View source for Rhododendron sect. Vireya

{{Short description|Group of shrubs}}
{{Automatic taxobox
| image = Rhododendron javanicum brookeanum (14012162344).jpg
| image_caption = ''[[Rhododendron javanicum]]''
| taxon = Rhododendron sect. Vireya
| authority = (Blume) [[Herbert Copeland (biologist)|H.F.Copel.]]
| type_species = ''[[Rhododendron javanicum]]''
| type_species_authority = (Blume) Benn.
| subdivision_ranks = Subsections
| subdivision = See text
| synonyms = ''Schistanthe'' <small>[[Schltr.]]</small>
}}
[[image:Vireya.jpg|thumb|''Vireya'' rhododendron]]
'''''Rhododendron'' section ''Vireya''''' (vireyas) is a tropical group of ''[[Rhododendron]]'' species, numbering about 300 in all.<ref name="craven2008"/> The group may also be treated as '''''Rhododendron'' subgenus ''Vireya'''''.<ref name=WFO_3500001320/> Vireyas are native to [[southeastern Asia]] and range from [[Thailand]] to [[Australia]].<ref name=Chamberlain/>
==Description==
[[File:Vireya Kamrau Bay.jpg|thumb|Rhododendron 'Kamrau Bay', a hybrid whose background includes ''R.{{nbsp}}zoelleri'' and ''[[Rhododendron laetum|R. laetum]]''<ref name=VHG/>]]
''Vireya'' are morphologically diverse, and characterised by [[seeds]] with tailed appendages, the presence of [[leaf]] idioblasts and capsule valves which twist upon opening.<ref name=Brown2006/>
The formal description (Craven 2008) is: Scales sessile or sometimes stalked, lobed to deeply incised or sometimes entire; corolla campanulate, trumpet-like, salver-shaped, tubular or funnel-shaped; stamens (5–)10(–16), exserted to included, staminal filaments glabrous or hairy from the base; capsule valves twisting after dehiscence; seeds with a distinct tail at each end.
==Taxonomy==
{{main|List of Sections in Subgenus Rhododendron}}
''Vireya'' is the largest of the three sections constituting [[subgenus]] ''Rhododendron'', and includes about a third of all ''Rhododendron'' species.<ref name="Goetsch"/> The exact classification has varied among various authors, some authors considering ''Vireya'' to be a separate [[subgenus]]<ref name="Argent 2006"/> rather than as here, a [[Section (botany)|section]] of the subgenus [[Rhododendron subg. Rhododendron|''Rhododendron'']].<ref name="craven2008" /><ref name=WFO_3500001320/> It has been suggested that taxonomic nomenclatural correctness requires changing the name of the ''Vireya'' rhododendrons to ''Schistanthe''. Thus the term 'Vireya' has been used to refer to Section ''Vireya'' (Sleumer), Subgenus ''Vireya'', Section ''Schistanthe'', or the majority of the [[Malesian]] tropical rhododendrons. (Fayaz). Goetsch (2011) gives the number of species as 320, and the total taxa including subspecies, forms and varieties as 380.
===Subdivision===
The section has traditionally been considered to consist of seven [[subsections]] based on morphology,<ref name=Sleumer66/> although Brown et{{nbsp}}al., using [[phylogenetic analysis]], found a lack of support for [[monophyly]] of these subsections, and rather a series of [[clades]] based on geographical distribution:<ref name=Brown2006/>
* R. subsect. ''Albovireya'' Sleumer, type ''[[Rhododendron album]]'' Blume
* R. subsect. ''Euvireya'' Copel.f., type ''[[Rhododendron javanicum]]'' (Blume) Benn
* R. subsect. ''Malayovireya'' Sleumer, type ''[[Rhododendron malayanum]]'' Jack
* R. subsect. ''Phaeovireya'' Sleumer, type ''[[Rhododendron beyerinckianum]]'' Koord.
* R. subsect. ''Pseudovireya'' Clarke, type ''[[Rhododendron vaccinioides]]'' Hook.f.
* R. subsect. ''Siphonovireya'' Sleumer, type ''[[Rhododendron habbemae]]'' Koord
* R. subsect. ''Solenovireya'' Copel.f., type ''[[Rhododendron jasminiflorum]]'' Hook.
