Editing Thuja plicata (section)

== Taxonomy ==
''Thuja plicata'' is one of two ''Thuja'' species native to North America, the other being [[Thuja occidentalis|''T.&nbsp;occidentalis'']]. [[Nuclear genome]] analysis indicates that it is likely more closely related to [[Thuja koraiensis|''T.&nbsp;koraiensis'']], which is native to the Korean Peninsula. The two species are hypothesized to have diverged in the [[Miocene]].<ref>{{cite journal |last1 = Peng |first1 = Dan |last2 = Wang |first2 = Xiao-Quan |date = June 2008 |title = Reticulate evolution in ''Thuja'' inferred from multiple gene sequences: Implications for the study of biogeographical disjunction between eastern Asia and North America |journal=[[Molecular Phylogenetics and Evolution]]|volume = 47 |issue = 3 |publisher =[[Elsevier]]|pages = 1190{{ndash}}1202 |doi = 10.1016/j.ympev.2008.02.001|pmid = 18346917 |bibcode = 2008MolPE..47.1190P }}</ref>

A 2008 study found that western redcedar populations in coastal areas of [[Washington (state)|Washington]] and [[Oregon]] are more genetically variable than populations in the [[Rocky Mountains]] and coastal [[British Columbia]], indicating that the species most likely spread throughout its current range from a single [[Refugium (population biology)|refugium]] in the southern portion of its range after the [[Last Glacial Maximum]].<ref>{{cite journal |last1 = O'Connell |first1 = Lisa M. |last2 = Ritland |first2 = Kermit |last3 = Thompson |first3 = Stacey Lee |date = 1 February 2008 |title = Patterns of post-glacial colonization by western redcedar (Thuja plicata, Cupressaceae) as revealed by microsatellite markers |journal =[[Botany (journal)|Botany]]|publisher=[[Canadian Science Publishing]]|volume = 86 |issue = 2 |pages = 194{{ndash}}203 |doi = 10.1139/B07-124|bibcode = 2008Botan..86..194O }}</ref> Some studies have suggested the existence of an inland refugium during the Last Glacial Maximum, likely in central [[Idaho]].<ref name="Ruffley">{{cite journal |last1 = Ruffley |first1 = Megan |last2 = Smith |first2 = Megan L. |last3 = Espíndola |first3 = Anahí |last4 = Turck |first4 = Daniel F. |last5 = Mitchell |first5 = Niels |last6 = Carstens |first6 = Brian |last7 = Sullivan |first7 = Jack |last8 = Tank |first8 = David C. |date = 24 March 2022 |editor-last = Sork |editor-first = Victoria |title = Genomic evidence of an ancient inland temperate rainforest in the Pacific Northwest of North America |journal =[[Molecular Ecology (journal)|Molecular Ecology]]|publisher =[[Wiley-Blackwell]]|volume = 31 |issue = 10 |pages = 2985{{ndash}}3001 |doi = 10.1111/mec.16431 |pmid = 35322900 |pmc = 9322681 |doi-access = free|bibcode = 2022MolEc..31.2985R }}</ref><ref>{{cite journal |last1 = Fernandez |first1 = Matias |last2 = Hu |first2 = Feng Sheng |last3 = Gavin |first3 = Daniel G. |last4 = de Lafontaine |first4 = Guillaume |last5 = Heath |first5 = Katy D. |date = 4 July 2021 |title = A tale of two conifers: Migration across a dispersal barrier outpaced regional expansion from refugia |journal =[[Journal of Biogeography]]|publisher =[[Wiley-Blackwell]]|volume = 48 |issue = 9 |pages = 2133{{ndash}}2143 |doi = 10.1111/jbi.14209 |doi-access = free|bibcode = 2021JBiog..48.2133F }}</ref> However, more recent genomic approaches corroborate the existence of only a single glacial refugium near the south of the current distribution, with subsequent expansion northward and inland since the last glacial maximum.<ref name="Shalev">{{cite journal |last1 = Shalev |first1 = Tal J. |last2 = Gamal El-Dien |first2 = Omnia |last3 = Yuen |first3 = Macaire M. S. |last4 = Shengqiang |first4 = Shu |last5 = Jackman |first5 = Shaun D. |last6 = Warren |first6 = Rene L. |last7 = Coombe |first7 = Lauren |last8 = van der Merwe |first8 = Lise |last9 = Stewart |first9 = Ada |last10 = Boston |first10 = Lori B. |last11 = Plott |first11 = Christopher |last12 = Jenkins |first12 = Jerry |last13 = He |first13 = Guifen |last14 = Yan |first14 = Juying |last15 = Yan |first15 = Mi |last16 = Guo |first16 = Jie |last17 = Breinholt |first17 = Jesse W. |last18 = Neves |first18 = Leandro G. |last19 = Grimwood |first19 = Jane |last20 = Rieseberg |first20 = Loren H. |last21 = Schmutz |first21 = Jeremy |last22 = Birol |first22 = Inanc |last23 = Kirst |first23 = Matias |last24 = Yanchuk |first24 = Alvin D. |last25 = Ritland |first25 = Carol |last26 = Russell |first26 = John H. |last27 = Bohlmann |first27 = Joerg |date = 15 September 2022 |title = The western redcedar genome reveals low genetic diversity in a self-compatible conifer |journal =[[Genome Research]]|publisher =[[Cold Spring Harbor Laboratory Press]]|volume = 32 |issue = 10 |pages = 1952{{ndash}}1964 |doi = 10.1101/gr.276358.121 |pmid = 36109148 |pmc = 9712635 |doi-access = free}}</ref> Refugial populations may have undergone repeated [[population bottlenecks]] during the glacial maxima of the [[Pleistocene]].<ref name="Ruffley"/><ref name="Shalev"/> [[Pollen core]]s indicate that ''T.&nbsp;plicata'' only became common in southern coastal British Columbia starting at approximately 6,000 [[before present|YBP]]. This coincides with a transition from the warmer, drier climate of the early [[Holocene]] to a cooler, wetter climate. The species arrived later in the [[Canadian Rockies]], as recently as 4,000–5,000 YBP.<ref>{{cite journal |last = Hebda |first = Richard J. |date = 1995 |title = British Columbia Vegetation and Climate History with Focus on 6 ka BP |journal = Géographie physique et Quaternaire |publisher = [[Presses de l'Université de Montréal]] |volume = 49 |issue = 1 |pages = 55{{ndash}}79 |doi = 10.7202/033030ar|doi-access = free }}</ref> Pollen Assemblages at [[Seeley Lake Provincial Park|Seeley Lake]], on the eastern slope of the [[Coast Mountains]] east of [[Haida Gwaii]], indicate that western redcedar became common there at approximately 2,200 YBP.<ref>{{cite journal |last1 = Gottesfield |first1 = Alan S. |last2 = Mathewes |first2 = Rolf W. |last3 = Johnson Gottesfield |first3 = Leslie M. |date = October 1991 |title = Holocene debris flows and environmental history, Hazelton area, British Columbia |journal = [[Canadian Journal of Earth Sciences]] |publisher = [[Canadian Science Publishing]] |volume = 28 |issue = 10 |pages = 1583{{ndash}}1593 |doi = 10.1139/e91-142|bibcode = 1991CaJES..28.1583G }}</ref>

