{{Short description|Species of flowering plant}} {{Redirect|Cursed thistle|the medicinal plant|Cnicus}} {{Speciesbox |image=Cirsium arvense with Bees Richard Bartz.jpg |status = {{TNCStatus}} |status_system = TNC |genus=Cirsium |species=arvense |authority=(L.) Scop. |synonyms_ref=<ref name=POWO>{{cite web |work=Plants of the World Online |title=Cirsium arvense (L.) Scop. |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:195034-1 |publisher=Royal Botanic Gardens Kew |access-date=5 July 2024 }}</ref> |synonyms={{collapsible list|bullets=true |title=<small>Synonyms</small> |''Breea arvensis'' <small>(L.) Less.</small> |''Carduus arvensis'' <small>(L.) Robson</small> |''Cephalonoplos arvensis'' <small>(L.) Fourr.</small> |''Cephalonoplos ochrolepidium'' <small>(Juz.) Juz. </small> |''Cnicus arvensis'' <small>(L.) Hoffm.</small> |''Serratula arvensis'' <small>L.</small> |}}}}
'''''Cirsium arvense''''' is a perennial species of flowering plant in the family Asteraceae, native throughout Europe and western Asia, northern Africa and widely introduced elsewhere.<ref>{{Cite book|last=Hodgson|first=Jesse M.|url=https://books.google.com/books?id=shZIxwabdBcC&pg=PA1|title=The Nature, Ecology, and Control of Canada Thistle|publisher=Agricultural Research Service, U.S. Dept. of Agriculture|year=1968|page=1}}</ref><ref name=jncc>Joint Nature Conservation Committee: [http://www.jncc.gov.uk/default.aspx?page=3316&SpeciesID=26769&type=species ''Cirsium arvense''] {{Webarchive|url=https://web.archive.org/web/20090811064030/http://www.jncc.gov.uk/default.aspx?page=3316&SpeciesID=26769&type=species |date=2009-08-11 }}</ref><ref>http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200023656 Flora of China, <big>丝路蓟</big> si lu ji, ''Cirsium arvense'' (Linnaeus) Scopoli]</ref><ref>[http://luirig.altervista.org/flora/taxa/index1.php?scientific-name=cirsium+arvense Altervista Flora Italiana, Cardo dei campi comune, Acker-Kratzdistel, åkertistel, ''Cirsium arvense'' (L.) Scop.] includes photos and distribution maps</ref> The standard English name in its native area is '''creeping thistle'''.<ref name=bsbi>Botanical Society of Britain and Ireland [http://www.bsbi.org.uk/html/database.html Database] {{webarchive|url=https://web.archive.org/web/20070808051058/http://bsbi.org.uk/html/database.html|date=2007-08-08 }}</ref> It is also commonly misnomered as '''Canada thistle''' and sometimes as '''field thistle'''.<ref>{{Cite web|url=http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200023656|title=Cirsium arvense in Flora of North America @ efloras.org|website=www.efloras.org|access-date=Sep 18, 2025}}</ref><ref>{{Cite web |url=http://www.nda.nebraska.gov/plant/noxious_weeds/pdf/canada.pdf |title=Nebraska Department of Agriculture Noxious Weed Program |access-date=2016-05-08 |archive-date=2022-01-19 |archive-url=https://web.archive.org/web/20220119043336/https://nda.nebraska.gov/plant/noxious_weeds/pdf/canada.pdf }}</ref>
==Alternative names== A number of other names are used in other areas or have been used in the past, including: '''Canadian thistle''', '''lettuce from hell thistle''', '''California thistle''',<ref>[http://www.landcareresearch.co.nz/research/biocons/weeds/weed_details.asp?WeedSpp_ID=10 ''Californian Thistle (Cirsium arvense)''], Landcare Research, New Zealand {{webarchive|url=https://web.archive.org/web/20100523211404/http://www.landcareresearch.co.nz/research/biocons/weeds/weed_details.asp?WeedSpp_ID=10|date=May 23, 2010 }}</ref> '''corn thistle''', '''cursed thistle''', '''field thistle''', '''green thistle''', '''hard thistle''', '''perennial thistle''', '''prickly thistle''', '''setose thistle''', '''small-flowered thistle''', '''way thistle''', and '''stinger-needles'''. Canada and Canadian thistle are in wide use in the United States, despite being a misleading designation, since it is not of Canadian origin.<ref>Invasive and Problem Plants of the United States: [http://www.thewildclassroom.com/biodiversity/problemplants/species/Canada%20Thistle.htm ''Cirsium arvense''] {{Webarchive|url=https://web.archive.org/web/20080705140654/http://www.thewildclassroom.com/biodiversity/problemplants/species/Canada%20Thistle.htm |date=2008-07-05 }}</ref>