In Argent's (2006) treatment of Vireya as a subgenus, he included seven sections, with ''Euvireya'' consisting of five subsections,<ref name="Argent 2006"/> but this is not supported by phylogenetic analysis.<ref name="craven2008"/> These studies, for instance that of Hall (2006),<ref name=Hall/> suggested a very different approach. The Asian mainland species represented by ''Pseudovireya'' appear as a [[sister group]] to the other six subsections, while the Malesian species within ''Pseudovireya'' also formed an [[Outgroup (cladistics)|outgroup]], resulting in three major [[clades]]. Thus Craven et{{nbsp}}al. proposed there be only two subsections of ''Vireya'', corresponding to the core species, ''Euvireya'' and the much smaller ''Malayovireya'' , while the other two groups formed out of ''Pseudovireya'' be raised to section rank, keeping the original name ''Pseudovireya'' for the mainland species, and using Argent's name, ''Discovireya'' for the Malesian species.<ref name="craven2008"/> For a comparison of the Sleumer, Argent and Craven schemata, see Craven (2008), Table{{nbsp}}1.
Thus the new subsection structure is:
* R. subsect. ''Euvireya'' Copel.f., type ''Rhododendron javanicum'' (Blume) Benn
* R. subsect. ''Malayovireya'' Sleumer, type ''[[Rhododendron malayanum]]'' Jack
Characteristics:(Craven 2008)
* ''Euvireya'' – Scales sessile or stalked, scattered or dense, not of two obviously different size classes, lobed to deeply incised (or sometimes entire) and the centre not dark-coloured.
* ''Malayovireya'' – Scales sessile, dense, of two obviously different size classes, lobed and the centre dark-coloured.
{{As of|2023|December}}, [[World Flora Online]] treated the group as ''R.''&nbsp;subg.''Vireya'', divided into seven sections:<ref name=WFO_3500001320>{{cite web |author=WFO |date=December 2023 |title=''Rhododendron'' subg. ''Vireya'' L.. |work=World Flora Online |url=https://list.worldfloraonline.org/wfo-3500001320 |access-date=2024-02-22}}</ref>
*[[Rhododendron sect. Albovireya|section ''Albovireya'']] {{small|(Sleumer) Argent}}
*[[Rhododendron sect. Discovireya|section ''Discovireya'']] {{small|(Sleumer) Argent}}
*[[Rhododendron sect. Hadranthe|section ''Hadranthe'']] {{small|Schltr.}}
*[[Rhododendron sect. Malayovireya|section ''Malayovireya'']] {{small|(Sleumer) Argent}}
*[[Rhododendron sect. Pseudovireya|section ''Pseudovireya'']] {{small|(Clarke) Sleumer}}
*[[Rhododendron sect. Schistanthe|section ''Schistanthe'']] {{small|Schltr.}}
*[[Rhododendron sect. Siphonovireya|section ''Siphonovireya'']] {{small|Argent}}
== Distribution ==
''Vireya'' are found throughout the [[Malesian Archipelago]] – Peninsular Malaysia, Sumatra, Borneo, Java, the Philippines, Sulawesi, the Lesser Sunda Islands, and Maluku – and in [[Papuasia]], which includes New Guinea, the Bismarck Archipelago, and the Solomon Islands. Some ''Vireya'' species also occur in Australia, China, India, Nepal, Taiwan, and Vietnam. Only a few non-''Vireya'' species occur in Malesia, in the Malay Peninsula, Sumatra, and the Philippines.<ref name=Brown2006/> Malesian species are found in all subsections, while species from other areas appear only in ''Euvvireya'', ''Malayovireya'' and ''Pseudovireya''.<ref name="craven2008"/>
[[New Guinea]] has the most ''Vireya'' species of any island, with 167 species. Borneo has 46 species, the second most of any island.<ref>G. Argent (1985) Vireya Rhododendrons in Borneo. ''Notes from the Royal Botanic Garden, Edinburgh'' 43 53–61</ref>
==References==
{{Reflist|3|refs=
<ref name="Argent 2006">Argent, G. ''Rhododendrons of subgenus Vireya''. 2006. Royal Horticultural Society. {{ISBN|1-902896-61-0}}</ref>
<ref name=Chamberlain>{{cite book|last1=Chamberlain|first1=DF|author2=Hyam R|author3=Argent G|author4=Fairweather G|author5=Walter KS|title=The genus ''Rhododendron'': its classification and synonymy|url=http://www.rbge.org.uk/about-us/publications/publications-catalogue/botanical-publications/rhododendron-publications|date=1996|publisher=Royal Botanic gardens Edinburgh|isbn=1-872291-66-X|accessdate=July 3, 2014|url-status=dead|archiveurl=https://web.archive.org/web/20140714144955/http://www.rbge.org.uk/about-us/publications/publications-catalogue/botanical-publications/rhododendron-publications|archivedate=July 14, 2014}}</ref>
