Sempervivum tectorum

Growing to {{convert|15|cm|0|abbr=on}} tall by {{convert|50|cm|0|abbr=on}} broad, it is a rosette-forming succulent evergreen perennial, spreading by offsets. It has grey-green, tufted, sessile leaves, {{convert|4|-|10|cm|0|abbr=on}} in diameter, which are often suffused with rose-red. In summer it bears clusters of reddish-purple flowers, in multiples of 8–16, on hairy erect flat-topped stems.{{cite book|editor-last=Brickell|editor-first=Christopher|title=The Royal Horticultural Society A-Z Encyclopedia of Garden Plants|edition=3rd|year=2008|publisher=Dorling Kindersley|location=London|isbn=978-1405332965|pages=1136}}{{citation|contribution=Sempervivum|last=Linnaeus|title=Gen. Pl.|edition=5|page=209|year=1754|url= http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=130076|access-date=6 July 2011}}{{citation|contribution=Sempervivum tectorum|last=Linnaeus|title=Species Plantarum|volume=1|page=464|year=1753|url= http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=220012387|publisher=Flora of North America|access-date=6 July 2011}} The species is highly variable, in part because hundreds of cultivars have been propagated, sold, and traded for nearly 200 years.

Sempervivum tectorum was described in 1753 by Linnaeus, who noted that its leaves are ciliate, that is, fringed with hairs.{{citation|last=Linnæus|title=Species plantarum|year=1753|publisher=Holmiae|volume=1|page=464|contribution=Sempervivum|url= http://www.botanicus.org/page/358483|access-date=6 July 2011}}

This plant has been known to humans for thousands of years, and has attracted many common names and traditions. In addition to common houseleek, names include variations of the following:

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• bullock's beard      
• devil's beard
• earwort
• fuet
• healing blade
• homewort
• imbroke
• Jove's beard
• Jupiter's eye
• poor Jan's leaf
• red-leaved houseleek      
• roof foil
• roof houseleek
• St. George's Beard
• St. Patrick's cabbage
• sengreen (its name in heraldry, as used in the arms of Gonville & Caius College, Cambridge)
• Thor's beard
• thunderplant

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• Welcome-home-husband-though-never-so-drunk{{cite book|last=Watts|first=Donald|title= Dictionary of Plant Lore|year= 2007|publisher= Elsevier | isbn= 978-0-12-374086-1| pages= 202|url= https://books.google.com/books?id=WAagnZNb0cAC}}—a name it sometimes shares with Sedum acre.{{cite magazine|last= Fenton |first=James|title=[John] Clare Was Right|url=http://www.nybooks.com/articles/archives/2005/jun/23/clare-was-right/ |magazine=The New York Review of Books|access-date=7 July 2011|volume=LII |number=11 |date= 23 June 2005|department=Letters}} – Addendum to:
• {{cite magazine |last1=Fenton |first1=James |title=John Clare's Genius |url=https://www.nybooks.com/articles/2004/09/23/john-clares-genius/ |magazine=The New York Review of Books |number=14 |date=23 September 2004 |volume=L1 |language=en|url-access=limited}}
• hen and chicks - a name shared with several other plants{{cite web | title=Hens and Chicks | author=David Beaulieu | url=http://landscaping.about.com/od/plantsforsunnydryareas/p/hens_and_chicks.htm}}

The specific epithet tectorum means "of house roofs", referring to a traditional location for these plants.{{cite book|last=Harrison|first=Lorraine|title=RHS Latin for gardeners|year=2012|publisher=Mitchell Beazley|location=United Kingdom|isbn=9781845337315|pages=224}}

File:Sempervivum tectorum (diameter 15 cm).jpg

Sempervivum tectorum is one of several houseleek species to be cultivated. It is valued as groundcover for hot, dry places. It has gained the Royal Horticultural Society's Award of Garden Merit.{{cite web|title=RHS Plant Selector - Sempervivum tectorum | url=https://www.rhs.org.uk/Plants/17164/Sempervivum-tectorum/Details | access-date = 5 March 2021}}{{cite web | url = https://www.rhs.org.uk/plants/pdfs/agm-lists/agm-ornamentals.pdf | title = AGM Plants - Ornamental | date = July 2017 | page = 96 | publisher = Royal Horticultural Society | access-date = 9 November 2018}}

Sempervivum tectorum multiplies horizontally by propagation of underground roots. Propagation occurs in the spring, when budding occurs. From each mother plant up to four or, on good days, ten new ones can be harvested. They come off easily when taking care not to break the roots. Seed propagation works in spring.{{cite web|title=Sempervivum tectorum (Common houseleek) | url=https://www.gardenia.net/plant/sempervivum-tectorum | access-date = 14 October 2022}}

