Cytisus scoparius

{{Short description|Ornamental broom shrub}} {{Speciesbox | image = Cytisus scoparius by Danny S. - 001.JPG | image_caption = Common broom | genus = Cytisus | species = scoparius | authority = ([[Carl Linnaeus|L.]]) [[Johann Heinrich Friedrich Link|Link]] | synonyms = {{Collapsible list | {{Plainlist | style = margin-left: 1em; text-indent: -1em; | *''Sarothamnus bourgaei'' Boiss. *''Sarothamnus oxyphyllus'' Boiss. *''Sarothamnus scoparius'' (L.) W.D.J.Koch *''Sarothamnus vulgaris'' Wimm. *''Spartium scoparium'' L. }} }} | synonyms_ref = <ref>{{cite web|url=http://www.theplantlist.org/tpl1.1/record/ild-8778|title=The Plant List: A Working List of All Plant Species|website=Theplantlist.org|access-date=April 3, 2014}}</ref> }}

'''''Cytisus scoparius''''' ([[synonym (taxonomy)|syn.]] ''Sarothamnus scoparius''), the '''common broom''' or '''Scotch broom''', is a [[deciduous]] [[leguminous]] [[shrub]] native to [[Western Europe|western]] and [[central Europe]].<ref name="flora">{{cite web|url=http://rbg-web2.rbge.org.uk/cgi-bin/nph-readbtree.pl/feout?FAMILY_XREF=&GENUS_XREF=Cytisus+&SPECIES_XREF=scoparius&TAXON_NAME_XREF=&RANK=|title=Flora Europaea Search Results|website=Rbg-web2.rbge.org.uk|access-date=15 August 2018}}</ref> In Great Britain and Ireland, the [[Common name|standard name]] is '''broom''';<ref name="blamey"/><ref>{{cite web|url=http://www.bsbi.org.uk/BSBI2003.zip|title=Botanical Society of Britain and Ireland (zip file)|website=Bsbi.org.uk|access-date=15 August 2018|archive-url=https://web.archive.org/web/20070203043721/http://bsbi.org.uk/BSBI2003.zip|archive-date=3 February 2007|url-status=dead}}</ref><ref name="vedel">{{cite book |author1=H. Vedel |title=Trees and Bushes |author2=J. Lange |publisher=Metheun |year=1960 |location=London}}</ref> this name is also used for other members of the [[Genisteae]] tribe, such as [[Genista monspessulana|French broom]] or [[Spartium|Spanish broom]]; and the term ''common broom'' is sometimes used for clarification.<ref>{{cite web|url=http://www.lenymede.demon.co.uk/nature/flowers.html|title=Wild Flowers of the Loch Lomond and Trossachs National Park, Scotland|website=Lenymede.demon.co.uk|access-date=15 August 2018|archive-url=https://web.archive.org/web/20061014025009/http://www.lenymede.demon.co.uk/nature/flowers.html|archive-date=14 October 2006|url-status=dead}}</ref><ref>{{Cite web |url=http://www.gardenworld.co.uk/broom2.asp |title=GardenWorld |access-date=2006-12-17 |archive-url=https://web.archive.org/web/20061006083627/http://www.gardenworld.co.uk/broom2.asp |archive-date=2006-10-06 |url-status=dead }}</ref> In other English-speaking countries, the most common name is "Scotch broom" (or '''Scots broom''');<ref name="NPSscotchbroom">{{Cite web |url=http://www.nps.gov/archive/redw/scotchbr.htm |title=What is Scotch Broom? |access-date=2006-11-20 |archive-url=https://web.archive.org/web/20061205235823/http://www.nps.gov/archive/redw/scotchbr.htm |archive-date=2006-12-05 |url-status=dead }}</ref> however, it is known as '''English broom''' in Australia.<ref>{{cite web|url=http://agriculture.vic.gov.au/agriculture/pests-diseases-and-weeds/weeds/a-z-of-weeds/english-broom|title=English broom|website=Agriculture.vic.gov.au|access-date=15 August 2018|archive-date=16 August 2018|archive-url=https://web.archive.org/web/20180816025618/http://agriculture.vic.gov.au/agriculture/pests-diseases-and-weeds/weeds/a-z-of-weeds/english-broom|url-status=dead}}</ref>

Though this plant is native to Europe, it has spread to many other parts of the world with human introduction. Scotch broom is now common in certain areas of North America and South America, and is considered an invasive species. In North America, Scotch broom was frequently planted in gardens, and was later used for erosion control along highway cuts and fills.<ref name=":0" /> Scotch broom is slightly toxic and unpalatable to livestock,<ref name=":0" /> and its seeds are viable for up to ten years, allowing them to regrow many years later, after extermination of the plant.

