Editing Euphorbia (section)

== Systematics and taxonomy ==
The present taxon "''Euphorbia''" corresponds to its own former subtribe, the [[Euphorbiinae]].{{citation needed|date=August 2014}} It has over 2000 species.<ref name= EPBIP/> [[Morphology (biology)|Morphological]] description using the presence of a cyathium (see section above) is consistent with nuclear and chloroplast DNA sequence data in testing of about 10% of its members. This testing supports inclusion of formerly other genera as being best placed in this single genus, including ''[[Chamaesyce]], Monadenium, Pedilanthus'', and poinsettia (''E. pulcherrima'').

Genetic tests have shown that similar flower head structures or forms within the genus, might not mean close ancestry within the genus. The genetic data show that within the genus, convergent evolution of [[inflorescence]] structures may be from ancestral subunits that are not related. So using morphology within the genus becomes problematic for further subgeneric grouping. As stated on the Euphorbia Planetary Biodiversity Inventory project webpage:<ref name= EPBIP/>
{{blockquote|Previous morphologically based delimitations of subgenera or sections within the genus should not be taken at face value. The genus is in fact rife with striking examples of morphological [[convergent evolution|convergence]] in cyathial and vegetative features, which justifies a global approach to studying the genus to obtain a proper phylogenetic understanding of the whole group.... The bottom line is that a number of clades have been placed inside or outside of Euphorbia at different times... few of the subgeneric circumscriptions hold up under DNA sequence analysis.}}

According to a 2002 publication on studies of [[DNA sequence]] data,<ref name="Steinmann_Porter">{{cite journal|vauthors=Steinmann VW, Porter JM|year=2002|title=Phylogenetic relationships in Euphorbieae (Euphorbiaceae) based on ITS and ndhF sequence data|journal=[[Annals of the Missouri Botanical Garden|Ann. Missouri Bot. Gard.]]|volume=89|issue=4|pages=453–490|jstor=3298591|doi=10.2307/3298591|bibcode=2002AnMBG..89..453S |url=https://www.biodiversitylibrary.org/part/16388}}</ref><ref name="Steinmann-2003">{{Cite journal|vauthors=Steinmann VW|date=2003|title=The submersion of Pedilanthus into Euphorbia (Euphorbiaceae)|journal=Acta Botanica Mexicana|language=en|issue=65|pages=45–50|doi=10.21829/abm65.2003.961|issn=2448-7589|doi-access=free}}</ref><ref name="Bruyns">{{cite journal|vauthors=Bruyns PV, Mapaya RJ, Hedderson TJ|year=2006|title=A new subgeneric classification for ''Euphorbia'' (Euphorbiaceae) in southern Africa based on ITS and ''psbA-trnH'' sequence data|journal=[[Taxon (journal)|Taxon]]|volume=55|issue=2|pages=397–420|doi=10.2307/25065587|jstor=25065587|bibcode=2006Taxon..55..397B }}</ref> most of the smaller "satellite genera" around the huge genus ''Euphorbia'' nest deep within the latter. Consequently, these [[taxa]], namely the never generally accepted genus ''Chamaesyce'', as well as the smaller genera ''[[Cubanthus]]'',<ref name="cubanthus">{{cite journal|vauthors=Steinmann VW, van Ee B, Berry PE, Gutiérrez J|year=2007|title=The systematic position of ''Cubanthus'' and other shrubby endemic species of ''Euphorbia'' (Euphorbiaceae) in Cuba|journal=[[Anales del Jardín Botánico de Madrid|Anales Jard. Bot. Madrid]]|volume=64|issue=2|pages=123–133|doi=10.3989/ajbm.2007.v64.i2.167|doi-access=|bibcode=2007AJBM...64..123S }}</ref> ''Elaeophorbia'', ''Endadenium'', ''Monadenium'', ''Synadenium'',
and ''Pedilanthus'' were transferred to ''Euphorbia''. The entire [[subtribe]] Euphorbiinae now consists solely of the genus ''Euphorbia''.

=== Selected species ===
See [[List of Euphorbia species|List of ''Euphorbia'' species]] for complete list.

