Picea breweriana

Brewer spruce is a large evergreen conifer growing to {{Convert|20–40|m}} tall, exceptionally 54 m, and with a trunk diameter of up to 1.5 m. The bark is thin and scaly, and purple-gray in color. The crown is very distinct, distinguished by level branches with vertically pendulous branchlets up to {{Convert|1.2-2.4|m|ft|abbr=on|frac=2}},{{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=96–97|language=en|oclc=1141235469|orig-date=1977}} each branch forming a 'curtain' of foliage. The pendulous foliage only develops when the tree grows to about 1.5–2 m tall; young trees smaller than this (up to about 10–20 years old) are open-crowned with sparse, level branchlets. The shoots are orange-brown, with dense short pubescence about 0.2 millimeters long and very rough with pulvini 1–2 mm long.

The leaves are borne singly on the pulvini, and are needle-like (though not sharp), 15–35 mm long, flattened in cross-section, glossy dark green above, and with two bands of white stomata below.

The cones are longer than most other North American spruces, pendulous, cylindrical, {{Convert|8–15|cm|frac=2}} long and 2 cm broad when closed, opening to 3–4 cm broad. They have smoothly rounded, thin, flexible scales 2 cm long. The immature cones are dark purple, maturing red-brown 5–7 months after pollination. The seeds are black, 3–4 mm long, with a slender, 12–18 mm long pale brown wing.

DNA analysesRan, J.-H., Wei, X.-X. & Wang, X.-Q. 2006. Molecular phylogeny and biogeography of Picea (Pinaceae): Implications for phylogeographical studies using cytoplasmic haplotypes. Mol Phylogenet Evol. 41(2): 405–19.Sigurgeirsson, A. & Szmidt, A.E. 1993. Phylogenetic and biogeographic implications of chloroplast DNA variation in Picea. Nordic Journal of Botany 13(3): 233–246. have shown that Picea breweriana has a basal position in the Picea clade, suggesting that Picea originated in North America.

Picea breweriana grows very slowly, typically less than {{convert|20|cm|0|abbr=on}} per year. It occurs mainly on ridgetop sites with very heavy winter snow to provide a steady source of meltwater through the spring, but dry in the summer. It is very well adapted to cope with heavy snow and ice loads, with tough branches, and the drooping branchlets shedding snow readily.Frank Lang's Nature Notes: [http://www.fs.fed.us/r6/siskiyou/lang_bre.htm US Forest Service ecology and the naming]

Because of its slow growth, Brewer's spruce cannot compete with other much faster-growing trees like Douglas-fir. It is also susceptible to wildfire due to its thin bark and pendulous foliage, and therefore is seen to occur in exposed sites with poor, rocky soils, often at high elevation, where competition with other fire-sustaining conifers is reduced. It may also be found sporadically in open montane forests alongside conifer species adapted to similar conditions such as white fir, red fir, or mountain hemlock. The shrub species huckleberry oak and deer oak are other common associates.{{Cite web |title=Picea breweriana Wats |url=https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_1/picea/breweriana.htm#:~:text=Brewer%20spruce%20is%20found%20on,the%20largest%20stands%20are%20located. |access-date=2024-03-09 |website=www.srs.fs.usda.gov}}{{Cite web |title=Picea breweriana (weeping spruce) description |url=https://www.conifers.org/pi/Picea_breweriana.php |access-date=2024-03-09 |website=www.conifers.org}}

The species is known to host several species of pathogens and parasites, including the root rot Heterobasidion annosum, the dwarf-mistletoe Arceuthobium campylopodum, and the adelgid Adelges cooleyi.

It is endemic to the Klamath Mountains of southwest Oregon and northwest California, and grows at moderately high altitudes, from {{Convert|1000–2700|m|abbr=on}} above sea level.Farjon, A. (1990). Pinaceae. Drawings and Descriptions of the Genera. Koeltz Scientific Books {{ISBN|3-87429-298-3}}.Rushforth, K. (1987). Conifers. Helm {{ISBN|0-7470-2801-X}}.{{Gymnosperm Database|family=Pinaceae|genus=Picea|species=breweriana}}{{Silvics|volume=1|genus=Picea|species=breweriana|first=Dale|last=Thornburgh}}

Outside its native range, P. breweriana is a highly-valued ornamental tree in gardens, particularly in Great Britain and Scandinavia, where it is appreciated for its dramatically pendulous foliage. This plant has gained the Royal Horticultural Society's Award of Garden Merit.{{cite web

| title=RHS Plant Selector – Picea breweriana

| url=https://www.rhs.org.uk/Plants/12936/Picea-breweriana/Details | access-date = 6 February 2021}}{{cite web | url = https://www.rhs.org.uk/plants/pdfs/agm-lists/agm-ornamentals.pdf | title = AGM Plants – Ornamental | date = July 2017 | page = 78

| publisher = Royal Horticultural Society | access-date = 25 April 2018}}

File:Picea breweriana foliage.JPG|Foliage of a young tree, Ridge above Bear Lake, Ca.

File:Picea breweriana RHu.JPG|Picea breweriana in a garden

File:Picea breweriana - weeping twigs2.jpg|The weeping twigs

File:Picea breweriana2.jpg|Foliage

File:Picea breweriana leaf1.jpg|Close-up foliage

File:Picea breweriana (flowers).jpg|Fresh female cones

File:Picea breweriana cones01.jpg|Mature male cones & developing female cone

File:Picea breweriana mature cone.jpg|Mature cone

File:Mature Picea breweriana, Royal Botanic Garden, Edinburgh.jpg|Mature Picea breweriana, Royal Botanic Garden, Edinburgh

{{Reflist}}

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• {{Jepson Manual |id=195,206,207 |link=1}}
• [http://www.catalogueoflife.org/show_species_details.php?record_id=5647750 Catalogue of Life: Picea breweriana] {{dead link|date=July 2019}}
• {{usurped|1=[https://web.archive.org/web/20111002050600/http://conifercountry.com/conifers/Pin/spruce/bs/index.html Picea breweriana on Conifer Country]}}
• {{CalPhotos|Picea|breweriana}}

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breweriana

Category:Flora of the Klamath Mountains

Category:Endemic flora of the United States

Category:Flora of California

Category:Flora of Oregon

Category:Trees of Northern America