Editing Rhododendron (section)

=== Early history ===
Although Rhododendrons had been known since the description of ''[[Rhododendron hirsutum]]'' by [[Charles de l'Écluse]] (Clusius) in the sixteenth century, and were known to classical writers (Magor 1990), and referred to as ''Chamaerhododendron'' (low-growing rose tree), the genus was first formally described by [[Carl Linnaeus|Linnaeus]] in his ''[[Species Plantarum]]'' in 1753.<ref name=LSPR/><ref>{{cite book |last=Linnaeus |first=C. |author-link=Carl Linnaeus |title=Genera Plantarum |edition=5th |page=185 |year=1754 |url=https://www.biodiversitylibrary.org/item/14678#page/1/mode/1up |publisher=Laurentii Salvii |location=Stockholm |access-date=1 October 2017}}</ref> He listed five species under ''Rhododendron'': [[Rhododendron ferrugineum|''R.''&nbsp;''ferrugineum'']] (the [[type species]]), ''[[Rhododendron dauricum|R.&nbsp;dauricum]]'', ''[[Rhododendron hirsutum|R.&nbsp;hirsutum]]'', ''R.&nbsp;chamaecistus'' (now ''[[Rhodothamnus chamaecistus]]'' (L.) Rchb.) and ''[[Rhododendron maximum|R.&nbsp;maximum]]''. At that time he considered the then known six species of ''[[Azalea]]''<ref name=LSPA>{{cite book |chapter-url=https://www.biodiversitylibrary.org/item/13829#page/162/mode/1up |last=Linnaeus |first=C. |author-link=Carl Linnaeus |title=Species Plantarum |chapter=Azalea |volume=Tomus I |page=150 |year=1753 |publisher=Laurentii Salvii |location=Stockholm |access-date=15 June 2014}}</ref> that he had described earlier in 1735 in his ''[[Systema Naturae]]'' as a separate genus.<ref name=WIAA>{{cite web |last=Andrews |first=Charles |url=http://azaleachapter.com/plant-info/plants/what-is-an-azalea |publisher=American Rhododendron Society (Azalea Chapter) |title=What is an Azalea?}}</ref><ref name=Spady>{{cite journal |url=http://scholar.lib.vt.edu/ejournals/JARS/v35n4/v35n4-spady.htm |first=Herbert A. |last=Spady |title=GROPING FOR GROUPING: Rhododendron Taxonomy |journal=The Quarterly Bulletin of the American Rhododendron Society |volume=35 |issue=4 |date=Fall 1981}}</ref>

Linnaeus' six species of ''Azalea'' were ''[[Rhododendron indicum|Azalea indica]]'', ''[[Rhododendron luteum|A.&nbsp;pontica]]'', ''[[Rhododendron calendulaceum|A.&nbsp;lutea]]'', ''[[Rhododendron viscosum|A.&nbsp;viscosa]]'', ''[[Rhododendron lapponicum|A.&nbsp;lapponica]]'' and ''A.&nbsp;procumbens'' (now ''[[Kalmia procumbens]]''), which he distinguished from ''Rhododendron'' by having five [[stamens]], as opposed to ten. As new species of what are now considered ''Rhododendron'' were discovered, they were assigned to separate genera if they seemed to differ significantly from the type species. For instance ''Rhodora'' (Linnaeus 1763) for ''[[Rhododendron canadense]]'', ''Vireya'' ([[Carl Ludwig Blume|Blume]] 1826)<ref>{{cite web |url=http://www.vireya.net/history.htm |first=Chris |last=Callard |title=The History of Vireya Rhododendron Culture |website=vireya.net |date=1998–2015 |access-date=28 September 2017}}</ref> and ''Hymenanthes'' (Blume 1826) for ''Rhododendron metternichii'', now [[Rhododendron degronianum|R. degronianum]]. Meanwhile, other botanists such as [[Richard Anthony Salisbury|Salisbury]] (1796)<ref>{{cite book |url=https://www.biodiversitylibrary.org/item/9522#page/293/mode/1up |last=Salisbury |first=R.A. |author-link=Richard Anthony Salisbury |title=Prodromus Stirpium in horto ad Chapel Allerton |date=1796 |page=286 |location=London |language=la}}</ref> and Tate (1831)<ref>{{cite book |chapter-url=http://www.british-history.ac.ok/vch/middx/vol12/pp150-155 |chapter=Economic history: Farm-gardening and market gardening |title=A History of the County of Middlesex: Volume 12, Chelsea |editor=Patricia E C Croot |location=London |date=2004 |pages=150–155 |publisher=British History Online}}</ref> began to question the distinction between ''Azalea'' and ''Rhododendron'', and finally in 1836, ''Azalea'' was incorporated into ''Rhododendron''<ref name=Don/> and the genus divided into eight sections. Of these ''Tsutsutsi'' (''[[Rhododendron subg. Tsutsuji|Tsutsusi]]''), ''[[Pentanthera]]'', ''[[Pogonanthum]]'', ''[[Ponticum]]'' and ''[[Rhodora]]'' are still used, the other sections being ''Lepipherum'', ''Booram'', and ''Chamaecistus''. This structure largely survived till recently (2004), following which the development of molecular phylogeny led to major {{Nowrap|re-examinations}} of traditional morphological classifications,<ref name=WIAA/><ref name=Spady/> although other authors such as Candolle, who described six sections,{{sfnp|Candolle |1838 |ref=Candolle}} used slightly different numeration.

Soon, as more species became available in the nineteenth century so did a better understanding of the characteristics necessary for the major divisions. Chief amongst these were [[Maximovicz]]'s ''Rhododendreae Asiae Orientali''<ref name=Maximovicz/> and [[Jules Émile Planchon|Planchon]]. Maximovicz used flower bud position and its relationship with leaf buds to create eight "Sections".{{sfnp|JIN |DING |ZHANG |HONG |2010 |ref=JDZH}} [[Bentham and Hooker]] used a similar scheme, but called the divisions "Series".<ref name=BH/> It was not until 1893 that [[Bernhard Adalbert Emil Koehne|Koehne]] appreciated the significance of scaling and hence the separation of lepidote and elepidote species. The large number of species that were available by the early twentieth century prompted a new approach when [[Isaac Bayley Balfour|Balfour]] introduced the concept of grouping species into [[Series (botany)|series]]. ''The Species of Rhododendron''<ref>{{cite book |editor-last=Stevenson |editor-first=J.B. |title=The Species of Rhododendron |publisher=The Rhododendron Society |location=Edinburgh |date=1930}}</ref> referred to this series concept as the Balfourian system. That system continued up to modern times in Davidian's four volume ''The Rhododendron Species''.{{sfnp|Davidian |ref=Davidian}}