Blue spruce: Difference between revisions

Latest revision as of 20:29, 10 December 2025

Template:Short description Template:Speciesbox

The blue spruce (Picea pungens), also commonly known as Colorado spruce or Colorado blue spruce, is a species of spruce tree native to North America in Arizona, Colorado, Idaho, New Mexico, Utah and Wyoming. It is noted for its often strongly glaucous blue-green needles, and has therefore been used as an ornamental tree in many places far beyond its native range.

Description

File:Picea pungens foliage Pecos Wilderness.jpg

Foliage and young cone, Pecos Wilderness, New Mexico

In the wild, Picea pungens grows to as much as Script error: No such module "convert". in height,Template:Sfn but more typically Template:Cvt tall.Template:Sfn When planted in parks and gardens it most often grows Template:Cvt tall with a spread of Template:Cvt.Template:Sfn It has scaly gray-brown bark with a slight amount of a cinnamon-red undertone on its trunk, not as rough as an Engelmann spruce.Template:Sfn On older trees the trunk bark becomes deeply furrowed and scaly.Template:Sfn The trunk diameter may reach as much as Template:Cvt.Template:Sfn The root system is of the blue spruce is dense and compact, lacking a taproot.Template:Sfn

Blue spruce is a conifer with a conical crown when young, but more open and irregular in shape as it becomes older.Template:Sfn The stout branches grow out horizontally in well defined whorls,Template:Sfn but lower branches droop downwards as trees age.Template:Sfn Young twigs never hang downwards and are yellow-brown in color.Template:Sfn

The narrow, needle-like, evergreen leaves are quite sharply pointed and may be dull green, blue, or pale white.Template:Sfn The white or blue glaucous color is caused by surface waxes on the needles and is most visible on newly emerging foliage and fades towards summer.Template:Sfn Template:Sfn In the wild stands of trees tend to have similar coloration.Template:Sfn Each of the needles is four sided with stomata on every side, stiff, and Script error: No such module "convert". long.Template:Sfn The needles are attached radially to their shoots, but curve upward. The leaf buds are golden brown and cone shaped.Template:Sfn The buds may be Script error: No such module "convert". in size and the tip may either be blunt or pointed.Template:Sfn

The pollen producing cones, more properly strobili, develop throughout the crown of blue spruce trees, but are more common in the upper half of the crown.Template:Sfn Pollen cones are mainly yellow with a touch of red and average Template:Cvt long.Template:Sfn The seed cones begin growing in May or June and release their mature seeds in the autumn of the same year in which they start to grow.Template:Sfn When young they are purple-brown in color.Template:Sfn When fully mature they are light brown, longer than they are wide, circular in cross section with thin, papery scales and can be curved or straight.Template:Sfn The cones can measure between Template:Cvt long, but are more typically Template:Cvt.Template:Sfn The seed cones are only found in the top tenth to quarter of the tree and are normally near the end of side branches.Template:Sfn

File:Picea pungens seeds.jpg

Seeds of blue spruce

The seeds are dark brown.Template:Sfn They average 4 mm in length with the papery wing extending beyond the tip almost twice this length.Template:Sfn

The blue spruce can be confused with four other spruce species, Engelmann spruce, European spruce (Picea abies), white spruce (Picea glauca), and black spruce Picea mariana),Template:Sfn however only the range of the Engelmann spruce overlaps with the blue spruce in the wild.Template:Sfn Though larger for the blue spruce, the measurements of their cones and cone scales overlap with the Engelmann spruce.Template:Sfn The cones of the Engelmann measuring 3–8 cm with the scales measuring 3–8 mm beyond the seed impression while the blue spruce measures 5–12 cm with scales that measure 8–10 mm beyond the seed impression. However, the twigs of the Engelman are always finely hairy while those of the blue are usually hairless.Template:Sfn

Chemistry

The phytochemistry of the blue spruce is relatively little studied.Template:Sfn The ripe seeds have a 1.17% yield of essential oils while the cones produce only 0.38% when steam distilled for four hours. The main component, over 40%, of the essential oils is limonene with β-Pinene and α-Pinene the next most significant.Template:Sfn

Taxonomy

File:Picea pungens (as Picea parryana) - Charles Edward Faxon.png

The branches and cones of Picea pungens, then called Picea parryana as illustrated by Charles Edward Faxon in The Silva of North AmericaTemplate:Sfn

Picea pungens was given its first valid scientific description by George Engelmann in 1879.Template:Sfn Template:Sfn He had previously named it Abies menziesii in 1862 and later as Picea menziesii in 1863, but both those names had already been used making them illegitimate names.Template:Sfn Template:Sfn The specimens of the tree used to describe it were collected by Charles Christopher Parry on Pikes Peak, also in 1862.Template:Sfn

There was confusion regarding the correct scientific name for the species during the late 1800s and early 1900s with Picea parryana believed by many to be the correct name, though with various authorities attached to it. This was caused by the 1876 description of it as a variety of Abies menziesii named parryana by André Michaux coming before its description by Engelmann in 1879.Template:Sfn Despite this, Picea pungens was used as the correct name throughout this time by well known scientists such as Ludwig Beissner, Alfred Rehder, and Augustine Henry.Template:Sfn Template:Sfn By 1925 Picea pungens was being used for the species in US government scientific publications.Template:Sfn It is classified in the genus Picea as part of the family Pinaceae. It has no accepted varieties, but has several in its Template:Table row counter heterotypic synonyms.Template:Sfn

Table of Synonyms
Name	Year	Rank	Notes
Abies commutata var. glauca ChargueraudScript error: No such module "Check for unknown parameters".	1889	variety
Abies menziesii Engelm.Script error: No such module "Check for unknown parameters".	1862	species	nom. illeg.Template:Sfn
Abies menziesii var. parryana AndréScript error: No such module "Check for unknown parameters".	1876	variety
Abies parlatorei Dallim. & A.B.Jacks.Script error: No such module "Check for unknown parameters".	1923	species
Picea commutata Beissn.Script error: No such module "Check for unknown parameters".	1891	species
Picea menziesii Engelm.Script error: No such module "Check for unknown parameters".	1863	species	nom. illeg.
Picea menziesii var. parryana AndréScript error: No such module "Check for unknown parameters".	1876	variety
Picea parryana (André) Sarg.Script error: No such module "Check for unknown parameters".	1905	species
Picea parryana argentea R.C.RosenthalScript error: No such module "Check for unknown parameters".	1887
Picea parryana glauca-pendens (Sudw.) Sudw.Script error: No such module "Check for unknown parameters".	1898
Picea parryana glauca-pendula (H.Kost. ex Beissn.) AndréScript error: No such module "Check for unknown parameters".	1901
Picea pungens f. argentea BrannerScript error: No such module "Check for unknown parameters".	1918	form	nom. illeg.
Picea pungens f. argentea (R.C.Rosenthal) Beissn.Script error: No such module "Check for unknown parameters".	1887	form
Picea pungens argentea-pendula Beissn.Script error: No such module "Check for unknown parameters".	1899		nom. subnud.
Picea pungens f. coerulea Beissn.Script error: No such module "Check for unknown parameters".	1891	form
Picea pungens var. compacta (Rehder) RehderScript error: No such module "Check for unknown parameters".	1916	variety
Picea pungens f. compacta RehderScript error: No such module "Check for unknown parameters".	1915	form
Picea pungens var. glauca RegelScript error: No such module "Check for unknown parameters".	1883	variety
Picea pungens f. glauca (Regel) Beissn.Script error: No such module "Check for unknown parameters".	1887	form
Picea pungens glauca-pendens Sudw.Script error: No such module "Check for unknown parameters".	1897
Picea pungens f. glauca-pendula H.Kost. ex Beissn.Script error: No such module "Check for unknown parameters".	1891	form
Picea pungens var. hunnewelliana Hornibr.Script error: No such module "Check for unknown parameters".	1923	variety
Picea pungens f. hunnewelliana (Hornibr.) RehderScript error: No such module "Check for unknown parameters".	1949	form
Picea pungens var. kosteriana A.HenryScript error: No such module "Check for unknown parameters".	1912	variety
Picea pungens f. kosteriana (A.Henry) O.L.LipaScript error: No such module "Check for unknown parameters".	1939	form
Picea pungens f. pendens RehderScript error: No such module "Check for unknown parameters".	1949	form
Picea pungens var. pendula (Mouill.) Zederb.Script error: No such module "Check for unknown parameters".	1907	variety
Picea pungens subvar. pendula Mouill.Script error: No such module "Check for unknown parameters".	1898	subvariety
Picea pungens f. pendula Schwer.Script error: No such module "Check for unknown parameters".	1920	form	nom. illeg.
Picea pungens f. perpendicularis Schwer.Script error: No such module "Check for unknown parameters".	1920	form
Picea pungens f. typica Schwer.Script error: No such module "Check for unknown parameters".	1920	form	not validly publ.
Picea pungens var. viridis RegelScript error: No such module "Check for unknown parameters".	1883	variety
Picea pungens f. viridis (Regel) O.L.LipaScript error: No such module "Check for unknown parameters".	1939	form
Pinus armata VossScript error: No such module "Check for unknown parameters".	1907	species
Pinus parryana (André) VossScript error: No such module "Check for unknown parameters".	1907	species	nom. illeg.

Genetic analysis of the genus Picea indicates that the closest living relative of the blue spruce may be Picea mexicana,Template:Sfn a disputed species from northern Mexico also known as Picea engelmannii subsp. mexicana.Template:Sfn Template:Sfn Together they are part of a group with seven other related species that includes all the species from North America except for Brewer's spruce (Picea breweriana). The related species include Sitka spruce (Picea sitchensis), white spruce (Picea glauca) and Engelmann spruce (Picea engelmannii), black spruce (Picea mariana), red spruce (Picea rubens), Chihuahua spruce (Picea chihuahuana), and Nuevo León spruce (Picea martinezii).Template:Sfn Though visually very similar,Template:Sfn the blue spruce and Engelmann spruce split from their common ancestor between 10 and 20 million years ago.Template:Sfn

Names

Picea, the genus name, is thought to come from the Latin word pix meaning "pitch", a reference to the typical sticky resin in spruce bark.Template:Sfn The specific epithet pungens means "sharply pointed", referring to the leaves.Template:Sfn

The most frequently used common name in English is blue spruce. It was first used for other trees in 1817 and is still used for any spruce tree with a glaucous blue color to their needles, but most frequently meaning Picea pungens.Template:Sfn Though this is the most common name, in the wild only part of the population has the waxy blue-gray coating for which the tree is named.Template:Sfn Less frequently, but still common, is Colorado blue spruce, a name first used in 1912. The usage of Colorado spruce dates to 1881, but is less frequent than the longer alternate.Template:Sfn Template:Sfn Due to its affinity with streams and well watered canyons it is also known as the water spruce.Template:Sfn Occasionally encountered are the names Parry's spruce, prickly spruce, silver spruce, and white spruce.Template:Sfn Blue spruces are also rarely called silvertip fir,Template:Sfn but this name is also applied to Abies magnifica especially when sold as Christmas trees.Template:Sfn In addition it is sometimes labeled as Colorado green spruce or green spruce by plant nurseries or tree farms.Template:Sfn Template:Sfn

Similar to the meaning of the scientific name, the Navajo name for this species is a compound c'ó deniní with c'ó meaning spruce and deniní meaning "it is sharp".Template:Sfn

Ecology

File:Poecile gambeli (29592861290).jpg

A mountain chickadee foraging in blue spruce foliage, Bryce Canyon

Blue Spruce occurs at high elevations, Script error: No such module "convert". in the forests of the South Central Rockies and Script error: No such module "convert". in the Southern Rocky Mountains.Template:Sfn It grows in mesic montane conifer forests, often associating with Rocky Mountain Douglas-fir, ponderosa pine, or white fir.Template:Sfn It has a riparian affinity, preferring moist soils such as those along streams or at the edges of wet meadows. The Douglas-fir or ponderosa pine only become associated with streams at lower, warmer elevations. It also may be found alongside the quaking aspen (Populus tremuloides) in the high mountain habitats of desert ranges in the Intermountain West.Template:Sfn At the lowest elevations of its range it also becomes associated with aspens in the well watered stream bottoms with their deep alluvial soils.Template:Sfn Though associated with the Rocky Mountain Douglas-fir, the blue spruce is more tolerant of drought and intense sunlight.Template:Sfn

Blue spruce usually grows in cool and humid climatic zones where the annual precipitation mainly occurs in the summer.Template:Sfn Blue spruce is generally considered to grow best with abundant moisture. Nevertheless, this species can withstand drought better than any other spruce.Template:Sfn It can withstand extremely low temperatures (-40 degrees C) as well. Furthermore, this species is more resistant to frost damage compared to other associated species.Template:Sfn

Distributed soil types and topography

Blue spruce generally exists on gentle uplands and sub irrigated slopes, in well-watered tributary drainage, extending down intermittent streams, and on lower northerly slopes.Template:Sfn

Blue spruce is considered as a pioneer tree species in moist soil in Utah.Template:Sfn

Rooting habits

Blue spruce seedlings have shallow roots that penetrate approximately Script error: No such module "convert". into the soil during the first year of growth.Template:Sfn Although freezing can't damage much in blue spruce, frost heaving will cause seedling loss. Shadows in late spring and early autumn minimize this frost heaving loss.Template:Sfn Despite the shallow roots, blue spruce is able to resist strong winds.Template:Sfn

Pests and diseases

The blue spruce is attacked by two species of Adelges, an aphid-like insect that causes galls to form. Nymphs of the pineapple gall adelgid form galls at the base of twigs which resemble miniature pineapples and those of the Cooley's spruce gall adelgid cause cone-shaped galls at the tips of branches. The larva of the spruce budworm eat the buds and growing shoots while the spruce needle miner hollows out the needles and makes them coalesce in a webbed mass.Template:Sfn An elongated white scale insect, the pine needle scale feeds on the needles causing fluffy white patches on the twigs and aphids also suck sap from the needles and may cause them to fall and possibly dieback.Template:Sfn Mites can also infest the blue spruce, especially in a dry summer, causing yellowing of the oldest needles.Template:Sfn An occasional insect pest is the spruce beetle (Dendroctonus rufipennis) which bores under the bark. It is much more likely to use Engelmann spruces as the host trees and generally prefers to feed on trees that have been knocked over unless their numbers become very high.Template:Sfn

The blue spruce is susceptible to several needle casting diseases which cause the needles to turn yellow, mottled or brown before they fall off. Various rust diseases also affect the tree causing yellowing of the needles as well as needle fall. Canker caused by Cytospora attacks one of the lower branches first and progressively makes its way higher up the tree. The first symptom is the needles turning reddish-brown and falling off. Meanwhile, patches of white resin appear on the bark and the branch eventually dies.Template:Sfn

In Britain and central Europe ornamental blue spruces are damaged by the spruce aphid (Elatobium abietinum), particularly after mild winters.Template:Sfn Template:Sfn This species has become established in North America since 1915 and in the southwestern United States since 1976.Template:Sfn In the southwest it attacks wild populations of Engelmann spruce and the blue spruce, though with a somewhat lower severity. Heavily infested trees will lose their needles or die for up to three years after being damaged.Template:Sfn

It is also relatively intolerant of light pollution and when planted near street lights or other outdoor lighting its preparation for winter can be delayed and parts of the tree may be damaged.Template:Sfn

Range

File:Picea pungens Bryce Canyon NP 2.jpg

Blue spruces in Bryce Canyon, Utah

The native range of the blue spruce is largely in the Central and Southern Rocky Mountains and moist mountain valleys and canyons to the west.Template:Sfn Template:Sfn In New Mexico it only grows naturally in the higher mountain ranges of the state such as the Sandia–Manzano Mountains, Sangre de Cristo Mountains, and San Juan Mountains, as well as on Sierra Blanca Peak to the south.Template:Sfn Template:Sfn In Arizona the range is even more limited, growing in just Coconino and Apache counties.Template:Sfn In Apache County it is found in the White Mountains in central eastern Arizona and the Lukachukai Mountains in the northeastern corner of the state. In Coconino County they only grow on the Kaibab Plateau.Template:Sfn The blue spruce grows in every county in the western two-thirds of Colorado;Template:Sfn approximately half of natural range of the species is in the mountains of Colorado.Template:Sfn In Utah they are a locally common part of forests in the Uinta Mountains. West of the Uintas blue spruces are less frequent in canyons south of Salt Lake City.Template:Sfn

The blue spruce has only very rarely become naturalized outside of its native range and is not considered an invasive species.Template:Sfn In North America has escaped from cultivation in the states of Minnesota, Maryland, Pennsylvania, New York, and Maine as well as in the Canadian provinces of Onterio and Nova Scotia,Template:Sfn Template:Sfn and it is considered naturalized in New York and New England.Template:Sfn In Europe it has been found outside cultivation in many areas including Iceland, on Great Britain, in Norway, and Sweden. It is also known from France, Belgium, Germany, Switzerland, Italy, and Austria.Template:Sfn

In the former Czechoslovakia in the 1970s and 1980s large areas of forest died due to sulpher dioxde pollution from coal fired power plants.Template:Sfn In the Ore Mountains the Ministry of Agriculture of the Czech Republic replanted many areas with non-native species including Script error: No such module "convert". with blue spruce, second in area only to the birch tree.Template:Sfn Small numbers were also planted on the upper plateau of the Jizera Mountains when new forests were established in the 1990s alongside the Serbian spruces (Picea omorica), although the majority of spruces planted were the native European spruce.Template:Sfn Despite the large areas planted they have not established themselves outside of cultivation.Template:Sfn

In Eastern Europe they are an introduced species in the Baltic States, central European Russia, Bulgaria, and the Transcaucasus.Template:Sfn

Notable trees

The tallest documented blue spruce tree is an individual in the San Juan Mountains of southern Colorado in the Hermosa Creek area. When measured by Matt Markworth in 2015 it was Script error: No such module "convert". tall.Template:Sfn Just three years later in 2018 it was threatened by the 416 Fire. Though the fire killed a shorter Template:Cvt American champion tree with a larger trunk and crown spread the tall tree was spared due to being located in a sheltered valley.Template:Sfn

The National Champion Tree for the species is one located in the Wasatch Range in Utah. When last measured in 2020 it was Template:Cvt tall with a crown spread of Template:Cvt and a diameter at breast height of Template:Cvt.Template:Sfn

