Editing Picea engelmannii

{{Short description|Species of North American spruce tree}}
{{Speciesbox
| image = Engelmann spruce on the PCT, Washington.JPG
| image_caption = Mature tree with female cones
| status = LC| status_system = IUCN3.1
| status_ref = <ref name="iucn status 12 November 2021">{{cite iucn |author=Farjon, A. |date=2013 |title=''Picea engelmannii'' |volume=2013 |page=e.T42322A2972365 |doi=10.2305/IUCN.UK.2013-1.RLTS.T42322A2972365.en |access-date=12 November 2021}}</ref>
| status2 = {{TNCStatus}}
| status2_system = TNC
| status2_ref = <ref name="NatureServe">{{cite web |last1=NatureServe |title=''Picea engelmannii'' |url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.161764/Picea_engelmannii |access-date=10 September 2024 |location=Arlington, Virginia |date=2024}}</ref>
| genus = Picea
| species = engelmannii
| authority = [[Charles Christopher Parry|Parry]] ex [[George Engelmann|Engelm.]]
| range_map = Picea engelmannii levila.png
}}

'''''Picea engelmannii''''', with the common names '''Engelmann spruce''',<ref name=Montana>{{cite web|url=http://montana.plant-life.org/sample/spruce01.htm|title=Montana Plant Life|access-date=2013-06-09|archive-url=https://web.archive.org/web/20160626212059/http://montana.plant-life.org/sample/spruce01.htm|archive-date=2016-06-26|url-status=dead}}</ref> '''white spruce''',<ref name=Montana/> '''mountain spruce''',<ref name=Montana/> and '''silver spruce''',<ref name=Montana/> is a species of [[spruce]] native to western [[North America]]. It is highly prized for producing distinctive [[tone wood]] for acoustic guitars and other instruments, it is mostly a high-elevation mountain tree but also appears in watered canyons.<ref>{{Cite web |title=Picea engelmannifiParry ex Engelm |url=https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_1/picea/engelmannii.htm |access-date=2023-12-24 |website=www.srs.fs.usda.gov}}</ref><ref>{{Cite web |title=Plant Guide: Engelmann Spruce |url=https://plants.usda.gov/DocumentLibrary/plantguide/pdf/pg_pien.pdf}}</ref>

==Description ==
{{See also|#Gallery}}

''Picea engelmannii'' is a medium-sized to large [[evergreen]] tree growing to {{convert|25-40|m|ft|abbr=off}} tall, exceptionally to {{convert|65|m|ft|abbr=on}} tall, and with a trunk diameter of up to {{convert|1.5|m|ftin|abbr=on}}. The reddish [[Bark (botany)|bark]] is thin and scaly,<ref name=":02">{{Cite book |last1=Arno |first1=Stephen F. |url=https://books.google.com/books?id=qDD4DwAAQBAJ |title=Northwest Trees: Identifying & Understanding the Region's Native Trees |last2=Hammerly |first2=Ramona P. |publisher=[[Mountaineers Books]] |year=2020 |isbn=978-1-68051-329-5 |edition=field guide |location=Seattle |pages=91–96 |language=en |oclc=1141235469 |orig-date=1977}}</ref> flaking off in small circular plates {{Convert|5–10|cm|frac=4}} across. The crown is narrow conic in young trees, becoming cylindric in older trees. The shoots are buff-brown to orange-brown, usually densely pubescent, and with prominent [[pulvini]]. The [[leaves]] are needle-like, {{Convert|15–30|mm|frac=8}} long, flexible,<ref name=":02" /> rhombic in cross-section, glaucous blue-green above with several thin lines of [[stomata]], and blue-white below with two broad bands of stomata. The needles have a pungent odour when crushed.<ref name=":02" />

Purple [[conifer cone|cones]] of about {{cvt|1|cm|in}} appear in spring, releasing yellow pollen when windy.<ref name=":02" /> The cones are pendulous, slender cylindrical, {{cvt|2.5|–|8|cm|in}} long<ref name=":02" /> and {{cvt|1.5|cm|in}} broad when closed, opening to {{cvt|3|cm|in}} broad. They have thin, flexible scales {{cvt|1.5|–|2|cm|in}} long, with a wavy margin. They are reddish to dark purple, maturing to light brown<ref name=":02" /> 4–7 months after pollination. The [[seed]]s are black, {{cvt|2|–|3|mm|in}} long, with a slender, {{cvt|5|–|8|mm|in}} long light brown wing.

