Scientific name: Pinus lambertiana D.Douglas 1827
Synonyms: Pinus lambertiana subsp. martirensis (Silba) Silba, Pinus lambertiana var. martirensis Silba, Pinus lambertiana var. minor Lemmon, Pinus lambertiana var. purpurea Lemmon, Strobus lambertiana (Douglas) Moldenke
Common names: Sugar pine
Description
Tree to 60(-85) m tall, often clear of branches for 30 m. trunk to 2(-3.5) m in diameter. Bark dark grayish brown in the deep, interconnecting furrows between reddish brown, interrupted, narrow, flat-topped vertical ridges. Crown raggedly oval, open, with numerous, widely spaced, slender, unequally long, horizontal branches turning up at the tips when not weighted down by seed cones and bearing relatively sparse foliage. Twigs light reddish brown, smooth, minutely hairy. Buds 5-8 mm, resinous. Needles in bundles of five, each needle 5-8(-10) cm long, stiff, twisted, and slightly diverging, lasting 2-3(-4) years, bluish green with wax. Individual needles with lines of stomates on all three faces, an undivided midvein, two small resin canals touching the epidermis of the outer face, and sometimes with a third resin canal near the juncture of the two inner faces, either touching the epidermis of one of them or immersed in the leaf tissue between them. Sheath (10-)15-20 mm long, soon shed. Pollen cones 10-15 mm long, straw-colored. Seed cones very large, (25-)30-45(-60) cm long mostly straight and broadly cylindrical with a slight taper toward the tip, with 150-250 seed scales or more, green before maturity, ripening medium yellowish brown, opening widely to release the seeds and then falling, on stalks 6-15 cm long. seed scales paddle-shaped, moderately thick and rigid, straight, the exposed portion a little cupped and with a sharp angle along the midline, with a narrow diamond-shaped umbo at the tip. Seed body 10-15(-20) mm long, the firmly attached wing 20-30 mm long.
Mountains of Pacific North America, from central Oregon through California and westernmost Nevada to northern Baja California (Mexico). Almost always mixed with other conifers (and often towering over many of them) in montane forest; 600-3,200 m.
Conservation Status
Red List Category & Criteria: Least Concern
Pinus lambertiana's large extent of occurrence and area of occupancy are well beyond any threshold for a threatened category, and the great number of mature trees inside and outside protected areas, and the absence of white pine blister rust in large subpopulations plus the development of resistant variants support an assessment of Least Concern.
This majestic pine is common in the mixed and varied conifer forests of the Transition Zone in the high mountains of Oregon and California commonly between 600 m and 2,400 m a.s.l., but reaching 2,800-3,200 m in the south of its range. In the Sierra Nevada of California it is restricted to the western slopes at middle elevation, between the warmer Upper Sonoran Zone and the colder Canadian Zone. Here one of the most impressive conifer forests in the world occurs, dominated by gigantic trees; indeed the largest tree species in the world, Sequoiadendron giganteum, is restricted to this zone and this mountain range. Other species are Pinus monticola, Pinus ponderosa, Pinus jeffreyi, Pinus contorta var. murrayana, Abies magnifica, Abies procera, Calocedrus decurrens, and in the north of the range Pseudotsuga menziesii. A hospitable climate with warm, sunny summers moistened by rain showers and snowy but not extremely cold winters marks this zone. In Oregon Pseudotsuga menziesii, Abies grandis, Tsuga heterophylla, Thuja plicata, and Calocedrus decurrens are its most common associate conifers. Broad-leaved trees are rare and much smaller, Arbutus menziesii and Quercus kelloggii are perhaps the most common. The ground is open, littered with conifer needles, interspersed with small, flowery meadows and lush stream-sides full of flowering shrubs. The bright yellow lichen Letharia vulpina festoons trunks and branches everywhere. This type of forest becomes restricted to the highest mountain summits further south and the diversity of conifers diminishes as does their size.
The pathogen Cronartium ribicola (Basidiomycota), or White Pine Blister Rust, is considered a threat serious enough to severely limit natural regeneration in areas of high risk, and thereby alter successional trends favouring other conifers. It is not known if this is leading to an overall reduction of the population. The pathogen is alien to North America and was introduced via Vancouver Island at the beginning of the 20th century. By 1990 it had reached the southern parts of the Sierra Nevada in California. Infection decreases southward with drier and hotter summers, so it is possible that the more southern subpopulations will escape this disease. There are also widely varying local conditions of microclimate and moisture levels causing damage in some localities while in others the trees remain unaffected. This species is among the more tolerant conifers to oxidant (ozone) air pollution, which affects parts of its range.
Sugar pine is the most valuable of the pines due to its enormous size and its light, soft, even-grained, knot-free wood of which very large, straight pieces can be sawn. Consequently, old growth stands of this species command very high prices; fortunately many are now protected in National Parks and other reserves. This species is used for high quality construction timber and the finished milled wood of this 'king of pines' as John Muir called it, makes it ideal for high standard windows and doors as well as foundry casting and even musical instruments such as organ pipes and piano keys. Plantation forestry has not been very successful and in Europe few trees have survived for long in arboreta and parks due to white pine blister rust (Cronartium ribicola, Basidiomycota) to which it is exceptionally sensitive. The vernacular name refers to the sugar content of the resin; in the past native tribes used it as a chewing gum. This use was first noted by David Douglas, who thought the native people were eating it.
Pinus lambertiana is present in many protected sites, including several famous national parks. Monitoring White Pine Blister Rust progress and its ecological limits is an important research programme that has being undertaken since the 1970s by the USDA Forest Service, among other agents. There is also research into resistant genetic variants, which is showing some positive results.
Cultivars:
Pinus lambertiana ‘Glauca’
Pinus lambertiana ‘Lindleyi’
Pinus lambertiana ‘Rost Resistent’
References
- Farjon, A. (2010). A Handbook of the World's Conifers. Koninklijke Brill, Leiden.
- Eckenwalder, J.E. (2009) Conifers of the World: The Complete Reference. Timber Press, Portland.
- IUCN Red List of Threatened Species, International Union for Conservation of Nature and Natural Resources. Cambridge, UK /Gland, Switzerland
Copyright © Aljos Farjon, James E. Eckenwalder, IUCN, Conifers Garden. All rights reserved.