A tree named Old Blue by researchers found in the Cedar Breaks National Monument when cored in 2024 was dated to sprouting in 1564, an age of Script error: No such module "age". years.Template:Sfn This is the oldest known blue spruce tree.Template:Sfn

Cultivation

File:2015-05-18 13 01 32 Blue Spruce new growth along Terrace Boulevard in Ewing, New Jersey.jpg

'Mission Blue' blue spruce new growth in spring

Picea pungens and its many cultivars are often grown as ornamental trees in gardens and parks.Template:Sfn Template:Sfn It is also grown for the Christmas tree industry.Template:Sfn Though the blue spruce prefers moist soils, in particularly wet or rocky soils it will root very shallowly in the soil and will therefore be vulnerable to windthrow, being blown over in high winds, in exposed locations.Template:Sfn It grows best in USDA growing zones 2 through 7, although when planted in zone 7 it has a hard time coping with high temperatures during the night.Template:Sfn

Common cultivars (those marked <templatestyles src="smallcaps/styles.css"/>agm have gained the Royal Horticultural Society's Award of Garden Merit):Template:Sfn

'Baby Blue Eyes',Template:Sfn 'Baby Blueeyes', or 'Baby Blueyes' – This is a semi-dwarf cultivar that grows slowly, but may eventually reach Template:Cvt in height. It has a pyramidal shape and holds its color well.Template:Sfn
'Edith' <templatestyles src="smallcaps/styles.css"/>agm – A small and slow growing tree that takes 20 to 50 years to reach a height of Template:Cvt with a spread of 1.5–2.5 m. Its shape is conical.Template:Sfn
'Fat Albert' <templatestyles src="smallcaps/styles.css"/>agm – A symetrical perfect cone reaching Template:Cvt in height and spreading 1.5–2.5 m after about 10 to 20 years.Template:Sfn When allowed to grow longer it can reach Template:Cvt. The needles are blue with less gray/silver tones and are softer than many other cultivars.Template:Sfn
'Globosa' <templatestyles src="smallcaps/styles.css"/>agmTemplate:Sfn – shrub from Template:Cvt in height,Template:Sfn though it takes 20–50 years to reach full sizeTemplate:Sfn
'Hoopsii' <templatestyles src="smallcaps/styles.css"/>agmTemplate:Sfn – A full size variety with a dense pyramidal habit known for "excellent" silver-blue color of its foliage. It reaches Template:Cvt tall when full grown.Template:Sfn
'Koster' or 'Kosteri'Template:Sfn – A medium sized conical cultivar that will reach Template:Cvt tall with a spread of 2.5–4 m after 20 to 50 years.Template:Sfn It was introduced to the plant trade in 1915,Template:Sfn but became less popular by the 2000s due to grafted trees haveing unpreditable qualities.Template:Sfn
'Montgomery' or 'R.H. Montgomery' – A slow growing dwarf variety. It will typically only grow Template:Cvt tall in eight years, but may eventually reach a height of over Template:Cvt.Template:Sfn It has tightly packed branches and silvery-blue needles.Template:Sfn
'Pendula' or 'Glauca Pendula'Template:Sfn – A Cultivar with drooping branches, spreads to about Template:Cvt wide by Script error: No such module "convert". tall.Template:Sfn It often must be tied to a stake for many years to prevent it growing on the ground.Template:Sfn
'Walnut Glen' or 'Goldie' – A cultivar that grows slowly to Template:Cvt, but can eventually reach Template:Cvt. It has cream colored new shoots in the spring that turn a more typical gray-blue. It requires shade in the morning to prevent being damaged by the sun and is also vulnerable to frost damage.Template:Sfn

File:Picea pungens 'Glauca globosa' in Autumn.JPG

Foliage of the cultivar 'Globosa'

Blue spruce trees are used in windbreaks around gardens, fields, or farm structures.Template:Sfn They are recommended for this use by extension services in Montana,Template:Sfn North Dakota,Template:Sfn Oregon,Template:Sfn and Pennsylvania.Template:Sfn

While in general broad leaved trees produce deeper and higher quality soils on mine reclamation sites, the blue spruce is among the best of the conifers.Template:Sfn Though it is less tolerant of drought conditions than other trees such as the ponderosa pine.Template:Sfn After 50 years on a reclaimed coal mine in Central Europe blue spruce trees formed organic soils with a depth of 4 cm.Template:Sfn

The wood of the blue spruce is very infrequently used due to being brittle and with an excessive number of knots as well as being a less common tree.Template:Sfn Template:Sfn It has only 65% of the bending strength of the European spruce (Picea abies).Template:Sfn

Culture

In the traditions of the Acoma and Laguna pueblos, the western Keres people, the blue spruce is used as a treatment for rheumatism and the common cold. The needles are infused in hot water and the patient bathes in it. It was also used in ceremonies where dancers would have spruce twigs attached to their arms. Audience members would take parts of these twigs to steep and drink for stomach health.Template:Sfn During the Navajo Chant of the Sun's House branches of Douglas-fir and blue spruce are used.Template:Sfn They also traditionally use very ripe fruit of the plains pricklypear (Opuntia polyacantha) with the addition of a handful of the bark or roots of blue spruce to make a dye to color wool pink.Template:Sfn

The blue spruce is the state tree of Colorado.Template:Sfn It officially became Colorado's state tree on 7 March 1939 when House Joint Resolution 7 was enacted by the legislature. Previously a vote of the state's school children was taken on Arbor Day in 1892 expressing their preference for the blue spruce as the state tree.Template:Sfn

From 1933 until 2014 the blue spruce was also the state tree of Utah. It was replaced by the quaking aspen because the aspen is a great deal more common than the blue spruce in Utah, making up 10% of the state's tree cover.Template:Sfn Template:Sfn

It is moderately popular as a Christmas tree in the United States and has been used as the Capitol Christmas Tree in Washington, D.C. four times since they began to be regularly erected in 1964.Template:Sfn

Gallery

Mature tree

Mature tree
Mature cone

Mature cone
Immature cone

Immature cone
Hoopsii

Hoopsii
Koster

Koster
Globosa

Globosa
Montgomery

Montgomery
Fat Albert

Fat Albert

Citations

Script error: No such module "Check for unknown parameters".

References

Sources

Books

Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".

Journals

Script error: No such module "Citation/CS1".
Script error: No such module "Citation/CS1".
Script error: No such module "Citation/CS1".
Script error: No such module "Citation/CS1".
Script error: No such module "Citation/CS1".
Script error: No such module "Citation/CS1".
Script error: No such module "Citation/CS1".
Script error: No such module "Citation/CS1".
Script error: No such module "Citation/CS1".
Script error: No such module "Citation/CS1".
Script error: No such module "Citation/CS1".
Script error: No such module "Citation/CS1".
Script error: No such module "Citation/CS1".
Script error: No such module "Citation/CS1".

News

Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".

Reports

Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".

Thesis

Template:Cite thesis

Web sources

Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Template:Cite iucn
Template:Cite NatureServe
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Template:Cite usda plants
Script error: No such module "template wrapper". Template:OEDsub
Script error: No such module "template wrapper". Template:OEDsub
Template:Cite POWO
Template:Cite POWO
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".
Script error: No such module "citation/CS1".

External links

Template:Sister project Script error: No such module "Sister project links".Script error: No such module "Check for unknown parameters".

Conifers.org: Picea pungens (blue spruce) description
Lady Bird Johnson Wildflower Center NPIN—Native Plant Information Network
Interactive Distribution Map of Picea pungens Template:Webarchive
Picea pungens—U.C. Berkeley Photo Gallery