<ref name=Brown2006>[https://www.researchgate.net/publication/235601539_Phylogenetic_relationships_of_Rhododendron_section_Vireya_(Ericaceae)_inferred_from_the_ITS_nrDNA_region/file/72e7e51e347034a1c1.pdf Gillian K. Brown, Lyn A. Craven, Frank Udovicic and Pauline Y. Ladiges. Phylogenetic relationships of Rhododendron section Vireya (Ericaceae) inferred from the ITS nrDNA region. Australian Systematic Botany 19, 329–342. August 2006. 10.1071/SB05019]</ref>
<ref name="craven2008">{{cite journal | doi = 10.3767/000651908X608070 | title = Classification of the ''Vireya'' group of ''Rhododendron'' (Ericaceae) | year = 2008 | last1 = Craven | first1 = L.A. | last2 = Goetsch | first2 = L.A. | last3 = Hall | first3 = B.D. | last4 = Brown | first4 = G.K. | journal = Blumea - Biodiversity, Evolution and Biogeography of Plants | volume = 53 | issue = 2 | pages = 435| url = http://www.repository.naturalis.nl/record/525519 }}</ref>
<ref name="Goetsch">{{cite journal|last=Goetsch|first=Loretta A.|author2=Eckert, Andrew J. |author3=Hall, Benjamin D.  |date=July–September 2005 |title=The molecular systematics of ''Rhododendron'' (Ericaceae): a phylogeny based upon ''RPB2'' gene sequences |journal=[[Systematic Botany]] |volume=30 |issue=3 |pages=616–626 |doi=10.1600/0363644054782170|s2cid=51949019}}</ref>
<ref name=Hall>Hall, B.D., L.A. Craven & L.A. Goetsch. 2006. The taxonomy of subsection Pseudovireya – two distinctly different taxa within subsection Pseudovireya and their relation to the rooting of section Vireya within subgenus Rhododendron. Rhododendron Sp. 1: 72, 91–97</ref>
<ref name=Sleumer66>Sleumer, Hermann Otto (1966) Ericaceae 1. ''Rhododendron'': An account of rhododendron in Malesia, in ‘Flora Malesiana’. (Ed. CGGJ van Steenis) pp. 469–656. (Wolters-Noordhoff Publishing: Groningen, The Netherlands</ref>
<ref name=VHG>{{cite web | url=http://www.vireya.net/gallery-hybK.htm | title=Vireya Hybrid Gallery: K}}</ref>
<ref name=WFO_3500001320>{{cite web |author=WFO |date=December 2023 |title=''Rhododendron'' subg. ''Vireya'' L.. |work=World Flora Online |url=https://list.worldfloraonline.org/wfo-3500001320 |access-date=2024-02-22}}</ref>
}}
== Bibliography ==
* [http://www.vireya.net/history.htm Chris Callard. The History of Vireya Rhododendron Culture. Vireya Rhododendrons. 1998 onwards]
* [http://www.rhododendron.fr/articles/2011%20Blumea%20classification%20of%20vireya.pdf L.A. Craven, F. Danet, J.F. Veldkamp, L.A. Goetsch, B.D. Hall. Vireya Rhododendrons: their monophyly and classification (''Ericaceae'', ''Rhododendron'' section ''Schistanthe''). Blumea 56, 2011: 153–158. 2011]
* [http://www.ingentaconnect.com/content/iapt/tax/2011/00000060/00000004/art00006 Goetsch, L.A., Craven, L.A. and Hall B.D. 2011. Major speciation accompanied the dispersal of Vireya Rhododendrons (Ericaceae, Rhododendron sect. Schistanthe) through the Malayan archipelago: Evidence from nuclear gene sequences. Taxon 60 (4): 1015–1028.]
* [http://www.whitecloudnursery.com/Vireya%20Phylogeny%20pt%20I.pdf Peter Adams. Evolution, Adaptive Radiation and Vireya Rhododendrons - Part I. JARS FALL 2012 pp. 201-3]
* [http://www.whitecloudnursery.com/Vireya%20Phylogeny%20pt%20II.pdf Peter Adams. Evolution, Adaptive Radiation and Vireya Rhododendrons - Part I. JARS SPRING 2013 pp. 74-76]
* [http://mro.massey.ac.nz/handle/10179/4468?show=full. Biodiversity of the Vireya group of ''Rhododendron'' L. (Ericaceae) collections in New Zealand and their potential contribution to international conservation. Fayaz A. PhD Thesis, Department of Plant Science, Massey University, New Zealand. 2012]
== External links ==
*{{cite web|url=http://www.rhododendron.org/taxonomictree.asp|title=Genus Rhododendron Taxonomic Tree|work=[[American Rhododendron Society]]|accessdate=18 June 2014}}
{{Commons category|Rhododendron sect. Schistanthe}}
{{Wikispecies}}
{{Rhododendron}}
{{Taxonbar|from=Q7321173}}
[[Category:Rhododendron|Vireya]]
[[Category:Plant sections]]
[[Category:Flora of Malesia]]
[[Category:Flora of Papuasia]]