Calocedrus decurrens

Calocedrus decurrens is a large tree, typically reaching heights of 30–40 meters (100–130 ft) and a trunk diameter up to 1.2 m (3 ft 11 in). The largest known tree, located in Klamath National Forest, Siskiyou County, California, is 47.98 m (157 ft 5 in) tall with a 12 m (39 ft 4 in) circumference trunk and a 17.5 m (57+1⁄2 ft) spread.[8] Specimens form a broad conic crown of spreading branches. The bark is orange-brown weathering grayish, smooth at first, becoming fissured and exfoliating in long strips on the lower trunk on old trees.[9] Specimens can live to over 500 years old.[9]

The foliage is produced in flattened sprays with scale-like leaves 2–15 mm (3⁄32–19⁄32 in) long; they are arranged in opposite decussate pairs, with the successive pairs closely then distantly spaced, so forming apparent whorls of four; the facial pairs are flat, with the lateral pairs folded over their bases. The leaves are bright green on both sides of the shoots, with only inconspicuous stomata.[7] The foliage, when crushed, gives off an aroma somewhat akin to shoe-polish.

The seed cones are 20–35 mm (3⁄4–1+3⁄8 in) long, pale green to yellow, with four (rarely six) scales arranged in opposite decussate pairs; the outer pair of scales each bears two winged seeds, the inner pair(s) usually being sterile and fused together in a flat plate. The cones turn orange to yellow-brown when mature about 8 months after pollination. The pollen cones are 6–8 mm (1⁄4–5⁄16 in) long.[7]

The bulk of the tree's range is in the United States, from central-southwestern Oregon through most of California[9] and the extreme west of Nevada, as well as a short distance into northwest Mexico in northern Baja California.

It grows at altitudes of 50–2,900 m (160–9,510 ft).

At lower elevations, associated trees include oaks and ponderosa pine.[9] Giant sequoia bears similarities to the species, but has sharp leaves. In the south–southwest U.S. some have confused bushy junipers for incense cedar.[9]

With its thick basal bark,[9] the incense cedar is one of the most fire- and drought-tolerant plants in California. Although the tree is killed by hot, stand-replacing crown fire, it spreads rapidly after lower-intensity burns.[10] This has given the incense cedar a competitive advantage over other species such as the bigcone Douglas-fir in recent years. Incense cedar is more shade tolerant than Douglas-fir, but not as much so as grand or white fir. It grows slowly when needed to outlast competition.[9]

This tree is the preferred host of a wood wasp, Syntexis libocedrii a species which lays its eggs in the smoldering wood immediately after a forest fire.[6] The tree is also host to incense-cedar mistletoe (Phoradendron libocedri), a parasitic plant which can often be found hanging from its branches.[11] Fire scars provide an entry point for Tyromyces amarus (pocket dry rot).[9] Gymnosporangium rust disease afflicts the trees, but is rarely fatal.[9]

For numerous birds during the wintertime, Calocedrus decurrens has been seen to be used for foraging.[12] According to the United States Department of Agriculture, in areas of the Western Sierra Nevada in California, numerous species of birds are thought to use the incense cedar as a "foraging substrate" so that they can attain as much food as needed.[12] Human impacts on these trees due to forest management practices have caused issues for many of these birds, threatening the use of the incense cedar as a forage substrate.[12]

The wood is soft and light, and has a pleasant odor and is generally resistant to rot. It has been used for external house siding, interior paneling, and to make moth-resistant hope chests.[9] It was once the primary material for wooden pencils, because it is soft and tends to sharpen easily without forming splinters.[9]

• Cedar wood
• List of California native plants
• Plants used in traditional Native American medicine

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  Adult specimen
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  Tree in McMinnville, Oregon
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  Trunks in Lassen Volcanic National Park, California
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  Cones and seeds
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  Foliage and pollen cones
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  Opened cones
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  Young female cones
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  Section of wood

Wikimedia Commons has media related to Calocedrus decurrens.

• Calflora
• Jepson eFlora, The Jepson Herbarium, University of California, Berkeley
• Calocedrus decurrens in the CalPhotos photo database, University of California, Berkeley