It hasbranchlets that typically hang downwards, and the largest cones of anyspruce, 9–17 cm long. It is very closely related to theSiberian spruce (Picea obovata), which replaces it east of theUral Mountains, and with which it hybridizes freely. The Norway spruce has a wide distribution for it being planted for its wood, and is the species used as the mainChristmas tree in several countries around the world. It was the firstgymnosperm to have itsgenome sequenced. The Latinspecific epithetabies means "likeAbies, Fir tree".[5]
An 1885 illustration ofP. abies, showing the cones and leaves.Young female cone
Norway spruce is a large, fast-growingevergreenconiferoustree growing 35–55 m (115–180 ft) tall and with a trunk diameter of 1 to 1.5 m. It can grow fast when young, up to 1 m per year for the first 25 years under good conditions, but becomes slower once over 20 m (65 ft) tall.[6] The shoots are orange-brown and glabrous. Theleaves are needle-like with blunt tips,[7] 12–14 mm long, quadrangular in cross-section, and dark green on all four sides with inconspicuousstomatal lines. Theseed cones are 9–17 cm long (the longest of any spruce), and have bluntly to sharply triangular-pointed scale tips. They are green or reddish, maturing brown 5–7 months after pollination. Theseeds are black, 4–5 mm long, with a pale brown 15 mm wing.[1][8][9][10]The tallest measured Norway spruce is 62.26 m (204 ft) tall and grows nearRibnica na Pohorju,Slovenia.[11]
The Norway spruce grows throughout Europe from Norway in the northwest and Poland eastward, and also in the mountains of central Europe, southwest to the western end of the Alps, and southeast in the Carpathians and Balkans to the extreme north of Greece. The northern limit is in the arctic, just north of70° N in Norway. Its eastern limit in Russia is hard to define, due to extensivehybridization and intergradation with theSiberian spruce, but is usually given as the Ural Mountains. However, trees showing some Siberian spruce characters extend as far west as much of northern Finland, with a few records in northeast Norway. The hybrid is known asPicea ×fennica (orP. abies subsp.fennica, if the twotaxa are consideredsubspecies), and can be distinguished by a tendency towards having hairy shoots and cones with smoothly rounded scales.[8][9][10]
Cones ofP. obovata are short and have rounded scales.
Cones ofP. abies are longer and have pointed scales.
Populations in southeast Europe tend to have on average longer cones with more pointed scales; these are sometimes distinguished asPicea abies var.acuminata, but there is extensive overlap in variation with trees from other parts of the range.[8][9][10]
Some botanists treatSiberian spruce as a subspecies of Norway spruce, though in their typical forms, they are very distinct, the Siberian spruce having cones only 5–10 cm long, with smoothly rounded scales, and pubescent shoots.[8][9][10]Genetically Norway and Siberian spruces have turned out to be extremely similar and may be considered as two closely relatedsubspecies ofP. abies.[12]
Another spruce with smoothly rounded cone scales and hairy shoots occurs rarely in the Central Alps in easternSwitzerland. It is also distinct in having thicker, blue-green leaves. Many texts treat this as a variant of Norway spruce, but it is as distinct as many other spruces, and appears to be more closely related to Siberian spruce (Picea obovata), Schrenk's spruce (Picea schrenkiana) from centralAsia and Morinda spruce (Picea smithiana) in theHimalaya. Treated as a distinct species, it takes the name Alpine spruce (Picea alpestris). As with Siberian spruce, it hybridizes extensively with Norway spruce; pure specimens are rare. Hybrids are commonly known as Norwegian spruce, which should not be confused with the pure species Norway spruce.[8][9][10]
The Norway spruce is one of the most widely planted spruces, both in and outside of its native range, and one of the most economically important coniferous species in Europe.[3] It is used as an ornamental tree inparks andgardens. It is also widely planted for use as aChristmas tree. Every Christmas, the Norwegian capital city, Oslo, provides the cities of London (theTrafalgar Square Christmas tree), Edinburgh and Washington, D.C., with a Norway spruce, which is placed at the central most square of each city. This is mainly a sign of gratitude for the aid these countries gave during the Second World War.[13]In North America, Norway spruce is widely planted, specifically in theNortheastern,Pacific Coast, andRocky Mountain states, as well as in southeastern Canada. It is naturalised in some parts of North America. There are naturalized populations occurring fromConnecticut toMichigan, and it is probable that they occur elsewhere.[3] Norway spruces prefer cool-summer areas and they will grow up to USDA Growing Zone 7.[14]
Seed production begins when the tree is in its fourth decade and total lifespan is up to 300 years in its natural range in Europe. Introduced Norway spruces in the British Isles and North America have a much shorter life expectancy. As the tree ages, its crown thins out and lower branches die off.
In the northern US and Canada, Norway spruce is reported as invasive in some locations; however, it does not pose a problem inZone 6 and up as the seeds have a significantly reduced germination rate in areas with hot, humid summers.
