Editing Birch (section)

==Taxonomy==
{{more citations needed|section|date=April 2021}}

=== Subdivision ===
{{main|List of Betula species}}
''Betula'' species are organised into five subgenera.
[[File:DosenmoorBirken1.jpg|thumb|Birch leaves]]
[[File:Björk - Birch - (Betula) - Ystad-2023.jpg|thumb|A birch-curtain in November in [[Ystad]].]]
[[File: Stam van een Berk (Betula). 07-02-2024. (d.j.b).jpg|thumb|Lying trunk of a birch (''Betula'') in total decomposition.]]
; Birches native to [[Eurasia]] include
# ''[[Betula albosinensis]]'' – Chinese red birch (northern + central China)
# ''[[Betula alnoides]]'' – alder-leaf birch (China, Himalayas, northern Indochina)
# ''[[Betula ashburneri]]'' – (Bhutan, Tibet, Sichuan, Yunnan Provinces in China)
# ''[[Betula baschkirica]]'' – (eastern European Russia)
# ''[[Betula bomiensis]]'' – (Tibet)
# ''[[Betula browicziana]]'' – (Turkey and Georgia)
#''[[Betula buggsii]]'' – (China)
# ''[[Betula calcicola]]'' – (Sichuan + Yunnan Provinces in China)
# ''[[Betula celtiberica]]'' – (Spain)
# ''[[Betula chichibuensis]]'' – ([[Chichibu, Saitama|Chichibu]] region of Japan)<ref name="Kinver-2015">{{cite web|last1=Kinver|first1=Mark|title=UK team germinates critically endangered Japanese birch|url=https://www.bbc.co.uk/news/science-environment-34378953|website=[[BBC News]]|publisher=[[BBC]]|access-date=30 September 2015|date=30 September 2015}}</ref>
# ''[[Betula chinensis]]'' – Chinese dwarf birch (China, Korea)
# ''[[Betula coriaceifolia]]'' – (Uzbekistan)
# ''[[Betula corylifolia]]'' – (Honshu Island in Japan)
# ''[[Betula costata]]'' – (northeastern China, Korea, Primorye region of Russia)
# ''[[Betula cylindrostachya]]'' – (Himalayas, southern China, Myanmar)
# ''[[Betula dahurica]]'' – (eastern Siberia, Russian Far East, northeastern China, Mongolia, Korea, Japan)
# ''[[Betula delavayi]]'' – (Tibet, southern China) 
# ''[[Betula ermanii]]'' – Erman's birch  (eastern Siberia, Russian Far East, northeastern China, Korea, Japan)
# ''[[Betula falcata]]'' – (Tajikistan)
# ''[[Betula fargesii]]''  – (Chongqing + Hubei Provinces in China)
# ''[[Betula fruticosa]]'' – (eastern Siberia, Russian Far East, northeastern China, Mongolia, Korea, Japan)
# ''[[Betula globispica]]'' – (Honshu Island in Japan)
# ''[[Betula gmelinii]]'' – (Siberia, Mongolia, northeastern China, Korea, Hokkaido Island in Japan)
# ''[[Betula grossa]]'' – Japanese cherry birch  (Japan)
# ''[[Betula gynoterminalis]]'' – (Yunnan Province in China)
# ''[[Betula honanensis]]'' – (Henan Province in China)
# ''[[Betula humilis]]'' or ''Betula kamtschatica'' – Kamchatka birch ''platyphylla''  (northern + central Europe, Siberia, Kazakhstan, Xinjiang, Mongolia, Korea)
# ''[[Betula insignis]]'' – (southern China)
# ''[[Betula karagandensis]]'' – (Kazakhstan)
# ''[[Betula klokovii]]'' – (Ukraine)
# ''[[Betula kotulae]]'' – (Ukraine)
# ''[[Betula luminifera]]'' – (China)
# ''[[Betula maximowicziana]]'' – monarch birch   (Japan, Kuril Islands)
# ''[[Betula medwediewii]]'' – Caucasian birch   (Turkey, Iran, Caucasus)
# ''[[Betula megrelica]]'' – (Republic of Georgia)
# ''[[Betula microphylla]]'' – (Siberia, Mongolia, Xinjiang, Kazakhstan, Kyrgyzstan, Uzbekistan)
# ''[[Betula nana]]'' – dwarf birch (northern + central Europe, Russia, Siberia, Greenland, Northwest Territories of Canada))
# ''[[Betula pendula]]'' – silver birch   (widespread in Europe and northern Asia; Morocco; naturalized in New Zealand and scattered locations in US + Canada)
# ''[[Betula platyphylla]]'' – (''Betula pendula'' var. ''platyphylla'')—Siberian silver birch   (Siberia, Russian Far East, Manchuria, Korea, Japan, Alaska, western Canada)
# ''[[Betula potamophila]]'' – (Tajikistan)
# ''[[Betula potaninii]]'' – (southern China)
# ''[[Betula psammophila]]'' – (Kazakhstan)
# ''[[Betula pubescens]]'' – downy birch, also known as white, European white or hairy birch (Europe, Siberia, Greenland, Newfoundland; naturalized in scattered locations in US)
# ''[[Betula raddeana]]'' – (Caucasus)
# ''[[Betula saksarensis]]'' – (Khakassiya region of Siberia)
# ''[[Betula saviczii]]'' – (Kazakhstan)
# ''[[Betula schmidtii]]'' – (northeastern China, Korea, Japan, Primorye region of Russia)
# ''[[Betula sunanensis]]'' – (Gansu Province of China)
# ''[[Betula szechuanica]]'' – (''Betula pendula'' var. ''szechuanica'')—Sichuan birch  (Tibet, southern China)
# ''[[Betula tianshanica]]'' – (Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan, Xinjiang, Mongolia) 
# ''[[Betula utilis]]'' – Himalayan birch  (Afghanistan, Central Asia, China, China, Tibet, Himalayas)
# ''[[Betula wuyiensis]]'' – (Fujian Province of China)
# ''[[Betula zinserlingii]]''  – (Kyrgyzstan)
Note: many American texts have ''B. pendula'' and ''B. pubescens'' confused, though they are distinct species with different chromosome numbers.