== Description == [[File:Cytisus scoparius - Köhler–s Medizinal-Pflanzen-200.jpg|thumb|left|upright|Illustration of ''C. scoparius'' from ''[[Köhler's Medicinal Plants]]'' (1887)]]

Plants of ''C. scoparius'' typically grow to {{convert|1–3|m|ft|abbr=off|frac=2}} tall, rarely to {{convert|4|m|ft|abbr=on}}, with main stems up to {{convert|5|cm|abbr=off|frac=2}} thick, rarely {{convert|10|cm|abbr=on|frac=2}}. Stems are ridged and green.<ref name=":0">{{Cite web |title=Exotic Species: Scotch Broom (U.S. National Park Service) |url=https://www.nps.gov/articles/scotch-broom.htm |access-date=2021-04-02 |website=www.nps.gov |language=en}}</ref> The shrubs have green shoots with small deciduous trifoliate [[leaf|leaves]] {{Convert|5–15|mm|abbr=out|frac=8}} long, and in spring and summer are covered in profuse golden yellow [[flower]]s {{Convert|20–30|mm|abbr=on|frac=8}} from top to bottom and 15–20 mm wide. Flowering occurs after 50–80 [[growing degree-day]]s. The seed pods have long hairs only along their seams.<ref name=":0" /> In late summer, its [[legume]]s ([[seed pod]]s) mature black, {{Convert|2–3|cm|abbr=on|frac=4}} long, {{Convert|8|mm|abbr=on|frac=8}} broad and 2–3 mm thick; they burst open, often with an audible crack, forcibly throwing seed from the parent plant. This species is adapted to [[Mediterranean]] and coastal climates, and its range is limited by cold winter temperatures. It also adapts to windy [[oceanic climate]]s. The seeds, seedlings, and young shoots are sensitive to frost; adult plants are hardier, and branches affected by freezing temperatures regenerate quickly.<ref name="blamey" /><ref name="vedel" /><ref name="bean">{{cite book |author=W. J. Bean |title=Trees and Shrubs Hardy in the British Isles |publisher=John Murray |year=1970 |isbn=0-7195-1790-7 |location=London}}</ref> ''C. scoparius'' contains toxic alkaloids that depress the heart and nervous system.<ref name="plants of the Pacific Northwest coast">{{cite book |author1=Jim Pojar |title=Plants of the Pacific Northwest Coast: Washington, Oregon, British Columbia & Alaska |author2=A. MacKinnon |author3=Paul B. Alaback |publisher=Lone Pine |year=1994 |location=Redmond, WA}}</ref>

As a [[legume]], this shrub can [[Nitrogen fixation|fix nitrogen]] in the soil through a [[symbiosis|symbiotic]] relationship with ''[[Rhizobium]]'' bacteria.

=== Phytochemicals === [[File:Cytisus scoparius (55025686647).jpg|thumb|Broom near [[Frederikshavn]], [[Denmark]] during winter. Note that the seed pods turn black ]] One of the main [[alkaloid]]s of this plant is [[cytisine]]. The characteristic constituents are [[biogenic]] [[amine]]s (mostly [[tyramine]] in the young shoots), [[flavonoid]]s ([[spiraeoside]] and scoparoside), [[isoflavone]]s and their [[glycoside]]s ([[genistin]]), as well as [[allelopathic]] [[quinolizidine alkaloid]]s (mostly [[sparteine]], lupanine, scoparin and hydroxy-derivatives), which defend the plant against insect infestation and [[herbivore]]s (with the exception of the resistant [[aphid]] species ''Aphis cytisorum'').<ref>{{cite journal |author1=Isamu Murakoshi |author2=Yoshiaki Yamashita |author3=Shigeru Ohmiya |author4=Hirotaka Otomasu |year=1986 |title=(−)-3β-13α-dihydroxylupanine from ''Cytisus scoparius'' |journal=[[Phytochemistry (journal)|Phytochemistry]] |volume=25 |issue=2 |pages=521–524 |doi=10.1016/S0031-9422(00)85514-4|bibcode=1986PChem..25..521M }}</ref><ref>{{cite journal |author1=Michael Wink |author2=Thomas Hartmann |author3=Ludger Witte |author4=Joachim Rheinheimer |year=1982 |title=Interrelationship between quinolizidine alkaloid producing legumes and infesting insects: exploitation of the alkaloid-containing phloem sap of ''Cytisus scoparius'' by the broom aphid ''Aphis cytisorum'' |url=http://www.uni-heidelberg.de/institute/fak14/ipmb/phazb/pdf-files/1982%20Pdf.Pubwink/6.%201982.pdf |journal=[[Zeitschrift für Naturforschung]] |volume=37 |issue=11–12 |pages=1081–1086 |doi=10.1515/znc-1982-11-1206 |s2cid=6640269}}</ref>

