Editing Douglas fir (section)

==Description==
Douglas-firs are medium-sized to extremely large [[evergreen]] trees, {{convert|20|-|100|m|abbr=off|-1}} tall (although only [[coast Douglas-fir]]s reach heights near 100&nbsp;m)<ref>{{cite book|title=Forest Giants of the World Past and Present|first=Al|last=Carder|year=1995|pages=3–4}}</ref> and commonly reach {{convert|8|ft|m|abbr=on|order=flip}} in diameter,<ref>{{cite encyclopedia|last=Brockman|first=C. Frank|year=1968|title=Trees of North America: A Guide to Field Identification|location=New York|publisher=Golden Press|isbn=0-307-13658-2|entry=Pseudotsuga menziesii|pages=44–45}}</ref> although trees with diameters of almost {{convert|5|m|abbr=on}} exist.<ref>{{cite web | url=https://ancientforestalliance.org/worlds-largest-douglas-fir-tree-the-red-creek-fir/ | title=World's Largest Douglas-fir Tree - the Red Creek Fir! | date=8 June 2011 }}</ref> The largest coast Douglas-firs regularly live over 500 years, with the oldest specimens living for over 1,300 years.<ref name=":0">{{Cite web|last=Van Pelt|first=Robert|date=2007|title=Identifying Mature and Old Forests In Western Washington|url=https://www.dnr.wa.gov/publications/lm_hcp_west_oldgrowth_guide_full_lowres.pdf|url-status=live|archive-url=https://web.archive.org/web/20201111224359/https://www.dnr.wa.gov/publications/lm_hcp_west_oldgrowth_guide_full_lowres.pdf|archive-date=11 November 2020|access-date=1 September 2021|publisher=Washington State Department of Natural Resources|type=pdf}}</ref> [[Rocky Mountain Douglas-fir]]s, found further to the east,<ref name=":02">{{Cite book |last1=Arno |first1=Stephen F. |url=https://books.google.com/books?id=qDD4DwAAQBAJ |title=Northwest Trees: Identifying & Understanding the Region's Native Trees |last2=Hammerly |first2=Ramona P. |publisher=[[Mountaineers Books]] |year=2020 |isbn=978-1-68051-329-5 |edition=field guide |location=Seattle |pages=101–110 |language=en |oclc=1141235469 |orig-date=1977}}</ref> are less long-lived, usually not exceeding 400 years in age.<ref>{{cite web|title=Douglas Fir: Pseudotsuga menziesii|access-date=1 September 2021|publisher=National Wildlife Federation|url=https://www.nwf.org/Educational-Resources/Wildlife-Guide/Plants-and-Fungi/Douglas-Fir}}</ref>

There are records of former coast Douglas-firs exceeding {{convert|120|m|abbr=on|-1}}<ref>{{cite web | url=https://rephaim23.wordpress.com/2012/11/12/tallest-douglas-fir-and-redwood-in-america/ | title=Tallest Douglas Fir in America | date=12 November 2012 }}</ref><ref>{{cite web | url=https://www.seattletimes.com/life/giant-logged-long-ago-but-not-forgotten/ | title=Giant logged long ago but not forgotten | date=4 September 2011 }}</ref> in height, which if alive today would make it the tallest tree species on Earth. Particular historical specimens with heights exceeding 400&nbsp;ft include the [[Lynn Valley Tree]] and the [[Nooksack Giant]].

The [[leaves]] are flat, soft, linear needles {{convert|1.5-4|cm|frac=4}} long,<ref name="tktimb">{{Cite book |last1=Turner |first1=Mark |url=https://books.google.com/books?id=VLbAAwAAQBAJ |title=Trees & Shrubs of the Pacific Northwest |last2=Kuhlmann |first2=Ellen |date=2014 |publisher=[[Timber Press]] |isbn=978-1-60469-263-1 |edition=1st |location=Portland, OR |pages=86}}</ref> generally resembling those of the firs, occurring singly rather than in [[fascicle (botany)|fascicle]]s; they completely encircle the branches, which can be useful in recognizing the species. As the trees grow taller in denser forest, they lose their lower branches, such that the foliage may start as high as {{convert|110|ft|m|abbr=on|order=flip}} off the ground.<ref>{{cite encyclopedia|last1=Russell|first1=Tony|last2=Cutler|first2=Catherine|last3=Walters|first3=Martin|year=2014|title=The Illustrated Encyclopedia of Trees of the World|location=London|publisher=Anness Publishing Ltd.|isbn=978-1-4351-5597-8|entry=Pseudotsuga menziesii|page=120}}</ref> Douglas-firs in environments with more light may have branches much closer to the ground.