Template:Taxonbar Template:Authority control

Blue spruce: Difference between revisions

Latest revision as of 20:29, 10 December 2025

Contents

Description

Chemistry

Taxonomy

Names

Ecology

Distributed soil types and topography

Rooting habits

Pests and diseases

Range

Notable trees

Cultivation

Culture

Gallery

See also

Citations

References

Sources

Books

Journals

News

Reports

Thesis

Web sources

External links

Navigation menu

@@ Line 1: / Line 1: @@
 {{Short description|Species of tree}}
 {{Speciesbox
-| image = Picea pungens tree.jpg
+| image = Blue Spruce (15905530369).jpg
+| image_caption = Blue spruces in [[San Juan National Forest]], Colorado
 | status = LC
 | status_system = IUCN3.1
-| status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=Farjon, A. |date=2013 |title=''Picea pungens'' |volume=2013 |page=e.T42333A2973433 |doi=10.2305/IUCN.UK.2013-1.RLTS.T42333A2973433.en |access-date=19 November 2021}}</ref>
+| status_ref = {{sfn|Farjon|2013}}
 | status2 = {{TNCStatus}}
 | status2_system = TNC
-| status2_ref = <ref name="NatureServe">{{cite web |last1=NatureServe |title=''Picea pungens'' |url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.148378/Picea_pungens |access-date=7 September 2024 |location=Arlington, Virginia |date=2024}}</ref>
+| status2_ref = {{sfn|NatureServe 2025}}
 | genus = Picea
 | species = pungens
-| authority = [[George Engelmann|Engelm.]], 1879
+| authority = [[George Engelmann|Engelm.]]
 | range_map = Picea pungens range map.png
-| synonyms_ref = <ref name="POWO" />
+| synonyms_ref = {{sfn|POWO 2025b}}
 | synonyms = {{Species list
-  | Abies menziesii | Engelm. (1862)
+  | Abies menziesii | Engelm.
-  | Abies parlatorei | Dallim. & A.B.Jacks. (1923)
+  | Abies parlatorei | Dallim. & A.B.Jacks.
-  | Picea commutata | Beissn. (1891)
+  | Picea commutata | Beissn.
-  | Picea menziesii | Engelm. (1863)
+  | Picea menziesii | Engelm.
-  | Picea parryana | (André) Sarg. (1905)
+  | Picea parryana | (André) Sarg.
-  | Pinus armata | Voss (1907)
+  | Pinus armata | Voss
-  | Pinus parryana | (André) Voss (1907)
+  | Pinus parryana | (André) Voss
 }}
 }}
-The '''blue spruce''' ('''''Picea pungens'''''), also commonly known as '''Colorado spruce''' or '''Colorado blue spruce''', is a [[species]] of [[Picea|spruce]] tree [[native plant|native]] to North America in Arizona, Colorado, Idaho, New Mexico, Utah and Wyoming.<ref>Flora of North America Editorial Committee, editor. 1993. Flora of North America North of Mexico. Volume 2. Pteridiophytes and Gymnosperms. Oxford University Press, New York, 475 pp</ref> It is noted for its blue-green colored needles, and has therefore been used as an ornamental tree in many places far beyond its native range.<ref name="Earle">{{cite web |url=https://www.conifers.org/pi/Picea_pungens.php |title=''Picea pungens'' (blue spruce) description |last=Earle |first=Christopher J. |date=26 February 2023 |website=The Gymnosperm Database |language=en |access-date=24 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20231211081155/https://www.conifers.org/pi/Picea_pungens.php |archive-date=11 December 2023}}</ref>
+The '''blue spruce''' ('''''Picea pungens'''''), also commonly known as '''Colorado spruce''' or '''Colorado blue spruce''', is a [[species]] of [[Picea|spruce]] tree [[native plant|native]] to North America in Arizona, Colorado, Idaho, New Mexico, Utah and Wyoming. It is noted for its often strongly glaucous blue-green needles, and has therefore been used as an ornamental tree in many places far beyond its native range.
 ==Description==
-In the wild, ''Picea pungens'' grows to as much as {{convert|50|m|ft|0|spell=us}} in height,<ref name="FNA">{{cite web |last1=Taylor |first1=onald J. |title=''Picea pungens'' |url=http://floranorthamerica.org/Picea_pungens |website=[[Flora of North America]] |access-date=21 September 2024 |date=5 November 2020}}</ref> but more typically {{cvt|30|m|ft|0}} tall.{{sfn|Cronquist et al. 1972|p=224}} When planted in parks and gardens it most often grows {{cvt|30 to 60|ft|m|0|order=flip}} tall with a spread of {{cvt|10 to 20|ft|m|0|order=flip}}.<ref name="MissouriBG">{{cite web |url=https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=284991 |title=''Picea pungens'' |website=Plant Finder |publisher=[[Missouri Botanical Garden]] |location=St. Louis, Missouri |language=en |access-date=21 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20240523174142/https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=284991 |archive-date=23 May 2024}}</ref> It has scaly grey-brown bark with a slight amount of a cinnamon-red undertone on its trunk, not as rough as an [[Engelmann spruce]].{{sfn|Cronquist et al. 1972|p=224}} On older trees the trunk bark will be deeply furrowed and scaly.{{sfn|Harrison|Dallimore|Jackson|1966|p=373}} The diameter of the trunk may reach as much as {{cvt|1.5|m|ft}}.<ref name="FNA" />
+[[File:Picea pungens foliage Pecos Wilderness.jpg|thumb|left|Foliage and young cone, [[Pecos Wilderness]], New Mexico]]
+In the wild, ''Picea pungens'' grows to as much as {{convert|50|m|ft|0|spell=us}} in height,{{sfn|Taylor|2020b}} but more typically {{cvt|30|m|ft|0}} tall.{{sfn|Cronquist et al. 1972|p=224}} When planted in parks and gardens it most often grows {{cvt|30 to 60|ft|m|0|order=flip}} tall with a spread of {{cvt|10 to 20|ft|m|0|order=flip}}.{{sfn|MBG Staff|2024a}} It has scaly gray-brown bark with a slight amount of a cinnamon-red undertone on its trunk, not as rough as an [[Engelmann spruce]].{{sfn|Cronquist et al. 1972|p=224}} On older trees the trunk bark becomes deeply furrowed and scaly.{{sfn|Harrison|Dallimore|Jackson|1966|p=373}} The trunk diameter may reach as much as {{cvt|1.5|m|ft}}.{{sfn|Taylor|2020b}} The root system is of the blue spruce is dense and compact, lacking a taproot.{{sfn|Pearson|1931|p=93}}
-Blue spruces are [[conifer]]s with a pyramidal or conical [[Crown (botany)|crown]] when young, but more open and irregular in shape as they become older.{{sfn|Cronquist et al. 1972|p=224}} The stout branches grow out horizontally in well defined [[Whorl (botany)|whorls]],{{sfn|Cronquist et al. 1972|p=224}} but lower branches droop downwards as trees age.<ref>{{cite web |title=''Picea pungens'' (Blue Spruce, Colorado Spruce) |url=https://plants.ces.ncsu.edu/plants/picea-pungens/ |website=North Carolina Extension Gardener Plant Toolbox |publisher=[[North Carolina State University]] |access-date=22 September 2024 |language=en}}</ref> Young twigs never hang downwards and are yellow-brown in color.<ref name="FNA" />
+Blue spruce is a [[conifer]] with a [[Glossary of botanical terms#conical|conical]] [[Crown (botany)|crown]] when young, but more open and irregular in shape as it becomes older.{{sfn|Cronquist et al. 1972|p=224}} The stout branches grow out horizontally in well defined [[Whorl (botany)|whorls]],{{sfn|Cronquist et al. 1972|p=224}} but lower branches droop downwards as trees age.{{sfn|NCCE Staff|2025a}} Young twigs never hang downwards and are yellow-brown in color.{{sfn|Taylor|2020b}}
-The narrow, needle-like, [[evergreen]] leaves are quite sharply pointed and may be dull green, blue, or pale white.{{sfn|Harrison|Dallimore|Jackson|1966|p=373}} Each of the needles is four sided with [[stomata]] on every side, stiff, and {{convert|1.6–3|cm|in|frac=4|spell=us}} long.<ref name="FNA" /> The needles are attached radially to their shoots, but curve upward. The leaf buds are golden brown and cone shaped.{{sfn|Krüssmann|1972|p=216}} The buds may be {{convert|6|to|12|mm|in|frac=4|spell=us}} in size and the tip may either be blunt or pointed.<ref name="FNA" />
+The narrow, needle-like, [[evergreen]] leaves are quite sharply pointed and may be dull green, blue, or pale white.{{sfn|Harrison|Dallimore|Jackson|1966|p=373}} The white or blue [[glaucous]] color is caused by surface waxes on the needles and is most visible on newly emerging foliage and fades towards summer.{{sfn|Fechner|1985|p=10}}{{sfn|Bloom|2002|p=25}} In the wild stands of trees tend to have similar coloration.{{sfn|Fechner|1985|p=10}} Each of the needles is four sided with [[stomata]] on every side, stiff, and {{convert|1.6–3|cm|in|frac=4|spell=us}} long.{{sfn|Taylor|2020b}} The needles are attached radially to their shoots, but curve upward. The leaf buds are golden brown and cone shaped.{{sfn|Krüssmann|1972|p=216}} The buds may be {{convert|6|to|12|mm|in|frac=4|spell=us}} in size and the tip may either be blunt or pointed.{{sfn|Taylor|2020b}}
-The pollen producing cones, more properly [[strobili]], develop throughout the crown of blue spruce trees, but are more common in the upper half of the crown.<ref name="SilvicsNA">{{Cite web <!--Deny Citation Bot-->|url=https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_1/picea/pungens.htm |title=''Picea pungens'' Engelm. |last1=Burns |first1=Russell M. |last2=Honkala |first2=Barbara H. |date=December 1990 |website=Silvics of North America |series= |publisher=[[United States Forest Service]] |agency=[[United States Department of Agriculture]] |location=Washington, D.C. |language=en |isbn=9780160271458 |lccn=91600537 |oclc=25008780 |access-date=24 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20240722121855/https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_1/picea/pungens.htm |archive-date=22 July 2024}}</ref> Pollen cones are mainly yellow with a touch of red and average {{cvt|1.5|cm|in|frac=4}} long.{{sfn|Cronquist et al. 1972|p=224}} The seed cones begin growing in May or June and release their mature seeds in the autumn of the same year in which they start to grow.{{sfn|Barnes|Wagner|1981|p=78}} When young they are purple-brown in color.{{sfn|Cronquist et al. 1972|p=224}} When fully mature they are light brown with thin, papery scales and are often curved. Overall they are longer than they are wide, between {{convert|8|and|15|cm|0|abbr=on}} long, and circular in cross section.{{sfn|Barnes|Wagner|1981|p=78}}{{sfn|Vedel|Lange|1960|p=119–120}} The seed cones are only found at the top of the tree. This helps to facilitate [[cross-pollination]].<ref name="Yale Nature Walk">{{Cite web |date=2021 |title=Yale Nature Walk, Blue Spruce |url=https://naturewalk.yale.edu/trees/pinaceae/picea-pungens/blue-spruce-56 |access-date=2021-02-21}}</ref>
+The pollen producing cones, more properly [[strobili]], develop throughout the crown of blue spruce trees, but are more common in the upper half of the crown.{{sfn|Fechner|1990}} Pollen cones are mainly yellow with a touch of red and average {{cvt|1.5|cm|in|frac=4}} long.{{sfn|Cronquist et al. 1972|p=224}} The seed cones begin growing in May or June and release their mature seeds in the autumn of the same year in which they start to grow.{{sfn|Barnes|Wagner|1981|p=78}} When young they are purple-brown in color.{{sfn|Cronquist et al. 1972|p=224}} When fully mature they are light brown, longer than they are wide, circular in cross section with thin, papery scales and can be curved or straight.{{sfn|Barnes|Wagner|1981|p=78}} The cones can measure between {{Cvt|5 and 12|cm|frac=4}} long, but are more typically {{Cvt|6 to 11|cm|frac=4}}.{{sfn|Taylor|2020b}} The seed cones are only found in the top tenth to quarter of the tree and are normally near the end of side branches.{{sfn|Fechner|1990}}
 [[File:Picea pungens seeds.jpg|thumb|left|Seeds of blue spruce]]
 The seeds are dark brown.{{sfn|Krüssmann|1972|p=217}} They average 4&nbsp;mm in length with the papery wing extending beyond the tip almost twice this length.{{sfn|Cronquist et al. 1972|p=224}}
+The blue spruce can be confused with four other spruce species, Engelmann spruce, [[European spruce]] (''Picea abies''), [[Picea glauca|white spruce]] (''Picea glauca''), and [[Picea mariana|black spruce]] ''Picea mariana''),{{sfn|Seiler et al. 2021}} however only the range of the Engelmann spruce overlaps with the blue spruce in the wild.{{sfn|Lockwood et al. 2013|p=719}} Though larger for the blue spruce, the measurements of their cones and cone scales overlap with the Engelmann spruce.{{sfn|Nesom|2003|p=1}} The cones of the Engelmann measuring 3–8&nbsp;cm with the scales measuring 3–8&nbsp;mm beyond the seed impression while the blue spruce measures 5–12&nbsp;cm with scales that measure 8–10&nbsp;mm beyond the seed impression. However, the twigs of the Engelman are always finely hairy while those of the blue are usually hairless.{{sfn|Taylor|2020a}}
 ===Chemistry===
-The [[phytochemistry]] of the blue spruce is relatively little studied.<ref name="Wajs‐Bonikowska et al">{{cite journal |last1=Wajs-Bonikowska |first1=Anna |last2=Szoka |first2=Łukasz |last3=Karna |first3=Ewa |last4=Wiktorowska-Owczarek |first4=Anna |last5=Sienkiewicz |first5=Monika |title=Composition and Biological Activity of ''Picea pungens'' and ''Picea orientalis'' Seed and Cone Essential Oils |journal=Chemistry & Biodiversity |date=March 2017 |volume=14 |issue=3 |doi=10.1002/cbdv.201600264|pmid=27735132 }}</ref> The ripe seeds have a 1.17% yield of essential oils while the cones produce only 0.38% when [[Steam distillation|steam distilled]] for four hours. The main component, over 40%, of the essential oils is [[limonene]] with [[β-Pinene]] and [[α-Pinene]] the next most significant.<ref name="Wajs‐Bonikowska et al" />
+The [[phytochemistry]] of the blue spruce is relatively little studied.{{sfn|Wajs-Bonikowska et al. 2017|p=2}} The ripe seeds have a 1.17% yield of essential oils while the cones produce only 0.38% when [[Steam distillation|steam distilled]] for four hours. The main component, over 40%, of the essential oils is [[limonene]] with [[β-Pinene]] and [[α-Pinene]] the next most significant.{{sfn|Wajs-Bonikowska et al. 2017|pp=2–3}}
 ==Taxonomy==
 [[File:Picea pungens (as Picea parryana) - Charles Edward Faxon.png|thumb|The branches and cones of ''Picea pungens'', then called ''Picea parryana'' as illustrated by [[Charles Edward Faxon]] in The Silva of North America{{sfn|Sargent|1898|p=Tab DC}}]]
-''Picea pungens'' was given its first valid scientific description by [[George Engelmann]] in 1879. He had previously named it ''Abies menziesii'' in 1862 and later as ''Picea menziesii'' in 1863, but both those names had already been used making them [[illegitimate name]]s.<ref name="POWO">{{cite POWO |id=30095300-2 |title=''Picea pungens'' Engelm. |access-date=24 September 2024}}</ref>
+''Picea pungens'' was given its first valid scientific description by [[George Engelmann]] in 1879.{{sfn|POWO 2025b}}{{sfn|Engelmann|1879|p=334}} He had previously named it ''Abies menziesii'' in 1862 and later as ''Picea menziesii'' in 1863, but both those names had already been used making them [[illegitimate name]]s.{{sfn|POWO 2025b}}{{sfn|Engelmann|Parry|1862|p=330}} The specimens of the tree used to describe it were collected by [[Charles Christopher Parry]] on [[Pikes Peak]], also in 1862.{{sfn|Sudworth|1916|p=14}}
-===Names===
+There was confusion regarding the correct scientific name for the species during the late 1800s and early 1900s with ''Picea parryana'' believed by many to be the correct name, though with various [[Author citation (botany)|authorities]] attached to it. This was caused by the 1876 description of it as a variety of ''Abies menziesii'' named ''parryana'' by [[André Michaux]] coming before its description by Engelmann in 1879.{{sfn|Sudworth|1916|p=14}} Despite this, ''Picea pungens'' was used as the correct name throughout this time by well known scientists such as [[Ludwig Beissner]], [[Alfred Rehder]], and [[Augustine Henry]].{{sfn|POWO 2025b}}{{sfn|Elwes|Henry|1912|p=1389}} By 1925 ''Picea pungens'' was being used for the species in US government scientific publications.{{sfn|Tidestrom|Shantz|Sampson|1925|p=54}} It is classified in the genus ''[[Picea]]'' as part of the family [[Pinaceae]]. It has no accepted [[Variety (botany)|varieties]], but has several in its {{table row counter|id=Synonyms}} [[heterotypic synonym]]s.{{sfn|POWO 2025b}}
-''Picea'', the genus name, is thought to come from the Latin word ''pix'' meaning "pitch", a reference to the typical sticky resin in spruce bark.<ref name="MissouriBG" /> The [[Botanical name#Binary name|specific epithet]] ''pungens'' means "sharply pointed", referring to the leaves.{{sfn|Harrison|2012|p=172}}
-The most frequently used [[common name]] in English is ''blue spruce''. It was first used for other trees in 1817 and is still used for any spruce tree with a glaucous blue color to their needles, but most frequently meaning ''Picea pungens''.<ref>{{Cite OED|blue spruce|7006545120}}</ref> Though this is the most common name, in the wild only part of the population has the waxy blue-gray coating for which the tree is named.{{sfn|Cronquist et al. 1972|p=224}} Less frequently, but still common, is ''Colorado blue spruce'', a name first used in 1912. The usage of ''Colorado spruce'' dates to 1881, but is less frequent than the longer alternate.{{sfn|Quattrocchi|2012|p=2923}}<ref>{{Cite OED|Colorado spruce|1207804688}}</ref> Occasionally encountered are the names ''Parry's spruce'', ''prickly spruce'', ''silver spruce'', and ''white spruce''.{{sfn|Harrison|Dallimore|Jackson|1966|p=373}} Blue spruces are also rarely called ''silvertip fir'',{{sfn|Heil et al. 2013|p=89}} but this name is also applied to ''[[Abies magnifica]]'' especially when sold as Christmas trees.{{sfn|Stuart|Sawyer|2001|p=31–32}} In addition it is sometimes labeled as "Colorado green spruce" or "green spruce" by plant nurseries or tree farms.<ref>{{cite web |title=Colorado Green Spruce (''Picea Pungens'') |url=https://www.foreststart.com/pines-spruce-firs/colorado-green-spruce-picea-pugens |website=Forest Start |access-date=25 September 2024}}</ref><ref>{{cite web |url=http://hvp.osu.edu/pocketgardener/source/description/pi_ngens.html |title=''Picea pungens'': Blue Spruce, Colorado Blue Spruce, or Green Spruce (Pinaceae - Pine Family) |department=Department of Horticulture and Crop Science |website=OSU PocketGardener |publisher=[[Ohio State University]] |location=Columbus, Ohio |access-date=25 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20240605220156/http://hvp.osu.edu/pocketgardener/source/description/pi_ngens.html |archive-date=5 June 2024}}</ref>
+{|class="wikitable sortable mw-collapsible mw-collapsed" id="Synonyms"
+|+ class="nowrap" | Table of Synonyms
+! Name
+! Year
+! Rank
+! Notes
+|-
+| ''Abies commutata'' var. ''glauca'' {{small|Chargueraud}}
