40 Facts About Western Red Cedar in Nature and Culture
A Common and Useful Tree
Western red cedar is a widespread and popular tree in the Pacific Northwest region of North America. It has been introduced to other parts of the world and is a useful as well as an interesting plant. It grows in both a wild and a cultivated form in Canada and the United States. It’s the official tree of British Columbia, where I live.
Historically, western red cedar was a very important plant for the indigenous or First Nations people who lived in the coastal area. In this article, I describe forty facts about the plant and the importance of the “tree of life” in the local culture. Unless otherwise stated, the photos of the tree were taken by me.
The genus Thuja contains five species: the western and eastern red cedars native to North America and three species native to Asia. The members of the genus are often known as arborvitaes from the Latin words for tree of life.
Classification and Habitat
1. Western red cedar is not a true cedar. It has the scientific name Thuja plicata and belongs to the cypress family, or the Cupressaceae. Cedars belong to the genus Cedrus and the pine family, or the Pinaceae.
2. To emphasize the plant's real lineage, some people join the last two words of its name together and call it the western redcedar.
3. The tree is most strongly associated with damp and sometimes foggy coastal forest. It's found from southern Alaska to Northern California. On the coast, it generally grows with Douglas fir and western hemlock.
4. A separate population of the tree can be found in damp areas in the interior of British Columbia. This population extends into Washington, Idaho, and Montana.
5. The plant is capable of growing in drier soil than is found in its coastal habitat and is sometimes seen at higher elevations.
Western red cedar is capable of living well over a thousand years. According to the Washington State Department of Natural Resources, many trees over 1,500 years old have been discovered.
Physical Features of the Plant
6. The bark of the western red cedar's trunk is red brown to grey. It tends to be brown when the trunk spends most of its time in the shade and grey when it's often exposed to the sun.
7. The bark is fissured. When it's mature, it can be pulled off in strips. First Nations people have made good use of these strips, as described below.
8. The trunk is often buttressed at the base. A buttress root branches from a tree's trunk above ground and then extends into the ground. It provides extra support for the tree and sometimes extra nutrients as well.
9. The normal branches of the red cedar trunk divide repeatedly to form ever narrowing branchlets.
10. The terminal branchlets bear flat rows of leaves on either side in an arrangement called a spray. Each leaf is a small scale only 2 to 3 mm long.
11. The species name of the tree means "plaited". The word likely refers to the complex arrangement of the leaf scales.
12. The leaves range from yellow green to medium green in colour, depending in part on the lighting conditions. They are a lighter shade of green on their undersurface, which sometimes has white markings.
13. A mature plant often has dead, orange leaves on the innermost part of its branches but can still look attractive due to the living leaves on the outermost part of the branches.
14. The tree is frequently conical but is sometimes irregularly shaped. It can reach a height of seventy metres.
The tree in my photos below emerges from the ground as one buttressed trunk but soon divides into two trunks. Western red cedars sometimes exhibit this characteristic, though the position of the division or divisions into different trunks varies.
Cones and Reproduction
15. The western red cedar is a conifer and therefore reproduces by cones. The female ones are known as seed cones and the male ones as pollen cones.
16. The seed cones are much bigger than the pollen ones. Both types of cones develop on the same tree and are woody in appearance when mature.
17. A pollen cone is about one to three millimetres long and is borne at the tip of a row of leaves. As its name suggests, it releases pollen grains.
18. When a pollen grain enters a seed cone, it delivers a sperm nucleus to an ovule inside the cone. Here the sperm fertilizes an egg cell and a seed is subsequently created.
19. Both the sperm and the egg are haploid, which means they have half the number of chromosomes found in the plant. When they join, they form a diploid zygote, which has the full number of chromosomes and becomes a new plant.
20. Each seed or female cone produces around three to six seeds on average. They have small wings and are distributed to new areas by wind. Conifers don't produce fruits. The seeds are released form the parent plant on their own.
21. Both self and cross pollination occur in the western red cedar.
22. The plant is capable of vegetative reproduction. Fallen branches sometimes develop roots, for example.
Conifers belong to a major group of plants known as gymnosperms. The name "gymnosperm" comes from two Greek words meaning naked seed. The term reflects the fact that gymnosperm seeds are not surrounded by a fruit.