The [[Bark (botany)|bark]] on young trees is thin, smooth, gray, and contains numerous [[resin]] blisters. On mature trees, usually exceeding 80 years,{{citation needed|date=March 2022}} it is very thick and corky, growing up to {{convert|14|in|cm|order=flip|abbr=on}} thick with distinctive, deep vertical fissures caused by the gradual expansion of the growing tree. Some of the mature bark is brown, while other parts are lighter colored with a cork-like texture; these develop in multiple layers.<ref name=":1">{{Cite web |title=Pseudotsuga menziesii var. menziesii |url=https://www.fs.fed.us/database/feis/plants/tree/psemenm/all.html#BOTANICAL%20AND%20ECOLOGICAL%20CHARACTERISTICS |url-status=dead |archive-url=https://web.archive.org/web/20210512010313/https://www.fs.fed.us/database/feis/plants/tree/psemenm/all.html#31 |archive-date=May 12, 2021 |access-date=2021-05-11 |website=www.fs.fed.us}}</ref> This thick bark makes the Douglas-fir one of the most fire-resistant tree native to the Pacific Northwest.<ref name=":2">{{Cite web|last=Van Pelt|first=Robert|date=2007|title=Identifying Mature and Old Forests In Western Washington|url=https://www.dnr.wa.gov/publications/lm_hcp_west_oldgrowth_guide_full_lowres.pdf|url-status=live|archive-url=https://web.archive.org/web/20201111224359/https://www.dnr.wa.gov/publications/lm_hcp_west_oldgrowth_guide_full_lowres.pdf|archive-date=11 November 2020|access-date=11 May 2021|publisher=Washington State Department of Natural Resources|type=pdf}}</ref>

The male [[Conifer cone|cones]] are yellowish red, {{Convert|5-12|mm|abbr=on|frac=8}} long. The female cones are green when young, maturing to reddish-brown or gray, {{Convert|6-10|cm|abbr=on|frac=4}} long;<ref name="tktimb" /> they are pendulous, with persistent scales, unlike those of true firs. They have distinctive long, [[Glossary of botanical terms|trifid]] (three-pointed) [[bract]]s which protrude prominently above each scale and are said to resemble the back half of a mouse, with two feet and a tail.<ref>{{Cite web|title=U.S. Fish and Wildlife Service, Open Spaces Blog|url=https://www.fws.gov/news/blog/index.cfm/2015/12/16/Douglas-Fir-A-Wildlife-Hero|access-date=2021-05-12|website=www.fws.gov}}</ref> The seeds are {{Convert|5|mm|abbr=on|frac=8}} long, with a longer wing.<ref name="tktimb" />

The massive mega-[[genome]] of Douglas-fir was sequenced in 2017 by the large PineRefSeq consortium, revealing a specialized photosynthetic apparatus in the light-harvesting complex of genes.<ref>{{cite journal|author=Neale DB|date=2017|title=The Douglas-Fir Genome Sequence Reveals Specialization of the Photosynthetic Apparatus in Pinaceae|journal=G3: Genes, Genomes, Genetics|volume=7|issue=9|pages=3157–3167|doi=10.1534/g3.117.300078|pmc=5592940|pmid=28751502}}</ref>

{{gallery| mode=packed
|File:Pseudotsuga menziesii 7971.JPG|Mature individual in the [[Wenatchee Mountains]]
|File:Pseudotsuga menziesii var. glauca young female cone - Keila.jpg|Young female cone
|File:Douglas fir cone.jpg|Mature female cone
}}