The plant has been traditionally thought to protect against thunderstorms, and grown on house roofs for that reason,{{citation | chapter = Hamƿyɼꞇ | title = Leechdoms, Wortcunning, and Starcraft of Early England: Being a Collection of Documents, for the most part never before printed, illustrating the History of Science in this Country Before the Norman Conquest | first = Oswald | last = Cockayne | series = Rerum Britannicarum Medii Aevi Scriptores or Chronicles and Memorials of Great Britain and Ireland During the Middle Ages [The Rolls Series] | number = 35 | volume = 3 | place = London | publisher = Longman | year = 1866 | page = 329}} which is why it is called House Leek. Many of its popular names in different languages reflect an association with the Roman thunder-god Jupiter, notably the Latin barba Jovis (Jupiter's beard), referred to in the Floridus traditionally attributed to Aemilius Macer,{{sfnp|Fernie|2008|p=189|ps=. "Quem sempervivam dicunt quoniam viret omni Tempore—'Barba Jovis' vulgari more vocatur" – "Which they call semperviva because it will live for all time—'beard of Jove' it is called by vulgar custom."}} and its French derivative joubarbe, which has in turn given rise to jubard and jo-barb in English; or with the Norse thunder-god Thor as in German Donnerbart.{{citation | authorlink = Jacob Grimm | first = Jacob | last = Grimm | translator = James Steven Stallybrass | title = Teutonic Mythology | volume = 1 | place = London | publisher = Bell | year = 1882 | page = [https://books.google.com/books?id=neQtAAAAIAAJ&dq=Grimm+Donnerbart&pg=PA183 183]}}; however, {{citation | title = Teutonic Mythology | last = Grimm | volume = 4 | year = 1883 | page = [https://books.google.com/books?id=xMAoAAAAYAAJ&q=donner-bart&pg=PA1672 1672]}} states that Donner-bart is sedum telephium. It is also called simply thunder-plant.{{citation | first1 = James | last1 = Britten | first2 = Robert | last2 = Holland | title = A Dictionary of English Plant-Names, English Dialect Society | place = London | publisher = Trübner | year = 1878 | url = https://books.google.com/books?id=nVUJAAAAQAAJ&q=sempervivum+tectorum&pg=PA271 | page = 610 and individual listings}}. Anglo-Saxon þunorwyrt{{sfnp|Grimm|1883|p=[https://books.google.com/books?id=xMAoAAAAYAAJ&q=house-leek+planted+on+cottage+roofs&pg=PA1672 1346]}}{{citation | url = http://bosworth.ff.cuni.cz/032243 | contribution = þunor-wyrt | title = An Anglo-Saxon Dictionary: Based on the Manuscript Collection of the late Joseph Bosworth | editor-first = T. Northcote | editor-last = Toller | place = Oxford | publisher = Oxford University | orig-year = 1898 | year = 1973}}, glossing it as "Thunder-plant". may have either meaning. However, the association with Jupiter has also been derived from a resemblance between the flowers and the god's beard; in modern times, it has also been called St. George's beard.{{cite book|first=William Thomas|last=Fernie|title=Herbal Simples Approved for Modern Uses of Cure|edition=3rd|orig-year=Bristol: Wright, 1914|location=Teddington|publisher=Echo Library|date=2008|isbn=978-1-4068-7552-2|page=[https://books.google.com/books?id=JGvHMBqGh8AC&dq=%22Quem+sempervivam+dicunt+quoniam+viret+omni+Tempore--%27Barba+Jovis%27+vulgari+more+vocatur,+Esse+refert+similem+predictoe+Plinius+istam%22&pg=PA189 189]}}

File:Bicknell Sempervivuim June 2020.jpg

Other common names, such as Anglo-Saxon singrēne, Modern English sigrim, sil-green, etc. and aye-green,{{sfnp|Cockayne|1866|p=344|ps=, glosses sinȝrene simply as "sedum".}}{{citation | title = Anglo-Saxon Dictionary | url = http://bosworth.ff.cuni.cz/finder/3/singrene | contribution = sin-gréne | last = Bosworth-Toller |id=– as sempervivum tectorum but notes it is also used of other plants.}} refer to its longevity. William Fernie tells a tale in support of this:

{{blockquote |History relates that a botanist tried hard for eighteen months to dry a plant of the House Leek for his herbarium, but failed in this object. He afterwards restored it to its first site when it grew again as if nothing had interfered with its ordinary life.}}