+| 1889
+|data-sort-value=D | variety
+|data-sort-value=B |
+|-
+| ''Abies menziesii'' {{small|Engelm.}}
+| 1862
+|data-sort-value=A | species
+|data-sort-value=B | [[nom. illeg.]]{{sfn|Engelmann|Parry|1862|p=330}}
+|-
+| ''Abies menziesii'' var. ''parryana'' {{small|André}}
+| 1876
+|data-sort-value=D | variety
+|data-sort-value=B |
+|-
+| ''Abies parlatorei'' {{small|Dallim. & A.B.Jacks.}}
+| 1923
+|data-sort-value=A | species
+|data-sort-value=B |
+|-
+| ''Picea commutata'' {{small|Beissn.}}
+| 1891
+|data-sort-value=A | species
+|data-sort-value=B |
+|-
+| ''Picea menziesii'' {{small|Engelm.}}
+| 1863
+|data-sort-value=A | species
+|data-sort-value=B | [[nom. illeg.]]
+|-
+| ''Picea menziesii'' var. ''parryana'' {{small|André}}
+| 1876
+|data-sort-value=D | variety
+|data-sort-value=B |
+|-
+| ''Picea parryana'' {{small|(André) Sarg.}}
+| 1905
+|data-sort-value=A | species
+|data-sort-value=B |
+|-
+| ''Picea parryana argentea'' {{small|R.C.Rosenthal}}
+| 1887
+|data-sort-value=J |
+|data-sort-value=B |
+|-
+| ''Picea parryana glauca-pendens'' {{small|(Sudw.) Sudw.}}
+| 1898
+|data-sort-value=J |
+|data-sort-value=B |
+|-
+| ''Picea parryana glauca-pendula'' {{small|(H.Kost. ex Beissn.) André}}
+| 1901
+|data-sort-value=J |
+|data-sort-value=B |
+|-
+| ''Picea pungens'' f. ''argentea'' {{small|Branner}}
+| 1918
+|data-sort-value=F | form
+|data-sort-value=B | [[nom. illeg.]]
+|-
+| ''Picea pungens'' f. ''argentea'' {{small|(R.C.Rosenthal) Beissn.}}
+| 1887
+|data-sort-value=F | form
+|data-sort-value=B |
+|-
+| ''Picea pungens argentea-pendula'' {{small|Beissn.}}
+| 1899
+|data-sort-value=J |
+|data-sort-value=B | [[nom. subnud.]]
+|-
+| ''Picea pungens'' f. ''coerulea'' {{small|Beissn.}}
+| 1891
+|data-sort-value=F | form
+|data-sort-value=B |
+|-
+| ''Picea pungens'' var. ''compacta'' {{small|(Rehder) Rehder}}
+| 1916
+|data-sort-value=D | variety
+|data-sort-value=B |
+|-
+| ''Picea pungens'' f. ''compacta'' {{small|Rehder}}
+| 1915
+|data-sort-value=F | form
+|data-sort-value=B |
+|-
+| ''Picea pungens'' var. ''glauca'' {{small|Regel}}
+| 1883
+|data-sort-value=D | variety
+|data-sort-value=B |
+|-
+| ''Picea pungens'' f. ''glauca'' {{small|(Regel) Beissn.}}
+| 1887
+|data-sort-value=F | form
+|data-sort-value=B |
+|-
+| ''Picea pungens glauca-pendens'' {{small|Sudw.}}
+| 1897
+|data-sort-value=J |
+|data-sort-value=B |
+|-
+| ''Picea pungens'' f. ''glauca-pendula'' {{small|H.Kost. ex Beissn.}}
+| 1891
+|data-sort-value=F | form
+|data-sort-value=B |
+|-
+| ''Picea pungens'' var. ''hunnewelliana'' {{small|Hornibr.}}
+| 1923
+|data-sort-value=D | variety
+|data-sort-value=B |
+|-
+| ''Picea pungens'' f. ''hunnewelliana'' {{small|(Hornibr.) Rehder}}
+| 1949
+|data-sort-value=F | form
+|data-sort-value=B |
+|-
+| ''Picea pungens'' var. ''kosteriana'' {{small|A.Henry}}
+| 1912
+|data-sort-value=D | variety
+|data-sort-value=B |
+|-
+| ''Picea pungens'' f. ''kosteriana'' {{small|(A.Henry) O.L.Lipa}}
+| 1939
+|data-sort-value=F | form
+|data-sort-value=B |
+|-
+| ''Picea pungens'' f. ''pendens'' {{small|Rehder}}
+| 1949
+|data-sort-value=F | form
+|data-sort-value=B |
+|-
+| ''Picea pungens'' var. ''pendula'' {{small|(Mouill.) Zederb.}}
+| 1907
+|data-sort-value=D | variety
+|data-sort-value=B |
+|-
+| ''Picea pungens'' subvar. ''pendula'' {{small|Mouill.}}
+| 1898
+|data-sort-value=E | subvariety
+|data-sort-value=B |
+|-
+| ''Picea pungens'' f. ''pendula'' {{small|Schwer.}}
+| 1920
+|data-sort-value=F | form
+|data-sort-value=B | [[nom. illeg.]]
+|-
+| ''Picea pungens'' f. ''perpendicularis'' {{small|Schwer.}}
+| 1920
+|data-sort-value=F | form
+|data-sort-value=B |
+|-
+| ''Picea pungens'' f. ''typica'' {{small|Schwer.}}
+| 1920
+|data-sort-value=F | form
+|data-sort-value=B | [[not validly publ.]]
+|-
+| ''Picea pungens'' var. ''viridis'' {{small|Regel}}
+| 1883
+|data-sort-value=D | variety
+|data-sort-value=B |
+|-
+| ''Picea pungens'' f. ''viridis'' {{small|(Regel) O.L.Lipa}}
+| 1939
+|data-sort-value=F | form
+|data-sort-value=B |
+|-
+| ''Pinus armata'' {{small|Voss}}
+| 1907
+|data-sort-value=A | species
+|data-sort-value=B |
+|-
+| ''Pinus parryana'' {{small|(André) Voss}}
+| 1907
+|data-sort-value=A | species
+|data-sort-value=B | [[nom. illeg.]]
+|}
-Similar to the meaning of the scientific name, the [[Navajo language|Navajo]] name for this species is a compound ''c’ó deniní'' with c’ó meaning spruce and deniní meaning "it is sharp".{{sfn|Young|Morgan|1980|p=296}}
+Genetic analysis of the genus ''Picea'' indicates that the closest living relative of the blue spruce may be ''Picea mexicana'',{{sfn|Lockwood et al. 2013|p=722}} a disputed species from northern Mexico also known as ''Picea engelmannii'' subsp. ''mexicana''.{{sfn|Lockwood et al. 2013|p=719}}{{sfn|POWO 2025a}} Together they are part of a group with seven other related species that includes all the species from North America except for [[Brewer's spruce]] (''Picea breweriana''). The related species include [[Sitka spruce]] (''Picea sitchensis''), white spruce (''Picea glauca'') and Engelmann spruce (''Picea engelmannii''), black spruce (''Picea mariana''), [[red spruce]] (''Picea rubens''), [[Chihuahua spruce]] (''Picea chihuahuana''), and [[Nuevo León spruce]] (''Picea martinezii'').{{sfn|Lockwood et al. 2013|p=722}} Though visually very similar,{{sfn|Birch|DeRose|Lutz|2024|p=3}} the blue spruce and Engelmann spruce split from their common ancestor between 10 and 20&nbsp;million years ago.{{sfn|Lockwood et al. 2013|p=725}}
-== Ecology ==
+===Names===
-Blue Spruce occurs at high elevations, {{convert|1830 to 2740|m|ft|-1|spell=us}} in the [[South Central Rockies forests|forests of the South Central Rockies]] and {{convert|2130 to 3050|m|ft|-1|spell=us}} in the [[Southern Rocky Mountains]].<ref name="SilvicsNA" /> It grows in [[Mesic habitat|mesic]] montane conifer forests, often associating with [[Douglas fir|Douglas-fir]], [[Pinus ponderosa|ponderosa pine]], or [[Abies concolor|white fir]].<ref name="Earle" /> It has a [[Riparian zone|riparian]] affinity, preferring moist soils such as those along streams or at the edges of wet meadows. The Douglas-fir or ponderosa pine only become associated with streams at lower, warmer elevations. It also may be found alongside the [[quaking aspen]] (''Populus tremuloides'') in the high mountain habitats of desert ranges in the [[Intermountain West]].{{sfn|Cronquist et al. 1972|p=108, 140, 145, 224}}
+''Picea'', the genus name, is thought to come from the Latin word ''pix'' meaning "pitch", a reference to the typical sticky resin in spruce bark.{{sfn|MBG Staff|2024a}} The [[Botanical name#Binary name|specific epithet]] ''pungens'' means "sharply pointed", referring to the leaves.{{sfn|Harrison|2012|p=172}}
-=== Climate ===
+The most frequently used [[common name]] in English is ''blue spruce''. It was first used for other trees in 1817 and is still used for any spruce tree with a glaucous blue color to their needles, but most frequently meaning ''Picea pungens''.{{sfn|OED 2025a}} Though this is the most common name, in the wild only part of the population has the waxy blue-gray coating for which the tree is named.{{sfn|Cronquist et al. 1972|p=224}} Less frequently, but still common, is ''Colorado blue spruce'', a name first used in 1912. The usage of ''Colorado spruce'' dates to 1881, but is less frequent than the longer alternate.{{sfn|Quattrocchi|2012|p=2923}}{{sfn|OED 2025b}} Due to its affinity with streams and well watered canyons it is also known as the ''water spruce''.{{sfn|Nesom|2003|p=2}} Occasionally encountered are the names ''Parry's spruce'', ''prickly spruce'', ''silver spruce'', and ''white spruce''.{{sfn|Harrison|Dallimore|Jackson|1966|p=373}} Blue spruces are also rarely called ''silvertip fir'',{{sfn|Heil et al. 2013|p=89}} but this name is also applied to ''[[Abies magnifica]]'' especially when sold as Christmas trees.{{sfn|Stuart|Sawyer|2001|p=31–32}} In addition it is sometimes labeled as ''Colorado green spruce'' or ''green spruce'' by plant nurseries or tree farms.{{sfn|Forest Start Staff|2021}}{{sfn|Rhodus|2013}}
-Blue spruce usually grows in cool and humid climatic zones where the annual precipitation mainly occurs in the summer.<ref name="srs.fs.usda.gov">{{Cite web |last=Fechner |first=Gilbert H. |title=Blue Spruce |url=https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_1/picea/pungens.htm |access-date=2018-11-23}}</ref>
-Blue spruce is most common in Colorado and the Southwest. The annual average temperature ranges from 3.9 to 6.1 degrees C (39 to 43 degrees F). And ranges from - 3.9 to - 2.8 degrees C (25 to 27 degrees F) in January. In July, the average temperature ranges from 13.9 to 15.0 degrees C (57 to 59 degrees F). The average minimum temperature in January ranges from - 11.1 to 8.9 degrees C (12 to 16 degrees F), and the average maximum temperature in July ranges from 21.1 to 22.2 C (70 to 72 degrees F). There is a frost-free period of about 55 to 60 days from June to August.<ref name="Bates 152p">{{Cite journal |last=Bates |first=Carlos C. |title=Forest types in the central Rocky Mountains as affected by climate and soils |journal=U.S. Department of Agriculture, Bulletin 1233 |pages=152p}}</ref><ref>{{Cite journal |last=Pearson |first=G. A. |title=Forest types in the Southwest as determined by climate and soil. |journal=U.S. Department of Agriculture, Technical Bulletin 247 |pages=144p}}</ref>
+Similar to the meaning of the scientific name, the [[Navajo language|Navajo]] name for this species is a compound ''c'ó deniní'' with c'ó meaning spruce and deniní meaning "it is sharp".{{sfn|Young|Morgan|1980|p=296}}
-Annual mean precipitation generally vary from 460 to 610 mm (18 to 24 in). Winter is the season with the poorest rainfall, the precipitation is usually less than 20 percent of the annual moisture falling from December to March. Fifty percent{{dubious|date=April 2021}} of the annual precipitation occurs during the growing season of the plants.<ref name="Bates 152p" /><ref>{{Cite journal |last=Pearson |first=G. A. |title=Forest types in the Southwest as determined by climate and soil |journal=U.S. Department of Agriculture, Technical Bulletin 247 |pages=144p}}</ref>
+== Ecology ==
+[[File:Poecile gambeli (29592861290).jpg|left|thumb|A [[mountain chickadee]] foraging in blue spruce foliage, Bryce Canyon]]
+Blue Spruce occurs at high elevations, {{convert|1830 to 2740|m|ft|-1|spell=us}} in the [[South Central Rockies forests|forests of the South Central Rockies]] and {{convert|2130 to 3050|m|ft|-1|spell=us}} in the [[Southern Rocky Mountains]].{{sfn|Fechner|1990}} It grows in [[Mesic habitat|mesic]] montane conifer forests, often associating with [[Rocky Mountain Douglas-fir]], [[ponderosa pine]], or [[Abies concolor|white fir]].{{sfn|Earle|2025}} It has a [[Riparian zone|riparian]] affinity, preferring moist soils such as those along streams or at the edges of wet meadows. The Douglas-fir or ponderosa pine only become associated with streams at lower, warmer elevations. It also may be found alongside the [[quaking aspen]] (''Populus tremuloides'') in the high mountain habitats of desert ranges in the [[Intermountain West]].{{sfn|Cronquist et al. 1972|p=108, 140, 145, 224}} At the lowest elevations of its range it also becomes associated with aspens in the well watered stream bottoms with their deep [[alluvial soil]]s.{{sfn|Moir|Ludwig|1979|p=17}} Though associated with the Rocky Mountain Douglas-fir, the blue spruce is more tolerant of drought and [[Insolation|intense sunlight]].{{sfn|Pearson|1931|p=111}}
-Blue spruce is generally considered to grow best with abundant moisture. Nevertheless, this species can withstand drought better than any other spruce.{{sfn|Goor|Barney|1968|p=330}} It can withstand extremely low temperatures (-40 degrees C) as well. Furthermore, this species is more resistant to high insolation and frost damage compared to other associated species.<ref name="srs.fs.usda.gov" />
+Blue spruce usually grows in cool and humid climatic zones where the annual precipitation mainly occurs in the summer.{{sfn|Fechner|1990}} Blue spruce is generally considered to grow best with abundant moisture. Nevertheless, this species can withstand drought better than any other spruce.{{sfn|Goor|Barney|1968|p=330}} It can withstand extremely low temperatures (-40 degrees C) as well. Furthermore, this species is more resistant to frost damage compared to other associated species.{{sfn|Fechner|1990}}
 === Distributed soil types and topography ===
-Blue spruce generally exists on gentle uplands and sub irrigated slopes, in well-watered tributary drainage, extending down intermittent streams, and on lower northerly slopes.<ref name="Fechner">{{Cite web |last=Fechner |first=Gilbert H. |title=Blue Spruce |url=https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_1/picea/pungens.htm |access-date=2018-11-22}}</ref>
+Blue spruce generally exists on gentle uplands and sub irrigated slopes, in well-watered tributary drainage, extending down intermittent streams, and on lower northerly slopes.{{sfn|Fechner|1990}}
-Blue spruce always grow naturally in the soils which are in the order Mollisols, and the soil will also be in the orders histosols and inceptisols in a lesser extent.<ref name="Fechner" /><ref name="Mauk & Henderson" /><ref>{{Cite journal |last1=Moir |first1=William H. |last2=Ludwig |first2=John A. |title=A classification of spruce-fir mixed conifer habitat types of Arizona and New Mexico. |journal=USDA Forest Service, Research Paper RM-207.}}</ref>
+Blue spruce is considered as a pioneer tree species in moist soil in Utah.{{sfn|Dixon|p=290}}
-Blue spruce is considered as a pioneer tree species in moist soil in Utah.<ref>{{Cite journal |last=Dixon |first=Helen |year=1935 |title=Ecological Studies on the High Plateaus of Utah. |journal=Botanical Gazette |volume=97 |issue=2 |pages=272–320 |doi=10.1086/334554 |jstor=2471603 |s2cid=84538967}}</ref>
 === Rooting habits ===
-Blue spruce seedlings have shallow roots that penetrate approximately {{convert|2.5|in|cm|0|order=flip|spell=us}} into the soil during the first year of growth.{{sfn|Jones|1973|p=47}} Although freezing can't damage much in blue spruce, [[frost heaving]] will cause seedling loss. Shadows in late spring and early autumn minimize this frost heaving loss.<ref>{{cite journal |last1=Alexander |first1=Robert R. |date=1974 |title=Silviculture of central and southern Rocky Mountain forests: a summary of the status of our knowledge by timber types |url=https://archive.org/details/CAT92273314 |journal=USDA Forest Service Research Paper |language=en |location=Fort Collins, Colorado |publisher=Rocky Mountain Forest and Range Experiment Station |issue=RM-120 |page=19 |access-date=5 October 2024}}</ref><ref name=":2">{{Cite journal |last=Pearson |first=G. A. |title=Forest types in the Southwest as determined by climate and soil. |journal=U.S. Department of Agriculture, Technical Bulletin 247}}</ref> Despite the shallow roots, blue spruce is able to resist strong winds.{{sfn|Goor|Barney|1968|p=330}} Five years before transplanting, the total root surface area of 2-meter-high trees was doubled by pruning the roots of blue spruce. It also increases the root concentration in drip irrigation pipeline from 40% to 60%, which is an advantage in landscape greening.<ref>{{cite journal |last1=Watson |first1=Gary |last2=Sydnor |first2=T. Davis |date=1 May 1987 |title=The Effect of Root Pruning on the Root System of Nursery Trees |url=https://auf.isa-arbor.com/content/13/5/126 |journal=Arboriculture & Urban Forestry |language=en |volume=13 |issue=5 |pages=126–130 |doi=10.48044/jauf.1987.027 |doi-access=free |access-date=5 October 2024}}</ref>
+Blue spruce seedlings have shallow roots that penetrate approximately {{convert|2.5|in|cm|0|order=flip|spell=us}} into the soil during the first year of growth.{{sfn|Jones|1973|p=47}} Although freezing can't damage much in blue spruce, [[frost heaving]] will cause seedling loss. Shadows in late spring and early autumn minimize this frost heaving loss.{{sfn|Alexander|1974|p=19}} Despite the shallow roots, blue spruce is able to resist strong winds.{{sfn|Goor|Barney|1968|p=330}}
 === Pests and diseases ===
-The blue spruce is attacked by two species of ''[[Adelges]]'', an aphid-like insect that causes galls to form. [[Nymph (biology)|Nymphs]] of the [[pineapple gall adelgid]] form galls at the base of twigs which resemble miniature pineapples and those of the [[Gall adelgid|Cooley's spruce gall adelgid]] cause cone-shaped galls at the tips of branches. The larva of the [[spruce budworm]] eat the buds and growing shoots while the [[spruce needle miner]] hollows out the needles and makes them coalesce in a webbed mass. An elongated white [[scale insect]], the [[Chionaspis pinifoliae|pine needle scale]] feeds on the needles causing fluffy white patches on the twigs and aphids also suck sap from the needles and may cause them to fall and possibly dieback. Mites can also infest the blue spruce, especially in a dry summer, causing yellowing of the oldest needles.<ref name="IFAS">{{cite web |author1=Gilman, Edward F. |author2=Watson, Dennis G. |date=2011-05-01 |title=''Picea pungens'': Colorado Spruce |url=http://edis.ifas.ufl.edu/st453 |access-date=2013-10-06 |work=EDIS |publisher=IFAS Extension Service: University of Florida}}</ref><ref>{{cite web |author=Cranshaw, W. S. |date=2013-06-13 |title=Scale Insects Affecting Conifers |url=http://www.ext.colostate.edu/pubs/insect/05514.html |access-date=2013-10-05 |publisher=Colorado State University Extension}}</ref> Another insect pest is the [[Dendroctonus rufipennis|spruce beetle]] (''Dendroctonus rufipennis'') which bores under the bark. It often first attacks trees which have blown over by the wind and when the larvae mature two years afterwards, a major outbreak occurs and vast numbers of beetles attack nearby standing trees.<ref>{{cite web |author=Ciesla, Bill |date=2013-04-19 |title=Spruce Beetle Threatens High Country Spruce Forests |url=http://www.ext.colostate.edu/pubs/columngw/gr120421.html |access-date=2013-10-05 |publisher=Colorado State University Extension}}</ref>