The tree grows in a ''[[krummholz]]'' form along the fringe of alpine tundras.<ref name=":02" />

==Distribution==

Engelmann spruce is mostly a higher-elevation mountain tree, in many areas reaching the [[tree line]], but at lower elevations occupies cool watered canyons.<ref name=":02" /> It grows from {{convert|520-3650|m|ft|abbr=on}} above sea level,<ref name=":02" /> rarely lower towards the northwest.

Englemann spruce is native to western [[North America]], common in the [[Rocky Mountains]] and east slopes of the [[Cascade Range]] from central [[British Columbia]] to [[Southern Oregon]] in the Cascades and [[Montana]], [[Idaho]], and [[Colorado]], and more sparsely towards [[Arizona]] and [[New Mexico]] in the [[Sky islands]];<ref name=":02" /> there are also two isolated populations in [[Northern Mexico]]. 

It appears in the canyons of the [[Idaho Panhandle]] and more limitedly in the northeastern [[Olympic Mountains]], which features some exceptionally large specimens, including one {{Convert|2.1|m|ft|abbr=on|frac=2}} in diameter and {{Convert|179|ft|abbr=on|order=flip}} tall.<ref name=":02" /> It can be found in the [[Cascade Range]], mostly on the eastern slopes, from elevations of {{Convert|900-1800|m|abbr=on}} and liberally in the [[Rocky Mountains]].<ref name=":02" /> It can also be found in the [[Monashee]] and [[Selkirk Mountains]], as well as the highlands surrounding the [[Interior Plateau]].

==Ecology==
[[File:Picea engelmannii Sierra Blanca NM.jpg|thumb|left|upright .6|Young Englemann Spruce seedling]]
Because transpiration is greatly reduced in small saplings while engulfed in snowpack, increased rates of [[transpiration]] in response to loss of snowpack, coupled with low sapwood water reserves and an extended period of soil frost in windswept areas, may prevent Engelmann spruce from regenerating in open areas both above and below the tree line. Both water uptake and water stored in [[root]]s appear to be critical for the survival of subalpine Engelmann spruce saplings that are exposed above the snowpack in later winter to early spring.<ref name="boyce">Boyce, R.L. and Lucero, S.A. 1999. Role of roots in winter water relations of Engelmann spruce saplings. Tree Physiol. 19:893–898.</ref> 

For exposed trees, the availability of soil water may be critical in late winter, when transpirational demands increase. Cuticular damage by windblown ice is probably more important at the tree line,<ref name="hadley1">Hadley, J.L.; Smith, W.K. 1983. Influence of wind exposure on needle desiccation and mortality for timberline conifers in Wyoming, USA. Arctic Alpine Res. 15:127–135. (Cited in Coates et al. 1994).</ref><ref name="hadley2">Hadley, J.L.; Smith, W.K. 1986. Wind effects on needles of timberline conifers seasonal influence on mortality. Ecology 67:12–19. Cited in Coates et al. (1994).</ref> but damage caused by desiccation is likely to be more important at lower elevations.<ref name="boyce" />

Despite wind damage, the species tends to grow taller than others at the tree line.<ref name=":02" /> It is [[shade tolerant]], but not so much as [[subalpine fir]], rendering it somewhat [[Fire ecology|dependent on fires]] to outgrow competitors, although its thin bark and shallow roots make it vulnerable to fire.<ref name=":02" /> [[Dendroctonus rufipennis|Spruce bark beetles]] attack the tree, being particularly deadly to groups which have stood for centuries.<ref name=":02" /> It is also susceptible to avalanches.<ref name=":02" />

Although older spruce forests are not very useful to animals for forage, they can become so after fires, as they often burn completely, allowing many other plants, especially deciduous, to rise.<ref name=":02" /> Engelmann spruce-shaded streams are exploited by [[trout]], <ref name=":02" /> and [[aphid]]s produce [[gall]]s which hang from the tree and look similar to cones when they dry out.<ref name=":02" />

