| Calocedrus decurrens | |
|---|---|
 | |
| Tree inYosemite National Park, California | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Gymnospermae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Cupressales |
| Family: | Cupressaceae |
| Genus: | Calocedrus |
| Species: | C. decurrens |
| Binomial name | |
| Calocedrus decurrens | |
 | |
| Distribution ofCalocedrus decurrens in the Western United States | |
| Synonyms[2] | |
| |
Calocedrus decurrens, with the common namesincense cedar[3] andCalifornia incense cedar[4] (syn.Libocedrus decurrens Torr.), is aspecies ofconiferous tree native to western North America. It is the most widely known species in the genus, and is often simply called incense cedar without the regional qualifier.[5][6][7]
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 inKlamath 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. Thebark 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-likeleaves2–15 mm (3⁄32–19⁄32 in) long; they are arranged in oppositedecussate 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 inconspicuousstomata.[7] The foliage, when crushed, gives off an aroma somewhat akin to shoe-polish.
Theseed cones are20–35 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 wingedseeds, 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 are6–8 mm (1⁄4–5⁄16 in) long.[7]
The bulk of the tree's range is in the United States, from central-southwesternOregon through most ofCalifornia[9] and the extreme west ofNevada, as well as a short distance into northwest Mexico in northernBaja California.
It grows at altitudes of 50–2,900 m (160–9,510 ft).
At lower elevations, associated trees include oaks andponderosa pine.[9]Giant sequoia bears similarities to the species, but has sharp leaves. In the south–southwest U.S. some have confused bushyjunipers 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 thebigcone Douglas-fir in recent years. Incense cedar is moreshade tolerant thanDouglas-fir, but not as much so asgrand orwhite fir. It grows slowly when needed to outlast competition.[9]
This tree is the preferred host of awood 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), aparasitic plant which can often be found hanging from its branches.[11] Fire scars provide an entry point forTyromyces 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 forforaging.[12] According to theUnited 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-resistanthope chests.[9] It was once the primary material for woodenpencils, because it is soft and tends to sharpen easily without forming splinters.[9]
Indigenous peoples of California use the plant in traditional medicine,[how?]basket making,hunting bows, building materials, and to produce fire by friction.[13] A Northern California tribe used branchlets to filter out sand from water when leaching toxins from acorn meal; foliage also served as a flavoring.[9]
TheMaiduConcow tribe name for the plant ishö'-tä (Konkow language).[14]
Calocedrus decurrens is cultivated as anornamental tree, for planting in gardens and parks. It is used in traditional,xeriscapic,native plant, andwildlife gardens; and also in designednatural landscaping andhabitat restoration projects in California. It is valued for its columnar form and evergreen foliage textures.
The tree is also grown in gardens and parks in cool summer climates, including thePacific Northwest in theNorthwestern United States andBritish Columbia, eastern Great Britain and continentalNorthern Europe. In these areas it can develop an especially narrow columnar crown, an unexplained consequence of the cooler climatic conditions that is rare in trees within its warm summer natural range in theCalifornia Floristic Province. Other cultivated species from the familyCupressaceae can have similar crown forms.[15]
This plant has gained theRoyal Horticultural Society'sAward of Garden Merit,[16] and has the cultivar 'Berrima Gold'.[17]
Various species in the family Cupressaceae can be utilized for the creation ofessential oils.[18] Scientific studies have shown that these essential oils have "strong antimicrobial properties."[18] Antimicrobial properties are those properties of a substance that lower the levels of microbes, such asbacteria andviruses. These antimicrobial properties could potentially be used for therapies in developing countries, although more testing andclinical trials should be done before such measures are implemented.[18]
.jpg)
| International | |
|---|---|
| National | |
| Other | |