==Description== thumb|Flowering creeping thistle ''Cirsium arvense'' is a C3 carbon fixation plant.<ref name=Sigurd/> The C3 plants originated during Mesozoic and Paleozoic eras, and tend to thrive in areas where sunlight intensity is moderate, temperatures are moderate, and ground water is plentiful. {{C3}} plants lose 97% of the water taken up through their roots to transpiration.<ref name=Raven2001>{{cite journal|author=Raven, J.A.|author2=Edwards, D.|year=2001|title=Roots: evolutionary origins and biogeochemical significance|journal=Journal of Experimental Botany|volume=52|issue=90001|pages=381–401|pmid=11326045|doi=10.1093/jexbot/52.suppl_1.381|doi-access=free}}</ref>
Creeping thistle is a herbaceous perennial plant growing up to 150 cm, forming extensive clonal colonies from thickened roots that send up numerous erect shoots during the growing season.<ref name=":0">{{Cite journal|last=MOORE|first=R. J.|date=1975-10-01|title=THE BIOLOGY OF CANADIAN WEEDS.: 13. Cirsium arvense (L.) Scop.|journal=Canadian Journal of Plant Science|volume=55|issue=4|pages=1033–1048|doi=10.4141/cjps75-163|issn=0008-4220|doi-access=free}}</ref> It is a ruderal species.<ref>{{Cite web|url=https://books.google.com/books?id=uK9R7N-QaJMC&q=arvense|title=p80|access-date=Sep 18, 2025}}</ref>
Given its adaptive nature, ''Cirsium arvense'' is one of the worst invasive weeds worldwide. Through comparison of its genetic expressions, the plant evolves differently with respect to where it has established itself. Differences can be seen in their R-protein mediated defenses, sensitivities to abiotic stresses, and developmental timing.<ref>{{cite journal | doi=10.1111/nph.12258 | title=Transcriptome divergence between introduced and native populations of Canada thistle, Cirsium arvense | year=2013 | last1=Guggisberg | first1=Alessia | last2=Lai | first2=Zhao | last3=Huang | first3=Jie | last4=Rieseberg | first4=Loren H. | journal=New Phytologist | volume=199 | issue=2 | pages=595–608 | pmid=23586922 | doi-access=free | bibcode=2013NewPh.199..595G }}</ref>
=== Taxonomy === ''Cirsium arvense'' is placed in the subtribe Carduinae, tribe Cardueae of the family Asteraceae. Unlike other species in the same genus, it is dioecious, although male plants sometimes produce bisexual flowers.<ref>{{cite journal|doi=10.1093/oxfordjournals.aob.a085102|title=Sexual Dimorphism in Cirsium arvense (L.) Scop|year=1976|last1=Lloyd|first1=D. G.|last2=Myall|first2=A. J.|journal=Annals of Botany|volume=40|pages=115–123}}</ref> It also differs from other native North American species in having large roots and multiple small flower heads on a branched stem.<ref>{{cite web|url=https://www.researchgate.net/publication/280659510 |title=Canada Thistle |date= |access-date=2022-05-01}}</ref> Cirsium arvense grows in diverse habitats (ranging from moist places to grasslands, mountain slopes, flooded lands, disturbed sites, etc.) at 100–4,300 m. Its native range is Temperate Eurasia, Northwest Africa. It has been introduced into North America, South America, Africa, Europe, Asia, Australia, and other regions.<ref>{{Cite journal |last=Balkrishna |first=Acharya |last2=Sharma |first2=Hemant |last3=Kukreti |first3=Ankita |last4=Kumari |first4=Amita |last5=Saini |first5=Priyanka |last6=Arya |first6=Vedpriya |last7=Kumar |first7=Ashwani |date=2024 |title=Traditional uses and phytopharmacology of Cirsium arvense: Bioprospecting potential of a weed from temperate biome |url=https://japsonline.com/abstract.php?article_id=4205&sts=2 |journal=Journal of Applied Pharmaceutical Science |volume=14 |issue=5 |pages=030–037 |doi=10.7324/JAPS.2024.168589|doi-access=free }} {{CC-notice|cc=by4}}</ref>
