Cedrus
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Cedrus, with the common English name cedar, is a genus of coniferous trees in the plant family Pinaceae (subfamily Abietoideae). They are native to the mountains of the western Himalayas and the Mediterranean region at high altitudes. The trees grow tall with a cylindrical trunk and a wide leafy crown. The cones are erect; the leaves grow in tufts of 15–45 needle leaves, which can be bright green or blue-green with a waxy coat. When the cones are mature, they disintegrate to release the seeds, which are winged. Both pollen and seeds are wind-dispersed.
Cedars are often planted as ornamental trees in parks and large gardens, while others are grown as bonsai. Cedar wood and cedarwood oil are naturally repellent to moths, and have an attractive, long-persistent scent.
Etymology
The generic name Cedrus derives from Old English ceder, from the Latin word cedrus. This in turn is derived from Greek κέδρος kédros, meaning cedar or juniper.<ref name="Online Etym">Template:Cite web</ref> Species of both trees are native to the area where Greek language and culture originated, though as the word kédros does not seem to be derived from any of the languages of the Middle East, it has been suggested the word may originally have applied to Greek species of juniper and was later adopted for species now classified in the genus Cedrus because of their aromatic woods.<ref>Template:Cite book</ref> The name was similarly applied to citron: the word citrus is derived from the same root.<ref name="Andrews 1961">Template:Cite journal</ref> As a loan word in English, cedar had become fixed to its biblical sense of Cedrus by the time of its first recorded usage in 1000 CE.<ref name=oed>Template:Cite dictionary</ref>
Description
Habit
Cedars are tall resinous trees growing to Template:Convert tall, rarely to Template:Cvt,<ref name=farjon/> with a cylindrical trunk and a narrow to wide crown, conical when young but often becoming irregular with age. In some individuals, several main branches may eventually rival the main trunk in size.<ref name="Gymnosperm Database"/> The bark is pale grey-brown and smooth in young trees, dark grey-brown to blackish and splitting into ridges and scales on older trees.<ref name="Gymnosperm Database"/>
Foliage
The shoots are dimorphic, made up of long thin leading shoots from terminal buds, each one accompanied by multiple short lateral shoots.<ref name="Gymnosperm Database"/> The leaves are evergreen and needle-like, Template:Convert long, arranged in an open spiral phyllotaxis on long shoots and in dense spiral clusters of 15–45 together on short shoots; they vary from bright grass-green to dark green to strongly glaucous pale blue-green, depending on the thickness of the white wax layer which protects the leaves from drying out.<ref name=farjon/>
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Bark on a young deodar cedar
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Bark on a mature Lebanon cedar
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Foliage of Lebanon cedar, showing long shoots with widely spaced needles, and short shoots with densely packed needles
Cones
Cedars are monoecious, with separate male and female cones on the same tree.<ref name="Gymnosperm Database">Template:Cite web</ref> The seed cones are barrel-shaped, Template:Convert long and 3–8 cm broad, green maturing grey-brown, and, as in Abies, disintegrate at maturity to release the winged seeds. The seeds are Template:Convert long, with a 20–30 mm wing; as in Abies, the seeds have two or three resin blisters, containing an unpleasant-tasting resin, thought to be a defence against squirrel predation. Cone maturation takes one year, with pollination in autumn and the seeds maturing at the same time a year later. The pollen cones are slender ovoid, 3–8 cm long, produced in late summer, and shed pollen in autumn.<ref name=farjon/><ref>Template:Cite book</ref>
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Female (seed) cones of Lebanon cedar
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Immature male (pollen) cone of Lebanon cedar
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Pollen cone of deodar cedar, shedding pollen in the wind
Evolution
Fossil history
The oldest fossil of Cedrus is Cedrus penzhinaensis known from fossil wood found in Early Cretaceous (Albian) sediments of Kamchatka, Russia.<ref>Template:Cite journal</ref> An Early Miocene species, Cedrus anatolica, also from petrified wood and thought to be close to C. atlantica, is known from Turkey.<ref name="Akkemik 2021">Template:Cite journal</ref>
Phylogeny
Cedars have a similar cone structure to firs (Abies) and were traditionally thought to be most closely related to them, but genetic evidence supports a basal position in the whole of the subfamily Abietoideae.<ref name="Ran">Template:Cite journal</ref><ref name="Gernandt">Template:Cite journal</ref><ref name=Stull>Template:Cite journal</ref>
Taxonomy and internal phylogeny