== Classification == There are two [[subspecies]] of ''Cytisus scoparius'':<ref name="flora"/><ref name="blamey"/> * ''Cytisus scoparius'' subsp. ''scoparius'' - throughout the species' range. * ''Cytisus scoparius'' subsp. ''maritimus'' (Rouy) Heywood - [[Western Europe]]an maritime cliffs and associated environments; differs with prostrate growth; not over 0.4 m tall; downy young shoots.

==Distribution and habitat== ''Cytisus scoparius'' is native to [[Western Europe|western]] and [[central Europe]],<ref name="flora" /> being common in [[Great Britain]] and [[Republic of Ireland]].<ref>Clapham, A.R., Tutin, T.G. and Warburg, E.F. 1968. ''Excursion Flora of the British Isles''. Cambridge Press. {{ISBN|0-521-04656-4}}</ref><ref>Parnell, J. and Curtis, T. 2012. ''Webb's An Irish Flora''. Cork University Press. {{ISBN|978-185918-4783}}</ref> It is found in sunny sites, usually on dry, sandy soils at low altitudes, tolerating very acidic soil conditions.<ref name="blamey">{{cite book |author1=M. Blamey |author2=C. Grey-Wilson |year=1989 |title=Flora of Britain and Northern Europe |publisher=Hodder & Stoughton |isbn=0-340-40170-2}}</ref>

Outside of its native range, it is an ecologically destructive [[Colonisation (biology)|colonizing]] [[invasive species]] in [[grassland]], [[California chaparral and woodlands|shrub and woodland]], and other [[habitat]]s.<ref name="usda">{{cite web |title=Species Profile – Scotch Broom (''Cytisus scoparius'' (L.)) |url=https://www.invasivespeciesinfo.gov/profile/scotch-broom |url-status=dead |archive-url=https://web.archive.org/web/20130726141225/http://www.invasivespeciesinfo.gov/plants/scotchbroom.shtml |archive-date=July 26, 2013 |access-date=October 9, 2013 |publisher=National Invasive Species Information Center, [[United States National Agricultural Library]]}}</ref><ref>{{cite journal |author1=Ashfaq Ahmed Zarri |author2=Asad R. Rahmani |author3=Mark J. Behan |year=2006 |title=Habitat modifications by Scotch broom ''Cytisus scoparius'' invasion of grasslands of the Upper Nilgiris in India |journal=[[Journal of the Bombay Natural History Society]] |volume=103 |issue=2–3 |pages=356–365}}</ref>

