The Gymnosperm Database
Trees, foliage and cones. Drawing by Matt Strieby, 2017.
The largest known specimen, near the Queets River, Olympic National Park, Washington [C.J. Earle, 2004.05.29].
A very large tree growing on a headland at the south end of Norwegian Memorial beach, Olympic National Park, Washington. Note the epiphytic growth of
[C.J. Earle, 2001.05.27].
Ripe cones on a tree at the beach, Olympic National Park, Washington [C.J. Earle, 2016.09.03].
Immature cones about 8 cm long, and foliage, on a coastal tree at Cape Disappointment State Park, Washington [C.J. Earle, 2002.06.16].
Bark on an 30 cm dbh tree at Cape Disappointment State Park, Washington [C.J. Earle, 2013.05.12].
Colonnade of trees established on a nurse log. Hall of Mosses Trail, Olympic National Park, Washington [Charles Webber (
Newly emerged foliage. Ruby Beach, Olympic National Park [C.J. Earle, 2003.05.17].
The top of a tree that snapped off in a big winter storm and skewered itself into the ground to a depth of 1-2 meters. The snapped-off stem is visible in the background. Queets valley, Olympic National Park. [C.J. Earle, 2004.05.30].
Epicormic branching on a tree at Cape Disappointment State Park, Washington. Sitka spruce is one of the conifers that can lose all of its live branches and still regrow a complete live crown through
[C.J. Earle, 2009.02.21].
A tree growing on the back beach at Cape Disappointment State Park, Washington, showing the characteristic stunted growth form developed in response to windborne salt spray (see text for discussion) [C.J. Earle, 2013.01.12].
Extremely glaucous foliage on a tree growing in the Skagit Delta, Washington. Glaucousness varies greatly in this species [C.J. Earle, 2002.02.02].
Windthrown tree near Mud Mountain Dam, Washington. This species is often found in wetlands that have largely anoxic soils. In such settings, roots are extremely shallow but can extend a considerable distance from the trunk [C.J. Earle, 1988.04.30].
The Quinault Spruce (see text). Though not the largest Sitka spruce, it certainly has the largest butt [C.J. Earle, 1992.09.05].
The San Juan spruce on the day of its discovery (see text) [C.J. Earle, 1998.12.14].
A bold and persistent tree growing by the beach at Kalaloch, Olympic National Park. A stream emerges beneath this tree [C.J. Earle, 2002.02.02].
Service pin for the Spruce Production Division (gold-plated brass).
Sitka spruce, tideland spruce, coast spruce, Menzies spruce (
), épinette de Sitka (
); also smrk sitka [Czech], Sitkagran [Danish, Swedish], Sitkaspar [Dutch], Sitka-Fichte [German], sprus Sitceach [Irish], peccio di Sitka [Italian], Sitka egle [Latvian], Sitkinė eglė [Lithuanian], Ель ситхи́нская [Russian], pícea de Sitka [Spanish], and Sitka ladini [Turkish].
(Douglas ex D. Don) Lindley 1835, not Mirbel 1825;
(Douglas ex D. Don) Carrière;
Douglas ex D. Don (
Freely hybridizes with
to form Lutz or Roche spruce,
P. × lutzii
, wherever the ranges of the two species overlap, such as along major river corridors across the British Columbia Coast Range and in coastal Alaska. Analysis of this introgression zone indicates that the region was first colonized by
during late Pleistocene deglaciation, with subsequent introgression when
arrived via dispersal from Alaskan or eastern Canadian refugia (Hamilton and Aitken 2013). In the Chilliwack River Valley of British Columbia, it occurs with and hybridizes with
. The area is near sea level and the Fraser Valley, yet comes right out of the heart of the North Cascades. This hybrid may occur elsewhere, where the species' ranges are contiguous (such as the Federation Forest/Crystal Mountain area of Washington) but has not been seen yet (
Van Pelt 1999
). Hybridization between
and "interior spruce" (the
P. glauca × P. engelmannii
hybrid) have been reported in the Skeena River area of British Columbia (Sutton et al. 1994).
A 2006 analysis of both paternal and maternal molecular markers (chloroplast and mitochondrial DNA) of all living species of
are basal to
, with the other species in the genus divisible into three clades derived from two episodes of dispersal to Eurasia via the Beringian land bridge (
Ran et al. 2006
). In this phylogeny, both
are equally closely related to
, a result consistent with the hybridization patterns noted above.