* ''[[Euphorbia albomarginata]]'' – rattlesnake weed, white-margined sandmat
* ''[[Euphorbia amygdaloides]]'' – wood spurge
* ''[[Euphorbia antisyphilitica]]'' – candelilla
* ''[[Euphorbia balsamifera]]'' – sweet tabaiba (Canary Islands)<ref>{{Cite web|url=http://www.floradecanarias.com/euphorbia_balsamifera.html|title=''Euphorbia balsamifera''|website=Flora de Canarias|access-date=1 Feb 2019}}</ref>
* ''[[Euphorbia bulbispina]]''
* ''[[Euphorbia caducifolia]]'' – leafless milk hedge<ref>{{cite web |url=https://www.flowersofindia.net/catalog/slides/Leafless%20Milk%20Hedge.html |title=Leafless milk hedge |publisher=Flowers of India |accessdate=29 September 2021}}</ref>
* ''[[Euphorbia canariensis]]'' – Canary Island spurge, Hercules club (Canary Islands)<ref>{{Cite web|url=http://www.floradecanarias.com/euphorbia_canariensis.html|title=''Euphorbia canariensis''|website=Flora de Canarias|access-date=1 Feb 2019}}</ref>
* ''[[Euphorbia candelabrum]]'' – [[candelabra tree]] of East Africa
* ''[[Euphorbia caput-medusae]]'' – Medusa's head (South Africa)
* ''[[Euphorbia ceratocarpa]]'' – (Sicily and southern Italy)
* ''[[Euphorbia characias]]'' – Mediterranean spurge
* ''[[:species:Euphorbia coerulescens|Euphorbia coerulescens]]'' - blue euphorbia<ref>[https://www.cactus-art.biz/schede/EUPHORBIA/Euphorbia_coerulescens/Euphorbia_coerulescens/Euphorbia_coerulescens.htm Euphorbia coerulescens]</ref>
* ''[[Euphorbia cotinifolia]]'' – copper tree
* ''[[Euphorbia cyathophora]]'' – fire-on-the-mountain
* ''[[Euphorbia cyparissias]]'' – Cypress spurge
* ''[[Euphorbia decidua]]''
* ''[[Euphorbia dendroides]]'' – tree spurge
* ''[[Euphorbia epithymoides]]'' – cushion spurge
* ''[[Euphorbia esula]]'' – leafy spurge
* ''[[Euphorbia franckiana]]''
* ''[[Euphorbia fulgens]]'' – scarlet plume
* ''[[Euphorbia grantii]]'' – African milk bush
* ''[[Euphorbia gregersenii]]'' – Gregersen's spurge
* ''[[Euphorbia griffithii]]'' – Griffith's spurge
* ''[[Euphorbia helioscopia]]'' – sun spurge
* ''[[Euphorbia heterophylla]]'' – painted euphorbia, desert poinsettia, fireplant, paint leaf, kaliko
* ''[[Euphorbia hirta]]'' – asthma-plant
* ''[[Euphorbia hispida]]''
* ''[[Euphorbia horrida]]'' – African milk barrel
* ''[[Euphorbia ingens]]'' – candelabra tree
* ''[[Euphorbia labatii]]''
* ''[[Euphorbia lactea]]'' – mottled spurge, frilled fan, elkhorn
* ''[[Euphorbia lathyris]]'' – caper spurge, paper spurge, gopher spurge, gopher plant, mole plant
* ''[[Euphorbia leuconeura]]'' – Madagascar jewel
* ''[[Euphorbia maculata]]'' – spotted spurge, prostrate spurge
* ''[[Euphorbia marginata]]'' – snow on the mountain
* ''[[Euphorbia mammillaris]]''
* ''[[Euphorbia maritae]]''
* ''[[Euphorbia milii]]'' – crown-of-thorns, Christ plant
* ''[[Euphorbia misera]]'' – cliff spurge, Baja California, Southern California
* ''[[Euphorbia myrsinites]]'' – myrtle spurge, creeping spurge, donkey tail
* ''[[Euphorbia nivulia]]'' – leafy milk hedge<ref>{{cite web |url=https://www.flowersofindia.net/catalog/slides/Leafy%20Milk%20Hedge.html |title=Leafy milk hedge |publisher=Flowers of India |accessdate=29 September 2021}}</ref>
* ''[[Euphorbia obesa]]''
* ''[[Euphorbia paralias]]'' – sea spurge
* ''[[Euphorbia pekinensis]]'' – Peking spurge
* ''[[Euphorbia peplis]]'' – purple spurge
* ''[[Euphorbia peplus]]'' – petty spurge
* ''[[Euphorbia polychroma]]'' – bonfire
* ''[[Euphorbia psammogeton]]'' – sand spurge
* ''[[Euphorbia pulcherrima]]'' – poinsettia, Mexican flame leaf, Christmas star, winter rose, ''noche buena'', ''lalupatae'', ''pascua'', ''Atatürk çiçeği'' ([[Turkish language|Turkish]])
* ''[[Euphorbia purpurea]]'' – Darlington's glade spurge, glade spurge, or purple spurge
* ''[[Euphorbia resinifera]]'' – resin spurge
* ''[[Euphorbia rigida]]''  – gopher spurge, upright myrtle spurge
* ''[[Euphorbia serrata]]'' – serrated spurge, sawtooth spurge
* ''[[Euphorbia tirucalli]]'' – Indian tree spurge, milk bush, pencil tree, firestick
* ''[[Euphorbia tithymaloides]]'' – devil's backbone, redbird cactus, ''cimora misha'' ([[Peru]])
* ''[[Euphorbia trigona]]'' – African milk tree, cathedral cactus, Abyssinian euphorbia
* ''[[Euphorbia tuberosa]]'' 
* ''[[Euphorbia virosa]]'' – gifboom or poison tree