===Underground network=== Its underground structure consists of four types, 1) long, thick, horizontal roots, 2) long, thick, vertical roots, 3) short, fine shoots, and 4) vertical, underground stems.<ref>{{cite journal|last=Hamdoun|first=A. M.|date=1970-09-01|title=The Anatomy of Subterranean Structures of Cirsium arvense (L.) Scop.|journal=Weed Research|language=en|volume=10|issue=3|pages=284–287|doi=10.1111/j.1365-3180.1970.tb00952.x|bibcode=1970WeedR..10..284H |issn=1365-3180}}</ref> Though asserted in some literature, creeping thistle does not form rhizomes.<ref name=":1">{{cite journal|last=Donald|first=William|date=1994|title=The Biology of Canada Thistle (Cirsium arvense)|url=https://www.ars.usda.gov/ARSUserFiles/50701000/cswq-0193-donald.pdf|journal=Weed Science|volume=6|access-date=2016-07-14}}</ref> Root buds form adventitiously on the thickened roots of creeping thistle, and give rise to new shoots. Shoots can also arise from the lateral buds on the underground portion of regular shoots, particularly if the shoots are cut off through mowing or when stem segments are buried.<ref name=":1"/>
===Shoots and leaves=== Stems are 30–150 cm, slender green, and freely branched,<ref name=":1"/> smooth and glabrous (having no trichomes or glaucousness), mostly without spiny wings. Leaves are alternate on the stem with their base sessile and clasping or shortly decurrent. The leaves are very spiny, lobed, and up to 15–20 cm long and 2–3 cm broad (smaller on the upper part of the flower stem).
=== Flower head fragrance === [[File:Maniola jurtina 2 RF.jpg|thumb|Meadow brown on creeping thistle]] Every plant species has a unique floral fragrance.<ref name=":2">{{Cite journal|last=Andersson|first=Susanna|date=2003-03-01|title=Antennal responses to floral scents in the butterflies Inachis io, Aglais urticae (Nymphalidae), and Gonepteryx rhamni (Pieridae)|journal=Chemoecology|volume=13|issue=1|pages=13–20|doi=10.1007/s000490300001|bibcode=2003Chmec..13...13A |s2cid=22444773|issn=0937-7409}}</ref> The fragrance that ''C. arvense'' emits attracts both pollinators and florivores containing compounds that attract each respectively. Honeybees are shown to have the highest visitation rate, followed by other bee species in the genera ''Halictus'' and ''Lasioglossum''. Hover flies are also commonly seen pollinating the flower heads of this plant.<ref>{{Cite book|last=Theis, Nina Aileen.|title=Targeting pollinators and evading herbivores: floral scent emission in two species of Cirsium|oclc=57595495}}</ref> Florivores such as beetles and grasshoppers are commonly seen as well. The compounds found in the fragrance may not be in the highest abundance but they are highly attractive. P-anisaldehyde is found in less than 1%, yet it attracts pollinators such as honey bees.<ref>{{Cite journal|last=Theis|first=Nina|date=May 2006|title=Fragrance of Canada Thistle (Cirsium arvense) Attracts Both Floral Herbivores and Pollinators|journal=Journal of Chemical Ecology|volume=32|issue=5|pages=917–927|doi=10.1007/s10886-006-9051-x|pmid=16739013|bibcode=2006JCEco..32..917T |s2cid=21222911|issn=0098-0331}}</ref> This is thought to be the result of additive and synergistic effects from the blend increasing the attraction to the plant. After pollination, it can be seen that fragrance emission decreases in ''C.arvense''. This is regulated through a regulatory feedback mechanism depending on the pollination status of the plant. This mechanism has only been observed in pistillate plants for dioecious ''C. arvense''. Fragrance emission increases with age.<ref>{{Cite journal|last1=Theis|first1=Nina|last2=Raguso|first2=Robert A.|date=2005-10-25|title=The Effect Of Pollination On Floral Fragrance in Thistles|journal=Journal of Chemical Ecology|volume=31|issue=11|pages=2581–2600|doi=10.1007/s10886-005-7615-9|pmid=16273430|bibcode=2005JCEco..31.2581T |s2cid=5722787|issn=0098-0331}}</ref>
