Diarthron

{{Short description|Genus of flowering plants}} {{Automatic taxobox | image = Diarthron altaica 44315652.jpg | image_caption = ''Diarthron altaica'' | taxon = Diarthron | authority = Turcz. (1832)<ref name=IPNI_39228-1/> | synonyms = *''Dendrostellera'' {{small|(C.A.Mey.) Tiegh. (1893)}} *''Stelleropsis'' {{small|Pobed. (1950)}} | synonyms_ref = <ref name=powo>{{cite web |title=''Diarthron'' Turcz. |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:39228-1 |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=16 September 2024}}</ref> }}

'''''Diarthron''''' is a genus of flowering plant in the family Thymelaeaceae. The precise limits of the genus are uncertain. When broadly circumscribed to include '''''Dendrostellera''''' and '''''Stelleropsis''''', it consists of annual and perennial herbaceous plants and small shrubs, with reddish, white or green flowers lacking petals. It includes 16 species which range from southern European Russia and the Caucasus through Western and Central Asia through China and Mongolia to Korea and the Russian Far East.<ref name = powo/>

==Description== When broadly circumscribed (i.e. including ''Dendrostellera'' and ''Stelleropsis''), ''Diarthron'' is a genus of annual or perennial herbaceous plants or short deciduous shrubs. Prior to a review in 1982, only the annual species were placed in ''Diarthron'', with the perennial herbs being in ''Stelleropsis'' and the shrubs in ''Dendrostellera''. The flowers lack petals. There are usually four (sometimes five) sepals, united at the base into a tube with lobes at the end, reddish, white or green in colour. The ovary has a single chamber (locule). The fruit is dry with the seed enclosed in a thin glossy black pericarp.<ref name=FoC_Diarthron/>

==Taxonomy== The genus ''Diarthron'' was first described in 1832 by Nikolai Turczaninow for the species ''Diarthron linifolium''. Many species were added to the genus in 1982 by Kit Tan, being transferred from related genera.<ref name=IPNI_Diarthron/><ref name=Tan82/> A 2006 study suggested that as circumscribed, ''Diarthron'' is not monophyletic, so that ''Dendrostellera'' and ''Stelleropsis'' which Tan had merged into ''Diarthron'' should be reinstated.<ref name=Gali06/> Studies in 2002 and 2009, based on chloroplast DNA, placed ''Diarthron'' in a small group of related genera, sister to a clade consisting of ''Thymelaea'' and ''Daphne''; however for most genera only one species was included.<ref name=BankFayChas02/><ref name=BeauEdwaMannMaur09/>

{{clade|style=line-height:100% |1={{clade |1=''Edgeworthia'' |2={{clade |1={{clade |1=''Wikstroemia'' |2=''Stellera'' }} |2={{clade |1=''Diarthron'' |2={{clade |1=''Thymelaea'' |2=''Daphne'' }} }} }} }} }}

===Species=== 16 species are currently accepted.<ref name = powo/> *''Diarthron altaicum'' (Thiéb.-Bern.) Kit Tan *''Diarthron ammodendron'' (Kar. & Kir.) ined. *''Diarthron antoniniae'' (Pobed.) Kit Tan *''Diarthron arenarium'' (Pobed.) Kit Tan *''Diarthron caucasicum'' (Pobed.) Kit Tan *''Diarthron iranicum'' (Pobed.) Kit Tan *''Diarthron issykkulense'' (Pobed.) Kit Tan *''Diarthron lessertii'' (Wikstr.) Kit Tan *''Diarthron linearifolium'' (Pobed.) Kit Tan *''Diarthron linifolium'' Turcz. *''Diarthron macrorhachis'' (Pobed.) Kit Tan *''Diarthron magakjanii'' (Sosn.) Kit Tan *''Diarthron tarbagataicum'' (Pobed.) Kit Tan *''Diarthron tianschanicum'' (Pobed.) Kit Tan *''Diarthron turkmenorum'' (Pobed.) Kit Tan *''Diarthron vesiculosum'' (Fisch. & C.A.Mey.) C.A.Mey.

==References== {{Reflist|refs= <ref name=BankFayChas02>{{Citation |last1=van der Bank |first1=Michelle |last2=Fay |first2=Michael F. |last3=Chase |first3=Mark W. |date=2002 |title=Molecular Phylogenetics of Thymelaeaceae with particular reference to African and Australian genera |journal=Taxon |volume=51 |issue=2 |pages=329–339 |doi=10.2307/1554901 |jstor=1554930 |name-list-style=amp }}</ref>

<ref name=BeauEdwaMannMaur09>{{Citation |last1=Beaumont |first1=Angela J. |last2=Edwards |first2=Trevor J. |last3=Manning |first3=John |last4=Maurin |first4=Olivier |last5=Rautenbach |first5=Marline |last6=Motsi |first6=Moleboheng C. |last7=Fay |first7=Michael F. |last8=Chase |first8=Mark W. |last9=Van Der Bank |first9=Michelle |date=2009 |title=Gnidia (Thymelaeaceae) is not monophyletic: taxonomic implications for Thymelaeoideae and a partial new generic taxonomy for ''Gnidia'' |journal=Botanical Journal of the Linnean Society |volume=160 |issue=4 |pages=402–417 |doi=10.1111/j.1095-8339.2009.00988.x |name-list-style=amp |doi-access=free }}</ref>

<ref name=FoC_Diarthron>{{citation |first1=Yinzheng |last1=Wang |first2=Michael G. |last2=Gilbert |contribution=Diarthron |contribution-url=http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=109817 |access-date=2017-11-26 |editor-last=Wu |editor-first=Zhengyi |editor2-last=Raven |editor2-first=Peter H. |editor3-last=Hong |editor3-first=Deyuan  |title=Flora of China ''(online)'' |publisher=eFloras.org |url=http://www.efloras.org/flora_page.aspx?flora_id=2 |name-list-style=amp }}</ref>

<ref name=Gali06>{{Citation |last1=Galicia-Herbada |first1=D. |date=2006 |title=Origin and diversification of ''Thymelaea'' (Thymelaeaceae): inferences from a phylogenetic study based on ITS (rDNA) sequences |journal=Plant Systematics and Evolution |volume=257 |issue=3–4 |pages=159–187 |doi=10.1007/s00606-005-0371-z |bibcode=2006PSyEv.257..159G }}</ref>

<ref name=IPNI_39228-1>{{citation |title=Plant Name Details for ''Diarthron'' Turcz. |work=The International Plant Names Index |url=http://www.ipni.org/ipni/idPlantNameSearch.do?id=39228-1 |access-date=2017-11-26 }}</ref>

<ref name=IPNI_Diarthron>{{citation |title=Search for ''Diarthron'' |work=The International Plant Names Index |url=http://www.ipni.org/ipni/advPlantNameSearch.do?find_genus=Diarthron |access-date=2017-11-26 }}</ref>

<ref name=Tan82>{{Citation |last1=Tan |first1=K. |date=1982 |title=Studies in the Thymelaeaceae III: the status of ''Diarthron'', ''Dendrostellera'', ''Stelleropsis'' and ''Stellera'' |journal=Notes from the Royal Botanic Garden, Edinburgh |volume=40 |pages=213–221 }}, cited in {{Harvtxt|Galicia-Herbada|2006}}</ref> }}

Category:Thymelaeoideae Category:Thymelaeaceae genera Category:Paleotropical flora Category:Taxa described in 1832 Category:Taxa named by Nikolai Turczaninow