''Calocedrus decurrens'', with the common names incense cedar and California incense-cedar (syn. ''Libocedrus decurrens'' Torr.), is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All ext ...

ous 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.Farjon, A. (2005). ''Monograph of Cupressaceae and Sciadopitys''. Royal Botanic Gardens, Kew.

Description

''Calocedrus decurrens'' is a large tree, typically reaching heights of and a trunk diameter of up to . The largest known tree, located in Klamath National Forest,

Siskiyou County, California Siskiyou County (, ) is a county in the northernmost part of the U.S. state of California. As of the 2020 census, the population was 44,076. Its county seat is Yreka and its highest point is Mount Shasta. It falls within the Cascadia bioregio ...

, is tall with a circumference trunk and a spread. Specimens form a broad conic crown of spreading branches. The

bark Bark may refer to: * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Places * Bark, Germany * Bark, Warmian-Masurian Voivodeship, Poland Arts, e ...

is orange-brown weathering grayish, smooth at first, becoming fissured and exfoliating in long strips on the lower trunk on old trees. Specimens can live to over 500 years old. The foliage is produced in flattened sprays with scale-like

leaves A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...

long; they are arranged in opposite

decussate Decussation is used in biological contexts to describe a crossing (due to the shape of the Roman numeral for ten, an uppercase 'X' (), ). In Latin anatomical terms, the form is used, e.g. . Similarly, the anatomical term chiasma is named af ...

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

stoma In botany, a stoma (from Greek ''στόμα'', "mouth", plural "stomata"), also called a stomate (plural "stomates"), is a pore found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange. The pore is bo ...

ta. The foliage, when crushed, gives off an aroma somewhat akin to shoe-polish. The seed cones are long, pale green to yellow, with four (rarely six) scales arranged in opposite decussate pairs; the outer pair of scales each bears two winged

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosper ...

s, 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 long.

Distribution

The bulk of the tree's range is in the United States, from central-southwestern

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

through most of

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

and the extreme west of

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

, as well as a short distance into northwest Mexico in northern

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

. It grows at altitudes of .

Ecology

At lower elevations, associated trees include oaks and

ponderosa pine ''Pinus ponderosa'', commonly known as the ponderosa pine, bull pine, blackjack pine, western yellow-pine, or filipinus pine is a very large pine tree species of variable habitat native to mountainous regions of western North America. It is the ...

Giant sequoia ''Sequoiadendron giganteum'' (giant sequoia; also known as giant redwood, Sierra redwood, Sierran redwood, California big tree, Wellingtonia or simply big treea nickname also used by John Muir) is the sole living species in the genus ''Sequoiade ...

bears similarities to the species, but has sharp leaves. In the south–southwest U.S. some have confused bushy

juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' () of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere, from the Arc ...

s for incense cedar. With its thick basal bark, 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. This has given the incense cedar a competitive advantage over other species such as the

bigcone Douglas-fir ''Pseudotsuga macrocarpa'', commonly called the bigcone spruce or bigcone Douglas-fir, is an evergreen conifer native to the mountains of southern California. It is notable for having the largest (by far) cones in the genus ''Pseudotsuga'', henc ...

in recent years. Incense cedar is more

shade tolerant In ecology, shade tolerance is a plant's ability to tolerate low light levels. The term is also used in horticulture and landscaping, although in this context its use is sometimes imprecise, especially in labeling of plants for sale in commercial ...

than

Douglas-fir The Douglas fir (''Pseudotsuga menziesii'') is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. There are three va ...

, but not as much so as

grand Grand may refer to: People with the name * Grand (surname) * Grand L. Bush (born 1955), American actor * Grand Mixer DXT, American turntablist * Grand Puba (born 1966), American rapper Places * Grand, Oklahoma * Grand, Vosges, village and comm ...

white fir ''Abies concolor'', the white fir, is a coniferous tree in the pine family Pinaceae. This tree is native to the mountains of western North America, including the Cascade Range and southern Rocky Mountains, and into the isolated mountain ranges ...

. It grows slowly when needed to outlast competition. This tree is the preferred host of a

wood wasp Sawflies are the insects of the suborder Symphyta within the order Hymenoptera, alongside ants, bees, and wasps. The common name comes from the saw-like appearance of the ovipositor, which the females use to cut into the plants where they lay ...

, ''

Syntexis libocedrii ''Syntexis libocedrii'', (also called the cedar wood wasp or incense-cedar wood wasp) is the only living species in the wood wasp family Anaxyelidae, within the Symphyta, though the family has an extensive Mesozoic fossil record. This species i ...

'' a species which lays its eggs in the smoldering wood immediately after a forest fire. The tree is also host to incense-cedar mistletoe (''

Phoradendron libocedri ''Phoradendron libocedri'' is a species of flowering plant in the sandalwood family known by the common name incense-cedar mistletoe. It is native to western North America from Oregon to Baja California, where it grows in forests on its host tre ...

''), a

parasitic plant A parasitic plant is a plant that derives some or all of its nutritional requirements from another living plant. They make up about 1% of angiosperms and are found in almost every biome. All parasitic plants develop a specialized organ called th ...

which can often be found hanging from its branches. Fire scars provide an entry point for ''Tyromyces amarus'' (pocket dry rot). ''

Gymnosporangium ''Gymnosporangium'' is a genus of heteroecious plant-pathogenic fungi which alternately infect members of the family Cupressaceae, primarily species in the genus ''Juniperus'' (junipers), and members of the family Rosaceae in the subfamily Am ...

'' rust disease afflicts the trees, but is rarely fatal. For numerous birds during the wintertime, ''Calocedrus decurrens'' has been seen to be used for

foraging Foraging is searching for wild food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce. Foraging theory is a branch of behavioral ecology that studies the foraging behavi ...