+The blue spruce is attacked by two species of ''[[Adelges]]'', an aphid-like insect that causes galls to form. [[Nymph (biology)|Nymphs]] of the [[pineapple gall adelgid]] form galls at the base of twigs which resemble miniature pineapples and those of the [[Gall adelgid|Cooley's spruce gall adelgid]] cause cone-shaped galls at the tips of branches. The larva of the [[spruce budworm]] eat the buds and growing shoots while the [[Taniva|spruce needle miner]] hollows out the needles and makes them coalesce in a webbed mass.{{sfn|Gilman|Watson|2006|p=3}} An elongated white [[scale insect]], the [[Chionaspis pinifoliae|pine needle scale]] feeds on the needles causing fluffy white patches on the twigs and aphids also suck sap from the needles and may cause them to fall and possibly dieback.{{sfn|Cranshaw|2013|p=1}} Mites can also infest the blue spruce, especially in a dry summer, causing yellowing of the oldest needles.{{sfn|Gilman|Watson|2006|p=3}} An occasional insect pest is the [[spruce beetle]] (''Dendroctonus rufipennis'') which bores under the bark. It is much more likely to use Engelmann spruces as the host trees and generally prefers to feed on trees that have been knocked over unless their numbers become very high.{{sfn|Grant et al. 2014|p=1}}
-The blue spruce is susceptible to several needle casting diseases which cause the needles to turn yellow, mottled or brown before they fall off. Various rust diseases also affect the tree causing yellowing of the needles as well as needle fall. [[Canker]] caused by ''[[Cytospora]]'' attacks one of the lower branches first and progressively makes its way higher up the tree. The first symptom is the needles turning reddish-brown and falling off. Meanwhile, patches of white [[resin]] appear on the bark and the branch eventually dies.<ref name="IFAS" />
+The blue spruce is susceptible to several needle casting diseases which cause the needles to turn yellow, mottled or brown before they fall off. Various rust diseases also affect the tree causing yellowing of the needles as well as needle fall. [[Canker]] caused by ''[[Cytospora]]'' attacks one of the lower branches first and progressively makes its way higher up the tree. The first symptom is the needles turning reddish-brown and falling off. Meanwhile, patches of white [[resin]] appear on the bark and the branch eventually dies.{{sfn|Gilman|Watson|2006|p=3}}
+In Britain and central Europe ornamental blue spruces are damaged by the [[Elatobium abietinum|spruce aphid]] (''Elatobium abietinum''), particularly after mild winters.{{sfn|Johnson|2014|pp=7–8}}{{sfn|Forest Research|2025}} This species has become established in North America since 1915 and in the southwestern United States since 1976.{{sfn|Lynch|2014|p=259}} In the southwest it attacks wild populations of Engelmann spruce and the blue spruce, though with a somewhat lower severity. Heavily infested trees will lose their needles or die for up to three years after being damaged.{{sfn|Lynch|2014|p=261}}
 It is also relatively intolerant of light pollution and when planted near street lights or other outdoor lighting its preparation for winter can be delayed and parts of the tree may be damaged.{{sfn|Sjöman|Anderson|2023|p=161–163}}
 ==Range==
-The native range of the blue spruce is largely in the [[Central Rocky Mountains|Central]] and [[Southern Rocky Mountains]] and moist mountain valleys and canyons to the west.{{sfn|Barnes|Wagner|1981|p=78}}{{sfn|Cronquist et al. 1972|p=224}} In New Mexico it only grows naturally in the higher mountain ranges of the state such as the [[Sandia–Manzano Mountains]], [[Sangre de Cristo Mountains]], and [[San Juan Mountains]], as well as on [[Sierra Blanca Peak]] to the south.{{sfn|Wooton|Standley|1915|p=34}}{{sfn|Little|1950|p=18}} In Arizona the range is even more limited, growing in just [[Coconino County, Arizona|Coconio]] and [[Apache County, Arizona|Apache]] counties.<ref name="USDA">{{cite usda plants|symbol=PIPU |title=Picea pungens |date=5 October 2024}}</ref> In Apache County it is found in the [[White Mountains (Arizona)|White Mountains]] in central eastern Arizona and the [[Lukachukai Mountains]] in the northeastern corner of the state. In Coconino County they only grow on the [[Kaibab Plateau]].{{sfn|Little|1950|p=18}} The blue spruce grows in every county in the western two-thirds of Colorado;{{sfn|Ackerfield|2015|p=61}} approximately half of natural range of the species is in the mountains of Colorado.{{sfn|Johnson|2014|p=2}} In Utah they are a locally common part of forests in the [[Uinta Mountains]]. West of the Uintas blue spruces are less frequent in canyons south of Salt Lake City.<ref name="Mauk & Henderson">{{cite journal |last1=Mauk |first1=Ronald L. |last2=Henderson |first2=Jan A. |date=1984 |title=Coniferous Forest Habitat Types of Northern Utah |url=https://archive.org/details/CAT85822482 |journal=USDA Forest Service General Technical Report |language=en |location=Ogden, Utah |publisher=Intermountain Forest and Range Experiment Station |issue=INT-170 |pages=31–32 |access-date=9 October 2024}}</ref>
+[[File:Picea pungens Bryce Canyon NP 2.jpg|thumb|Blue spruces in [[Bryce Canyon]], Utah]]
+The native range of the blue spruce is largely in the [[Central Rocky Mountains|Central]] and [[Southern Rocky Mountains]] and moist mountain valleys and canyons to the west.{{sfn|Barnes|Wagner|1981|p=78}}{{sfn|Cronquist et al. 1972|p=224}} In New Mexico it only grows naturally in the higher mountain ranges of the state such as the [[Sandia–Manzano Mountains]], [[Sangre de Cristo Mountains]], and [[San Juan Mountains]], as well as on [[Sierra Blanca Peak]] to the south.{{sfn|Wooton|Standley|1915|p=34}}{{sfn|Little|1950|p=18}} In Arizona the range is even more limited, growing in just [[Coconino County, Arizona|Coconino]] and [[Apache County, Arizona|Apache]] counties.{{sfn|NRCS 2025}} In Apache County it is found in the [[White Mountains (Arizona)|White Mountains]] in central eastern Arizona and the [[Lukachukai Mountains]] in the northeastern corner of the state. In Coconino County they only grow on the [[Kaibab Plateau]].{{sfn|Little|1950|p=18}} The blue spruce grows in every county in the western two-thirds of Colorado;{{sfn|Ackerfield|2015|p=61}} approximately half of natural range of the species is in the mountains of Colorado.{{sfn|Johnson|2014|p=2}} In Utah they are a locally common part of forests in the [[Uinta Mountains]]. West of the Uintas blue spruces are less frequent in canyons south of Salt Lake City.{{sfn|Mauk & Henderson 1984|pp=31–32}}
-The blue spruce has become [[Naturalisation (biology)|naturalized]] outside of its native range. In North America has escaped from cultivation in the states of Minnesota and New York. It has also become established to some extent in many western and northern European countries including Iceland, Norway, Sweden, the United Kingdom, France, and Belgium. In middle and southern Europe it is found in Germany, Switzerland, Austria, the former Czechoslovakia, and mainland Italy. To the east it grows in European portions of Russia, the Caucasus, and Bulgaria.<ref name="POWO" />
+The blue spruce has only very rarely become [[Naturalisation (biology)|naturalized]] outside of its native range and is not considered an [[invasive species]].{{sfn|Richardson|Rejmánek|2004|p=325}} In North America has escaped from cultivation in the states of Minnesota, Maryland, Pennsylvania, New York, and Maine as well as in the Canadian provinces of Onterio and Nova Scotia,{{sfn|NRCS 2025}}{{sfn|VASCAN 2025}} and it is considered naturalized in New York and New England.{{sfn|Richardson|Rejmánek|2004|p=331}} In Europe it has been found outside cultivation in many areas including Iceland, on Great Britain, in Norway, and Sweden. It is also known from France, Belgium, Germany, Switzerland, Italy, and Austria.{{sfn|POWO 2025b}}
+In the former Czechoslovakia in the 1970s and 1980s large areas of forest died due to sulpher dioxde pollution from coal fired power plants.{{sfn|Šrámek et al. 2008|p=216}} In the [[Ore Mountains]] the Ministry of Agriculture of the Czech Republic replanted many areas with non-native species including {{Convert|8800|ha|sp=us}} with blue spruce, second in area only to the birch tree.{{sfn|Šrámek et al. 2008|pp=216, 2018}} Small numbers were also planted on the upper plateau of the [[Jizera Mountains]] when new forests were established in the 1990s alongside the [[Serbian spruce]]s (''Picea omorica''), although the majority of spruces planted were the native European spruce.{{sfn|Kuneš|Baláš|Lánský|2020|pp=D8–D9}} Despite the large areas planted they have not established themselves outside of cultivation.{{sfn|Krivánek|Pyšek|Jarošík|2006|p=1489}}
+In Eastern Europe they are an introduced species in the [[Baltic States]], central European Russia, Bulgaria, and the [[Transcaucasus]].{{sfn|POWO 2025b}}
 ==Notable trees==
-The tallest documented blue spruce tree is an individual in the [[San Juan Mountains]] of southern Colorado in the [[Hermosa Creek]] area. When measured by Matt Markworth in 2015 it was {{convert|54.9|m|ft|spell=us}} tall.<ref name="Earle" /> Just three years later in 2018 it was threatened by the [[416 Fire]]. Though the fire killed a shorter {{cvt|165.5|ft|m|order=flip}} American [[National Register of Champion Trees|champion tree]] with a larger trunk and crown spread the tall tree was spared due to being located in a sheltered valley.<ref>{{Cite web |url=https://www.americanforests.org/article/a-tale-of-two-trees-and-a-wildfire/ |title=A Tale of Two Trees and a Wildfire |last1=Harper |first1=Liz |website=American Forests |language=en |access-date=30 November 2024 |url-status=live |archive-url=https://web.archive.org/web/20241130045318/https://www.americanforests.org/article/a-tale-of-two-trees-and-a-wildfire/ |archive-date=30 November 2024}}</ref>
+The tallest documented blue spruce tree is an individual in the [[San Juan Mountains]] of southern Colorado in the [[Hermosa Creek]] area. When measured by Matt Markworth in 2015 it was {{convert|54.9|m|ft|spell=us}} tall.{{sfn|Earle|2025}} Just three years later in 2018 it was threatened by the [[416 Fire]]. Though the fire killed a shorter {{cvt|165.5|ft|m|order=flip}} American [[National Register of Champion Trees|champion tree]] with a larger trunk and crown spread the tall tree was spared due to being located in a sheltered valley.{{sfn|Harper|2018}}
+The National Champion Tree for the species is one located in the Wasatch Range in Utah. When last measured in 2020 it was {{Cvt|129|ft|order=flip}} tall with a crown spread of {{Cvt|41|ft|order=flip}} and a diameter at breast height of {{Cvt|63.5|in|m|1|order=flip}}.{{sfn|NCTP Staff|2020}}
+A tree named Old Blue by researchers found in the [[Cedar Breaks National Monument]] when cored in 2024 was dated to sprouting in 1564, an age of {{age|1564|3|01}} years.{{sfn|Birch|DeRose|Lutz|2024|pp=2, 5}} This is the oldest known blue spruce tree.{{sfn|Birch|DeRose|Lutz|2024|p=8}}
 ==Cultivation==
-[[File:2015-05-18 13 01 32 Blue Spruce new growth along Terrace Boulevard in Ewing, New Jersey.jpg|thumb|'Mission Blue' blue spruce new growth in spring]]''Picea pungens'' and its many [[cultivar]]s are often grown as [[ornamental tree]]s in gardens and parks.{{sfn|Barnes|Wagner|1981|p=78}}<ref name="Earle" /> It is also grown for the [[Christmas tree]] industry.<ref name="SilvicsNA" /> It grows best in USDA [[Hardiness zone|growing zones]] 1 through 7,<ref>{{cite web |title=Colorado Blue Spruce |url=https://treecanada.ca/resources/trees-of-canada/colorado-blue-spruce-picea-pungens/ |access-date=2018-11-20 |publisher=treecanada.ca}}</ref> though it also does well in zones warmer than 7 where summer heat is moderate, as at [[San Francisco]].<ref>{{cite web |date=11 February 2023 |title=Blue spruce (Picea pungens) |url=https://inaturalist.ca/observations/148544834}}</ref>
+[[File:2015-05-18 13 01 32 Blue Spruce new growth along Terrace Boulevard in Ewing, New Jersey.jpg|thumb|'Mission Blue' blue spruce new growth in spring]]''Picea pungens'' and its many [[cultivar]]s are often grown as [[ornamental tree]]s in gardens and parks.{{sfn|Barnes|Wagner|1981|p=78}}{{sfn|Earle|2025}} It is also grown for the [[Christmas tree]] industry.{{sfn|Fechner|1990}} Though the blue spruce prefers moist soils, in particularly wet or rocky soils it will root very shallowly in the soil and will therefore be vulnerable to [[windthrow]], being blown over in high winds, in exposed locations.{{sfn|Barnes|Wagner|1981|p=78}} It grows best in USDA [[Hardiness zone|growing zones]] 2 through 7, although when planted in zone 7 it has a hard time coping with high temperatures during the night.{{sfn|Bayer|Brazee|Simisky|2020}}
-Common cultivars (those marked {{smallcaps|agm}} have gained the [[Royal Horticultural Society]]'s [[Award of Garden Merit]]):<ref>{{cite web |date=July 2017 |title=AGM Plants - Ornamental |url=https://www.rhs.org.uk/plants/pdfs/agm-lists/agm-ornamentals.pdf |access-date=25 April 2018 |publisher=Royal Horticultural Society |page=78}}</ref>
+Common cultivars (those marked {{smallcaps|agm}} have gained the [[Royal Horticultural Society]]'s [[Award of Garden Merit]]):{{sfn|RHS Staff|2024|p=94}}
-*'Baby Blue Eyes', 'Baby Blueeyes', or 'Baby Blue'<ref>{{cite web |url=https://www.pnwplants.wsu.edu/PlantDisplay.aspx?PlantID=243 |title=Baby Blue Colorado Spruce - ''Picea pungens'' 'Baby Blue Eyes' |website=WSU Clark County Extension – PNW Plants |publisher=[[Washington State University]] |location=Pullman, Washington |language=en |access-date=24 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20240713230735/https://pnwplants.wsu.edu/PlantDisplay.aspx?PlantID=243 |archive-date=13 July 2024}}</ref> – This is a semi-dwarf cultivar that grows slowly, but may eventually reach {{convert|15|–|20|ft|m|order=flip|spell=us}} in height. It has a pyramidal shape and holds its color well.<ref>{{cite web |url=https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=267995 |title=''Picea pungens'' 'Baby Blueeyes' |website=Plant Finder |publisher=[[Missouri Botanical Garden]] |location=St. Louis, Missouri |language=en |access-date=24 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20240924214557/https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=267995 |archive-date=24 September 2024}}</ref>
+*'Baby Blue Eyes',{{sfn|Brough|Weber|1997|p=65}} 'Baby Blueeyes', or 'Baby Blueyes' – This is a semi-dwarf cultivar that grows slowly, but may eventually reach {{Cvt|15|–|20|ft|m|order=flip}} in height. It has a pyramidal shape and holds its color well.{{sfn|MBG Staff|2024b}}
-*'Fat Albert' – compact perfect cone to {{convert|10|–|15|ft|m|order=flip|spell=us}} of a silver blue color<ref>{{cite web |url=https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=e660 |title=''Picea pungens'' 'Fat Albert' |website=Plant Finder |publisher=[[Missouri Botanical Garden]] |location=St. Louis, Missouri |language=en |access-date=24 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20230228205616/https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=e660 |archive-date=28 February 2023}}</ref>
+*'Edith' {{smallcaps|agm}} – A small and slow growing tree that takes 20 to 50 years to reach a height of {{Cvt|2.5–4|m}} with a spread of 1.5–2.5&nbsp;m. Its shape is conical.{{sfn|RHS Staff|2025a}}
-*'Globosa' {{smallcaps|agm}}<ref>{{cite web |url=https://www.rhs.org.uk/plants/91537/picea-pungens-(glauca-group)-globosa/details |title=''Picea pungens'' (Glauca Group) 'Globosa' – Colorado spruce 'Globosa' |website=Conifers/RHS |publisher=[[Royal Horticultural Society]] |location=London |language=en |access-date=24 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20240228133347/https://www.rhs.org.uk/plants/91537/picea-pungens-(glauca-group)-globosa/details |archive-date=28 February 2024}}</ref> – shrub from {{convert|3|–|5|ft|cm|-1|order=flip|spell=us}} in height<ref>{{cite web |url=https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=c825 |title=''Picea pungens'' 'Glauca Globosa' |website=Plant Finder |publisher=[[Missouri Botanical Garden]] |location=St. Louis, Missouri |language=en |access-date=24 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20240523081243/http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=c825 |archive-date=23 May 2024}}</ref>
+*'Fat Albert' {{smallcaps|agm}} – A symetrical perfect cone reaching {{Cvt|2.5–4|m}} in height and spreading 1.5–2.5&nbsp;m after about 10 to 20 years.{{sfn|RHS Staff|2025b}} When allowed to grow longer it can reach {{cvt|15–20|m}}. The needles are blue with less gray/silver tones and are softer than many other cultivars.{{sfn|Bloom|2002|p=134}}
-*'Hoopsii' {{smallcaps|agm}}<ref>{{cite web |url=https://www.rhs.org.uk/plants/98036/picea-pungens-(glauca-group)-hoopsii/details |title=''Picea pungens'' (Glauca Group) 'Hoopsii' – Colorado spruce 'Hoopsii' |website=Conifers/RHS |publisher=[[Royal Horticultural Society]] |location=London |language=en |access-date=24 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20211208133848/https://www.rhs.org.uk/plants/98036/picea-pungens-(glauca-group)-hoopsii/details |archive-date=8 December 2021}}</ref> – A full size variety with a dense pyramidal habit known for "excellent" silver-blue color of its foliage. It reaches {{convert|30|–|50|ft|m|order=flip|spell=us}} tall when full grown.<ref>{{cite web |url=https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=255100 |title=''Picea pungens'' 'Hoopsii' |website=Plant Finder |publisher=[[Missouri Botanical Garden]] |location=St. Louis, Missouri |language=en |access-date=24 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20240703052242/https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=255100 |archive-date=3 July 2024}}</ref>
+*'Globosa' {{smallcaps|agm}}{{sfn|RHS Staff|2025c}} – shrub from {{Cvt|3|–|5|ft|cm|-1|order=flip}} in height,{{sfn|MBG Staff|2024c}} though it takes 20–50 years to reach full size{{sfn|RHS Staff|2025c}}
-*'Koster' – A medium sized cultivar that will reach {{convert|8|–|10|m|ft|spell=us}}<ref> with a conical shape{{cite web |url=https://www.rhs.org.uk/plants/59991/picea-pungens-(glauca-group)-koster/details |title=''Picea pungens'' (Glauca Group) 'Koster' – Colorado spruce 'Koster' |website=Conifers/RHS |publisher=[[Royal Horticultural Society]] |location=London |language=en |access-date=24 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20240924213602/https://www.rhs.org.uk/plants/59991/picea-pungens-(glauca-group)-koster/details |archive-date=24 September 2024}}</ref>
