Cytisus scoparius

File:Cytisus scoparius - Köhler–s Medizinal-Pflanzen-200.jpg (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.{{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}} The shrubs have green shoots with small deciduous trifoliate leaves {{Convert|5–15|mm|abbr=out|frac=8}} long, and in spring and summer are covered in profuse golden yellow flowers {{Convert|20–30|mm|abbr=on|frac=8}} from top to bottom and 15–20 mm wide. Flowering occurs after 50–80 growing degree-days. The seed pods have long hairs only along their seams. In late summer, its legumes (seed pods) 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 climates. The seeds, seedlings, and young shoots are sensitive to frost; adult plants are hardier, and branches affected by freezing temperatures regenerate quickly.{{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}} C. scoparius contains toxic alkaloids that depress the heart and nervous system.{{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}}

A legume, this shrub can fix nitrogen in the soil through a symbiotic relationship with Rhizobium bacteria.

One of the main alkaloids of this plant is cytisine. The characteristic constituents are biogenic amines (mostly tyramine in the young shoots), flavonoids (spiraeoside and scoparoside), isoflavones and their glycosides (genistin), as well as allelopathic quinolizidine alkaloids (mostly sparteine, lupanine, scoparin and hydroxy-derivatives), which defend the plant against insect infestation and herbivores (with the exception of the resistant aphid species Aphis cytisorum).{{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 |volume=25 |issue=2 |pages=521–524 |doi=10.1016/S0031-9422(00)85514-4|bibcode=1986PChem..25..521M }}{{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}}

The two subspecies of Cytisus scoparius are:

• Cytisus scoparius subsp. scoparius - throughout the species' range.
• Cytisus scoparius subsp. maritimus (Rouy) Heywood - Western European maritime cliffs and associated environments; differs with prostrate growth; not over 0.4 m tall; downy young shoots.

Cytisus scoparius is native to western and central Europe, being common in Great Britain and Republic of Ireland.Clapham, A.R., Tutin, T.G. and Warburg, E.F. 1968. Excursion Flora of the British Isles. Cambridge Press. {{ISBN|0-521-04656-4}}Parnell, J. and Curtis, T. 2012. Webb's An Irish Flora. Cork University Press. {{ISBN|978-185918-4783}} It is found in sunny sites, usually on dry, sandy soils at low altitudes, tolerating very acidic soil conditions.{{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}}

Outside of its native range, it is an ecologically destructive colonizing invasive species in grassland, shrub and woodland, and other habitats.{{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}}{{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}}

File:Cytisus scoparius USGS.jpg

Cytisus scoparius has been introduced into several other countries and continents, outside of its native range, and is commonly classified as a noxious invasive species in western North America, mainly in British Columbia (including on Vancouver Island), California, Oregon, Washington (west of the Cascades), the Sierra Nevada range,{{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}} fragmented areas of North America's eastern seaboard, as well as Australia (where it is a declared weed),{{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}}{{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 }} New Zealand,{{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}} and in India.{{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 }} 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 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.{{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}} It is estimated that broom is responsible for US$47 million in lost timber production each year in the state of Oregon.{{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 }} 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.{{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 }}

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).{{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 }}{{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}}

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, the sprouting and seedling plants between late spring and mid-fall; late fall through winter (possibly to mid-spring) are preferred times to eradicate mature plants.{{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}} There are several methods, cutting, pulling, burning, herbicide or introducing chickens and goats.{{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}} 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.{{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 }} 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.{{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}} Often new plants will grow from roots or seed, requiring repeated treatments.

Cytisus scoparius is widely cultivated as an ornamental plant, with several cultivars 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.

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.A Modern Herbal, Grieve, Maude, {{ISBN|9780486227986}}, p. 127 A decoction or infusion of broom can be used to treat dropsy due to its diuretic action.A Modern Herbal, Grieve, Maude, {{ISBN|9780486227986}}, pp 126–127 An ointment can be made from the flowers to treat gout. 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. A medicinal beer was brewed from this herb, called broom ale, as a remedy for dropsy.{{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. }}

In Welsh mythology, Blodeuwedd is the name of a woman made from the flowers of broom, 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 Fourth Branch of the Mabinogi, the tale of Math son of Mathonwy.D.C. Watts {{google books|WAagnZNb0cAC|Dictionary of Plant Lore|page=47}}

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

In Italy, the shrub was burnt with the intent of stopping witches.

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.{{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}}{{rp|9}}{{cite book |last1=Jones|first1=Dan |date=2013|title=The Plantagenets: The Warrior Kings and Queens Who Made England|publisher=Viking|isbn=9780670026654 }}{{rp|1}} The plant was used as a heraldic badge by Geoffrey V of Anjou and five Plantagenet kings of England as a royal emblem.J. Bernard Burke {{google books|18KhDgAAQBAJ|The Heraldic Register|page=65}} The broomscod, or seed-pod, was the personal emblem of Charles VI of France.

• Broom of the Cowdenknowes

{{Reflist}}

• {{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}}

• {{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}}

{{Taxonbar|from=Q145781}}

scoparius

Category:Flora of Europe

Category:Flora of Scotland

Category:Flora of Ireland

Category:Plants described in 1753

Category:Taxa named by Carl Linnaeus