. According to the

United States Department of Agriculture The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of comme ...

, 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. 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.

Uses

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 chest A hope chest, also called dowry chest, cedar chest, trousseau chest, or glory box is a piece of furniture traditionally used by unmarried young women to collect items, such as clothing and household linen, in anticipation of married life. Th ...

s. It was once the primary material for wooden

pencil A pencil () is a writing or drawing implement with a solid pigment core in a protective casing that reduces the risk of core breakage, and keeps it from marking the user's hand. Pencils create marks by physical abrasion, leaving a tra ...

s, because it is soft and tends to sharpen easily without forming splinters.

Native Americans

Indigenous peoples of California The indigenous peoples of California (known as Native Californians) are the indigenous inhabitants who have lived or currently live in the geographic area within the current boundaries of California before and after the arrival of Europeans. ...

use the plant in traditional medicine,

basket making Basket weaving (also basketry or basket making) is the process of weaving or sewing pliable materials into three-dimensional artifacts, such as baskets, mats, mesh bags or even furniture. Craftspeople and artists specialized in making baskets ...

, hunting bows, building materials, and to produce fire by friction. A Northern California tribe used branchlets to filter out sand from water when leaching toxins from acorn meal; foliage also served as a flavoring. The

Maidu The Maidu are a Native Americans in the United States, Native American people of northern California. They reside in the central Sierra Nevada (U.S.), Sierra Nevada, in the watershed area of the Feather River, Feather and American River, American ...

Concow tribe name for the plant is hö'-tä ( Konkow language).

Cultivation

''Calocedrus decurrens'' is cultivated as an

ornamental tree Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that ...

, for planting in gardens and parks. It is used in traditional, xeriscapic,

native plant In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution (though often popularised as "with no human intervention") during history. The term is eq ...

, and

wildlife garden A wildlife garden (or wild garden) is an environment created by a gardener that serves as a sustainable haven for surrounding wildlife. Wildlife gardens contain a variety of habitats that cater to native and local plants, birds, amphibians, ...

s; and also in designed

natural landscaping Natural landscaping, also called native gardening, is the use of native plants and adapted species, including trees, shrubs, groundcover, and grasses which are local to the geographic area of the garden. Benefits Maintenance Natural land ...

and

habitat restoration Restoration ecology is the scientific study supporting the practice of ecological restoration, which is the practice of renewing and restoring degraded, damaged, or destroyed ecosystems and habitats in the environment by active human interrupt ...

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 the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Thou ...

in the

Northwestern United States The Northwestern United States, also known as the American Northwest or simply the Northwest, is an informal geographic region of the United States. The region consistently includes the states of Oregon, Washington, Idaho, Montana and Wyoming. ...

and

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...

, eastern Great Britain and continental

Northern Europe The northern region of Europe has several definitions. A restrictive definition may describe Northern Europe as being roughly north of the southern coast of the Baltic Sea, which is about 54°N, or may be based on other geographical factors ...

. 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 the

California Floristic Province The California Floristic Province (CFP) is a floristic province with a Mediterranean-type climate located on the Pacific Coast of North America with a distinctive flora similar to other regions with a winter rainfall and summer drought climate ...

. Other cultivated species from the family

Cupressaceae Cupressaceae is a conifer family, the cypress family, with worldwide distribution. The family includes 27–30 genera (17 monotypic), which include the junipers and redwoods, with about 130–140 species in total. They are monoecious, subdioeci ...

can have similar crown forms.Mitchell, A. F. (1996). ''Alan Mitchell's Trees of Britain''. Collins .

Award of Garden Merit

This plant has gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nor ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

, and has the cultivar 'Berrima Gold'.

Essential oils

Various species in the family Cupressaceae can be utilized for the creation of

essential oil An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...

s. Scientific studies have shown that these essential oils have "strong antimicrobial properties." Antimicrobial properties are those properties of a substance that lower the levels of microbes, such as

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

and

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsk ...

es. These antimicrobial properties could potentially be used for therapies in developing countries, although more testing and

clinical trial Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, diet ...

s should be done before such measures are implemented.

Gallery

Calocedrus decurrens copa.jpg, Adult specimen Calocedrus decurrens Incense Cedar.jpg, Tree in

McMinnville, Oregon McMinnville is the county seat of and largest city in Yamhill County, Oregon, United States. The city is named after McMinnville, Tennessee. As of the 2019 census, the city had a population estimate of 34,743. McMinnville is at the confluence of ...

Incense Cedar in Lassen VNP.jpg, Trunks in

Lassen Volcanic National Park Lassen Volcanic National Park is an American national park in northeastern California. The dominant feature of the park is Lassen Peak, the largest plug dome volcano in the world and the southernmost volcano in the Cascade Range. Lassen Vol ...

, California Calocedrus decurrens MHNT.BOT.2004.0.810.jpg, Cones and seeds Calocedrus decurrens 7976.jpg, Foliage and pollen cones Calocedrus decurrens 7947.jpg, Opened cones Calocedrus decurrens (young female cones).jpg, Young female cones Calocedrus decurrens_CL_MHNT.jpg , Section of wood

References

External links

* * * {{Taxonbar, from=Q1399164 decurrens Least concern plants Trees of Baja California Trees of the Northwestern United States Trees of the Southwestern United States Flora of California Flora of Oregon Flora of the Cascade Range Flora of the Klamath Mountains Flora of the Sierra Nevada (United States) Natural history of the California Coast Ranges Natural history of the Peninsular Ranges Natural history of the Transverse Ranges Plants used in traditional Native American medicine Least concern flora of North America Least concern flora of the United States