The fragrance contains several compounds that attract diverse insects. Looking at certain butterflies species, it can be seen that the fragrance blend is highly attractive to them, being sensitive to their antennae. High antennal response are seen in consequence to the phenylacetaldehyde as well as the terpenes (oxoisophoroneoxide, oxoisophorone, and dihydrooxoisophorone) found in the blend. This was seen in both natural plants emitting the fragrance and emitting the scent synthetically.<ref>{{Cite journal|last1=Theis|first1=Nina|last2=Raguso|first2=Robert A.|date=November 2005|title=The effect of pollination on floral fragrance in thistles|journal=Journal of Chemical Ecology|volume=31|issue=11|pages=2581–2600|doi=10.1007/s10886-005-7615-9|issn=0098-0331|pmid=16273430|bibcode=2005JCEco..31.2581T |s2cid=5722787}}</ref> It is believed that general arousal can be stimulated through exposure of a single compound, whereas the accumulated exposure of all the compounds influence the foraging behaviour of the butterflies.<ref name=":2" />
===Flowers and seeds=== The inflorescence compound cyme is {{convert|10|–|22|mm|abbr=on}} in diameter, pink-purple, with all the florets of similar form (no division into disc and ray florets). The flowers are usually dioecious, but not invariably so, with some plants bearing hermaphrodite flowers.<ref name=":1"/> The seeds are 4–5 mm long, with a feathery pappus which assists in wind dispersal.<ref name=fnwe>Flora of Northwest Europe: [http://ip30.eti.uva.nl/BIS/flora.php?selected=beschrijving&menuentry=soorten&id=3863 ''Cirsium arvense''] {{webarchive|url=https://web.archive.org/web/20080705161942/http://ip30.eti.uva.nl/BIS/flora.php?selected=beschrijving&menuentry=soorten&id=3863|date=2008-07-05 }}</ref><ref name=blamey>Blamey, M. & Grey-Wilson, C. (1989). ''Flora of Britain and Northern Europe''. {{ISBN|0-340-40170-2}}</ref><ref name=kay>Kay, Q. O. N. (1985). Hermaphrodites and subhermaphrodites in a reputedly dioecious plant, ''Cirsium arvense'' (L.) Scop. ''New Phytol.'' 100: 457-472. Available [https://www.doi.org/10.1111/j.1469-8137.1985.tb02794.x online] (pdf file).</ref> One to 5 flower heads occur per branch, with plants in very favourable conditions producing up to 100 heads per shoot.<ref name=":0"/> Each head contains an average of 100 florets. Average seed production per plant has been estimated at 1530. More seeds are produced when male and female plants are closer together, as flowers are primarily insect-pollinated.<ref name=":0"/> The plant can bloom from seed in a year then subsequently the seeds produced can emerge in the following year.<ref name="rapidcityjournal.com">{{cite web|url=https://rapidcityjournal.com/community/hot-springs/local-news/america-s-most-weeded-canada-thistle/article_62d104c0-4a99-11e5-8409-abcc1ccafd7a.html|title=America's most weeded: Canada Thistle|date=25 August 2015 }}</ref>
{{Gallery |Cirsium arvense - pappus (aka).jpg|Pappus of ''Cirsium arvense'' |Thistle with cuckoo spit.jpeg|A creeping thistle with a "cuckoo spit" }}
==Varieties== Variation in leaf characters (texture, vestiture, segmentation, spininess) is the basis for determining creeping thistle varieties.<ref name=":0"/> According to Flora of Northwest Europe<ref name=fnwe/> the two varieties are: *''Cirsium arvense'' var. ''arvense''. Most of Europe. Leaves hairless or thinly hairy beneath. *''Cirsium arvense'' var. ''incanum'' (Fisch.) Ledeb. Southern Europe. Leaves thickly hairy beneath. The Biology of Canadian Weeds: ''Cirsium arvense''<ref name=":0"/> list four varieties: *''Cirsium arvense'' var. ''vestitum (''Wimm. & Grab). Leaves gray-tomentose below. *''Cirsium arvense'' var. ''integrifolium'' ''(''Wimm. & Grab). Leaves all entire or the upper leaves entire and the lower stem leaves shallowly and regularly pinnatifid or undulating. *''Cirsium arvense'' var. ''arvense''. Leaves shallowly to deeply pinnatifid, often asymmetrical. *''Cirsium arvense'' var. ''horridum'' (Wimm. & Grab). Leaves thick, subcoriaceous, surface wavy, marginal spines long and stout.