===Hybrids===
''Euphorbia'' has been extensively [[Hybrid (biology)#In plants|hybridised]] for garden use, with many [[cultivar]]s available commercially. Moreover, some hybrid plants have been found growing in the wild, for instance [[Euphorbia × martini|''E.'' × ''martini'']] Rouy,<ref>{{cite web|url=http://wcsp.science.kew.org/namedetail.do?name_id=80791|title=World Checklist of Selected Plant Families (WCSP) - ''Euphorbia'' × ''martini'' Rouy, Ill. Pl. Eur. 13: 107 (1900)|website=Kew Science|publisher=[[Royal Botanic Gardens, Kew]]|access-date=26 Feb 2018}}</ref> a cross of [[Euphorbia amygdaloides|''E. amygdaloides'']] × [[Euphorbia characias|''E. characias'']] subsp. ''characias'', found in southern France.

=== Subgenera ===
[[Image:Euphorbiinae tree.png|thumb|Simplified diagram of relations in subtribe [[Euphorbiinae]], 2006<ref name="Bruyns"/>]]

The genus ''Euphorbia'' is one of the largest and most complex genera of flowering plants, and several botanists have made unsuccessful attempts to subdivide the genus into numerous smaller genera. According to the recent [[phylogenetic]] studies,<ref name="Steinmann_Porter"/><ref name="Steinmann-2003" /><ref name="Bruyns"/> ''Euphorbia'' can be divided into four subgenera, each containing several [[section (botany)|section]]s and groups. Of these, subgenus ''[[Euphorbia esula|Esula]]'' is the most [[basal (evolution)|basal]]. The subgenera ''[[Chamaesyce]]'' and ''[[Euphorbia (subgenus)|Euphorbia]]'' are probably [[sister taxa]], but very closely related to subgenus ''Rhizanthium''. Extensive [[xeromorph]] adaptations in all probability [[evolution|evolve]]d several times;<ref>{{Cite journal |last1=Horn |first1=James W. |last2=van Ee |first2=Benjamin W. |last3=Morawetz |first3=Jeffery J. |last4=Riina |first4=Ricarda |last5=Steinmann |first5=Victor W. |last6=Berry |first6=Paul E. |last7=Wurdack |first7=Kenneth J. |date=May 2012 |title=Phylogenetics and the evolution of major structural characters in the giant genus Euphorbia L. (Euphorbiaceae) |url=https://pubmed.ncbi.nlm.nih.gov/22273597/ |journal=Molecular Phylogenetics and Evolution |volume=63 |issue=2 |pages=305–326 |doi=10.1016/j.ympev.2011.12.022 |issn=1095-9513 |pmid=22273597|bibcode=2012MolPE..63..305H |hdl=10261/169091 |s2cid=22055432 |hdl-access=free }}</ref> it is not known if the common ancestor of the cactus-like ''Rhizanthium'' and ''Euphorbia'' lineages had been xeromorphic—in which case a more normal morphology would have re-evolved namely in ''Chamaesyce''—or whether extensive xeromorphism is entirely [[polyphyletic]] even to the level of the subgenera.