The genus Cedrus was described by the German botanist Christoph Jacob Trew in his Plantae Selectae Quarum Imagines in 1757.<ref name="Gymnosperm Database"/> The Cedrus taxa are assigned according to taxonomic opinion to between one and four species.<ref name="Gymnosperm Database"/><ref name="NCBI">Template:Cite web</ref><ref name="Flora of China">Template:Cite web</ref><ref name="Qiao 2007">Template:Cite journal</ref> The deodar cedar is sister to the Mediterranean cedars. The Cyprus cedar for example is variously considered to be a variety or subspecies of Cedrus libani, or a species C. brevifolia in its own right;<ref name = powo>Template:Cite web</ref> some evidence from allozymes suggests it may even be embedded within the range of variation in the Turkish cedar.<ref name="h070">Template:Cite journal</ref> Divergence ages are marked on the cladogram.<ref name="Qiao 2007"/><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>
The species cannot hybridise in nature due to their geographical separation, but when brought together in cultivation, they do so freely. However, because cedars (particularly between the Mediterranean taxa) are so similar to each other, hybrids are notoriously to detect and identify. Hybrids between Atlas and Deodar cedars have been deliberately bred by the Tesi nursery in northern Italy since the 1980s, and were named in 2021 as the cultivar group Cedrus Tesi Group.<ref>Template:Cite journal</ref><ref name="Tesi">Template:Cite web</ref>
Distribution and ecology
Cedars are adapted to mountainous climates; in the Mediterranean, they receive winter precipitation, mainly as snow, and summer drought, while in the western Himalaya, they receive primarily summer monsoon rainfall and occasional winter snowfall.<ref name=farjon/> They are native to the mountains of the western Himalayas and the Mediterranean region, occurring at altitudes of Template:Convert in the Himalayas and Template:Convert in the Mediterranean.<ref name=farjon>Template:Cite book</ref> In Lebanon, a small number of cedars of Lebanon survive in protected areas including the Cedars of God near the Qadisha Valley, a World Heritage Site.<ref>Template:Cite web</ref>
Fungal diseases of cedars include canker; collar, crown, and root rot; needle blight; Gymnosporangium rusts;<ref name="UCIPM"/> and sirococcus blight, caused by Sirococcus tsugae, which kills shoots and branches.<ref>Template:Cite web</ref> Cedar trees are robust but become vulnerable to bark beetles in drought conditions.<ref name="UCIPM">Template:Cite web</ref> Other pests include the giant conifer aphid, scale insects, and nematodes such as the pine wilt nematode.<ref name="UCIPM"/> Caterpillars of the pine processionary moth sometimes make their nests in cedars.<ref>Template:Cite web</ref>
Uses
Template:See also Cedars have long been highly valued for their scented, durable, and decay-resistant wood, being in demand for building temples and palaces for over 4,000 years from the period of the Epic of Gilgamesh onwards, the longest record of any conifer in human use.<ref name="Gymnosperm Database"/> Cultivation of cedars for their wood has an equally long history, with recent genetic and environment studies corroborating local oral mythology and Hittite cuneiform text records that two small geographically isolated populations of Lebanon cedar in northern Anatolia 500 km north of its main native area are of human origin, deliberately planted over 3,200 years ago for cedar wood supply to the nearby capital of the Hittite Empire at Hattusa.<ref>Template:Cite journal</ref>
Cedars are popular ornamental trees and are often cultivated in temperate climates where winter temperatures do not fall below −25 °C. The Turkish cedar is slightly hardier, to −30 °C or just below. Extensive mortality of planted specimens can occur in severe winters when temperatures fall lower.<ref name=odum>Ødum, S. (1985). "Report on frost damage to trees in Denmark after the severe 1981/82 and 1984/85 winters". Hørsholm Arboretum, Denmark.</ref> Cedars are suitable for training as bonsai in varied styles.<ref>Template:Cite web</ref> Cedar wood and cedarwood oil are naturally repellent to moths.<ref>Template:Cite web</ref>
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Formally planted ornamental cedars at Chiswick House, London.
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Glaucous Atlas cedar
trained as a bonsai
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Cedar wood has a strong sweet spicy-resinous scent, and a distinctive colour and grain.
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Freshly cut cedar wood has yellowish sapwood and orange-brown heartwood, and exudes strongly scented resin.
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Cedar wood panel from the reign of Thutmose IV, circa 1400-1391 B.C.
See also
References
External links
Template:Acrogymnospermae classification Template:Plant classification Template:Woodworking Template:Taxonbar Template:Authority control