==Ecology== thumb|A European goldfinch (''Carduelis carduelis'') feeding on the seeds The seeds are an important food for the goldfinch and the linnet, and to a lesser extent for other finches.<ref>Cramp, S., & Perrins, C. M. (1994). ''The Birds of the Western Palearctic. Vol. VIII: Crows to Finches''. Oxford University Press, Oxford.</ref> Creeping thistle foliage is used as a food by over 20 species of Lepidoptera, including the painted lady butterfly and the engrailed moth, and several species of aphids.<ref>Finnish Lepidoptera [http://www.funet.fi/pub/sci/bio/life/plants/magnoliophyta/magnoliophytina/magnoliopsida/asteraceae/cirsium/index.html#arvense ''Cirsium arvense'']</ref><ref>The Ecology of Commanster: [http://popgen.unimaas.nl/~jlindsey/commanster/Plants/Flowers/SuFlowers/Cirsium.arvense.html ''Cirsium arvense''] {{Webarchive|url=https://web.archive.org/web/20070826201927/http://popgen.unimaas.nl/~jlindsey/commanster/Plants/Flowers/SuFlowers/Cirsium.arvense.html |date=2007-08-26 }}</ref><ref>Ecological Flora of the British Isles: [http://www.ecoflora.co.uk/search_phytinsect.php?plant_no=1691180600 Phytophagous Insects for ''Cirsium arvense'']</ref> The ''C. arvense'' species is also noted to be a food source for the ''Altica cirsicola'' beetle species.<ref>{{Cite journal |last1=Laroche |first1=A. |last2=DeClerck-Floate |first2=R. A. |last3=LeSage |first3=L. |last4=Floate |first4=K. D. |last5=Demeke |first5=T. |date=1996-06-01 |title=AreAltica carduorumandAltica cirsicola(Coleoptera: Chrysomelidae) Different Species? Implications for the Release of A. cirsicolafor the Biocontrol of Canada Thistle in Canada |url=https://www.sciencedirect.com/science/article/pii/S1049964496900390 |journal=Biological Control |volume=6 |issue=3 |pages=306–314 |doi=10.1006/bcon.1996.0039 |bibcode=1996BiolC...6..306L |issn=1049-9644|url-access=subscription }}</ref>
The flowers are visited by a wide variety of insects such as bees, moths, wasps and beetles<ref>{{Cite journal|last1=El-Sayed|first1=A. M.|last2=Byers|first2=J. A.|last3=Manning|first3=L. M.|last4=Jürgens|first4=A.|last5=Mitchell|first5=V. J.|last6=Suckling|first6=D. M.|date=June 2008|title=Floral scent of Canada thistle and its potential as a generic insect attractant|journal=Journal of Economic Entomology|volume=101|issue=3|pages=720–727|doi=10.1603/0022-0493(2008)101[720:FSOCTA]2.0.CO;2|issn=0022-0493|pmid=18613571|s2cid=14419740 |doi-access=free}}</ref> (the generalised pollination syndrome).<ref>{{cite journal|doi=10.1111/plb.12328|pmid=25754608|title=Competition for pollinators and intra-communal spectral dissimilarity of flowers|journal=Plant Biology|volume=18|issue=1|pages=56–62|year=2015|last1=Van Der Kooi|first1=C. J.|last2=Pen|first2=I.|last3=Staal|first3=M.|last4=Stavenga|first4=D. G.|last5=Elzenga|first5=J. T. M.