Calocedrus decurrens (Incense-cedar)

Calocedrus decurrens (Incense-cedar) with the leaves outlined by soot

I am finally ready to start profiling the so called cedars of our region. The first thing I have to mention about these trees we call cedars is that they are not true cedars (which is why these common names are hyphenated), and in fact are not even in the same family as true cedars. True cedars are in the genus Cedrus in the family Pinaceae, and are all native to southern Eurasia. Our native ‘cedars’ are in the cypress family, Cupressaceae, along with the redwoods, junipers, and cypress. The reason that early settlers started calling our trees cedars is because they felt like they smelled like the true cedars of Eurasia. 

For anyone curious about my absence, or the changes in the form of these profiles, please see my recent blog ‘Equinoctial evaluations’.

Calocedrus decurrens (Incense-cedar)

The first time I noticed one of these trees was several years ago while looking for moss and lichens along the McKenzie River. I had no idea what it was, but the leaves looked completely different than those of the western red-cedar, with which I was familiar. As soon as I started paging through ‘Trees and Shrubs of the Pacific Northwest’ (Turner/Kuhlmann; 2014) I realized it had to be incense-cedar (Calocedrus decurrens), because the leaves were much longer than those of Western red-cedar, Port Orford-cedar, or Alaska-cedar. Since then I’ve seen these trees quite often, because they are a popular ornamental (there are a half dozen in a nearby neighborhood park), but until my November trip (details of which are recounted in the post titled ‘Pivoting‘) I hadn’t managed to find another wild one. 

Calocedrus decurrens (Incense-cedar)

But I found plenty on that trip, first sporadically in the area of 2020’s Holiday Farm Fire, and then commonly in the Smith River canyon area of n California, although in the latter location they weren’t nearly as abundant as the Port Orford-cedar. It is not particularly difficult to tell the two apart, nor is it hard to distinguish incense-cedar from western red-cedar, because incense-cedar has long (1/4-1/2”), scale-like outer leaves that form a wineglass pattern and give a long, thin, sparse, rounded appearance to the branchlets, whereas Port Orford-cedar and western red-cedar have stubby (1/8-1/4”) flattened leaves which make the branchlets appear more dense. 

Calocedrus decurrens (Incense-cedar)
Chamaecyparis lawsoniana Port Orford-cedar
Thuja plicata (Western red-cedar)

Most of the modern commercial harvest of this tree goes for siding, pencils, storage chests, interiors, and fence posts. Indigenous peoples used it mostly for construction, basketry, and wooden implements, though some tribes used it to season acorns during the leaching process, and it was also steamed as a decongestant, and decoctions were used for stomach ailments. For a more complete picture of its use by native peoples see the 18 entries on the Native American Ethnobotany Database

Calocedrus decurrens (Incense-cedar)

For more information on the ecology of this tree I recommend the incense cedar treatment in Silvics of North America; Vol 1, the conifers, by Powers and Oliver, or the Calocedrus decurrens entry by Jennifer Tollefson on the Forest Service’s FEIS site. There is also interesting information at Incense-cedar, Calocedrus decurrens (incense-cedar) description, Incense Cedar | The World’s Best Gardening Blog, Incense Cedar | University of Redlands, Doreen Fogle: Incense Cedar — native, common and a great landscape tree | Home & Garden |, and The Only True Cedars — In Defense of Plants

Calocedrus decurrens (Incense-cedar)

Description-Medium to large (up to 200’ tall and 10’ dbh) conifer, with sparse and thin sprays of leaves; bark is 3-4” thick, furrowed, and grayish purple. 

Similar species-For western red-cedar and Port Orford-cedar, see above; Callitropsis nootkatensis  (Alaska-cedar) lacks stomatal bloom on the leaves, and has round cones with points on them; junipers and cypress in our region have round to 4 sided groupings of leaves about the stem. 

Calocedrus decurrens (Incense-cedar)

Habitat– Drier slopes and forested meadows up to 7,000’ elevation in areas with dry summers. 

Range-From the Columbia River to Baja California and east to the eastern slope of the Sierras; in our region occurs naturally from the east slope of the Cascades in Oregon, to the Pacific, in the Siskiyou and Klamath Mountains, and in nw California; is not native to Washington state, but is widely planted as an ornamental and sometimes volunteers there, as well as in other locations where it has been planted. 

Calocedrus decurrens (Incense-cedar)

Eaten by-Some deer browse the foliage, and some birds eat the cones and seeds; larval host for the Nelson’s Hairstreak butterfly, and for the moths Periploca dentella, Digrammia burneyata, Eupithecia placidata, E. sabulosata, Neoalcis californiaria, Lithophane gausapata, Cydia cupressana, Argyresthia arceuthobiella, A. libocedrella; the leaf beetles Glyptoscelis albida, G. juniperi, G. longior, G. yosemitae, G. sequoiae, and Thricolema anomala; dead and dying trees are utilized as larval hosts by the longhorn beetles Atimia dorsalis, A. gannoni, Callidium californicum, Cortodera placerensis, Dicentris bluthneri, Dorcasina grossa, D. mathewsii, Judolia impura, Ortholeptura valida, Phymatodes nitidus, Semanotus amethystinus , S. amplus, and Stenopotes pallidus. 

Charred Calocedrus decurrens (Incense-cedar) along the McKenzie River in Oregon

Reproductive timing-Pollen strobili and female cones appear in September, pollen is shed in late winter early spring, and cones mature by late summer. 

Etymology of namesCalocedrus is from the Greek words for ‘beautiful cedar’. The specific epithet decurrens is from the Latin word for ‘extending down’, and refers to the distinctive trait of the leaves extending down the twig. The reason they are called incense-cedar is because of the odor produced by crushing the leaves. 

Calocedrus decurrens (Incense-cedar)


Libocedrus decurrens Torr

Calocedrus decurrens (incense-cedar) description

BRIT – Native American Ethnobotany Database

Incense Cedar | The World’s Best Gardening Blog

Calocedrus decurrens

Incense Cedar | University of Redlands

Doreen Fogle: Incense Cedar — native, common and a great landscape tree | Home & Garden |

OregonFlora Calocedrus decurrens

Charred Calocedrus decurrens (Incense-cedar) along the McKenzie River in Oregon

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