+*'Hoopsii' {{smallcaps|agm}}{{sfn|RHS Staff|2025d}} – A full size variety with a dense pyramidal habit known for "excellent" silver-blue color of its foliage. It reaches {{Cvt|30|–|50|ft|m|order=flip}} tall when full grown.{{sfn|MBG Staff|2024d}}
-*'Montgomery' – a slow growing dwarf variety. It will typically only grow {{convert|3|–|4|ft|cm|-1|order=flip|spell=us}} tall in eight years, but may eventually reach a height of over {{convert|8|ft|m|order=flip|spell=us}}.<ref>{{cite web |url=https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=263630 |title=''Picea pungens'' 'Montgomery' |website=Plant Finder |publisher=[[Missouri Botanical Garden]] |location=St. Louis, Missouri |language=en |access-date=24 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20240921173347/https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=263630 |archive-date=21 September 2024}}</ref>
+*'Koster' or 'Kosteri'{{sfn|Brand|2015}} – A medium sized conical cultivar that will reach {{Cvt|8|–|12|m|ft}} tall with a spread of 2.5–4&nbsp;m after 20 to 50 years.{{sfn|RHS Staff|2025d}} It was introduced to the plant trade in 1915,{{sfn|Krüssmann|1972|p=95}} but became less popular by the 2000s due to grafted trees haveing unpreditable qualities.{{sfn|Brand|2015}}
-*'Pendula' – drooping branches, spreads to about {{convert|4|–|10|ft|m|order=flip|spell=us}} wide by {{convert|2|–|6|ft|m|1|order=flip|spell=us}} tall<ref>{{cite web |url=https://plants.ces.ncsu.edu/plants/picea-pungens-pendula/ |title=''Picea pungens'' 'Pendula' |website=North Carolina Extension Gardener Plant Toolbox |publisher=[[North Carolina State University]] |location=Raleigh, North Carolina |language=en |access-date=24 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20240922202453/https://plants.ces.ncsu.edu/plants/picea-pungens-pendula/ |archive-date=22 September 2024}}</ref>
+*'Montgomery' or 'R.H. Montgomery' – A slow growing dwarf variety. It will typically only grow {{Cvt|3|–|4|ft|cm|-1|order=flip}} tall in eight years, but may eventually reach a height of over {{Cvt|8|ft|m|order=flip}}.{{sfn|MBG Staff|2024e}} It has tightly packed branches and silvery-blue needles.{{sfn|Brand|2015}}
-*'Sester's Dwarf' – denser foliage than the species, slowly grows to about {{convert|6|–|8|ft|m|1|order=flip|spell=us}} tall<ref>{{cite web |url=https://pnwplants.wsu.edu/PlantDisplay.aspx?PlantID=253 |title=Sester's Dwarf Blue Spruce - ''Picea pungens'' 'Sester's Dwarf' |website=WSU Clark County Extension – PNW Plants |publisher=[[Washington State University]] |location=Pullman, Washington |language=en |access-date=24 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20240707110222/https://www.pnwplants.wsu.edu/PlantDisplay.aspx?PlantID=253 |archive-date=7 July 2024}}</ref>
+*'Pendula' or 'Glauca Pendula'{{sfn|Bloom|2002|p=136}} – A Cultivar with drooping branches, spreads to about {{Cvt|4|–|10|ft|m|order=flip}} wide by {{convert|2|–|6|ft|m|1|order=flip|spell=us}} tall.{{sfn|NCCE Staff|2025b}} It often must be tied to a stake for many years to prevent it growing on the ground.{{sfn|Bloom|2002|p=136}}
+*'Walnut Glen' or 'Goldie' – A cultivar that grows slowly to {{Cvt|1.5–1.8|m}}, but can eventually reach {{Cvt|7–10|m}}. It has cream colored new shoots in the spring that turn a more typical gray-blue. It requires shade in the morning to prevent being damaged by the sun and is also vulnerable to frost damage.{{sfn|Bloom|2002|pp=136–137}}
 [[File:Picea pungens 'Glauca globosa' in Autumn.JPG|thumb|Foliage of the cultivar 'Globosa']]
+Blue spruce trees are used in [[windbreak]]s around gardens, fields, or farm structures.{{sfn|Bloom|2002|p=36}} They are recommended for this use by [[Agricultural extension|extension services]] in Montana,{{sfn|Kolb|2023|pp=10–12}} North Dakota,{{sfn|Herman et al. 1996}} Oregon,{{sfn|Detweiler|2005}} and Pennsylvania.{{sfn|Swackhamer|Sellmer|2023}}
+While in general broad leaved trees produce deeper and higher quality soils on mine reclamation sites, the blue spruce is among the best of the conifers.{{sfn|Spasić et al. 2024|p=561}} Though it is less tolerant of drought conditions than other trees such as the [[ponderosa pine]].{{sfn|Spasić et al. 2024|p=577}} After 50 years on a reclaimed coal mine in Central Europe blue spruce trees formed organic soils with a depth of 4&nbsp;cm.{{sfn|Spasić et al. 2024|p=566}}
+The wood of the blue spruce is very infrequently used due to being brittle and with an excessive number of [[Knot (wood)|knots]] as well as being a less common tree.{{sfn|Zeidler et al. 2024|p=3}}{{sfn|Nesom|2003|p=1}} It has only 65% of the bending strength of the European spruce (''Picea abies'').{{sfn|Zeidler et al. 2024|p=6}}
 ==Culture==
-The [[Navajo people|Navajo]] and [[Keresan languages|Keres]] Native Americans use this tree as a traditional [[medicinal plant]] and a ceremonial item, and twigs are given as gifts to bring good fortune. In traditional medicine, an infusion of the needles is used to treat colds and settle the stomach. This liquid is also used externally for rheumatic pains.<ref>[http://naeb.brit.org/uses/species/2936/ U. Michigan-Dearborn: Ethnobotany] Accessed 2020-12-20</ref>
+In the traditions of the [[Acoma Pueblo|Acoma]] and [[Laguna Pueblo|Laguna]] pueblos, the western [[Keres people]], the blue spruce is used as a treatment for [[rheumatism]] and the [[common cold]]. The needles are infused in hot water and the patient bathes in it. It was also used in ceremonies where dancers would have spruce twigs attached to their arms. Audience members would take parts of these twigs to steep and drink for stomach health.{{sfn|Swank|1932|p=60}} During the [[Navajo people|Navajo]] Chant of the Sun's House branches of Douglas-fir and blue spruce are used.{{sfn|Elmore|1944|pp=20–21}} They also traditionally use very ripe fruit of the [[plains pricklypear]] (''Opuntia polyacantha'') with the addition of a handful of the bark or roots of blue spruce to make a dye to color wool pink.{{sfn|Elmore|1944|p=65}}
-The blue spruce is the [[state tree]] of [[Colorado]].<ref>{{cite web |date=June 11, 2009 |title=State Trees & State Flowers |url=http://www.usna.usda.gov/Gardens/collections/statetreeflower.html |url-status=dead |archive-url=https://web.archive.org/web/20101206125016/http://www.usna.usda.gov/Gardens/collections/statetreeflower.html |archive-date=2010-12-06 |access-date=2010-05-26 |publisher=[[United States National Arboretum]]}}</ref> It officially became Colorado's state tree on 7 March 1939 when House Joint Resolution 7 was enacted by the legislature. Previously a vote of the state's school children was taken on [[Arbor Day]] in 1892 expressing their preference for the blue spruce as the state tree.<ref>{{cite web |url=https://archives.colorado.gov/collections/symbols-emblems |title=Symbols & Emblems |website=Colorado State Archives |publisher=[[Government of Colorado]] |access-date=25 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20240818200929/https://archives.colorado.gov/collections/symbols-emblems |archive-date=18 August 2024}}</ref>
+The blue spruce is the [[state tree]] of [[Colorado]].{{sfn|Jorgenson|1992|p=18}} It officially became Colorado's state tree on 7 March 1939 when House Joint Resolution 7 was enacted by the legislature. Previously a vote of the state's school children was taken on [[Arbor Day]] in 1892 expressing their preference for the blue spruce as the state tree.{{sfn|CO Archives|2024}}
-From 1933 until 2014 the blue spruce was also the state tree of Utah. It was replaced by the [[quaking aspen]] because the aspen is a great deal more common than the blue spruce in Utah, making up 10% of the state's tree cover.<ref>{{cite news |last1=Randle |first1=Sterling |date=13 February 2014 |title=Quaking Aspen moves closer to replacing Blue Spruce as State Tree |url=https://universe.byu.edu/2014/02/13/quaking-aspen-moves-closer-to-replacing-blue-spruce-as-state-tree/ |url-status=live |work=BYU Daily Universe |language=en |publisher=[[Brigham Young University]] |archive-url=https://web.archive.org/web/20240603120256/https://universe.byu.edu/2014/02/13/quaking-aspen-moves-closer-to-replacing-blue-spruce-as-state-tree/ |archive-date=3 June 2024 |access-date=25 September 2024}}</ref><ref>{{cite news |last1=Wood |first1=Benjamin |date=26 March 2024 |title=Student-advocated state tree bill signed into law |url=https://www.deseret.com/2014/3/26/20538192/student-advocated-state-tree-bill-signed-into-law/ |url-status=live |work=Deseret News |location=Monroe, Utah |archive-url=https://web.archive.org/web/20221123173256/https://www.deseret.com/2014/3/26/20538192/student-advocated-state-tree-bill-signed-into-law |archive-date=23 November 2022 |access-date= }}</ref>
+From 1933 until 2014 the blue spruce was also the state tree of Utah. It was replaced by the [[quaking aspen]] because the aspen is a great deal more common than the blue spruce in Utah, making up 10% of the state's tree cover.{{sfn|Randle|2014}}{{sfn|Wood|2014}}
+It is moderately popular as a Christmas tree in the United States and has been used as the [[Capitol Christmas Tree]] in Washington, D.C. four times since they began to be regularly erected in 1964.{{sfn|Earle|2025}}
 ==Gallery==
@@ Line 129: / Line 332: @@
 ==References==
-; Books
+===Sources===
-{{Refbegin}}
+====Books====
-* {{cite book |last1=Ackerfield |first1=Jennifer |editor-last1=Lipscomb |date=2015 |title=Flora of Colorado |language=en |edition=First |location=Fort Worth, Texas |publisher=Botanical Research Institute of Texas |page=61 |isbn=978-1-889878-45-4 |oclc=910162216}}
+{{Refbegin|30em}}
-* {{cite book |last1=Barnes |first1=Burton V. |author-link1=Burton V. Barnes |last2=Wagner |first2=Warren H. Jr. |author-link2=Warren H. Wagner |others=Illustrations by Sarah Phelps |date=1981 |orig-date=1913 |title=Michigan Trees: A Guide to the Trees of Michigan and the Great Lakes Region |url=https://archive.org/details/michigantreesgui00barn/page/78 |url-access=registration |language=en |edition=Revised and Enlarged |location=Ann Arbor, Michigan |publisher=University of Michigan Press |pages=78–79 |isbn=978-0-472-08018-2 |lccn=80039717 |oclc=7170918 |access-date=1 October 2024}}
+* {{Cite book |last1=Ackerfield |first1=Jennifer |editor-last1=Lipscomb |date=2015 |title=Flora of Colorado |language=en |edition=First |location=Fort Worth, Texas |publisher=Botanical Research Institute of Texas |isbn=978-1-889878-45-4 |oclc=910162216}}
-* {{Cite book |last1=Cronquist |first1=Arthur |author-link1=Arthur Cronquist |last2=Holmgren |first2=Arthur H. |last3=Holmgren |first3=Noel H. |last4=Reveal |first4=James L. |author-link4=James L. Reveal |date=1972 |title=Intermountain Flora: Vascular Plants of the Intermountain West, U.S.A. |url=https://archive.org/details/intermountainflo0001aeta/page/224 |url-access=registration |language=en |volume=1. Geological and Botanical History of the Region, Its Plant Geography and a Glossary. The Vascular Cryptogams and the Gymnosperms |edition=First |location=Bronx, New York |publisher=New York Botanical Garden |oclc=320442 |access-date=30 November 2024 |ref={{sfnref|Cronquist et al. 1972}}}}
+* {{Cite book |last1=Barnes |first1=Burton V. |author-link1=Burton V. Barnes |last2=Wagner |first2=Warren H. Jr. |author-link2=Warren H. Wagner |others=Illustrations by Sarah Phelps |date=1981 |orig-date=1913 |title=Michigan Trees: A Guide to the Trees of Michigan and the Great Lakes Region |url=https://archive.org/details/michigantreesgui00barn |url-access=registration |language=en |edition=Revised and Enlarged |location=Ann Arbor, Michigan |publisher=University of Michigan Press |isbn=978-0-472-08018-2 |lccn=80039717 |oclc=7170918 |access-date=1 October 2024}}
-* {{cite book |last1=Goor |first1=Amihud Y. |last2=Barney |first2=Charles Wesley |date=1968 |title=Forest Tree Planting in Arid Zones |url=https://archive.org/details/foresttreeplanti0000goor/page/330 |url-access=registration |language=en |edition=First |location=New York |publisher=Ronald Press Company |page=330 |oclc=419436 |access-date=3 December 2024}}
+* {{Cite book |last1=Bloom |first1=Adrian |date=2002 |title=Gardening With Conifers |url=https://archive.org/details/gardeningwithcon0000bloo |location=Willowdale, Onterio |publisher=Firefly Books |isbn=978-1-55209-635-2 |oclc=47161059 |access-date=8 November 2025}}
-* {{cite book |last1=Harrison |first1=S.G. |last2=Dallimore |first2=William |author-link2=William Dallimore |last3=Jackson |first3=A. Bruce |author-link3=Albert Bruce Jackson |date=1966 |chapter-url-access= |chapter-format= |title=A Handbook of Coniferae and Ginkgoaceae |url=https://archive.org/details/handbookofconife0000wdal/page/373 |url-access=registration |language=en |edition=Forth |location=London |publisher=[[Edward Arnold (publisher)|Edward Arnold]] |page=373 |oclc=1703374 |access-date=22 September 2024}}
+* {{Cite book |last1=Brough |first1=Sherman G. |last2=Weber |first2=Darrell J. |date=1997 |title=Trees in Idaho |url=https://archive.org/details/treesinidaho0000brou |edition=First |location=Orem, Utah |publisher=Bristlecone Press |isbn=978-0-9635617-1-8 |oclc=37644171 |access-date=14 November 2025}}
-* {{cite book |last1=Harrison |first1=Lorraine |date=2012 |title=RHS Latin for Gardeners |language=en |edition=First |location=London |publisher=Quid Publishing |page=172 |isbn=978-1-84533-731-5 |oclc=797981038}}
+* {{Cite book |last1=Cronquist |first1=Arthur |author-link1=Arthur Cronquist |last2=Holmgren |first2=Arthur H. |last3=Holmgren |first3=Noel H. |last4=Reveal |first4=James L. |author-link4=James L. Reveal |date=1972 |title=Intermountain Flora: Vascular Plants of the Intermountain West, U.S.A. |url=https://archive.org/details/intermountainflo0001aeta |url-access=registration |language=en |volume=1. Geological and Botanical History of the Region, Its Plant Geography and a Glossary. The Vascular Cryptogams and the Gymnosperms |edition=First |location=Bronx, New York |publisher=New York Botanical Garden |oclc=320442 |access-date=30 November 2024 |ref={{sfnref|Cronquist et al. 1972}}}}
-* {{cite book |last1=Heil |first1=Kenneth D. |last2=O'Kane, Jr. |first2=Steve L. |last3=Reeves |first3=Linda Mary |last4=Clifford |first4=Arnold |date=2013 |title=Flora of the Four Corners Region: Vascular Plants of the San Juan River Drainage, Arizona, Colorado, New Mexico, and Utah |url=https://archive.org/details/mobot31753003888887/page/93 |language=en |edition=First |location=St. Louis, Missouri |publisher=[[Missouri Botanical Garden]] |page=89 |isbn=978-1-930723-84-9 |issn=0161-1542 |lccn=2012949654 |oclc=859541992 |access-date=6 October 2024 |ref={{sfnref|Heil et al. 2013}}}}
+* {{Cite book |last1=Elmore |first1=Francis Hapgood |date=1944 |title=Ethnobotany of the Navajo |url=http://hdl.handle.net/2027/inu.32000002340190 |location=Alburquerque, New Mexico |publisher=University of New Mexico Press |oclc=645240856 |access-date=16 November 2025}}
-* {{cite book |last1=Johnson |first1=David W. |editor-last1=Stimm |editor-first1=Bernd |editor-last2=Roloff |editor-first2=Andreas |editor-link2=Andreas Roloff |editor-last3=Lang |editor-first3=Ulla M. |editor-last4=Weisgerber |editor-first4=Horst |date=2014 |chapter=''Picea pungens'' |title=Enzyklopädie der Holzgewächse: Handbuch und Atlas der Dendrologie |trans-title=Encyclopedia of Woody Plants: Handbook and Atlas of Dendrology |language=de |location=Weinheim, Germany |publisher=Wiley |pages=1–8 |doi=10.1002/9783527678518 |isbn=978-3-527678518 |oclc=900416230}}
+* {{Cite book |last1=Elwes |first1=Henry John |author-link1=Henry John Elwes |last2=Henry |first2=Augustine |author-link2=Augustine Henry |date=1912 |title=The Trees of Great Britain & Ireland |url=https://www.biodiversitylibrary.org/page/37616397 |volume=VI |location=Edinburgh, Scotland |publisher=Priv. Print |page=26 November 2025 |oclc=5922510 |access-date=26 November 2025}}
-* {{cite book |last1=Jones |first1=John R. |date=1973 |chapter=Southwestern Mixed Conifers |title=Silvicultural systems for the Major Forest Types of the United States |chapter-url=https://archive.org/details/silviculturalsys00unit/page/47 |series=Agriculture Handbook No. 445 |language=en |edition=First |location=Washington, D.C. |publisher=U.S. Department of Agriculture |page=47 |access-date=5 October 2024}}
+* {{Cite book |last1=Goor |first1=Amihud Y. |last2=Barney |first2=Charles Wesley |date=1968 |title=Forest Tree Planting in Arid Zones |url=https://archive.org/details/foresttreeplanti0000goor |url-access=registration |language=en |edition=First |location=New York |publisher=Ronald Press Company |oclc=419436 |access-date=3 December 2024}}
-* {{cite book |last1=Krüssmann |first1=Gerd |author-link1=Johann Gerd Krüssmann |date=1972 |title=Handbuch der Nadelgehölze |script-title= |trans-title=Handbook of Conifers |title-link= |url=https://archive.org/details/manualofcultivat0000gerd/page/216 |url-access=registration |language=de |location=Berlin |publisher=Paul Parey |pages=216–217 |isbn=3-489-71422-9 |oclc=304738 |access-date=23 September 2024}}
+* {{Cite book |last1=Harrison |first1=S.G. |last2=Dallimore |first2=William |author-link2=William Dallimore |last3=Jackson |first3=A. Bruce |author-link3=Albert Bruce Jackson |date=1966 |title=A Handbook of Coniferae and Ginkgoaceae |url=https://archive.org/details/handbookofconife0000wdal |url-access=registration |language=en |edition=Forth |location=London |publisher=[[Edward Arnold (publisher)|Edward Arnold]] |oclc=1703374 |access-date=22 September 2024}}
-* {{cite book |last1=Little |first1=Elbert L. |author1-link=Elbert Luther Little |title=Southwestern Trees: A Guide to the Native Species of New Mexico and Arizona |date=1950 |publisher=U.S. Department of Agriculture |location=Washington, D.C. |pages=17–18 |language=en |edition=First |url=https://archive.org/details/southwesterntree00litt/page/17 |url-access=registration |access-date=5 October 2024}}
+* {{Cite book |last1=Harrison |first1=Lorraine |date=2012 |title=RHS Latin for Gardeners |language=en |edition=First |location=London |publisher=Quid Publishing |isbn=978-1-84533-731-5 |oclc=797981038}}
-* {{cite book |last1=Quattrocchi |first1=Umberto |date=2012 |title=CRC World Dictionary of Medicinal and Poisonous Plants |url=https://archive.org/details/crc-world-dictionary-of-medicinal-and-poisonous-plants/page/2923 |language=en |location=Boca Raton, Florida |publisher=[[CRC Press]] |page=2923 |isbn=978-1-4822-5064-0 |lccn= |oclc=774639599}}