==Ecology==

=== As an invasive species === [[File:Cytisus scoparius USGS.jpg|thumb|right|Broom is an invasive species in North America.]] ''Cytisus scoparius'' has been introduced into several other countries and continents, outside of its native range, and is commonly classified as a [[noxious weed|noxious]] [[invasive species]] in western [[North America]], mainly in [[British Columbia]] (including on [[Vancouver Island]]), [[California]], [[Oregon]], [[Washington (state)|Washington]] (west of the [[Cascade Range|Cascades]]), the [[Sierra Nevada]] range,<ref name="feis">{{cite web |title=Cytisus scoparius, C. striatus |url=https://www.fs.fed.us/database/feis/plants/shrub/cytspp/all.html |access-date=18 August 2019 |website=www.feis-crs.org}}</ref> fragmented areas of North America's [[east Coast of the United States|eastern seaboard]],<ref name="usda" /> as well as [[Australia]] (where it is highly invasive and an environmental weed),<ref>{{cite web |title=Broom |url=http://dpipwe.tas.gov.au/invasive-species/weeds/weeds-index/declared-weeds-index/broom |access-date=15 August 2018 |website=Dpipwe.tas.gov.au}}</ref><ref>{{cite journal |author1=Andrew W. Sheppard |author2=Peter Hodge |author3=Quentin Paynter |author4=Mark Rees |year=2002 |title=Factors affecting invasion and persistence of broom ''Cytisus scoparius'' in Australia |journal=[[Journal of Applied Ecology]] |volume=39 |issue=5 |pages=721–734 |jstor=827200 |doi=10.1046/j.1365-2664.2002.00750.x|doi-access=free |bibcode=2002JApEc..39..721S }}</ref><ref>{{Cite journal |last=Downey |first=P. O. |last2=Smith |first2=J. M. B. |date=2000 |title=Demography of the invasive shrub Scotch broom (''Cytisus scoparius'') at Barrington Tops, New South Wales: insights for management. |url=https://doi.org/10.1046/j.1442-9993.2000.01083.x |journal=Austral Ecology |volume=25 |issue=5 |pages=477–485 |doi=10.1046/j.1442-9993.2000.01083.x |issn=1442-9985|url-access=subscription }}</ref><ref>{{Cite journal |last=Paynter |first=Quentin |last2=Downey |first2=Paul O. |last3=Sheppard |first3=Andrew W. |date=2003 |title=Age structure and growth of the woody legume weed ''Cytisus scoparius'' in native and exotic habitats: implications for control |url=https://doi.org/10.1046/j.1365-2664.2003.00817.x |journal=Journal of Applied Ecology |volume=40 |issue=3 |pages=470–480 |doi=10.1046/j.1365-2664.2003.00817.x |issn=0021-8901|url-access=subscription }}</ref>[[New Zealand]],<ref>{{cite web|title=Broom – outside Howard – St Arnaud|url=http://www.nelsoncitycouncil.co.nz/broom|work=Pest Management|publisher=Nelson City Council|access-date=8 February 2012}}</ref> and in [[India]].<ref>{{cite journal |author1=K. J. B. Potter |author2=D. J. Kriticos |author3=M. S. Wait |author4=A. Leriche |year=2009 |title=The current and future potential distribution of ''Cytisus scoparius'': a weed of pastoral systems, natural ecosystems and plantation forestry |journal=Weed Research |volume=49 |issue=3 |pages=271–282 |doi=10.1111/j.1365-3180.2009.00697.x|bibcode=2009WeedR..49..271P }}</ref> These shrubs are sometimes utilized for civic and public landscaping projects in the American west due to their hardiness, and will seasonally reseed themselves, growing in disturbed areas, and along utility and transportation [[right-of-way (transportation)|rights-of-way]]. The prolific growth of the plants after timber harvest or wildfire events clearly inhibits reforestation efforts, the sprouts competing with native plant seedlings and trees.<ref>{{Cite web| title = Invasive Plant Species Management Plan: Appendix 7| work = McDonald-Dunn Forest Plan| publisher = Oregon State University, College of Forestry| url = http://deansoffice.forestry.oregonstate.edu/sites/default/files/fec-files/FEC11-7-06%20Appendix%207.pdf| page = 10| access-date = 2006-12-20| archive-url = https://web.archive.org/web/20140504001359/http://deansoffice.forestry.oregonstate.edu/sites/default/files/fec-files/FEC11-7-06%20Appendix%207.pdf| archive-date = 2014-05-04| url-status = dead}}</ref> It is estimated that broom is responsible for US$47 million in lost timber production each year in the state of Oregon.<ref>{{Cite web | title = Scotch broom | work = ODA Plant Division, Noxious Weed Control | url = http://www.oregon.gov/ODA/PLANT/WEEDS/profile_scotchbroom.shtml | access-date = 2006-09-03 }}</ref> In New Zealand, broom is estimated to cost the forestry industry NZ$90 million, and to cost farmers an additional NZ$10 million in losses.<ref>{{Cite web | last = Press release | title = New bio-controls for pest plant | publisher = [[Landcare Research]] | date = 2008-02-12 | url = http://www.landcareresearch.co.nz/news/release.asp?Ne_ID=263 | access-date = 2008-03-02 | archive-date = 2008-03-06 | archive-url = https://web.archive.org/web/20080306033043/http://www.landcareresearch.co.nz/news/release.asp?Ne_ID=263 | url-status = dead }}</ref>