== Subspecies and hybrids ==
[[File:Engelmann spruce below Boulder Pond Payette NF.jpg|thumb|Forest floor under Engelmann spruces]]
Two geographical subspecies (treated as [[Variety (botany)|varieties]] by some authors, and as distinct species by others) occur:
*''Picea engelmannii'' subsp. ''engelmannii'' ('''Engelmann spruce'''). All of the range except as below.
*''Picea engelmannii'' subsp. ''mexicana'' ('''Mexican spruce'''). Two isolated populations on high mountains in northern Mexico, on the Sierra del Carmen in [[Coahuila]] ([[Sierra Madre Oriental]]) and on [[Cerro Mohinora]] in [[Chihuahua (state)|Chihuahua]] ([[Sierra Madre Occidental]]). Engelmann spruces of the [[Madrean sky islands]] mountains in the extreme southeast of Arizona and southwest of New Mexico also probably belong to this subspecies, though this is disputed.

The Engelmann spruce [[Hybrid (biology)|hybridises]] and [[Intergradation|intergrades]] extensively with the closely related [[Picea glauca|white spruce]]<ref name=":02" /> (forming a species complex known as ''[[Picea × albertiana]]''; Alberta spruce, or interior spruce) in interior Canada, and to a lesser extent with the closely related [[Picea sitchensis|Sitka spruce]] where they meet on the western fringes of the Cascades.

== Uses ==
Native Americans made various medicines from the resin and foliage.<ref name=":02" />

Engelmann spruce is of economic importance for its [[wood]], being light and fairly strong.<ref name=":02" /> It is harvested for [[paper]]-making and general construction.<ref name=":02" /> Wood from slow-grown trees at high elevation is especially prized for making soundboards for musical instruments such as acoustic [[guitar]]s, [[harp]]s, [[violin]]s, and [[piano]]s.<ref name=":02" />

Because it is odourless and has little resin, it has been used for food containers such as barrels.<ref name=":02" /> It is also used to a small extent as a [[Christmas tree]].

== Gallery ==
<gallery mode="packed">
File:Picea engelmannii foliage cones.jpg|Forest, with mature female cones in foreground
File:Picea engelmannii UGA1.jpg|Dangling somewhat immature (unopened) female cone
File:Picea engelmannii UGA2.jpg|Dangling mature female cone
File:Engelmann Spruce cones RMNP.jpg|Purple immature cones and yellow mature cones from the previous year. No male pollen cones are visible; the brownish-golden branch tips are protective [[bud scales]] being shed from the spruce buds<ref>{{Cite web|url=http://www.conifers.org/pi/Picea_engelmannii.php|title=Picea engelmannii (Engelmann spruce) description}}</ref>
</gallery>

== References ==
{{Reflist}}

==Further reading==
*[http://www.conifers.org/pi/Picea_engelmannii.php The Gymnosperm Database]
*[http://www.fs.fed.us/database/feis/plants/tree/piceng/all.html US Forest Service: Fire Effects Information System]
*[[Elbert Luther Little|Little, Elbert L.]] (1980), ''National Audubon Society Field Guide to Trees: Western Region''

==External links==
{{Commons category}}
*[http://ucjeps.berkeley.edu/cgi-bin/get_JM_treatment.pl?195,206,208 Jepson Manual Treatment]
*[http://www.pinetum.org/cones/PICEAcones.htm Arboretum de Villardebelle] – Photographs related spruce cones
*[http://calphotos.berkeley.edu/cgi/img_query?query_src=photos_index&where-taxon=Picea+engelmannii CalPhotos]

{{Taxonbar|from=Q165387}}
{{Authority control}}

[[Category:Picea|engelmannii]]
[[Category:Flora of the Northwestern United States]]
[[Category:Flora of the Southwestern United States]]
[[Category:Flora of Alberta]]
[[Category:Flora of British Columbia]]
[[Category:Flora of Coahuila]]
[[Category:Flora of Chihuahua (state)]]
[[Category:Flora of New Mexico]]
[[Category:Flora of Nuevo León]]
[[Category:Flora of Sonora]]
[[Category:Flora of Tamaulipas]]
[[Category:Plants described in 1863]]
[[Category:Taxa named by George Engelmann]]
[[Category:Taxa named by Charles Christopher Parry]]
[[Category:Trees of Northern America]]