It has been believed to protect more generally against decay and against witchcraft. Jacob Grimm quotes a Provençal troubadour: "e daquel erba tenon pro li vilan sobra lur maiso" — "and that plant they keep against evil atop their house."{{sfnp|Grimm|1882|loc=[https://archive.org/details/teutonicmytholo05stalgoog/page/n197 p. 183, footnote 3]}} In his Capitulare de villis vel curtis imperii, Charlemagne recommended it be grown on top of houses.{{citation | quote = Et ille hortulanus habeat super domum suam Iovis barbam | url = http://www.le.ac.uk/hi/polyptyques/capitulare/latin.html | language = la| title = The Capitulare de Villis, Carolingian Polyptiques | publisher = University of Leicester | date = January 2008 | access-date = 5 July 2011}} — {{citation | quote = And the gardener shall have house-leeks growing on his house. | url = http://www.le.ac.uk/hi/polyptyques/capitulare/trans.html#70 | title = English}}; however, "Barba Iovis", in {{harvp|von Pauly|Wissowa|1896|p=[https://books.google.com/books?id=wy9oAAAAMAAJ&dq=Macer+Floridus+sempervivam&pg=PA2818 2818]}} says he recommended including it in the garden as a domestic remedy. In some places, S. tectorum is still traditionally grown on the roofs of houses.{{cite web|title=The Sempervivum Page Linnaeus (1757)|url=http://www.succulent-plant.com/families/crassulaceae/sempervivum.html|publisher=Richard J. Hodgkiss|access-date=7 July 2011}}{{cite web|title=Pale Green Sempervivum tectorum Hen & Chicks|url=http://www.paghat.com/semptectorum.html|publisher=Paghat|quote=In Slavic nations, the tradition of roof-top houseleeks is still practiced. |access-date=7 July 2011}}

In Ireland, the houseleek was known as {{lang|ga|tóirpín}} and was placed over doorways and in cow-dung; it was believed to protect a house from lightning-strike or burning.Ulster Folklife. (1970:25). United Kingdom: Ulster Folk and Transport Museum.Sinsear. (1993:22). Ireland: Roinn Bhéaloideas Éireann, Coláiste na hOllscoile.{{Cite web|url=https://www.duchas.ie/en/cbes/4922055/4848041/5009351|title=In thatched country farmhouses, a little plant called a "toirpín" is always placed over the door and set in a cow-dung...|date=July 12, 2017|publisher=National Folklore Collection, University College Dublin|website=Dúchas.ie }} Other names included {{lang|ga|buachaill tí}} ("house-boy"), roofleek, waxplant or {{lang|ga|luibh a’ tóiteáin}} ("herb of the fire").{{Cite web|url=https://www.from-ireland.net/custom/luck-objects/|title=Luck Objects|first=Dr Jane|last=Lyons|date=March 1, 2013|website=From-Ireland.net}}

The juice has been used in herbal medicine as an astringent and treatment for skin and eye diseases, including by Galen and Dioscorides, to ease inflammation and, mixed with honey, to treat thrush; however, large doses have an emetic effect.{{sfnp|Fernie|2008|pp=189–190}} Pliny also mentions it, and Marcellus Empiricus listed it as a component in external treatments for contusions, nervous disorders, intestinal problems and abdominal pain, and mixed with honey, as part of the antidotum Hadriani (Hadrian's antidote), a broad-spectrum palliative for internal complaints.{{cite book|first1=August Friedrich|last1=von Pauly|first2=Georg |last2=Wissowa|title=Paulys Real-Encyclopädie der classischen Altertumswissenschaft|volume=2|edition=rev.|location=Stuttgart|publisher=Metzler|date=1896|language=de}}

Romans grew the plant in containers in front of windows and associated it with love medicine.

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Image:Sempervivum Tectorum Greenii, Huntington.jpg|Sempervivum tectorum "Greenii", Huntington Desert Garden

Image:Sempervivum tectorum boutignyanum-1.JPG|Sempervivum tectorum boutignyanum in flower

Image:Sempervivum tectorum (1) 1 (ex Pyrenees).JPG|Rosette with drops of dew

Image:Illustration Sempervivum tectorum0.jpg|Illustration from Otto Wilhelm Thomé, Flora von Deutschland, Österreich und der Schweiz, 1885

Image:SempervivumTectorum.jpg|Sempervivum tectorum with flowers in Uppsala Botaniska Trädgården

Image:Sempervivum_tectorum_abl1.JPG|Flower of cultivated variety, photographed in Spain

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{{Taxonbar|from=Q161724}}

tectorum

Category:Garden plants

Category:Plants described in 1753

Category:Taxa named by Carl Linnaeus