General: Cypress family Cupressaceae. Incense cedar (Calocedrus decurrens is a medium sized tree eighty to one hundred twenty feet high (Preston 1989). The leaves are small, scale-like, oblong-ovate, in whorls of four, decurrent, and closely adnate on the branchlets and aromatic when crushed. The flowers are monecious, appearing in January on the ends of short lateral branchlets of the previous year. The fruit is reddish-brown or yellowish-brown that ripens in the early autumn and remains on the tree until spring. The bark is bright cinnamon-red, broken into irregularly ridges, and covered with closely appressed plate-like scales (Sargent 1961).

Distribution: Calocedrus decurrens is native to the mountains from western Oregon in higher Coast Ranges and Sierra Nevada to southern California and western Nevada. For current distribution, please consult the Plant profile page for this species on the PLANTS Web site.

California incense cedar, California white cedar, bastard cedar, California calocedar, post cedar, white cedar, red cedar

Thuja decurrens (Torr.) Voss:
United States (North America)

Libocedrus decurrens Torr.:
United States (North America)

Calocedrus decurrens (Torr.) Florin:
Mexico (Mesoamerica)
United States (North America)

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Distributed from Mount Hood, Oregon, through the mountains of California and western Nevada into Baja California (Record and Hess 1943).

Incense cedar prefers moist, well-drained, fertile soil. It grows best in full sun or light shade. This species is not tolerant of smoggy or wind-swept conditions (Dirr 1990). It shows good adaptability to different soil types (Ibid.). This tree is often found in mixed coniferous stands with sugar pine, ponderosa pine, Jeffrey pine, western white pine, white fir, and Douglas fir (Preston 1989).

Tree, Evergreen, Monoecious, Habit erect, Trees without or rarely having knees, Tree with bark rough or scaly, Tree with bark shaggy or peeling, Young shoots in flat sprays, Buds not resinous, Leaves scale-like, Leaves opposite, Leaves whorled, Non-needle-like leaf margins entire, Leaf apex acute, Leaves < 5 cm long, Leaves < 10 cm long, Leaves not blue-green, Scale leaves without raised glands, Scale leaf glands not ruptured, Scale leaves overlapping, Twigs glabrous, Twigs not viscid, Twigs without peg-like projections or large fascicles after needles fall, Berry-like cones orange, Woody seed cones < 5 cm long, Bracts of seed cone included, Seeds tan, Seeds brown, Seeds winged, Seeds unequally winged, Seed wings narrower than body.

Incense-cedar is an important commercial softwood species. Its wood, exceptionally resistant to decay and highly durable when exposed to weather, is manufactured into many products, including lumber, pencil stock (for which it is the major United States source), fence posts, shakes, and landscape timbers, which are attractive because of punky spots resulting from fungus. The tree is widely grown as a handsome ornamental.

Trees to 57 m; trunk to 3.6 m diam. Bark cinnamon brown, fibrous, furrowed and ridged. Branchlet segments mostly 2 or more times longer than wide, broadening distally. Leaves 3--14 mm, including long-decurrent base, rounded abaxially, apex acute (often abruptly), usually mucronate. Pollen cones red-brown to light brown. Seed cones oblong-ovate when closed, red-brown to golden brown, proximal scales often reflexed at cone maturity, median scales then widely spreading to recurved, distal scales erect. Seeds 4 or fewer in cone, 14--25 mm (including wings), light brown. 2 n = 22.

Libocedrus decurrens Torrey, Smithsonian Contr. Knowl. 5(1) [6(2)]: 7, plate 3. 1853

Systems

• Terrestrial

Montane forests; 300--2800 m; Calif., Nev., Oreg.; Mexico in Baja California.

Propagation for Seed: Sow seeds in the early spring in a greenhouse. Seeds require a stratification period for about eight weeks at 32-40ºF for good germination. When the seedlings are large enough to handle, place them into individual pots to grow in a light shaded area in a greenhouse or cold frame for the first winter. Plant them out in the late spring or early summer.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 6
Species: 10
Species With Barcodes: 1

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Reasons: Distributed from Mount Hood, Oregon, through the mountains of California and western Nevada into Baja California. It attains its best development at elevations of 5000 to 7000 ft above sea level in the Sierra Nevada Mts. of Central California.

Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status, such as, state noxious status and wetland indicator values.

Contact your local Natural Resources Conservation Service (formerly Soil Conservation Service) office for more information. Look in the phone book under ”United States Government.” The Natural Resources Conservation Service will be listed under the subheading “Department of Agriculture.”

Incense cedar has aromatic wood that resists insects and decay. Practically no pests attack the tree, but in the forests where it is native, mature tree trunk are often infested with dry rot of the heartwood (Wyman 1965).

In its younger years, especially when growing strongly in the open, incense cedar forms an almost geometrically perfect pyramid, its lower branches nearly touching the ground, and the whole mass so densely overlapping that it sheds both rain and snow (Lemmon 1952). In old age, after battling the elements for perhaps a thousand years, it is far more irregular and picturesque, often with several summits trying to replace the old one destroyed long before lightening or a great wind (Ibid.).

Comments: Most of the timber is employed locally for building purposes, posts, and poles. Most of the finest grade is used as a substitute for juniper in making lead pencils (Record and Hess 1943).

Medicinal: A decoction of the leaves was used to treat stomach troubles (Moerman 1998). Steam from an infusion of incense cedar bark was inhaled in the treatment of colds (Ibid.). The bark was used to make baskets and the twigs were used to make brooms.

Economic: Incense cedar has aromatic wood that resists decay and insects. The wood is used as window sashes, sheathing under stucco or brick veneer construction, mudsills, fencing, greenhouse benches, and poles. It is also widely used for interior and exterior siding. The soft and pliable wood makes it one of the few species suitable for making pencils.

Landscaping & Wildlife: Incense cedar is an attractive landscape tree that is excellent for large areas and formal plantings (Dirr 1990). This tree is a splendid park and large home-grounds species in climates suitable for them (Lemmon 1952). It is browsed moderately by mule deer. Small mammals eat the seeds. This species is primarily used by wildlife species for cover.

Agroforestry: Calocedrus decurrens is used in tree strips for windbreaks. It is planted and managed to protect livestock, enhance production, and control soil erosion. Windbreaks can help communities with harsh winter conditions better handle the impact of winter storms and reduce home heating costs during the winter months. Incense cedar is also widely planted in the mountains for erosion control.