|url=https://www.researchgate.net/publication/273158762|hdl=11370/caee8d0d-9724-4056-9d45-93162a5a7afc|hdl-access=free}}</ref> The plant is beneficial for pollinators that rely on nectar. It also was a top producer of nectar sugar in a 2016 study in Britain, with a second-place ranking due to a production per floral unit of ({{val|2609|239|u=μg}}).<ref>{{cite journal|last1=Hicks|first1=DM|last2=Ouvrard|first2=P|last3=Baldock|first3=KCR|title=Food for Pollinators: Quantifying the Nectar and Pollen Resources of Urban Flower Meadows|journal=PLOS ONE|volume=11|issue=6|article-number=e0158117|date=2016|doi=10.1371/journal.pone.0158117|pmid=27341588|pmc=4920406|bibcode=2016PLoSO..1158117H|doi-access=free}}</ref>{{Primary source inline|date=April 2025}}
==Status as a weed== The species is widely considered a weed even where it is native, for example being designated an "injurious weed" in the United Kingdom under the Weeds Act 1959.<ref>DEFRA: [http://www.defra.gov.uk/farm/wildlife/weeds/weedsidentify.htm Identification of injurious weeds] {{webarchive|url=https://web.archive.org/web/20070626023904/http://www.defra.gov.uk/farm/wildlife/weeds/weedsidentify.htm|date=2007-06-26}}</ref> It is also a serious invasive species in many additional regions where it has been introduced, usually accidentally as a contaminant in cereal crop seeds. It is cited as a noxious weed in several countries; for example Australia, Brazil, Canada, Ireland, New Zealand, and the United States. Many countries regulate this plant, or its parts (i.e., seed) as a contaminant of other imported products such as grains for consumption or seeds for propagation. In Canada, ''C. arvense'' is classified as a primary noxious weed seed in the Weed Seeds Order 2005 which applies to Canada's Seeds Regulations.<ref>[http://www.gazette.gc.ca/archives/p1/2005/2005-02-26/pdf/g1-13909.pdf Weed Seeds Order 2005] {{webarchive|url=https://web.archive.org/web/20120321012542/http://www.gazette.gc.ca/archives/p1/2005/2005-02-26/pdf/g1-13909.pdf|date=2012-03-21 }}, Canada Gazette Part I, Vol. 139, No. 9</ref>
A study conducted has shown that with future global atmospheric carbon levels, ''C. arvense'' have a risk of increased growth which could expand its range and outcompete native species.<ref>{{Cite journal |last=Ziska |first=L. H. |date=2003-01-02 |title=Evaluation of the growth response of six invasive species to past, present and future atmospheric carbon dioxide |journal=Journal of Experimental Botany |volume=54 |issue=381 |pages=395–404 |doi=10.1093/jxb/erg027 |pmid=12493868 |issn=0022-0957}}</ref>
==Control==
===Organic=== Control methods include cutting at flower stem extension before the flower buds open to prevent seed spread. Repeated cutting at the same growth stage over several years may "wear down" the plant.