[[biological pest control|Biological control]] for broom has been investigated since the mid-1980s, with a number of insect species being tested. Some of the tested invertebrates include the broom twig miner (''[[Leucoptera spartifoliella]]''), broom seed beetles (''[[Bruchidius villosus]]''), broom gall mites (''[[Aceria genistae]]''), sap-sucking broom psyllids (''[[Arytainilla spartiophila]]''), the Scotch broom seed weevil (''[[Exapion fuscirostre]]'') and recently, the broom leaf beetle (''[[Gonioctena olivacea]]'') and broom shoot moths (''[[Agonopterix assimilella]]'').<ref>{{Cite web | title = What's New In Biological Control of Weeds? | publisher = [[Landcare Research]] | date = November 2006 | url = http://www.landcareresearch.co.nz/publications/newsletters/weeds/wtsnew38.pdf | access-date = 2008-03-02 | archive-date = 2007-12-11 | archive-url = https://web.archive.org/web/20071211024112/http://www.landcareresearch.co.nz/publications/newsletters/weeds/wtsnew38.pdf | url-status = dead }}</ref><ref>{{cite web|url=http://www.csiro-europe.org/cytisus.html|title=CSIRO: Biological control|website=Landcareresearch.co.nz|access-date=15 August 2018|archive-url=https://web.archive.org/web/20080229040435/http://www.csiro-europe.org/cytisus.html|archive-date=29 February 2008|url-status=dead}}</ref>

==== Eradication ==== The method used to remove broom is dependent on its prolific seed cycle. Care should be taken to avoid disturbing (aerating, loosening, etc.) the adjacent ground due to seed activation. The most effective method for eradication is cutting flowering plants just below the soil with loppers; late fall through winter (possibly to mid-spring) are preferred times to pull small plants.<ref>{{cite web|url=http://www.goert.ca/documents/Best_Practices_for_Broom_revised.pdf|title=Best Practices for Invasive Species Management in Garry Oak and Associated Ecosystems : Scotch Broom (Cytisus scoparius)|website=Goert.ca|access-date=15 August 2018|archive-date=22 July 2018|archive-url=https://web.archive.org/web/20180722024824/http://www.goert.ca/documents/Best_Practices_for_Broom_revised.pdf|url-status=dead}}</ref> There are several methods, cutting, pulling, burning, herbicide or introducing chickens and goats.<ref>{{cite web|url=http://bcinvasives.ca/documents/Scotch_Broom_TIPS_Final_08_06_2014.pdf|title=Scotch Broom : Cytisus scoparius : Tips|website=Bcinvasives.ca|access-date=15 August 2018|archive-date=27 May 2015|archive-url=https://web.archive.org/web/20150527041515/http://bcinvasives.ca/documents/Scotch_Broom_TIPS_Final_08_06_2014.pdf|url-status=dead}}</ref> Drought areas respond well to cutting while the [[seed pods]] are young and still green. In cooler, wetter areas pulling is the preferred method, and hand-operated broom pullers are available.<ref>{{Cite web |url=http://www.broombusters.org/howtocutbroom.html |title=Broombusters |access-date=2015-05-27 |archive-url=https://web.archive.org/web/20150527040645/http://www.broombusters.org/howtocutbroom.html |archive-date=2015-05-27 |url-status=dead }}</ref> Low temperature fires, such as a grass fire, will increase seed germination and new sprouts may form on the burned stumps of mature broom. A spring fire followed by drought conditions will reduce seedling survival.<ref>{{cite web|url=https://www.fs.fed.us/database/feis/plants/shrub/cytspp/all.html#FIRE+ECOLOGY|title=Cytisus scoparius, C. striatus|website=Fs.fed.us|access-date=15 August 2018}}</ref> Often new plants will grow from roots or seed, requiring repeated treatments.

== Cultivation == ''Cytisus scoparius'' is widely cultivated as an [[ornamental plant]], with several [[cultivar]]s selected for variation in flower colour, including "Moonlight" with deep yellow flowers, "Andreanus" and "Firefly" with dark orange-red flowers, and growth habit, including "Pendula" with pendulous branchlets.<ref name="bean" />