=== Etymology ===
The species name ''plicata'' derives from the Latin word {{wikt-lang|la|plico|plicāre}} and means 'folded in plaits' or 'braided,' a reference to the pattern of its small leaves.{{sfn|Stewart|1984|p=24}}

Most authorities, both in Canada<ref>British Columbia Forests & Range Tree Book: [http://www.for.gov.bc.ca/hfd/library/documents/treebook/westernredcedar.htm ''Thuja plicata''] {{Webarchive|url=https://web.archive.org/web/20100626073844/http://www.for.gov.bc.ca/hfd/library/documents/treebook/westernredcedar.htm|date=26 June 2010}}</ref><ref>British Columbia Tree Species Compendium [http://www.for.gov.bc.ca/hfp/silviculture/Compendium/WesternRedcedar.htm Western redcedar] {{Webarchive|url=https://web.archive.org/web/20100618151538/http://www.for.gov.bc.ca/hfp/silviculture/Compendium/WesternRedcedar.htm|date=18 June 2010}}</ref> and the United States<ref name="Silvics" /><ref name="PLANTS" /><ref name="Tesky">{{FEIS|type=tree|genus=Thuja|species=plicata|last=Tesky|first=Julie L.|date=1992}} {{webarchive|url=https://web.archive.org/web/20230813155144/https://www.fs.usda.gov/database/feis/plants/tree/thupli/all.html|date=13 August 2023}} {{source-attribution}}</ref> transliterate the English name in two words as 'western redcedar', or occasionally hyphenated as 'western red-cedar',{{sfn|Farjon|2005}} to indicate that it is not a true cedar (''[[Cedrus]]''), but it also appears as 'western red cedar' in some popular works. In the American [[horticultural]] trade, it is also known as the giant [[arborvitae]], by comparison with arborvitae for its close relative ''T.&nbsp;occidentalis''. Other names include giant red cedar, Pacific red cedar, shinglewood, [[British Columbia]] cedar (being the province's [[List of Canadian provincial and territorial symbols|official tree]]),<ref name="Arno" /> canoe cedar, and red cedar.<ref name="Gymnosperm" />{{sfn|Stewart|1984|p=22}} ''Arborvitae'' comes from the [[Latin]] for 'tree of life'; coincidentally, Native Americans of the West Coast also address the species as "long life maker".{{sfn|Stewart|1984|p=22}}

One endonymous name for the tree is the [[Halkomelem]] word '''xepá:y''',<ref>Dictionary of Upriver Halkomelem, Volume II pp. 1605. Galloway, Brent Douglas</ref> from the roots {{lang|hur|xíp}}, meaning 'scratch' or 'line', and {{lang|hur|á:y}}, 'bark';<ref>Dictionary of Upriver Halkomelem, Volume I pp. 996. Galloway, Brent Douglas</ref> the former root may be in reference to both the lined or "folded/braided" appearance of the bark and the tree's ubiquity in carving and other forms of woodwork. It is called '''x̱ápay̓ay''' in the [[Squamish language]].<ref>{{cite web |last1=Duncan |first1=Rebecca |title=Indigenous Plant Guide: Sḵwx̱wú7mesh sníchim |url=https://museumofvancouver.ca/indigenous-plant-guide-in-squamish-language |url-status=live |archive-url=https://web.archive.org/web/20230319030718/https://museumofvancouver.ca/indigenous-plant-guide-in-squamish-language |archive-date=19 March 2023 |access-date=19 March 2023 |website=Museum of Vancouver |publisher=Sḵwx̱wú7mesh Úxwumixw}}</ref> Further south, in the [[Lushootseed|Lushootseed language]], the root for red cedar is '''x̌payʔ''' and '''x̌payʔac''' refers to a red cedar tree.<ref>{{Cite book |last1=Bates |first1=Dawn |title=Lushootseed Dictionary |last2=Hess |first2=Thom |last3=Hilbert |first3=Vi |publisher=University of Washington Press |year=1995 |location=Seattle |pages=600}}</ref>