Tree to 80 m tall and 500 cm dbh with straight trunk from buttressed base and an open, conical crown of horizontal branches. Bark grey, smooth, thin, becoming dark purplish-brown with scaly plates. Branches somewhat drooping; twigs not or slightly pendent, rather stout, pinkish brown, glabrous, rough, with peglike bases. Buds reddish brown, 5-10 mm, apex rounded. Needles (1.2)1.5-2.5(3) cm, flattened or broadly triangular in cross section (lower surface rounded or slightly angular), rather rigid (painfully sharp), blue-green to light yellow-green, upper surface darker green with stomatal bands very narrow or absent, lower surface glaucous with conspicuous stomatal bands separated by ridge, apex sharp-pointed, dark green, 15-25 mm long. Ovulate cones 5-9 (-10) cm long, cylindrical, short-stalked, green or reddish, ripening pale buff to light orange-brown, pendant from ends of twigs, opening at maturity and falling soon after. Cone scales variable, elliptic to narrowly diamond-shaped, 15-22 × 12-16 mm, rather thin and flexible, margin at apex erose, apex extending 4-8 mm beyond seed-wing impression. 2
). Bract scale the longest of any spruce, to 7-8 mm long and very occasionally slightly exserted by up to 0.5 mm on basal scales.
Distribution and Ecology
Along the northwest coast of North America from Kodiak Island in the western Gulf of Alaska to Mendocino County, California, never more than 200 km from the sea and usually much closer. See also
. USDA hardiness zone 7 (Californian origins zone 8; hybrid
P. × lutzii
zone 5). Grows at timberline (ca. 1000 m) in Alaska, while remaining below 400 m in California. Typically found in areas with high rainfall and a cool climate, although a considerable range of precipitation and temperature values is encountered across this species' wide latitudinal range. Usually found growing on well-drained acidic soils, in pure stands or with
. Other frequent associates, as they might be encountered traveling from the southern to northern limits of Sitka spruce's range, include the conifers
. An important hardwood associate is
, which often colonizes gravel bars along large rivers at the same time as Sitka spruce (
Distribution data from
Hardy to Zone 7 (cold hardiness limit between -17.7°C and -12.2°C) (
Bannister and Neuner 2001
Sitka spruce is the world's largest spruce (
), and in terms of wood volume, is the second-largest species in the Pinaceae after
. In old growth stands, trees may commonly reach a height of 70 m and diameter of 300 cm. The very largest known specimen (see top photo) grows near road's end in the Queets River valley of Olympic National Park. Bob Van Pelt relates that "Bob Wood first told me about this tree during the late 1980's when I began measuring western trees. He indicated that it had a huge, 15 foot (457 cm) thick trunk, and that it was taller than the tree at Quinault Lake. He also mentioned that a recent study on the growth of this tree indicated that the growth rings are still relatively large, so much so that the tree adds a foot to its circumference every 35 years or so. The implication of this, since the tree has approximately 5,300 ft
) of living cambium, is that close to 46 ft
) per year are produced by this tree, making it one of the fastest growing trees on the planet!" This tree has a measured diameter of 455 cm and height of 75.6 m, with an estimated wood volume of 337 m
Van Pelt 2001
The second-largest known tree is the San Juan spruce, which grows at a campsite beside the San Juan River on Vancouver Island, a few miles from the largest known tree in the Pinaceae. In fact, the San Juan spruce is the third largest tree in the Pinaceae, with a diameter of 371 cm, a height of 62.5 m, and a wood volume of 333 m
Van Pelt 2001
Neither of these trees is widely known, but at least two other spruces have been proclaimed to be 'the world's largest spruce.' One, a very large specimen near Lake Quinault in Olympic National Forest, WA, has 539 cm dbh due to a large butt swell; it is 58.2 m tall with a wood volume of 298 m
Van Pelt 2001
). It could be called the world's largest spruce if the only criterion is diameter at a height of 1.4 m, which is sort of like determining the world's largest man by the size of his ankles. The other putative largest tree, near Seaside, OR, fell in a 2006 winter storm. The principal cause of its death was extensive stem rot that had been apparent for many years (pers. obs. by C.J. Earle and R. Van Pelt), and the proximal cause was likely wind stress due to a nearby recent clearcut that exposed the tree to winds it had not previously experienced (Mario Vaden email 2014.05.16).