== Uses == Broom contains scoparin, which is a [[diuretic]]. The plant also is used as a [[cathartic]] and as a [[cardiac stimulant]], which is credited to the presence of sparteine.<ref name="A Modern Herbal p127">''A Modern Herbal'', Grieve, Maude, {{ISBN|9780486227986}}, p. 127</ref> A decoction or infusion of broom can be used to treat [[dropsy]] due to its diuretic action.<ref>''A Modern Herbal'', Grieve, Maude, {{ISBN|9780486227986}}, pp 126–127</ref> An ointment can be made from the flowers to treat [[gout]].<ref name=Watts/> Oxysparteine, produced from the action of acid on the sparteine, is useful as a cardiac stimulant and has the advantage over digoxin that it does not accumulate in the body.<ref name="A Modern Herbal p127"/> A medicinal beer was brewed from this herb, called broom ale, as a remedy for dropsy.<ref>{{cite book |title=Every Man His Own Gauger |url=https://books.google.com/books?id=46hKngEACAAJ |author=Lightbody, James |year=1695 |page=[https://books.google.com/books?id=46hKngEACAAJ&pg=PA100 100] |publisher=London: Printed for Hugh Newman. }}</ref>

==Culture== In [[Welsh mythology]], [[Blodeuwedd]] is the name of a woman made from the flowers of broom, [[Filipendula ulmaria|meadowsweet]] (''Filipendula ulmaria'') and the [[oak]] by [[Math fab Mathonwy]] and [[Gwydion]] to be the wife of [[Lleu Llaw Gyffes]]. Her story is part of the [[Four Branches of the Mabinogi|Fourth Branch of the Mabinogi]], the tale of ''[[Math son of Mathonwy]]''.<ref name=Watts>D.C. Watts {{google books|WAagnZNb0cAC|Dictionary of Plant Lore|page=47}}</ref>

Broom was considered a sign of plenty when it bore many flowers.<ref name="A Modern Herbal p126">''A Modern Herbal'', Grieve, Maude, {{ISBN|9780486227986}}, p. 126</ref> However a traditional rhyme from [[Sussex]] warns: "Sweep the house with blossomed broom in May/sweep the head of the household away."<ref name=Watts/> Broom was also used in a decorated bundle of broom at weddings in place of rosemary when that was scarce,<ref name="A Modern Herbal p126"/> and its strong smell was said to be able to tame wild horses and dogs.<ref>Roberto Dainotto {{google books|YvOsDAAAQBAJ|The Mafia: A Cultural History|page=106}}</ref>

In Italy, the shrub was burnt with the intent of stopping witches.<ref name=Watts/>

=== Royal symbols === The name of the [[House of Plantagenet]], rulers of England in the Middle Ages, may have been derived from common broom, which was then known as '''''planta genista''''' in Latin.<ref name=Costain>{{cite book |last1=Costain|first1=Thomas B |date=1962|title=The Conquering Family|url=https://archive.org/details/conqueringfamily00cost|url-access=registration|publisher= New York: Popular Library}}</ref>{{rp|9}}<ref name=JonesP>{{cite book |last1=Jones|first1=Dan |date=2013|title=The Plantagenets: The Warrior Kings and Queens Who Made England|publisher=Viking|isbn=9780670026654 }}</ref>{{rp|1}} The plant was used as a [[heraldic badge]] by [[Geoffrey V of Anjou]] and five Plantagenet kings of England as a [[Royal Badges of England|royal emblem]].<ref>J. Bernard Burke {{google books|18KhDgAAQBAJ|The Heraldic Register|page=65}}</ref> The ''broomscod'', or [[seed-pod]], was the personal [[emblem]] of [[Charles VI of France]].

== See also == * [[Broom of the Cowdenknowes]]

==References== {{Reflist}}

==Further reading== *{{cite web|url=http://sites.google.com/ucsc.edu/parker-lab/info-for-practitioners/scotch-broom?authuser=0|title=Scotch Broom|website=Ingrid Parker's Lab • Ecology and Evolutionary Biology • UC Santa Cruz|publisher=Joint Base Lewis-McChord}}

==External links== *{{Commons-inline}} *{{Wikispecies-inline|Cytisus scoparius}} * [http://www.bioimages.org.uk/html/r151074.htm Bioimages – numerous photos] * [http://www.goert.ca/about/invasive_species.php Garry Oak ecosystems: Invasive species] {{Webarchive|url=https://web.archive.org/web/20190821171117/http://www.goert.ca/about/invasive_species.php |date=2019-08-21 }} * [https://www.invasivespeciesinfo.gov/profile/scotch-broom Species Profile - Scotch Broom(''Cytisus scoparius'')], National Invasive Species Information Center, [[United States National Agricultural Library]]. * {{CalPhotos|Cytisus|scoparius}}

[[Category:Cytisus|scoparius]] [[Category:Flora of Europe]] [[Category:Plants described in 1753]] [[Category:Botanical taxa named by Carl Linnaeus]] [[Category:Plants with compound leaves]]