The Norway spruce tolerates acidic soils well, but does not do well on dry or deficient soils. From 1928 until the 1960s it was planted on surface mine spoils in Indiana.[3]
Severalcultivars have been selected as ornamentals ('Barrya', 'Capitata', 'Decumbens', 'Dumosa', 'Clanbrassiliana', 'Gregoryana', 'Inversa', 'Microsperma', 'Nidiformis', 'Ohlendorffii', 'Repens', 'Tabuliformis', 'Maxwellii', 'Virgata', 'Inversa', 'Pendula'), with a wide variety of sizes and shapes, from full-sized forest trees to extremely slow-growing, prostrate forms. They are occasionally traded under the obsoletescientific namePicea excelsa (anillegitimate name).[15] The following cultivars have gained theRoyal Horticultural Society'sAward of Garden Merit:[16]
The Norwegian companyBorregaard produces the synthetic substitute for natural vanillaVanillin using the Norwegian spruce.[23] They are currently the only company to produce wood based vanillin and is claimed by the company to be preferred by their customers due to, among other reasons, its much lower carbon footprint than petrochemically synthesized vanillin.[24]
It is esteemed as a source oftonewood by stringed-instrument makers, and is commonly used forviolins.[25] One form of the tree calledHaselfichte [de] (Hazel-spruce) grows in the European Alps and has been recognized byUNESCO as intangible cultural heritage. This form was used byStradivarius for instruments.[26]
The tree is the source ofspruce beer, which was once used to prevent and even curescurvy.[27]
Norway spruce shoot tips have been used in traditional Austrian medicine internally (as syrup or tea) and externally (as baths, for inhalation, as ointments, as resin application or as tea) for treatment of disorders of the respiratory tract, skin, locomotor system, gastrointestinal tract and infections.[28]
During the production ofMont d'Or cheese it is wrapped in a "sangle" made from thecambium of a Norway spruce (French:Épicéa commun [fr]) for about two weeks at least, which gives the cheese a unique flavour.[29]
InFinland, Norway spruce tips (Finnish:kuusenkerkkä) are used as a spice, for example, in syrup, herbal tea, alcohol, smoothies, salt, and desserts.[30][31][32] Spruce tip syrup is also used as acold medicine.[33]
A press release fromUmeå University says that a Norway spruce clone namedOld Tjikko, carbon dated as 9,550 years old, is the "oldest living tree".[34] The oldest individual specimen of Norway spruce discovered by tree ring dating found in 2012 in a nature reserve of Buskerud County, Norway, was found to be 532 years old.[35]
However,Pando, a stand of 47,000quaking aspen clones, is estimated to be between 14,000 and one million years old.[36][37][38]
The stress is on the difference between the singular "oldest tree" and the multiple "oldest trees", and between "oldest clone" and "oldest non-clone". Old Tjikko is one of a series of genetically identical clones growing from a root system, one part of which is estimated to be 9,550 years old based on carbon dating. The oldest known individual tree (that has not taken advantage ofvegetative cloning) is a Great Basinbristlecone pine over 5,000 years old (germination in 3051 BC).[39]
The genome ofPicea abies was sequenced in 2013, the first gymnosperm genome to be completely sequenced.[40] The genome contains approximately 20 billion base pairs and is about six times the size of the human genome, despite possessing a similar number of genes. A large proportion of the spruce genome consists of repetitive DNA sequences, including long terminal repeattransposable elements. Despite recent advances in massively parallel DNA sequencing, the assembly of such a large and repetitive genome is a particularly challenging task, mainly from a computational perspective.[41]
Within populations ofPicea abies there is great genetic variability, which most likely reflect populations' isolation in glacialrefugia and post-glacial evolutionary history. Genetic diversity can in particular be detected when looking at how the populations respond to climatic conditions. E.g. variations in timing and length of the annual growth period as well as differences in frost-hardiness in spring and autumn. These annual growth patterns are important to recognize in order to choose the proper reforestation material ofPicea abies.[42]
^abcdSullivan, Janet (1994)."Picea abies".Fire Effects Information System (FEIS). US Department of Agriculture (USDA), Forest Service (USFS), Rocky Mountain Research Station, Fire Sciences Laboratory. Retrieved18 November 2009.
^Skrøppa, T. (2003)."Picea abies - Norway spruce"(PDF).EUFORGEN; Technical Guidelines for Genetic Conservation and Use. Archived fromthe original(PDF) on 2016-10-22. Retrieved2016-10-21.
^Lindberg, M.; Lundgren, L.; Gref, R.; Johansson, M. (1 May 1992). "Stilbenes and resin acids in relation to the penetration of Heterobasidion annosum through the bark ofPicea abies".Forest Pathology.22 (2):95–106.doi:10.1111/j.1439-0329.1992.tb01436.x.
^Slanc, Petra; Doljak, Bojan; Kreft, Samo; Lunder, Mojca; Janeš, Damjan; šTrukelj, Borut (2009). "Screening of selected food and medicinal plant extracts for pancreatic lipase inhibition".Phytotherapy Research.23 (6):874–877.doi:10.1002/ptr.2718.PMID19107742.S2CID22562789.
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