Growing forages such as alfalfa can help control the species as a weed: by frequently cutting the alfalfa to add nutrients to the soil, the weeds also get cut and have a harder time re-establishing themselves, which reduces the shoot density.<ref>{{cite web|url=http://www.soilcc.ca/ggmp_fact_sheets/pdf/Forages%20in%20rotation.pdf|title=Forages in Rotation|year=2016|publisher=Saskatchewan Soil Conservation Association|access-date=2016-12-01|archive-date=2016-12-02|archive-url=https://web.archive.org/web/20161202101131/http://www.soilcc.ca/ggmp_fact_sheets/pdf/Forages%20in%20rotation.pdf}}</ref>
''Orellia ruficauda'' feeds on Canada thistle and has been reported to be the most effective biological control agent for that plant.<ref>Moore 1975, Maw 1976</ref> Its larvae parasitize the seed heads, feeding solely upon fertile seed heads.<ref>[http://ir.lib.sfu.ca/bitstream/1892/6217/1/b14461626.pdf Lalonde]</ref>
The weevil ''Larinus planus'' also feeds on the thistle and has been used as a control agent in Canada.<ref>{{cite book|title=Operational Field Guide to the Propagation and Establishment of the Bioagent Larinus Planus|date=May 2001|publisher=Province of British Columbia, Ministry of Forests|url=https://www.for.gov.bc.ca/hra/plants/downloads/FieldGuide_Larinus_planus.pdf|access-date=2019-01-30|archive-url=https://web.archive.org/web/20181113204115/https://www.for.gov.bc.ca/hra/plants/downloads/FieldGuide_Larinus_planus.pdf|archive-date=2018-11-13}}</ref> One larva of the species can consume up to 95% of seeds in a particular flower bud.<ref name=BCMF>{{cite web|title=Larinus planus|url=https://www.for.gov.bc.ca/hra/plants/biocontrol/detailed_bioagent_pages/Larinus_planus.htm|website=Ministry of Forests, Lands, and Natural Resource Operations|publisher=Province of British Columbia, Ministry of Forests|language=en|date=17 May 2007|access-date=30 January 2019|archive-url=https://web.archive.org/web/20190130220841/https://www.for.gov.bc.ca/hra/plants/biocontrol/detailed_bioagent_pages/Larinus_planus.htm|archive-date=30 January 2019}}</ref> However, use of this weevil has had a damaging effect on other thistle species as well, include some that are threatened.<ref name=Louda>{{cite journal|last1=Louda|first1=Svaa M.|last2=O'Brien|first2=Charles W.|title=Unexpected Ecological Effects of Distributing the Exotic Weevil, Larinus planus (F.), for the Biological Control of Canada Thistle|journal=Conservation Biology|date=June 2002|volume=16|issue=3|pages=717–727|doi=10.1046/j.1523-1739.2002.00541.x|bibcode=2002ConBi..16..717L |s2cid=2367835|url=http://web.wits.ac.za/NR/rdonlyres/CD7EB87D-64DC-419C-95BA-2F1A7E60329D/0/LoudaandOBrien2002.pdf}}{{Dead link|date=July 2019 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> It may therefore not be a desirable control agent. It is unclear if the government continues to use this weevil to control Canada thistles or not.
The rust species ''Puccinia obtegens'' has shown some promise for controlling Canada thistle, but it must be used in conjunction with other control measures to be effective.<ref>Turner et al. 1980.</ref> Also ''Puccinia punctiformis'' is used in North America and New Zealand in biological control.<ref>R. C. French, A. R. Lightfield: ''Induction of Systemic Aecial Infection in Canada Thistle (Cirsium arvense) by Teliospores of Puccinia punctiformis.'' In: ''Phytopathology.'' Band 80, Nr. 8, 1990, S. 872–877, DOI:10.1094/Phyto-80-872</ref> In 2013, in four countries in three continents, epidemics of systemic disease caused by this rust fungus could be routinely and easily established.<ref>Berner, D. K., et al. (2013) Successful establishment of epiphytotics of Puccinia punctiformis for biological control of Cirsium arvense. Biological Control 67:350-360.</ref> The procedure for establishing this control agent involves three simple steps and is a long-term sustainable control solution that is free and does not involve herbicides. Plants systemically diseased with the rust gradually but surely die. Reductions in thistle density were estimated, in 10 sites in the U.S., Greece, and Russia, to average 43%, 64%, and 81% by 18, 30, and 42 months, respectively, after a single application of spores of the fungus.<ref>Berner, D. K., et al. (2015) Asymptomatic systemic disease of Canada thistle (Cirsium arvense) caused by Puccinia punctiformis and changes in shoot density following inoculation. Biological Control 86:28-35.</ref>
[[File:Rust Mite, Aceria anthocoptes.jpg|thumb|Electron scan micrography of ''Aceria anthocoptes'']] ''Aceria anthocoptes'' feeds on this species and is considered to be a good potential biological control agent.