The tallest two trees on record, 96.7 m and 96.4 m, are in Prairie Creek Redwoods State Park, California, which is also home to many of the very tallest
(Steve Sillett, pers. comm. 2001.07.14, reporting data collected by Chris Atkins and Michael Taylor, who measured the trees using a survey laser). Third tallest known is the Carmanah Giant, 96.0 m with a dbh of 305 cm, in Pacific Rim National Park in BC (
Lewis and Clark, when they first encountered this tree, wrote of that it is "a species which grows to immence size ... we have found them as much as 36 feet in the girth or 12 feet diameter perfectly solid and entire, they frequently rise to the hight of 230 feet, and one hundred and twenty or 30 of that hight without a limb."
Thought to be 700 or 800 years (
), but no supporting data are available.
Sitka spruce has not been widely used in dendrochronological studies. A 2017 literature review identified several studies of ecological topics including tree sapling responses to deer browsing, successional change following glacial retreat and river flood events, and the history of bark beetle outbreaks.
The sharp needles were believed to give this tree special powers of protection against evil thoughts. Various Northwest Coast peoples have eaten the inner bark or the young shoots; the latter are an excellent source of vitamin C (also much appreciated by the native elk,
). The pitch was chewed for pleasure and as a medicine for various skin irritations. The roots, peeled, split and dried, were used to make twined, water-tight hats and baskets (
Pojar and MacKinnon 1994
). In the 21st Century, the main dietary or medicinal use of this species is
to make beer
Western society regards Sitka spruce as one of the foremost timber species in its native region and also in NW Europe, where it a widely planted timber tree. It is by far the most common tree in the United Kingdom, with a coverage of 66,500 km
(most of which is in Scotland) (Forestry Commission 2017). It is also the most widely planted tree in
), and it is the most successful agroforestry species to have been introduced to Iceland, which is now well on its way to having a viable timber industry (Icelandic Forest Service 2017). Significant commercial harvest also occurs in France and Denmark (Houston Durrant et al. 2016).
The lumber has a high strength-to-weight ratio. Historically, it was widely used in aircraft; from 1917 to 1919 the U.S. Army operated the "Spruce Production Division" that, at its height, employed nearly 30,000 men in production of lumber for manufacturing military aircraft (Tonsfeldt 2013). Spruce continued to be widely used in aircraft manufacturing until aluminum became affordable and widely available (aside: the largest wooden airplane ever built, the "Spruce Goose," was actually made of birch), and remains an important material in construction of some experimental and hobby aircraft (see this
of the topic). It makes superior ladders, and is popular in boat building as a source of masts, spars, and oars (
). Sitka spruce is also extremely popular for use as a piano sounding board (it's the sole species used in Steinway pianos) and for the tops of many stringed instruments (see
Uses of Conifer Wood in Musical Instruments
); this is one of the primary uses of the diminishing supplies of old-growth timber, now largely sourced from southeast Alaska.
The most famous, and perhaps the best, places to see old growth Sitka spruce forests are the Queets, Hoh and other river valleys of western Olympic National Park (Washington), and Pacific Rim National Park and Carmanah Pacific Provincial Park on Vancouver Island (British Columbia). The former site includes some of the largest spruce, and the latter some of the tallest. See Randy Stoltmann's book, "Hiking the ancient forests of British Columbia and Washington" (1996. Vancouver, BC: Lone Pine) for details on visiting these areas and finding the largest trees.
The epithet refers to the type locality: Sitka, now in Alaska, but the capital of Russian America when the species was described in 1832.
Together, Sitka spruce and
dominate one of the great forest types of North America, the coastal forest of the Pacific Northwest. Their native environment is characterized by a cool, moist maritime climate (
The most widespread forest disturbance in this environment is windthrow. Severe storms, occurring at intervals of decades to centuries, may flatten entire forests. Wind is also an important chronic disturbance, contributing to about 80% of within-stand mortality in these forests (
). Both spruce and hemlock have adapted to this situation in a distinctive way: their seedlings typically germinate and thrive on a substrate of decaying conifer wood. An old growth spruce-hemlock forest is thus characterized by the presence of "nurse logs," logs that may be covered with seedlings of hemlock and spruce (
Kirk and Franklin 1992
One consequence of life in a cool, moist maritime climate is the development of huge aboveground biomass accumulations, mostly in the form of live and decaying wood. Old growth Sitka spruce-western hemlock forests have been found to have an average aboveground biomass of 1163 tonnes per hectare, a value exceeded only by forests of
), and perhaps by some
-dominated rainforests of Tasmania.
