View source for Biology:Lactuca

{{Short description|Genus of lettuces}}
{{Automatic taxobox
|image = Lactuca tuberosa 2.jpg
|image_caption = ''[[Biology:Lactuca tuberosa|Lactuca tuberosa]]''
|display_parents = 3
|taxon = Lactuca
|authority = [[Biography:Carl Linnaeus|L.]]
|synonyms_ref = <ref name=china/>
|synonyms =
*''Agathyrsus'' <small>D. Don</small>
*''Lactucopsis'' <small>Schultz Bipontinus ex Visiani</small>
*''Lagedium'' <small>Soják</small>
*''Mulgedium'' <small>Cassini</small>
*''Phaenixopus'' <small>Cassini</small>
*''Pterocypsela'' <small>C. Shih</small>
*''Scariola'' <small>F. W. Schmidt</small>
*''Steptorhamphus'' <small>Bunge.</small>
}}

'''''Lactuca''''', commonly known as [[Biology:Lettuce|lettuce]], is a [[Biology:Genus|genus]] of flowering plants in the family [[Biology:Asteraceae|Asteraceae]]. The genus includes at least 50 species, distributed worldwide, but mainly in temperate [[Earth:Eurasia|Eurasia]].

Its best-known representative is the [[Biology:Lettuce|garden lettuce]] (''Lactuca sativa''), with its many varieties. "Wild lettuce" commonly refers to the wild-growing relatives of common garden lettuce. Many species are common weeds. ''Lactuca'' species are diverse and take a wide variety of forms. They are annuals, biennials, perennials, or shrubs.<ref name=leb>{{Cite journal | doi=10.1663/0006-8101(2004)070[0328:GDOWLS]2.0.CO;2|year = 2004|volume = 70| issue=3|pages = 328–356| title=Geographical Distribution of Wild Lactuca Species (Asteraceae, Lactuceae)| journal=The Botanical Review| last1=Lebeda| first1=Aleš| last2=Dolezalová| first2=Ivana| last3=Feráková| first3=Viera| last4=Astley| first4=Dave}}</ref> Their [[Biology:Pseudanthium|flower heads]] have yellow, blue, or white ray florets. Some species are bitter-tasting.

Most wild lettuces are [[Biology:Xerophyte|xerophyte]]s, adapted to dry habitat types. Some occur in more moist areas, such as the mountains of central [[Earth:Africa|Africa]].<ref name=leb/>

==Diversity==
[[File:Illustration Lactuca virosa0.jpg|thumb|right|Wild lettuce (''Lactuca virosa'') by Otto Wilhelm Thome in ''Flora von Deutschland, Österreich und der Schweiz'', 1885]]
[[File:Lactucaserriola2web.jpg|thumb|right|Prickly lettuce (''Lactuca serriola'')]] 
[[File:Lactuca tenerrima.jpg|thumb|right|''Lactuca tenerrima'']]
[[File:Lactuca serriola flowers RJP 01.jpg|thumb|right|''Lactuca serriola'']]
[[File:Lactuca tatarica.jpeg|thumb|right|''Lactuca tatarica'']]
There are different concepts of the species within ''Lactuca''. It is not clear how many distinct species are known, and estimates vary from 50<ref name=china>[http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=117438 ''Lactuca''.] Flora of China.</ref> to 75<ref name=fna>[http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=117438 ''Lactuca''.] Flora of North America.</ref> so far.

Species include:<ref name=china/><ref name=fna/><ref name=grin>[https://archive.today/20130708062241/http://www.ars-grin.gov/cgi-bin/npgs/html/splist.pl?6451 GRIN Species Records of ''Lactuca''.] Germplasm Resources Information Network (GRIN).</ref><ref name=pl>[http://www.theplantlist.org/browse/A/Compositae/Lactuca/ ''Lactuca''.] The Plant List. Royal Botanic Gardens, Kew, and Missouri Botanical Garden.</ref>