===Chemical=== Applying herbicide: Herbicides dominated by phenoxy compounds (especially MCPA) caused drastic declines in thistle infestation in Sweden in the 1950s.<ref name=Sigurd>''[https://books.google.com/books?id=PlDdblTo07oC&dq=Cirsium+arvense+dicot+control&pg=PA242 Weeds and weed management on arable land: an ecological approach]'' Sigurd Håkansson CABI Publishing Series, 2003, {{ISBN|0-85199-651-5}}</ref> MCPA and clopyralid are approved in some regions. Glyphosate is a non-selective herbicide that can be used when the plant has grown a few inches tall, where the herbicide can be absorbed by the leaf surfaces.<ref name="rapidcityjournal.com"/>
Crop tolerance and weed control ratings were conducted in the spring of 2012, and the Prepass herbicide by DOW AgroSciences was found to be most effective at controlling the species as a weed problem in alfalfa fields.<ref>{{cite web|url=http://www.forageseed.net/index.php?option=com_content&view=article&id=170:201%09112-nfall-alfalfa-herbicide-trials-for-control-of-canada-thistle&catid=60:2012-%09research&Itemid=149|title=2011/12 Fall Alfalfa Herbicide Trials for Control of Canada Thistle|last=Administrator|website=www.forageseed.net|access-date=2016-12-01|archive-url=https://web.archive.org/web/20161202165345/http://www.forageseed.net/index.php?option=com_content&view=article&id=170:201%09112-nfall-alfalfa-herbicide-trials-for-control-of-canada-thistle&catid=60:2012-%09research&Itemid=149|archive-date=2016-12-02}}</ref>
==Uses== Like other ''Cirsium'' species, the roots are edible, though rarely used, not in the least because of their propensity to induce flatulence in some people. The taproot is considered the most nutritious part.{{citation needed|date=December 2013}} The leaves are also edible, though the spines make their preparation for food too tedious to be worthwhile. The stalks, however, are also edible and more easily despined.<ref name=pfaf>Plants for a Future: [http://www.pfaf.org/database/plants.php?Cirsium+arvense ''Cirsium arvense'']</ref> Bruichladdich distillery on Isle of Islay lists creeping thistle as one of the 22 botanical forages used in their gin, The Botanist.<ref>{{cite web| url=http://www.thebotanist.com/distilled/the-22| title=The Botanist| access-date=2015-04-18| archive-url=https://web.archive.org/web/20170427033527/https://www.thebotanist.com/distilled/the-22| archive-date=2017-04-27}}</ref>
The feathery pappus is also used by the Cherokee to fletch blowgun darts.<ref>{{cite web|url=http://www.youtube.com/watch?v=ySjOxBJ0AEQ |archive-url=https://ghostarchive.org/varchive/youtube/20211221/ySjOxBJ0AEQ |archive-date=2021-12-21 |url-status=live|title=Culture Keepers: Blowgun|publisher=YouTube|date=2013-04-12|access-date=2017-08-25}}{{cbignore}}</ref>
==References== {{Reflist}}
==External links== *[http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2745.2010.01678.x/full Tiley, G.E.D. "Biological Flora of the British Isles: ''Cirsium arvense'' (L.) Scop." Journal of Ecology 98, no. 4 (2010): 938-983.] *[https://www.invasivespeciesinfo.gov/terrestrial/plants/canada-thistle Species Profile- Canada Thistle (''Cirsium arvense'')], National Invasive Species Information Center, United States National Agricultural Library. Lists general information and resources for Canada thistle. *[http://www.naturemanitoba.ca/sites/default/files/CanThistle.pdf Profile: Canada Thistle (''Cirsium arvense'')] Photos, Drawings, Text. (''Wild Plants of Winnipeg'' from Nature Manitoba)
{{Taxonbar|from=Q341600}} {{Authority control}}
arvense Category:Edible plants Category:Flora of Asia Category:Flora of Europe Category:Plants described in 1753 Category:Botanical taxa named by Carl Linnaeus Category:Taxa named by Giovanni Antonio Scopoli