* '''''Esula'''''<ref>{{Cite journal |last1=Riina |first1=Ricarda |last2=Peirson |first2=Jess A. |last3=Geltman |first3=Dmitry V. |last4=Molero |first4=Julián |last5=Frajman |first5=Božo |last6=Pahlevani |first6=Amirhossein |last7=Barres |first7=Laia |last8=Morawetz |first8=Jeffery J. |last9=Salmaki |first9=Yasaman |last10=Zarre |first10=Shahin |last11=Kryukov |first11=Aleksey |last12=Bruyns |first12=Peter V. |last13=Berry |first13=Paul E. |date=2013-04-20 |title=A worldwide molecular phylogeny and classification of the leafy spurges, Euphorbia subgenus Esula (Euphorbiaceae) |url=http://doi.wiley.com/10.12705/622.3 |journal=Taxon |language=en |volume=62 |issue=2 |pages=316–342 |doi=10.12705/622.3|bibcode=2013Taxon..62..316R }}</ref>
<gallery>
Image:Light green flowers.jpg|[[Wood spurge]]<br/>''Euphorbia amygdaloides''
Image:Zypressenwolfsmilch01.jpg|[[Cypress spurge]]<br/>''Euphorbia cyparissias''
Image:Euphorbia esula.jpeg|[[Leafy spurge]]<br/>''Euphorbia esula''
Image:Euphorbia myrsinites.JPG|[[Myrtle spurge]]<br />''Euphorbia myrsinites''
</gallery>

* '''''Rhizanthium'''''
<gallery>
Image:Euphorbia ferox2 ies.jpg|''[[Euphorbia ferox]]''
Image:E flanaganii ies.jpg|''[[Euphorbia flanaganii]]''
Image:E meloformis valida ies.jpg|[[Euphorbia meloformis|''Euphorbia meloformis'' ssp. ''valida'']]
Image:E obesa symmetrica ies.jpg|[[Euphorbia obesa|''Euphorbia obesa'' ssp. ''symmetrica'']]
</gallery>

* '''''Chamaesyce'''''<ref>{{Cite journal |last1=Yang |first1=Ya |last2=Riina |first2=Ricarda |last3=Morawetz |first3=Jeffery J. |last4=Haevermans |first4=Thomas |last5=Aubriot |first5=Xavier |last6=Berry |first6=Paul E. |date=August 2012 |title=Molecular phylogenetics and classification of Euphorbia subgenus Chamaesyce (Euphorbiaceae) |url=https://onlinelibrary.wiley.com/doi/10.1002/tax.614005 |journal=Taxon |language=en |volume=61 |issue=4 |pages=764–789 |doi=10.1002/tax.614005|bibcode=2012Taxon..61..764Y |hdl=2027.42/146846 |hdl-access=free }}</ref>
<gallery>
Image:Chamaesyce cyathia.jpg|''[[Euphorbia celastroides]]''
Image:Euphorbia heterophylla with cyathia.JPG|[[Painted euphorbia]]<br />''Euphorbia heterophylla''
Image:E pulcherrima ies.jpg|[[Poinsettia]]<br />''Euphorbia pulcherrima''
Image:E rivae ies.jpg|''[[Euphorbia rivae]]''
</gallery>

* '''''Euphorbia'''''<ref>{{Cite journal |last1=Dorsey |first1=Brian L. |last2=Haevermans |first2=Thomas |last3=Aubriot |first3=Xavier |last4=Morawetz |first4=Jeffery J. |last5=Riina |first5=Ricarda |last6=Steinmann |first6=Victor W. |last7=Berry |first7=Paul E. |date=2013-04-20 |title=Phylogenetics, morphological evolution, and classification of Euphorbia subgenus Euphorbia |url=http://doi.wiley.com/10.12705/622.1 |journal=Taxon |language=en |volume=62 |issue=2 |pages=291–315 |doi=10.12705/622.1|bibcode=2013Taxon..62..291D |hdl=2027.42/146962 |s2cid=87352157 |hdl-access=free }}</ref>
<gallery>
Image:E actinoclada ies.jpg|''[[Euphorbia actinoclada]]''
Image:E attastoma attastoma ies.jpg|[[Euphorbia attastoma|''Euphorbia attastoma'' var. ''attastoma'']]
Image:E confinalis rhodesica ies.jpg|[[Euphorbia confinalis|''Euphorbia confinalis'' ssp. ''rhodesica'']]
Image:E lupulina ies.jpg|''[[Euphorbia lupulina]]''
Image:Euphorbia neriifolia Hong Kong.jpg|''[[Euphorbia neriifolia]]''
</gallery>