+* {{Cite book |last1=Heil |first1=Kenneth D. |last2=O'Kane, Jr. |first2=Steve L. |last3=Reeves |first3=Linda Mary |last4=Clifford |first4=Arnold |date=2013 |title=Flora of the Four Corners Region: Vascular Plants of the San Juan River Drainage, Arizona, Colorado, New Mexico, and Utah |url=https://archive.org/details/mobot31753003888887 |language=en |edition=First |location=St. Louis, Missouri |publisher=[[Missouri Botanical Garden]] |isbn=978-1-930723-84-9 |issn=0161-1542 |lccn=2012949654 |oclc=859541992 |access-date=6 October 2024 |ref={{sfnref|Heil et al. 2013}}}}
-* {{cite book |last1=Sargent |first1=Charles Sprague |author1-link=Charles Sprague Sargent |others=Illustrated by [[Charles Edward Faxon]] |date=1898 |title=The Silva of North America: A Description of the Trees Which Grow Naturally in North America Exclusive of Mexico |url=https://www.biodiversitylibrary.org/page/14580022 |language=en |volume=XII Coniferae (Abietinece after Pinus) |edition=First |location=Boston, Massachusetts |publisher=Houghton, Mifflin and Company |pages=47–49, Tab DC |oclc=1077591401 |access-date=27 November 2024}}
+* {{Cite book |last1=Johnson |first1=David W. |editor-last1=Stimm |editor-first1=Bernd |editor-last2=Roloff |editor-first2=Andreas |editor-link2=Andreas Roloff |editor-last3=Lang |editor-first3=Ulla M. |editor-last4=Weisgerber |editor-first4=Horst |date=2014 |chapter=''Picea pungens'' |title=Enzyklopädie der Holzgewächse: Handbuch und Atlas der Dendrologie |trans-title=Encyclopedia of Woody Plants: Handbook and Atlas of Dendrology |language=de |location=Weinheim, Germany |publisher=Wiley |doi=10.1002/9783527678518 |isbn=978-3-527678518 |oclc=900416230}}
-* {{Cite book |last1=Sjöman |first1=Henrik |last2=Anderson |first2=Arit |date=2023 |title=The Essential Tree Selection Guide: For Climate Resilience, Carbon Storage, Species Diversity and Other Ecosystem Benefits |language=en |edition=First |location=Bath, England |publisher=Filbert Press |pages=161–163 |isbn=978-1-7399039-4-7 |oclc=1400102923}}
+* {{Cite book |last1=Jones |first1=John R. |date=1973 |chapter=Southwestern Mixed Conifers |title=Silvicultural systems for the Major Forest Types of the United States |chapter-url=https://archive.org/details/silviculturalsys00unit/page/47 |series=Agriculture Handbook No. 445 |language=en |edition=First |location=Washington, D.C. |publisher=U.S. Department of Agriculture |access-date=5 October 2024}}
-* {{cite book |last1=Stuart |first1=John David |last2=Sawyer |first2=John O. |others=Illustrated by Andrea J. Pickart |date=2001 |title=Trees and Shrubs of California |language=en |edition=First |location=Berkeley, California |publisher=University of California Press |pages=31–32 |isbn=978-0-520-22109-3 |oclc=44267780}}
+* {{Cite book |last1=Jorgenson |first1=Lisa |date=1992 |title=Grand Trees of America: Our State and Champion Trees |url=https://archive.org/details/grandtreesofamer0000jorg |location=Niwot, Colo |publisher=Roberts Rinehart Publishers |isbn=978-1-879373-15-0 |oclc=26517765 |access-date=16 November 2025}}
-* {{cite book |last1=Vedel |first1=Helge |last2=Lange |first2=Johan |translator-last1=Hillman |translator-first1=C.H.R. |translator-last2=Edlin |translator-first2=H.L. |date=1960 |orig-date=1958 |title=Trees and Bushes in Wood and Hedgerow |url=https://archive.org/details/treesbushesinwoo0000vede/page/119 |url-access=registration |language=en |edition=First English |location=London |publisher=Methuen & Co |pages=119–120 |isbn=978-0-416-61780-1 |oclc=1151411431 |access-date=2 December 2024}}
+* {{Cite book |last1=Krüssmann |first1=Gerd |author-link1=Johann Gerd Krüssmann |date=1972 |title=Handbuch der Nadelgehölze |script-title= |trans-title=Handbook of Conifers |title-link= |url=https://archive.org/details/manualofcultivat0000gerd |url-access=registration |language=de |location=Berlin |publisher=Paul Parey |isbn=3-489-71422-9 |oclc=304738 |access-date=23 September 2024}}
-* {{cite book |last1=Wooton |first1=Elmer Ottis |author-link1=E. O. Wooton |last2=Standley |first2=Paul Carpenter |author-link2=Paul Carpenter Standley |date=1915 |title=Flora of New Mexico |url=https://archive.org/details/floraofnewmexico00woot/page/34 |series=Contributions from the United States National Herbarium, Volume 19 |language=en |edition=First |location=Washington, D.C. |publisher=Smithsonian Institution |page=34 |lccn=agr15001072 |oclc=3786500 |access-date=5 October 2024}}
+* {{Cite book |last1=Little |first1=Elbert L. |author1-link=Elbert Luther Little |title=Southwestern Trees: A Guide to the Native Species of New Mexico and Arizona |date=1950 |publisher=U.S. Department of Agriculture |location=Washington, D.C. |language=en |edition=First |url=https://archive.org/details/southwesterntree00litt |url-access=registration |access-date=5 October 2024}}
-* {{cite book |last1=Young |first1=Robert W. |author1-link=Robert W. Young |last2=Morgan |first2=William |author2-link=William Morgan (Navajo scholar) |date=1980 |title=The Navajo Language: A Grammar and Colloquial Dictionary |url=https://archive.org/details/navajolanguagegr0000youn/page/296 |url-access=registration |language=en, nv |edition=First |location=Albuquerque, New Mexico |publisher=University of New Mexico Press |page=296 |isbn=978-0-8263-0536-7 |oclc=6597162 |access-date=5 October 2024}}
+* {{Cite book |last1=Lynch |first1=Ann M. |date=2014 |chapter=XXIV Spruce Aphid (''Elatobium abietinum'' Walker) (Hemiptera: Aphididae) |chapter-url=https://www.fs.fed.us/rm/pubs_journals/2014/rmrs_2014_lynch_a001.pdf |editor-last1=Van Driesche |editor-first1=Roy |editor-last2=Reardon |editor-first2=Richard C. |title=The Use of Classical Biological Control to Preserve Forests in North America |location=Morgantown, West Virginia |publisher=United States Department of Agriculture, Forest Service, Forest Health Technology Enterprise Team |oclc=903247564 |url-status=dead |archive-url=https://web.archive.org/web/20220120055804/https://www.fs.fed.us/rm/pubs_journals/2014/rmrs_2014_lynch_a001.pdf |archive-date=20 January 2022 |access-date=14 November 2025}}
+* {{Cite book |last1=Quattrocchi |first1=Umberto |date=2012 |title=CRC World Dictionary of Medicinal and Poisonous Plants |url=https://archive.org/details/crc-world-dictionary-of-medicinal-and-poisonous-plants |language=en |location=Boca Raton, Florida |publisher=[[CRC Press]] |isbn=978-1-4822-5064-0 |lccn= |oclc=774639599}}
+* {{Cite book |last1=Sargent |first1=Charles Sprague |author1-link=Charles Sprague Sargent |others=Illustrated by [[Charles Edward Faxon]] |date=1898 |title=The Silva of North America: A Description of the Trees Which Grow Naturally in North America Exclusive of Mexico |url=https://www.biodiversitylibrary.org/page/14580022 |language=en |volume=XII Coniferae (Abietinece after Pinus) |edition=First |location=Boston, Massachusetts |publisher=Houghton, Mifflin and Company |oclc=1077591401 |access-date=27 November 2024}}
+* {{Cite book |last1=Sjöman |first1=Henrik |last2=Anderson |first2=Arit |date=2023 |title=The Essential Tree Selection Guide: For Climate Resilience, Carbon Storage, Species Diversity and Other Ecosystem Benefits |language=en |edition=First |location=Bath, England |publisher=Filbert Press |isbn=978-1-7399039-4-7 |oclc=1400102923}}
+* {{Cite book |last1=Stuart |first1=John David |last2=Sawyer |first2=John O. |others=Illustrated by Andrea J. Pickart |date=2001 |title=Trees and Shrubs of California |language=en |edition=First |location=Berkeley, California |publisher=University of California Press |isbn=978-0-520-22109-3 |oclc=44267780}}
+* {{Cite book |last1=Wooton |first1=Elmer Ottis |author-link1=E. O. Wooton |last2=Standley |first2=Paul Carpenter |author-link2=Paul Carpenter Standley |date=1915 |title=Flora of New Mexico |url=https://archive.org/details/floraofnewmexico00woot/page/34 |series=Contributions from the United States National Herbarium, Volume 19 |language=en |edition=First |location=Washington, D.C. |publisher=Smithsonian Institution |lccn=agr15001072 |oclc=3786500 |access-date=5 October 2024}}
+* {{Cite book |last1=Young |first1=Robert W. |author1-link=Robert W. Young |last2=Morgan |first2=William |author2-link=William Morgan (Navajo scholar) |date=1980 |title=The Navajo Language: A Grammar and Colloquial Dictionary |url=https://archive.org/details/navajolanguagegr0000youn |url-access=registration |language=en, nv |edition=First |location=Albuquerque, New Mexico |publisher=University of New Mexico Press |isbn=978-0-8263-0536-7 |oclc=6597162 |access-date=5 October 2024}}
+{{Refend}}
+====Journals====
+{{Refbegin|30em}}
+* {{Cite journal |last1=Birch |first1=Joseph D. |last2=DeRose |first2=R. Justin |last3=Lutz |first3=James A. |date=November 2024 |title=Spruce up your climate analysis: Dendroclimatology of ''Picea engelmannii'' and ''Picea pungens'' |journal=Ecosphere |volume=15 |issue=11 |doi=10.1002/ecs2.70047 |doi-access=free |issn=2150-8925}}
+* {{Cite journal |last1=Dixon |first1=Helen |title=Ecological Studies on the High Plateaus of Utah |journal=Botanical Gazette |volume=97 |issue=2 |pages=272–320 |doi=10.1086/334554 |jstor=2471603 |s2cid=84538967}}
+* {{Cite journal |last1=Engelmann |first1=G. |author-link1=George Engelmann |last2=Parry |first2=C. C. |author-link2=Charles Christopher Parry |date=November 1862 |title=Supplements to the Enumeration of Plants of Dr. Parry's Collection in the Rocky Mountains, Supplement I.—Coniferae |url=https://www.biodiversitylibrary.org/page/36839782 |journal=The American Journal of Science and Arts |volume=34 |access-date=26 November 2025}}
+* {{Cite journal |last1=Engelmann |first1=George |author-link1=George Engelmann |date=15 March 1879 |title=The American Spruces |url=https://www.biodiversitylibrary.org/page/26083572 |journal=The Gardeners' Chronicle :A Weekly Illustrated Journal of Horticulture and Allied Subjects |volume=11 |pmid=14014656 |access-date=26 November 2025}}
+* {{Cite journal |last1=Kuneš |first1=Ivan |last2=Baláš |first2=Martin |last3=Lánský |first3=Pavel |date=30 November 2020 |title=Structural and Tree Species Diversification as a Challenging Task in Forests of the Air-polluted Jizera Mountains, Czech Republic |journal=Mountain Research and Development |volume=40 |issue=2 |doi=10.1659/MRD-JOURNAL-D-19-00059.1 |doi-access=free |jstor=27002394 |jstor-access=free}}
+* {{Cite journal |last1=Krivánek |first1=Martin |last2=Pyšek |first2=Petr |last3=Jarošík |first3=Vojtěch |date=October 2006 |title=Planting History and Propagule Pressure as Predictors of Invasion by Woody Species in a Temperate Region |url=https://www.researchgate.net/publication/262064200_Planting_History_and_Propagule_Pressure_as_Predictors_of_Invasion_by_Woody_Species_in_a_Temperate_Region |journal=Conservation Biology |volume=20 |issue=5 |pages=1487–1498 |doi=10.1111/j.1523-1739.2006.00477.x |pmid=17002766 |access-date=13 November 2025}}
+* {{Cite journal |last1=Lockwood |first1=Jared D. |last2=Aleksić |first2=Jelena M. |last3=Zou |first3=Jiabin |last4=Wang |first4=Jing |last5=Liu |first5=Jianquan |last6=Renner |first6=Susanne S. |date=December 2013 |title=A new phylogeny for the genus ''Picea'' from plastid, mitochondrial, and nuclear sequences |url=https://www.researchgate.net/publication/250923424_A_New_Phylogeny_for_the_Genus_Picea_from_Plastid_Mitochondrial_And_Nuclear_Sequences |journal=Molecular Phylogenetics and Evolution |volume=69 |issue=3 |pages=717–727 |doi=10.1016/j.ympev.2013.07.004 |pmid=23871916 |access-date=7 November 2025 |ref={{sfnref|Lockwood et al. 2013}}}}
+* {{Cite journal |last1=Richardson |first1=David M. |last2=Rejmánek |first2=Marcel |date=September 2004 |title=Conifers as invasive aliens: a global survey and predictive framework |url=https://www.researchgate.net/file.PostFileLoader.html?id=588c78453d7f4b466e6f6ed4&assetKey=AS%3A455457077764096%401485600837264 |journal=Diversity and Distributions |volume=10 |issue=5-6 |pages=321–331 |doi=10.1111/j.1366-9516.2004.00096.x |jstor=3246735 |url-status=live |archive-url=https://web.archive.org/web/20240116093010/https://www.researchgate.net/file.PostFileLoader.html?id=588c78453d7f4b466e6f6ed4&assetKey=AS%3A455457077764096%401485600837264 |archive-date=16 January 2024 |access-date=12 November 2025}}
+* {{Cite journal |last1=Spasić |first1=Marko |last2=Vacek |first2=Oldřich |last3=Vejvodová |first3=Kateřina |last4=Tejnecký |first4=Václav |last5=Vokurková |first5=Petra |last6=Križová |first6=Petra |last7=Polák |first7=Filip |last8=Vašát |first8=Radim |last9=Borůvka |first9=Luboš |last10=Drábek |first10=Ondřej |date=April 2024 |title=Which trees form the best soil? Reclaimed mine soil properties under 22 tree species: 50 years later—assessment of physical and chemical properties |journal=European Journal of Forest Research |volume=143 |issue=2 |pages=561–579 |bibcode=2024EJFR..143..561S |doi=10.1007/s10342-023-01637-x |ref={{sfnref|Spasić et al. 2024}}}}
+* {{Cite journal |last1=Šrámek |first1=Vít |last2=Slodičák |first2=Marian |last3=Lomský |first3=Bohumír |last4=Balcar |first4=Vratislav |last5=Kulhavý |first5=Jiří |last6=Hadaš |first6=Pavel |last7=Pulkráb |first7=Karel |last8=Šišák |first8=Luděk |last9=Pěnička |first9=Libor |last10=Sloup |first10=Miroslav |date=August 2008 |title=The Ore Mountains: Will Successive Recovery of Forests from Lethal Disease Be Successful |journal=Mountain Research and Development |volume=28 |issue=3/4 |pages=216–221 |doi=10.1659/mrd.1040 |doi-access=free |jstor=25578195 |jstor-access=free |ref={{sfnref|Šrámek et al. 2008}}}}
+* {{Cite journal |last1=Sudworth |first1=George B. |author-link1=George Bishop Sudworth |date=19 February 1916 |title=The spruce and balsam fir trees of the Rocky Mountain region |url=https://www.biodiversitylibrary.org/page/48644577 |journal=Bulletin of the U.S. Department of Agriculture |volume=327 |doi=10.5962/bhl.title.108207 |pmid=14014656 |access-date=25 November 2025}}
+* {{Cite journal |last1=Tidestrom |first1=Ivar |last2=Shantz |first2=H. L. |last3=Sampson |first3=Arthur W. |date=1925 |title=Flora of Utah and Nevada |journal=Contributions from the United States National Herbarium |volume=25 |pages=1–665 |jstor=23492412 |pmid=14014656}}
+* {{Cite journal |last1=Wajs-Bonikowska |first1=Anna |last2=Szoka |first2=Łukasz |last3=Karna |first3=Ewa |last4=Wiktorowska-Owczarek |first4=Anna |last5=Sienkiewicz |first5=Monika |date=March 2017 |title=Composition and Biological Activity of ''Picea pungens'' and ''Picea orientalis'' Seed and Cone Essential Oils |journal=Chemistry & Biodiversity |volume=14 |issue=3 |article-number=e1600264 |doi=10.1002/cbdv.20160026 |pmid=27735132 |ref={{sfnref|Wajs-Bonikowska et al. 2017}}}}
+* {{Cite journal |last1=Zeidler |first1=Aleš |last2=Borůvka |first2=Vlastimil |last3=Brabec |first3=Pavel |last4=Tomczak |first4=Karol |last5=Bedřich |first5=Jakub |last6=Vacek |first6=Zdeněk |last7=Cukor |first7=Jan |last8=Vacek |first8=Stanislav |date=29 January 2024 |title=The Possibility of Using Non-Native Spruces for Norway Spruce Wood Replacement—A Case Study from the Czech Republic |url=https://www.mdpi.com/1999-4907/15/2/255 |journal=Forests |volume=15 |issue=2 |pages=255 |access-date=10 November 2025 |ref={{sfnref|Zeidler et al. 2024}}}}
+{{Refend}}
+====News====
+{{Refbegin|30em}}
+* {{Cite news |last1=Randle |first1=Sterling |date=13 February 2014 |title=Quaking Aspen moves closer to replacing Blue Spruce as State Tree |url=https://universe.byu.edu/2014/02/13/quaking-aspen-moves-closer-to-replacing-blue-spruce-as-state-tree/ |work=BYU Daily Universe |language=en-us |publisher=[[Brigham Young University]] |archive-url=https://web.archive.org/web/20240603120256/https://universe.byu.edu/2014/02/13/quaking-aspen-moves-closer-to-replacing-blue-spruce-as-state-tree/ |archive-date=3 June 2024 |access-date=25 September 2024}}
+* {{Cite news |last1=Wood |first1=Benjamin |date=26 March 2014 |title=Student-advocated state tree bill signed into law |url=https://www.deseret.com/2014/3/26/20538192/student-advocated-state-tree-bill-signed-into-law/ |work=Deseret News |language=en-us |location=Monroe, Utah |url-status=live |archive-url=https://web.archive.org/web/20221123173256/https://www.deseret.com/2014/3/26/20538192/student-advocated-state-tree-bill-signed-into-law |archive-date=23 November 2022 |access-date=26 March 2024}}
+{{Refend}}
+====Reports====
+{{Refbegin|30em}}
+* {{Cite report |last1=Alexander |first1=Robert R. |date=1974 |title=Silviculture of central and southern Rocky Mountain forests: a summary of the status of our knowledge by timber types |url=https://archive.org/details/CAT92273314 |series=Research paper RM, 120 |language=en-US |location=Fort Collins, Colorado |publisher=Rocky Mountain Forest and Range Experiment Station, Forest Service, US Department of Agriculture |oclc=8104779 |access-date=5 October 2024}}
+* {{Cite report |last1=Fechner |first1=Gilbert H. |date=April 1985 |title=Silvical Characteristics of Blue Spruce |url=https://archive.org/details/IND85048712 |series=General technical report RM, 117 |language=en-us |location=Fort Collins, Colorado |publisher=US Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station |oclc=13145459 |access-date=25 November 2025}}
+* {{Cite report |last1=Mauk |first1=Ronald L. |last2=Henderson |first2=Jan A. |date=1984 |title=Coniferous Forest Habitat Types of Northern Utah |url=https://archive.org/details/CAT85822482 |series=General technical report INT, 170 |language=en-US |location=Ogden, Utah |publisher=US Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station |oclc=11424816 |access-date=9 October 2024 |ref={{sfnref|Mauk & Henderson 1984}}}}
+* {{Cite report |last1=Moir |first1=William H. |last2=Ludwig |first2=John A. |date=July 1979 |title=A Classification of Spruce-fir and Mixed Conifer Habitat Types of Arizona and New Mexico |url=https://archive.org/details/CAT79727141 |series=Research paper RM, 207 |language=en-US |location=Fort Collins, Colorado |publisher=Rocky Mountain Forest and Range Experiment Station, Forest Service, US Department of Agriculture |oclc=5733939 |access-date=9 November 2025}}
+* {{Cite report |last1=Pearson |first1=Gustaf Adolph |date=1931 |title=Forest Types in the Southwest as Determined by Climate and Soil |url=https://books.google.com/books/about/Forest_Types_in_the_Southwest_as_Determi.html?id=3wFJAAAAMAAJ |series=Technical bulletin (United States. Department of Agriculture), no. 247 |language=en-US |location=Washington, D.C. |publisher=US Department of Agriculture |oclc=9626024}}