Sitka spruce is also somewhat noteworthy for its tolerance to salt spray, which permits this species to occur on rocky sites along the seashore, sometimes with lodgepole pine, another species tolerant of the salt. Spruce growing in such an environment often show a gnarled and twisted growth form reminiscent of trees growing at timberline. This growth form has been shown to be related to the production of increased amounts of coumarin, a growth hormone widespread among conifers (
Trees typically begin to produce cones at 15 to 40 years of age. Seeds are small, with an average weight of 2.2 mg. Most seed is dispersed within 6 weeks of initial cone opening, and dispersal is by wind. Trees grow slowly for the first few years after germination but growth then increases rapidly, with heights at 100 years of age ranging from 33 m in Alaska to 48 m in Oregon (
); in cultivation in Britain, growth rates of 40 m in 43 years, and 60 m in 110 years, are recorded on the best sites (A F Mitchell).
This is one of the conifer species that can produce epicormic branches. If a stand is opened up to light, for instance by an adjacent clearcut, new branches may originate along the exposed tree trunks (
Sitka spruce is the state tree of Alaska (
Forestry Commission. 2017.
Forestry Statistics 2017, Chapter 1: Woodland Areas and Planting
, accessed 2017.11.01.
Jill A. Hamilton and Sally N. Aitken. 2013. Genetic and morphological structure of a spruce hybrid (
Picea sitchensis × P. glauca
) zone along a climatic gradient.
American Journal of Botany
T. Houston Durrant, A. Mauri, D. de Rigo, and G. Caudullo. 2016.
in Europe: distribution, habitat, usage and threats.
, accessed 2017.11.01.
Icelandic Forest Service. 2017. Forestry in a treeless land.
, accessed 2017.11.01.
B. C. S. Sutton, S. C. Pritchard, J. R. Gawley, C. H. Newton, and G. K. Kiss. 1994. Analysis of Sitka spruce–interior spruce introgression in British Columbia using cytoplasmic and nuclear DNA probes.
Canadian Journal of Forest Research
W. Tonsfeldt. 2013. The U.S. Army Spruce Production Division at Vancouver Barracks, Washington, 1917-1919.
, accessed 2017.11.02.
This page co-edited with Michael P. Frankis, 1998.12.
Daubenmire, R. 1968. Some geographic variations in
and their ecologic interpretation.
Canadian Journal of Botany
Franklin and Dyrness 1988
Van Pelt 2001
Sitka spruce growing on a stump in the Copalis estuary, Washington. This was an old-growth Picea-Tsuga-Thuja forest on the evening of
January 26, 1700
when the last great Cascadia earthquake and tsunami occurred, lowering the land by 3 m. Saltwater intrusion killed the trees, but a number of standing snags and stumps still remain. This tree apparently subsists on fresh water that accumulates in the stump during winter rains [C.J. Earle, 2017.07.09].
A coastal forest of Sitka spruce at Ruby Beach, Olympic National Park. The stand is developed on the back beach at the base of a coastal bluff, and thus is subject to considerable salt water exposure during winter storms, evidence of the species' tolerance of elevated salinity. Every tree is Sitka spruce. Windward trees show branch trimming due to salt spray exposure [C.J. Earle, 2005.07.10].
Typical mature forest in the Queets valley of Olympic National Park. This forest, dated as 140 years old, is developed on the floodplain. Both
) are pioneer tree species. Understory is dominated by
[C.J. Earle, 2007.06.30].
The view from the canopy of an old-growth tree in the Queets valley of Olympic National Park. The top of the canopy is a warm and dry place, relative to the forest floor, so a transition from moss epiphytes to lichen epiphytes occurs with increasing height into the canopy [C.J. Earle, 2004.05.29].
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Edited by Christopher J. Earle
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