broomrape minor or clover broomrape, is a holoparasitic flowering plant belonging to the family Orobanchaceae. It is one of about 150 non-photosynthetic plants in the genus Orobanche that parasitize autotrophic plants.

Characteristics and growth requirements

Orobanche minor grows to {{convert|0.5|m|ftin|abbr=on}} and is a perennial.{{citation needed|date=July 2024}}

The flowers are hermaphrodite.{{citation needed| reason = please also add the correct soffit to "hermaphrodite". |date=May 2025}}

Common broomrape grows in a wide variety of soils, namely moist, light (sandy), medium (loamy) and heavy (clay) soils that are acid, neutral or basic. It can grow in semi-shade or in full sunlight.[http://www.pfaf.org/user/Plant.aspx?LatinName=Orobanche+minor Plants for a Future] Retrieved: 2011-08-07

The species appears in a wide range of colours from red-brown, yellow-brown to purple. Yellow specimens are also not uncommon and it is this extreme variability that makes identification on the basis of size or colour uncertain.[http://www.first-nature.com/flowers/orobanche_minor.php First Nature] {{Webarchive|url=https://web.archive.org/web/20110929164126/http://www.first-nature.com/flowers/orobanche_minor.php |date=2011-09-29 }} Retrieved: 2011-08-07

It is parasitic on various members of the pea (Fabaceae) and daisy (Asteraceae) families. Although widespread, its appearance is sporadic; despite this, it can occur in vast colonies from time to time. The main flowering season in the northern hemisphere is from May until the end of August and from August to January in the southern hemisphere.{{cite web|url=http://agpest.co.nz/?pesttypes=broomrape|publisher=AgPest New Zealand|access-date=1 December 2016|title=Broomrape}} The species has efficient seed dispersal and is largely inbreeding so that populations preferentially parasitizing a particular species which has its own clear ecological preferences may become effectively isolated and eventually may produce distinct taxa.[http://www.watsonia.org.uk/Wats18p257.pdf Watsonia] Retrieved: 2011-08-07

The plants are attached to their host by means of haustoria, which transfer nutrients from the host to the parasite. Only the hemiparasitic species possess an additional extensive root system. The root system is reduced as its function is mainly anchorage of the plant.{{citation needed|date=May 2025}}

Distribution

Common broomrape is one of the most widespread species, and is native to Southern Europe,Kreutz, C.A.J. (1995) Orobanche: Die Sommerwurzarten Europas. Maastricht: Stichting Natuurpublicaties (Limburg, Germany). but has been widely introduced elsewhere, for example in the United States.{{cite journal | last1 = Eizenberg | first1 = H. | last2 = Colquhoun | first2 = JB. | last3 = Mallory-Smith | first3 = C.A. | year = 2003 | title = Variation in clover response to small broomrape (Orobanche minor) | journal = Weed Science | volume = 51 | issue = 5| pages = 759–763 | doi=10.1614/ws-03-029r| s2cid = 86330666 }} In New Zealand it is the only species of the genus present where it is regarded as an agricultural pest. In the United Kingdom it is widely recorded in southern England, less common in Wales, rarely recorded in lowland Scotland and absent from the Highlands and outer islands.[https://data.nbn.org.uk/Taxa/NHMSYS0000461381/Grid_Map NBN Gateway] Retrieved: 2011-08-08

Taxonomy

Phylogenetic analyses have placed this species in the taxonomically difficult Minores species complex.{{cite journal | last1 = Manen | first1 = JF | last2 = Habashi | first2 = C | last3 = Jeanmonod | first3 = D | last4 = Park | first4 = JM | last5 = Schneeweiss | first5 = GM | year = 2004 | title = Phylogeny and intraspecific variability of holoparasitic Orobanche (Orobanchaceae) inferred from plastid rbcL sequences | journal = Molecular Phylogenetics and Evolution | volume = 33 | issue = 2| pages = 482–500 | doi=10.1016/j.ympev.2004.06.010 | pmid=15336681}}{{cite journal | last1 = Schneeweiss | first1 = G.M. | last2 = Colwell | first2 = A. | last3 = Park | first3 = J-M. | last4 = Jang | first4 = C-G. | last5 = Stuessy | first5 = T.F. | year = 2004 | title = Phylogeny of holoparasitic Orobanche (Orobanchaceae) inferred from nuclear ITS sequences | journal = Molecular Phylogenetics and Evolution | volume = 30 | issue = 2| pages = 465–478 | doi=10.1016/s1055-7903(03)00210-0| pmid = 14715236 }} Four infraspecific taxa of Common broomrape are currently recognised in the United Kingdom: O. minor var. minor, O. minor var. flava, O. minor var. compositarum and O. minor subsp. maritima.{{cite journal | last1 = Rumsey | first1 = F.J. | year = 2007 | title = A reconsideration of Orobanche maritima Pugsley (Orobanchaceae) and related taxa in southern England and the Channel Islands | journal = Watsonia | volume = 26 | pages = 473–476 }} Chromosome No.: 2n = 38. The genetic structure of populations of O. minor are under investigation using molecular markers and DNA sequencing to help resolve the taxonomic and nomenclatural problems that have historically been linked with this species.[http://sppaccounts.bsbi.org.uk/content/orobanche-minor BSBI] Retrieved: 2011-08-07

Hosts and speciation

The common broomrape is highly generalist in its host range, and can infect hundreds of species in families from the Ranunculaceae to the Poaceae (=Gramineae) but with a clear preference for the Fabaceae (=Leguminosae) and Asteraceae (=Compositae).{{cite journal | last1 = Rumsey | first1 = F.J. | last2 = Jury | first2 = S | year = 1991 | title = An account of Orobanche L. in Britain and Ireland | journal = Watsonia | volume = 18 | pages = 257–295 }} However races occurring on different species of host are genetically divergent{{cite journal | last1 = Thorogood | first1 = C.J. | last2 = Rumsey | first2 = F.J. | last3 = Harris | first3 = S | last4 = Hiscock | first4 = S.J. | year = 2008 | title = Host-driven divergence in the parasitic plant Orobanche minor Sm. (Orobanchaceae) | journal = Molecular Ecology | volume = 17 | issue = 19| pages = 4289–4303 | doi=10.1111/j.1365-294x.2008.03915.x| pmid = 19378406 | s2cid = 42331081 }} and physiologically adapted to their local hosts, and may therefore be in a state of incipient speciation.{{cite journal | last1 = Thorogood | first1 = C.J. | last2 = Rumsey | first2 = F.J. | last3 = Hiscock | first3 = S.J. | year = 2009 | title = Host-specific races in the holoparasitic angiosperm Orobanche minor: implications for speciation in parasitic plants | journal = Annals of Botany | volume = 103 | issue = 7| pages = 1005–1014 | doi=10.1093/aob/mcp034 | pmid=19251714 | pmc=2707918}} Urgent conservation efforts are required as the survival of some intraspecific taxa is very uncertain.

References

External links

[https://www.youtube.com/watch?v=RwBR2p0rx9Q Video of common broomrape] at Ardrossan