*''Lactuca acanthifolia'' (Crete, [[Place:Turkey|Turkey]])
*''[[Biology:Lactuca aculeata|Lactuca aculeata]]'' ([[Earth:Asia Minor|Asia Minor]])
*''Lactuca acuminata'' 
*''Lactuca adenophora'' 
*''[[Biology:Lactuca alpestris|Lactuca alpestris]]'' (Crete)
*''Lactuca alpina'' (syn. ''[[Biology:Cicerbita alpina|Cicerbita alpina]]'')<ref name=alpina>{{GRIN | ''Cicerbita alpina'' | 104152 | accessdate = 17 December 2017}}</ref> ([[Earth:Europe|Europe]]) - alpine sow-thistle, alpine blue-sow-thistle, tall blue lettuce
*''Lactuca altaica'' (Eurasia)
*''Lactuca attenuata''<ref name=attenuata>[http://apps.kew.org/efloras/namedetail.do?flora=fz&taxon=4998&nameid=12070 ''Lactuca attenuata''.] ''Flora Zambesiaca''. Royal Botanic Gardens, Kew.</ref> (Africa)
*''Lactuca aurea'' (Europe)
*''Lactuca azerbaijanica'' ([[Religion:Iran|Iran]])
*''[[Biology:Lactuca biennis|Lactuca biennis]]'' (North America) – tall blue lettuce, blue wood lettuce
*''Lactuca calophylla'' (Africa)
*''[[Biology:Lactuca canadensis|Lactuca canadensis]]'' (North America) – Canada wild lettuce, tall lettuce
*''Lactuca corymbosa'' (Congo)
*''Lactuca crambifolia'' ([[Place:Turkestan|Turkestan]])
*''[[Biology:Lactuca cyprica|Lactuca cyprica]]'' ([[Place:Cyprus|Cyprus]]) - Cyprus lettuce
*''Lactuca deltoidea'' 
*''[[Biology:Lactuca dissecta|Lactuca dissecta]]'' (Asia)
*''[[Biology:Lactuca dolichophylla|Lactuca dolichophylla]]'' (Asia)
*''Lactuca dregeana'' ({{wipe|South Africa}}) – ''melkdissel'', ''slaaidissel''
*''Lactuca dumicola''
*''Lactuca erostrata''<ref name=bano>Bano, R. and M. Qaiser. (2011). [http://www.pakbs.org/pjbot/PDFs/43%285%29/PJB43%285%292259.pdf A taxonomic revision of the genus ''Lactuca'' L. (Cichorieae-Asteraceae) from Pakistan and Kashmir.] ''Pakistan Journal of Botany'' 43(5) 2259–268.</ref> ({{wipe|Pakistan}})
*''Lactuca fenzlii''
*''[[Biology:Lactuca floridana|Lactuca floridana]]'' (North America) – Florida lettuce, woodland lettuce
*''Lactuca georgica'' (Asia)
*''Lactuca glaucifolia'' (Asia)
*''Lactuca graciliflora'' (Asia)
*''[[Biology:Lactuca graminifolia|Lactuca graminifolia]]'' (Americas) – grassleaf lettuce
*''Lactuca haimanniana''
*''Lactuca henryi''
*''[[Biology:Lactuca hirsuta|Lactuca hirsuta]]'' (North America) – downy lettuce, hairy lettuce
*''Lactuca hispida'' 
*''Lactuca homblei''<ref name=homblei>[http://apps.kew.org/efloras/namedetail.do?qry=namelist&flora=fz&taxon=4989&nameid=12046 ''Lactuca homblei''.] ''Flora Zambesiaca''. Royal Botanic Gardens, Kew.</ref> (Zaire, Zambia)
*''Lactuca imbricata''<ref name=imbric>[http://apps.kew.org/efloras/namedetail.do?flora=fz&taxon=4991&nameid=12048 ''Lactuca imbricata''.] ''Flora Zambesiaca''. Royal Botanic Gardens, Kew.</ref> (Africa)
*''[[Biology:Lactuca indica|Lactuca indica]]'' (Asia) - Indian lettuce
*''[[Biology:Lactuca inermis|Lactuca inermis]]'' (Africa, [[Place:Arabian Peninsula|Arabian Peninsula]])
*''Lactuca intricata'' (Albania, Greece, Turkey)
*''Lactuca jamaicensis'' (Jamaica)
*''Lactuca kanitziana''
*''Lactuca kochiana''
*''Lactuca lasiorhiza''<ref name=lasio>[http://apps.kew.org/efloras/namedetail.do?flora=fz&taxon=4982&nameid=12033 ''Lactuca lasiorhiza''.] ''Flora Zambesiaca''. Royal Botanic Gardens, Kew.</ref> (Africa)
*''[[Biology:Lactuca ludoviciana|Lactuca ludoviciana]]'' (North America) – biannual lettuce
*''[[Biology:Lactuca macrophylla|Lactuca macrophylla]]''
*''Lactuca mira''
*''[[Biology:Lactuca muralis|Lactuca muralis]]''
*''Lactuca mwinilungensis''<ref name=mwini>[http://apps.kew.org/efloras/namedetail.do?flora=fz&taxon=4984&nameid=12039 ''Lactuca mwinilungensis''.] ''Flora Zambesiaca''. Royal Botanic Gardens, Kew.</ref> (Zaire, Zambia)
*''Lactuca nana''<ref name=nana>[http://apps.kew.org/efloras/namedetail.do?flora=fz&taxon=5010&nameid=12112 ''Lactuca nana''.] ''Flora Zambesiaca''. Royal Botanic Gardens, Kew.</ref> (Africa)
*''[[Biology:Lactuca orientalis|Lactuca orientalis]]'' (Asia, [[Place:Egypt|Egypt]])