+{{Refend}}
+====Thesis====
+{{Refbegin|30em}}
+* {{cite thesis |last1=Swank |first1=George R. |date=1932 |title=The Ethnobotany of the Acoma and Laguna Indians |url= https://digitalrepository.unm.edu/biol_etds/212 |degree=Master of Arts in the Department of Biology |language=en-us |location=Albuquerque, New Mexico |publisher=University of New Mexico |oclc=1278057 |url-status=live |archive-url=https://web.archive.org/web/20231216151111/https://digitalrepository.unm.edu/cgi/viewcontent.cgi?article=1224&context=biol_etds |archive-date=16 December 2023 |access-date=16 November 2025}}
+{{Refend}}
+====Web sources====
+{{Refbegin|30em}}
+* {{Cite web |last1=Bayer |first1=Amanda |last2=Brazee |first2=Nicholas |last3=Simisky |first3=Tawny |date=8 April 2020 |title=Blue Spruce: Common Health Issues in the Landscape |url=https://www.umass.edu/agriculture-food-environment/landscape/fact-sheets/blue-spruce-common-health-issues-in-landscape |website=UMass Extension Landscape, Nursery and Urban Forestry Program |language=en-US |publisher=University of Massachusetts Amherst |url-status=live |archive-url=https://web.archive.org/web/20250613222509/https://www.umass.edu/agriculture-food-environment/landscape/fact-sheets/blue-spruce-common-health-issues-in-landscape |archive-date=13 June 2025 |access-date=14 November 2025}}
+* {{Cite web |last1=Brand |first1=Mark H. |date=2015 |title=''Picea pungens'' |url=https://plantdatabase.uconn.edu/detail.php?pid=315 |website=Plant Database |language=en-us |publisher=University of Connecticut |access-date=15 November 2025}}
+* {{Cite web |last1=Cranshaw |first1=W.S. |date=June 2013 |title=Scale Insects Affecting Conifers - Fact Sheet No. 5.514 |url=http://www.ext.colostate.edu/pubs/insect/05514.pdf |website=Colorado State University Extension |language=en-US |url-status=dead |archive-url=https://web.archive.org/web/20150612001338/http://www.ext.colostate.edu/pubs/insect/05514.pdf |archive-date=12 June 2015 |access-date=13 November 2025}}
+* {{Cite web |last1=CO Archives |date=2024 |title=Symbols & Emblems |url=https://archives.colorado.gov/collections/symbols-emblems |website=Colorado State Archives |publisher=[[Government of Colorado]] |url-status=live |archive-url=https://web.archive.org/web/20240818200929/https://archives.colorado.gov/collections/symbols-emblems |archive-date=18 August 2024 |access-date=25 September 2024}}
+* {{Cite web |last1=Detweiler |first1=Amy Jo |date=November 2005 |title=Plant selection for windbreaks in Central Oregon |url=https://extension.oregonstate.edu/gardening/flowers-shrubs-trees/plant-selection-windbreaks-central-oregon |website=Ag - Community Horticulture/Landscape |language=en-US |publisher=Oregon State University |url-status=live |archive-url=https://web.archive.org/web/20250206223652/https://extension.oregonstate.edu/gardening/flowers-shrubs-trees/plant-selection-windbreaks-central-oregon |archive-date=6 February 2025 |access-date=8 November 2025}}
+* {{Cite web <!--Deny Citation Bot-->|last1=Fechner |first1=Gilbert H. |date=December 1990 |editor-last1=Burns |editor-first1=Russell M. |editor-last2=Honkala |editor-first2=Barbara H. |title=''Picea pungens'' Engelm. |url=https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_1/picea/pungens.htm |website=Silvics of North America |language=en-US |location=Washington, D.C. |publisher=[[United States Forest Service]] |agency=[[United States Department of Agriculture]] |isbn=978-0-16-027145-8 |lccn=91600537 |oclc=25008780 |url-status=live |archive-url=https://web.archive.org/web/20240722121855/https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_1/picea/pungens.htm |archive-date=22 July 2024 |access-date=24 September 2024}}
+* {{Cite web |last1=Earle |first1=Christopher J. |date=22 February 2025 |title=''Picea pungens'' (blue spruce) description |url=https://www.conifers.org/pi/Picea_pungens.php |website=The Gymnosperm Database |language=en |url-status=live |archive-url=https://web.archive.org/web/20231211081155/https://www.conifers.org/pi/Picea_pungens.php |archive-date=11 December 2023 |access-date=5 November 2025}}
+* {{Cite web |last1=Forest Research |date=2025 |title=Green spruce aphid (''Elatobium abietinum'') |url=https://www.forestresearch.gov.uk/tools-and-resources/fthr/pest-and-disease-resources/green-spruce-aphid-elatobium-abietinum/ |website=Forest Research |publisher=Forestry Commission, Department for Environment, Food and Rural Affairs |access-date=14 November 2025}}
+* {{Cite web |last1=Forest Start Staff |date=2021 |title=Colorado Green Spruce (''Picea Pungens'') |url=https://www.foreststart.com/pines-spruce-firs/colorado-green-spruce-picea-pugens |website=Forest Start |language=en-US |url-status=live |archive-url=https://web.archive.org/web/20240925191749/https://www.foreststart.com/pines-spruce-firs/colorado-green-spruce-picea-pugens |archive-date=25 September 2024 |access-date=25 September 2024}}
+* {{Cite iucn |last1=Farjon |first1=A. |date=2013 |title=''Picea pungens'' |volume=2013 |article-number=e.T42333A2973433 |doi=10.2305/IUCN.UK.2013-1.RLTS.T42333A2973433.en |access-date=19 November 2021}}
+* {{Cite NatureServe |date=1 November 2025 |id=2.148378 |title=''Picea pungens'' |access-date=4 November 2025 |ref={{sfnref|NatureServe 2025}}}}
+* {{Cite web |last1=Gilman |first1=Edward F. |last2=Watson |first2=Dennis G. |date=December 2006 |title=''Picea pungens'': Colorado Spruce ENH-612 |url=http://edis.ifas.ufl.edu/pdffiles/ST/ST45300.pdf |website=IFAS Extension |publisher=University of Florida |url-status=dead |archive-url=https://web.archive.org/web/20191113095240/http://edis.ifas.ufl.edu/pdffiles/ST/ST45300.pdf |archive-date=13 November 2019 |access-date=6 October 2013}}
+* {{Cite web |last1=Grant |first1=Kent |last2=Hardgrave |first2=Kathryn |last3=Lockwood |first3=Ryan |last4=Mason |first4=Lisa |last5=Moore |first5=Adam |last6=Pankratz |first6=Sam |last7=Peterson |first7=Courtney |last8=Rogers |first8=Kelly |last9=Timm |first9=Katherine |date=August 2014 |title=Spruce Beetle Quick Guide – FM 2014-1 |url=https://csfs.colostate.edu/wp-content/uploads/2014/02/Spruce-Beetle-QuickGuide-FM2014-1.pdf |website=Colorado State Forest Service |publisher=Colorado State University |archive-url=https://web.archive.org/web/20250611112841/https://csfs.colostate.edu/wp-content/uploads/2014/02/Spruce-Beetle-QuickGuide-FM2014-1.pdf |archive-date=11 June 2025 |access-date=13 November 2025 |ref={{sfnref|Grant et al. 2014}}}}
+* {{Cite web |last1=Harper |first1=Liz |date=12 December 2018 |title=A Tale of Two Trees and a Wildfire |url=https://www.americanforests.org/article/a-tale-of-two-trees-and-a-wildfire/ |website=American Forests |language=en-US |url-status=live |archive-url=https://web.archive.org/web/20241130045318/https://www.americanforests.org/article/a-tale-of-two-trees-and-a-wildfire/ |archive-date=30 November 2024 |access-date=30 November 2024}}
+* {{Cite web |date=1996 |editor-last1=Herman |editor-first1=Dale E. |editor-last2=Stange |editor-first2=Craig M. |editor-last3=Quam |editor-first3=Vernon C. |title=Colorado (Blue) Spruce (''Picea pungens'') |url=https://www.ag.ndsu.edu/trees/handbook/th-3-177.pdf |website=North Dakota Tree Handbook |language=en-US |publisher=North Dakota State University |url-status=live |archive-url=https://web.archive.org/web/20250330101453/https://www.ag.ndsu.edu/trees/handbook/th-3-177.pdf |archive-date=30 March 2025 |access-date=8 November 2025 |ref={{sfnref|Herman et al. 1996}}}}
+* {{Cite web |last1=Kolb |first1=Peter |date=2023 |title=Trees and Shelterbelts |url=https://www.montana.edu/extension/forestry/publications/fact-sheets/FF_windbreakhandout_PK.pdf |website=Montana State University Extension Service |language=en-US |url-status=live |archive-url=https://web.archive.org/web/20250930000102/https://www.montana.edu/extension/forestry/publications/fact-sheets/FF_windbreakhandout_PK.pdf |archive-date=30 September 2025 |access-date=8 November 2025}}
+* {{Cite web |last1=MBG Staff |date=2024a |title=''Picea pungens'' |url=https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=284991 |website=Plant Finder |language=en-us |location=St. Louis, Missouri |publisher=[[Missouri Botanical Garden]] |url-status=live |archive-url=https://web.archive.org/web/20240523174142/https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=284991 |archive-date=23 May 2024 |access-date=21 September 2024}}
+* {{Cite web |last1=MBG Staff |date=2024b |title=''Picea pungens'' 'Baby Blueeyes' |url=https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=267995 |website=Plant Finder |language=en-us |location=St. Louis, Missouri |publisher=[[Missouri Botanical Garden]] |url-status=live |archive-url=https://web.archive.org/web/20240924214557/https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=267995 |archive-date=24 September 2024 |access-date=24 September 2024}}
+* {{Cite web |last1=MBG Staff |date=2024c |title=''Picea pungens'' 'Glauca Globosa' |url=https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=c825 |website=Plant Finder |language=en-us |location=St. Louis, Missouri |publisher=[[Missouri Botanical Garden]] |url-status=live |archive-url=https://web.archive.org/web/20240523081243/http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=c825 |archive-date=23 May 2024 |access-date=24 September 2024}}
+* {{Cite web |last1=MBG Staff |date=2024d |title=''Picea pungens'' 'Hoopsii' |url=https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=255100 |website=Plant Finder |language=en-us |location=St. Louis, Missouri |publisher=[[Missouri Botanical Garden]] |url-status=live |archive-url=https://web.archive.org/web/20240703052242/https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=255100 |archive-date=3 July 2024 |access-date=24 September 2024}}
+* {{Cite web |last1=MBG Staff |date=2024e |title=''Picea pungens'' 'Montgomery' |url=https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=263630 |website=Plant Finder |language=en-us |location=St. Louis, Missouri |publisher=[[Missouri Botanical Garden]] |url-status=live |archive-url=https://web.archive.org/web/20240921173347/https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=263630 |archive-date=21 September 2024 |access-date=24 September 2024}}
+* {{Cite web |last1=NCCE Staff |date=2025a |title=''Picea pungens'' (Blue Spruce, Colorado Spruce) |url=https://plants.ces.ncsu.edu/plants/picea-pungens/ |website=North Carolina Extension Gardener Plant Toolbox |language=en-US |publisher=[[North Carolina State University]] |archive-url=https://web.archive.org/web/20251006043941/https://plants.ces.ncsu.edu/plants/picea-pungens/ |archive-date=6 October 2025 |access-date=7 November 2025}}
+* {{Cite web |last1=NCCE Staff |date=2025b |title=''Picea pungens'' 'Pendula' |url=https://plants.ces.ncsu.edu/plants/picea-pungens-pendula/ |website=North Carolina Extension Gardener Plant Toolbox |language=en-US |location=Raleigh, North Carolina |publisher=[[North Carolina State University]] |url-status=live |archive-url=https://web.archive.org/web/20240922202453/https://plants.ces.ncsu.edu/plants/picea-pungens-pendula/ |archive-date=22 September 2024 |access-date=7 November 2025}}
+* {{Cite web |last1=NCTP Staff |date=2020 |title=''Picea pungens'' - UT |url=https://nationalchampiontree.org/championTree/3383/ |website=National Champion Tree Program |publisher=University of Tennessee Institute of Agriculture’s School of Natural Resources |url-status=live |archive-url=https://web.archive.org/web/20251105223229/https://nationalchampiontree.org/championTree/3383/ |archive-date=5 November 2025 |access-date=5 November 2025}}
+* {{Cite web |last1=Nesom |first1=Guy |date=13 February 2003 |title=Blue Spruce |url=https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_pipu.pdf |website=USDA Fact Sheets & Plant Guides |publisher=USDA Natural Resources Conservation Service |url-status=live |archive-url=https://web.archive.org/web/20250418115641/https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_pipu.pdf |archive-date=18 April 2025 |access-date=10 November 2025}}
+* {{Cite usda plants|symbol=PIPU |title=Picea pungens |date=12 November 2025 |ref={{sfnref|NRCS 2025}}}}
+* {{Cite OED |last1=OED |date=2025a |Blue Spruce, N. |7006545120 |ref={{sfnref|OED 2025a}}}}
+* {{Cite OED |last1=OED |date=2025b |Colorado Spruce' in Colorado, N. (2), Sense 2. |1207804688 |ref={{sfnref|OED 2025b}}}}
+* {{Cite POWO |last1=POWO |date=2025a |id=195894-2 |title=''Picea mexicana'' Martínez |access-date=4 November 2025 |ref={{sfnref|POWO 2025a}}}}
+* {{Cite POWO |last1=POWO |date=2025b |id=30095300-2 |title=''Picea pungens'' Engelm. |access-date=4 November 2025 |ref={{sfnref|POWO 2025b}}}}
+* {{Cite web |last1=Rhodus |first1=Tim |date=2013 |title=''Picea pungens'': Blue Spruce, Colorado Blue Spruce, or Green Spruce (Pinaceae - Pine Family) |url=http://hvp.osu.edu/pocketgardener/source/description/pi_ngens.html |website=OSU PocketGardener |language=en-US |location=Columbus, Ohio |publisher=[[Ohio State University]] |url-status=live |archive-url=https://web.archive.org/web/20240605220156/http://hvp.osu.edu/pocketgardener/source/description/pi_ngens.html |archive-date=5 June 2024 |access-date=25 September 2024}}
+* {{Cite web |last1=RHS Staff |date=December 2024 |title=AGM Plants - Ornamental |url=https://www.rhs.org.uk/plants/pdfs/agm-lists/agm-ornamentals.pdf |website=RHS Plants |language=en-gb |publisher=Royal Horticultural Society |url-status=live |archive-url=https://web.archive.org/web/20250624183106/https://www.rhs.org.uk/plants/pdfs/agm-lists/agm-ornamentals.pdf |archive-date=24 June 2025 |access-date=14 November 2025}}
+* {{Cite web |last1=RHS Staff |date=2025a |title=Picea pungens 'Edith' – Colorado spruce 'Edith' |url=https://www.rhs.org.uk/plants/195010/picea-pungens-edith/details |website=Conifers/RHS |language=en-gb |publisher=Royal Horticultural Society |access-date=14 November 2025}}
+* {{Cite web |last1=RHS Staff |date=2025b |title=Picea pungens 'Fat Albert' – Colorado spruce 'Fat Albert' |url=https://www.rhs.org.uk/plants/66446/picea-pungens-fat-albert/details |website=Conifers/RHS |language=en-gb |publisher=Royal Horticultural Society |access-date=14 November 2025}}
+* {{Cite web |last1=RHS Staff |date=2025c |title=''Picea pungens'' (Glauca Group) 'Globosa' – Colorado spruce 'Globosa' |url=https://www.rhs.org.uk/plants/91537/picea-pungens-(glauca-group)-globosa/details |website=Conifers/RHS |language=en-gb |publisher=Royal Horticultural Society |access-date=14 November 2025}}
+* {{Cite web |last1=RHS Staff |date=2025d |title=''Picea pungens'' (Glauca Group) 'Hoopsii' – Colorado spruce 'Hoopsii' |url=https://www.rhs.org.uk/plants/98036/picea-pungens-(glauca-group)-hoopsii/details |website=Conifers/RHS |language=en-gb |publisher=Royal Horticultural Society |access-date=14 November 2025}}
+* {{Cite web |last1=RHS Staff |date=2025e |title=''Picea pungens'' (Glauca Group) 'Koster' – Colorado spruce 'Koster' |url=https://www.rhs.org.uk/plants/59991/picea-pungens-(glauca-group)-koster/details |website=Conifers/RHS |language=en-gb |publisher=Royal Horticultural Society |access-date=14 November 2025}}
+* {{Cite web |last1=Seiler |first1=John |last2=Jensen |first2=Edward |last3=Niemiera |first3=Alex |last4=Peterson |first4=John |date=2021 |title=Blue Spruce |url=https://dendro.cnre.vt.edu/dendrology/syllabus/factsheet.cfm?ID=109 |website=Virginia Tech Dendrology Fact Sheets |url-status=live |archive-url=https://web.archive.org/web/20250209064702/https://dendro.cnre.vt.edu/dendrology/syllabus/factsheet.cfm?ID=109 |archive-date=9 February 2025 |access-date=11 November 2025 |ref={{sfnref|Seiler et al. 2021}}}}
+* {{Cite web |last1=Swackhamer |first1=Emelie |last2=Sellmer |first2=Jim |date=31 January 2023 |title=Using Trees and Shrubs for Privacy and Wind Screening |url=https://extension.psu.edu/using-trees-and-shrubs-for-privacy-and-wind-screening |website=PennState Extension |language=en-US |publisher=College of Agricultural Sciences, Pennsylvania State University |url-status=live |archive-url=https://web.archive.org/web/20250911080604/https://extension.psu.edu/using-trees-and-shrubs-for-privacy-and-wind-screening |archive-date=11 September 2025 |access-date=8 November 2025}}
+* {{Cite web <!--Deny Citation Bot-->|last1=Taylor |first1=Ronald J. |date=6 November 2020a |orig-date=In print 1993 |url=https://floranorthamerica.org/Picea |title=''Picea'' |website=[[Flora of North America]] |language=en |isbn=978-0-19-508242-5 |oclc=504195332 |access-date=16 November 2024 |url-status=live |archive-url=https://web.archive.org/web/20250120224704/https://floranorthamerica.org/Picea |archive-date=20 January 2025}}
+* {{Cite web <!--Deny Citation Bot-->|last1=Taylor |first1=Ronald J. |date=5 November 2020b |orig-date=In print 1993 |url=https://floranorthamerica.org/Picea_pungens |title=''Picea pungens'' |website=[[Flora of North America]] |language=en |isbn=978-0-19-508242-5 |oclc=504195332 |access-date=21 September 2024 |url-status=live |archive-url=https://web.archive.org/web/20240921174018/https://floranorthamerica.org/Picea_pungens |archive-date=21 September 2024}}
+* {{Cite web |last1=VASCAN |last2=Acadia University |last3=Université de Montréal Biodiversity Centre |last4=University of Toronto Mississauga |last5=University of British Columbia |date=2025 |title=''Picea pungens'' - Database of Vascular Plants of Canada (VASCAN) |url=https://data.canadensys.net/vascan/taxon/7176?lang=en |website=Canadensys |language=en |url-status=live |archive-url=https://web.archive.org/web/20231127232125/https://data.canadensys.net/vascan/taxon/7176?lang=en |archive-date=27 November 2023 |access-date=12 November 2025 |ref={{sfnref|VASCAN 2025}}}}
 {{Refend}}
 ==External links==
+{{Commons category|Picea pungens|''Picea pungens''}}
 {{Sister project links|auto=yes}}
 * [http://www.conifers.org/pi/Picea_pungens.php Conifers.org: Picea pungens (blue spruce) description]

Blue spruce: Difference between revisions

Latest revision as of 20:29, 10 December 2025

Description

Chemistry

Taxonomy

Names

Ecology

Distributed soil types and topography

Rooting habits

Pests and diseases

Range

Notable trees

Cultivation

Culture

Gallery

See also

Citations

References

Sources

Books

Journals

News

Reports

Thesis

Web sources

External links

Navigation menu

Search