Thuja plicata
Published by Daniel Mosquin on February 7, 2020
Family / Families: Cupressaceae
Scientific Name(s): Thuja plicata Donn ex D.Don
Institution(s): David C. Lam Asian Garden, University of British Columbia Botanical Garden
Accession Number(s): 2016-0421.36
Location(s): Vancouver, British Columbia, Canada
Entry Author(s): Daniel Mosquin
Copyright Holder(s): Daniel Mosquin
Image License: Creative Commons License
Tags: British Columbia, Canada, Cupressaceae, Photo by Daniel, UBC Botanical Garden

Foliage spray of Thuja plicata
The overlapping leaves of Thuja plicata are small, only 3-6mm in length (and sometimes as small as 1mm). In quantity, though, they can sustain trees exceeding 70m (230 ft.) in height.
Although currently considered globally secure, new threats do seem to be emerging for western redcedar: A mystery at the core of Canada’s western redcedar.
Read more about this western North American native conifer via The Gymnosperm Database.
**Botany Photo of the Day will be returning in early March.**
Read More | 28 Comments
Hi, first post in a few months of none.
Thanks and welcome back!
Three more weeks before the next one, but then we’ll be back to our semi-regular schedule.
With respect to fungi attacking the base of western redcedars, I noticed this in the Garden the other day.
Glad you are back. What a depressing image of the redcedar roots. I hope the research gains some insight quickly.
Great to find a BPotD message in my mail box 🙂 And Thuja is a favorite—such a beautiful tree.
Best wishes.
Welcome back Daniel and such a beauty close up of the Thuja plicata foliage structure.
Sad to hear about the imminent threats.
Looking forward to more entries in the coming weeks
wonderful to see a new post!
I was looking at Atlantic white cedar (Chamaecyparis thyoides) “leaves” at 30x recently- pairs of folded triangular devices going this way and that way-oppositely- and nothing “leaflike” in any typical sense I was thinking…and considered “scales”‘ in reference materials, to add to my bewilderment.
totally beautiful- but perplexing structures unlike anything other than a moss; and nearly identical to your illustration.
each “triangle” face is decorated w/ approx. 20 raised parrallel lines in C. thyoides- would Thuja exhibit similar “decorative” elements? would these lines serve a purpose similar to leaf veins?
SSSoooooooo glad to have you back. THough we are in the middle of a snow storm, my juices are already flowing with spring fever!
One of my favorite trees and yes, I too have noticed a greater numbers than seems normal, dying at the lower levels here is West Vancouver. Thank you for the NRCan link. From the foliage photo, I can really see the “plicata” pattern in the foliage. The name plicata comes from a Greek word meaning “folded in plaits,” in reference to the arrangement of the leaves.
Thanks for the extra information, Cliff!
Ditto to all of the Glad-you’re-back sentiments Daniel!!!!!!
Totem Cedar! What a way to return!
Our wonderful world!
So happy to have a new Botany Photo show up. Knew you were missing, but thought it might be my computer. While thuja plicata is fairly common out here (in the Pacific NW), it is also a beautiful tree. Sorry to hear that it may be having “issues”.
I have made a spreadsheet of tree diseases and pests in my area of Nova Scotia. It is pretty depressing…most have one or more serious invasive threats. Many trees, such as our beech, cherry, and elm are essentially useless for wood other than to burn. I can see grandchildren with no healthy trees of any size. There is one guy here in charge of tree diseases…he is a wonderful man doing the best he can. If people cannot realize that plants are the basis of our existence, then we are in huge trouble. Stick planetary temperature shifts and you have a mess. No one seems to understand the threat. This is just one more.
You are absolutely right . . . trees and insects and bacteria are the basis of our existence and we’re losing them all at a crisis-level rate. I’m in Massachusetts and we’re seeing tree decline in super hardy native species . . . White Pine, White and Black Oak, Prunus serotina, etc. Meanwhile in our super messed up and broken U.S. government, Nero fiddles while Rome burns. So to speak. ;-(
Yay! Back again! And with a taxon I know! 😉
Daniel! SO GLAD BPOTD will be BACK!!! Missed you! 🙂
Maybe a series on threatened species. Sadly, it would run for quite a while…
Great to see this in the mailbox, however, as proof of life.
I was so pleased to find this message in my email inbox this morning. Looking forward to more! Thanks for all your efforts.
Welcome back! I missed your wonderful explanations….
Wow…!!! You were missed! So glad you’re back. Outside, a thin fresh sparkling layer of snow, ice all over thi tree branches and a blue sky… Inside, BOTD!!!! what a day!
So nice to receive latest Email Daniel , your interesting observations and pictures brighten the day, welcome back.
Hooray!! back to POTD with morning coffee! You’ve been missed, I look forward to your return.
Blessings to all at POTD
So glad you are back. You have been missed. I have always enjoyed the photos you bring.
Très heureuse de te lire à nouveau Daniel ! Merci pour ce retour et ces info botaniques si intéressantes ! J’attendrai mars avec impatience ! Meilleur souvenir de Belgique !
Daniel,
Your fan club in GA is also very happy your blog is back. Thank you for the time you put into this, and also to those who make comments.
I have used many references from y’all in my plant ID classes, and look forward to traveling to the UBC Botanical Garden in the near future.
It’s good to see BPOTD back, with a beautiful photo of a beloved tree. Thank you for the links. One next to our house – a pretty good-sized one – was cut down just yesterday. There wasn’t any green foliage left at all but I don’t know if the arborist knew what the issue was. Western redcedar trees seem to be struggling here (Fidalgo Island, WA). Drought is thought to play a big part – even if annual rainfall totals are OK, it could be that dry periods are too long. We have a citizen science project monitoring some of the trees in community forest lands.
Beautiful image Daniel! I’ve been drawing a spray of Thuja plicata, just to get more familiar with its structures. Tricky but mesmerizing!
THANK YOU for bringing a gift of beauty to my inbox!
Especially after the last storms we have endured here in eastern Oregon …
Your posts are much appreciated!!