; Birches native to [[North America]] include
[[File:Birch Trees, Ten Mile Estuary State Marine Conservation Area-L1004571.jpg|thumb|Birch trees in the Ten Mile Estuary State Marine Conservation Area south of Newport, California]]
# ''[[Betula alleghaniensis]]'' – yellow birch (''B. lutea'') (eastern Canada, Great Lakes, upper eastern US, Appalachians)
# ''[[Betula caerulea]]'' – blue birch (northeast of North America)
# ''[[Betula cordifolia]]'' – mountain paper birch (eastern Canada, Great Lakes, New England US)
# ''[[Betula glandulosa]]'' – American dwarf birch (Siberia, Mongolia, Russian Far East, Alaska, Canada, Greenland, mountains of western US and New England, Adirondacks)
# ''[[Betula kenaica]]''  –  Kenai birch ( Alaska, northwestern North America)
# ''[[Betula lenta]]'' – sweet birch, cherry birch, or black birch  (Quebec, Ontario, eastern US)
# ''[[Betula michauxii]]'' – Newfoundland dwarf birch   (Newfoundland, Labrador, Quebec, Nova Scotia)
# ''[[Betula minor]]'' – dwarf white birch (eastern Canada, mountains of northern New England and Adirondacks)
# ''[[Betula murrayana]]'' – Murray's birch (Great Lakes endemic)
# ''[[Betula nana]]'' – dwarf birch or bog birch (also in northern Europe and Asia)
# ''[[Betula neoalaskana]]'' – Alaska paper birch also known as Alaska birch or Resin birch (Alaska and northern Canada)
# ''[[Betula nigra]]'' – river birch or black birch  (eastern US)
# ''[[Betula occidentalis]]'' – water birch or red birch (''B. fontinalis'')   (Alaska, Yukon, Northwest Territories, western Canada, western US)
# ''[[Betula papyrifera]]'' – paper birch, canoe birch or American white birch   (Alaska, most of Canada, northern US)
# ''[[Betula populifolia]]'' – gray birch   (eastern Canada, northeastern US)
# ''[[Betula pumila]]'' – swamp birch   (Alaska, Canada, northern US)
# ''[[Betula uber]]'' – Virginia round-leaf birch (southwestern Virginia)

===Etymology===
{{unreferenced section|date=April 2021}}
The common name ''birch'' comes from [[Old English]] ''birce'', ''bierce'', from [[Proto-Germanic]] *''berk-jōn'' (cf. [[German language|German]] ''Birke'', [[West Frisian language|West Frisian]] ''bjirk''), an adjectival formation from *''berkōn'' (cf. [[Dutch language|Dutch]] ''berk'', [[Low German]] ''Bark'', [[Danish language|Danish]] ''birk'', [[Norwegian language|Norwegian]] ''bjørk''), itself from the [[Proto-Indo-European language|Proto-Indo-European]] root *''bʰerHǵ-'' ~ ''bʰrHǵ''-, which also gave [[Lithuanian language|Lithuanian]] ''béržas'', [[Latvian language|Latvian]] ''Bērzs'', [[Russian language|Russian]] ''берёза (berëza)'', [[Ukrainian language|Ukrainian]] береза (''beréza)'', [[Albanian language|Albanian]] ''bredh'' 'fir', [[Ossetic language|Ossetian]] ''bærz(æ)'', [[Sanskrit language|Sanskrit]] ''bhurja'', [[Polish language|Polish]] ''brzoza'', [[Latin language|Latin]] ''fraxinus'' 'ash (tree)'. This root is presumably derived from *''bʰreh₁ǵ-'' 'to shine, whiten', in reference to the birch's white bark. The [[Proto-Germanic]] [[rune]] ''[[berkanan]]'' is named after the birch.

The generic name ''Betula'' is from [[Latin]], which is a [[diminutive]] borrowed from [[Gaulish language|Gaulish]] ''betua'' (cf. [[Old Irish]] ''bethe'', [[Welsh language|Welsh]] ''bedw'').