*''[[Biology:Lactuca palmensis|Lactuca palmensis]]''<ref name=palm>{{cite iucn |author=Santos Guerra, A. |date=2011 |title=''Lactuca palmensis'' |volume=2011 |page=e.T172087A6821101 |doi=10.2305/IUCN.UK.2011-1.RLTS.T172087A6821101.en |access-date=18 November 2021}}</ref> (Canary Islands)
*''Lactuca paradoxa''
*''Lactuca parishii''
*''[[Biology:Lactuca perennis|Lactuca perennis]]'' (Europe) – blue lettuce, mountain lettuce
*''Lactuca persica'' 
*''Lactuca petrensis'' 
*''[[Biology:Lactuca quercina|Lactuca quercina]]'' (Eurasia)
*''Lactuca racemosa''
*''[[Biology:Lactuca raddeana|Lactuca raddeana]]'' (Asia)
*''Lactuca rechingeriana'' 
*''Lactuca rosularis'' (Iran, Turkmenistan)
*''[[Biology:Lactuca saligna|Lactuca saligna]]'' (Eurasia) – willow lettuce, least lettuce, narrow-leaf lettuce
*''[[Biology:Lactuca sativa|Lactuca sativa]]'' – lettuce, garden lettuce
*''Lactuca scarioloides'' (western Asia)
*''Lactuca schulzeana'' (Angola, Cameroon, Zaire)
*''Lactuca schweinfurthii'' (Africa)
*''[[Biology:Lactuca serriola|Lactuca serriola]]'' (Africa, Asia, Europe) – prickly lettuce, compassplant, scarole, milk thistle
*''Lactuca setosa'' (Africa)
*''[[Biology:Lactuca sibirica|Lactuca sibirica]]'' (Eurasia)
*''Lactuca singularis''<ref name=sing>{{cite iucn |author=Draper Munt, D. |date=2011 |title=''Lactuca singularis'' |volume=2011 |page=e.T172180A6844238 |doi=10.2305/IUCN.UK.2011-1.RLTS.T172180A6844238.en |access-date=18 November 2021}}</ref> (Spain)
*''Lactuca songeensis''
*''Lactuca spinidens'' (Tajikistan, Turkmenistan)
*''Lactuca stebbinsii''<ref name=kilian>Kilian, N. (2001). [http://www.bgbm.org/willdenowia/w-pdf/w31-1Kilian.pdf ''Lactuca stebbinsii'' (Lactuceae, Compositae), a puzzling new species from Angola.]{{dead link|date=December 2017 |bot=InternetArchiveBot |fix-attempted=yes }} ''Willdenowia - Annals of the Botanic Garden and Botanical Museum Berlin - Dahlem'' 31(1) 71–8.</ref> (Angola)
*''Lactuca takhtadzhianii'' (Armenia)
*''[[Biology:Lactuca tatarica|Lactuca tatarica]]'' (Northern Hemisphere) – blue lettuce
*''[[Biology:Lactuca tenerrima|Lactuca tenerrima]]'' (southern Europe, Morocco)
*''[[Biology:Lactuca tetrantha|Lactuca tetrantha]]''<ref name=tetra>{{cite iucn |author=Kyratzis, A. |author2=Christodoulou, C.S. |author3=Kailis, C. |author4=Papasavvas, C. |author5=Tsintides, T. |date=2011 |title=''Lactuca tetrantha'' |volume=2011 |page=e.T172257A6858989 |doi=10.2305/IUCN.UK.2011-1.RLTS.T172257A6858989.en |access-date=18 November 2021}}</ref> (Cyprus)
*''Lactuca tinctociliata''
*''Lactuca triangulata'' (Asia)
*''Lactuca triquetra''
*''[[Biology:Lactuca tuberosa|Lactuca tuberosa]]'' (Eurasia)
*''Lactuca ugandensis''
*''Lactuca undulata'' (Asia)
*''[[Biology:Lactuca viminea|Lactuca viminea]]'' (Africa, Asia, Europe) – pliant lettuce
*''[[Biology:Lactuca virosa|Lactuca virosa]]'' (Europe, northern Africa) – bitter lettuce, great lettuce
*''[[Biology:Lactuca watsoniana|Lactuca watsoniana]]''<ref name=wats>{{cite iucn |author=Schaefer, H. |date=2011 |title=''Lactuca watsoniana'' |volume=2011 |page=e.T161995A5525315 |doi=10.2305/IUCN.UK.2011-1.RLTS.T161995A5525315.en |access-date=18 November 2021}}</ref> (Azores)
*''Lactuca winkleri'' (Tajikistan)

==Ecology==
''Lactuca'' species are used as food plants by the [[Biology:Larva|larva]]e of many Lepidoptera species.

==Etymology==
'Lactuca' is derived from [[Social:Latin|Latin]] and means 'having milky sap'. 'Lactuca' and 'lactic' (of or relating to milk) have the same root word, 'lactis'.<ref name="gledhill">Gledhill, David (2008). "The Names of Plants". Cambridge University Press. {{ISBN|9780521866453}} (hardback), {{ISBN|9780521685535}} (paperback). pp 228</ref>

==References==
{{Reflist|32em}}

==External links==
*[http://ucjeps.berkeley.edu/cgi-bin/get_JM_treatment.pl?609,1466 Jepson Manual Treatment]

{{Taxonbar|from=Q578052}}

[[Category:Lactuca| ]]
[[Category:Asteraceae genera]]

{{Sourceattribution|Lactuca}}