Three Interesting Chemicals in the Tree
23. Thuja plicata contains three interesting chemicals (and probably many more that would be interesting to investigate). The wood contains plicatic acid, which can provoke asthma and allergies in sensitive people. This can be a major problem for people who work with the wood and is common enough to be considered an occupational hazard.
24. Plicatic acid can also provoke contact dermatitis, which is inflammation of the skin after touching a harmful substance. The condition generally involves redness and itching.
25. The plant contains a chemical called thujone, which produces a scent like menthol when the leaves are rubbed or crushed. Some people say that the smell of the crushed leaves is more like pineapple, but it isn't to me. Thujone is used in some perfumes. The quantity of the chemical that's used is often strictly limited because it can have harmful effects on the nervous system.
26. The wood contains a chemical called thujaplicin, which acts as a fungicide and a bactericide. This is one reason when the wood is often resistant to decay.
Nootka cypress or the yellow cedar is a somewhat similar plant to the red cedar. It has the same type of leaves but is a smaller and bushier tree. It also has pendulous branches. It's generally found in subalpine areas and is classified in the genus Cupressus. Historically, First Nations people made use of both plants.
HIstorical Uses and Importance
27. In earlier times, the western red cedar had both a cultural and a spiritual significance for the people of the First Nations. It's still valuable in their culture today.
28. Coast Salish people have a lovely legend about the creation of the tree. There once existed a good man who gave his belongings to people in need. When he died, the Creator created the western red cedar on top of his burial site so that the people could continue to receive what they needed.
29. The tree was once widely used by First Nations people, but the actual uses of the plant varied according to the culture of a specific group.
30. The wood of the tree was used to create totem poles, masks, canoes, paddles, spears, hooks for fishing, and longhouses. Fibres from the bark were used to create baskets, cords, ropes, and fishing nets.
31. Fibres from both the red and yellow cedar were used to weave clothing, hats, blankets, and mats.
32. The western red cedar was harvested with care. Only a section of bark was removed on a particular tree in order to keep it alive. Trees were cut down, but not excessively. Traditionally, a prayer was said and the tree's spirit thanked before it was cut.
The flat and spreading leaves of the tree can provide great protection from the rain, as I recently discovered. As the rain started to pour down, I moved under a large western red cedar tree and stayed amazingly dry. Very little rain reached me.
Modern Uses and Significance
33. Western red cedar timber has many uses in construction today. It's valued for both its durability and its relatively light weight.
34. The wood is used to build shingles for roofs, siding for homes, and indoor panels. In addition, it's used to make decks and both indoor and outdoor furniture.
35. The wood is also used to make guitars, sometimes in combination with other types of wood.
36. Several parts of the tree were once used medicinally by First Nations people. Today an oil is distilled from its leaves. As with other essential oils from plants, it's very important to investigate effectiveness and safety before using the liquid for any purpose. It's a concentrated substance. Other parts of the tree shouldn't be eaten, at least until more information is available in relation to safe and harmful amounts.
37. Researchers from the University of British Columbia and Simon Fraser University (another major university in the province) have found that the oil kills certain fungi and bacteria found in ventilation ducts of "sick buildings". This is the term used for buildings that cause symptoms of ill health in the people who work there.
38. Wildlife also makes use of the tree. It's an important source of food for deer, for example.
39. Bears, skunks, and raccoons build dens in cavities in the tree's trunk.
40. In addition, the tree provides a good place for some birds to nest.
Western red cedar trees are popular as ornamental plants in parks near my home and are used to form hedges in local gardens. Wild trees grow in the forests nearby. The tree is important today and its uses in the past are interesting. I think it definitely deserves the honour of being the official tree of the province.
Information about western red cedar from the Government of British Columbia
Thuja plicata entry from The Gymnosperm Database
Facts about Thuja plicata from the U.S. Department of Agriculture and Forestry Service
Information about the tree from the Washington State Department of Natural Resources
Ethnobotany of the tree from the University of British Columbia
Hudson, J., Kuo, M., & Vimalanathan, S. (2011). The Antimicrobial Properties of Cedar Leaf (Thuja plicata) Oil; A Safe and Efficient Decontamination Agent for Buildings. International Journal of Environmental Research and Public Health, 8(12), 4477–4487. http://doi.org/10.3390/ijerph8124477
© 2018 Linda Crampton