Scientific name: Pinus contorta Douglas ex Loudon 1838

Synonyms: Pinus bolanderi Parl., Pinus inops Bong., Pinus macintoshiana P.Lawson

Common names: Lodgepole pine, Shore pine, Twisted pine, Contorta pine

Description

Tree to 35(-50) m tall, with trunk to 1(-2) m in diameter, or a miniature tree just 1-2 m tall on soilless coastal hard pans. Bark variously pale reddish brown, gray, or blackish brown, flaking in small scales, remaining flaky or breaking up into irregular ridges separated by shallow furrows at the base of large trees. Crown narrowly conical to cylindrical, often spirelike in dense stands or multitrunked, open, and irregular on exposed headlands, with numerous thin, horizontal or upswept branches densely clothed with foliage only at the tips. Twigs yellowish brown to reddish brown, hairless, roughened by scale leaves and their bases. Buds 12-15 mm long, slightly resinous. Needles in bundles of two, each needle (2-)3-7(-8) cm long, stiff, often twisted, lasting 3-5(-8) years, dark green to yellowish green. Individual needles with lines of stomates on both faces, a two-stranded midvein, and usually two resin canals deep within the leaf tissue near the outer corners. Sheath 0.3-0.6(-1) cm long, only the shorter, outer scales persisting after the first year and falling with the bundles. Pollen cones 5-15 mm long, yellowish brown with a reddish blush. Seed cones (2-)3-5(-6) cm long, egg-shaped, often slightly asymmetrical, especially at the base, standing out from the twig or curved backward, with 75-90(-120) seed scales, green before maturity, ripening orange-brown, opening widely to release the seeds or, more commonly, remaining closed on the branches many years until opening after a fire, unstalked or with a short stalk to 1 cm. Seed scales paddle-shaped, woody and stiff, the exposed portion diamond-shaped, low or somewhat pyramidal near the base of the cone on the outer side, the diamond-shaped umbo with a slender, rigid prickle to 6 mm long. Seed body 3-5 mm long, mottled with black to all black, the easily detachable wing 10-12 mm long.

Western North America, from southwestern Yukon and southeastern Alaska south to southern Colorado and northern Baja California (Mexico). Commonly forming pure stands but also mixed with other trees in many fire-prone habitats, from coastal flats and bogs to subalpine forests; 0-3,500 m. Precipitation consequently ranges from only 250 mm at low elevations in the interior to 5,000 mm along the northern coast.

Conservation Status

Red List Category & Criteria: Least Concern

Pinus contorta is widespread and abundant in many parts of its range and is therefore assessed as Least Concern. All of its constituent varieties are also assessed as Least Concern. Pinus contorta occupies a large part of the North American West with a vast latitudinal range. It consequently has a wide ecological amplitude and grows form near sea level to 3,350 m or perhaps higher and from the relatively mild but cool and rainy Pacific coast to the cold and continental interior of the northern Rocky Mountains. In the interior, Lodgepole Pine forms pioneer stands of great density after forest fires and can form monotypic stands of great extent, especially on infertile soils. In other sites it is associated with many western conifers, most commonly in the north with Picea glauca and mixed with Betula papyrifera or Populus tremula; at higher altitudes with Tsuga mertensiana, Picea engelmannii and Abies lasiocarpa. Further south, the species diversity increases and in California it is a component of the mixed conifer forest as well as subalpine conifer woodland and meadows with numerous conifer species. Here soils are more nutrient rich and fires are less frequent, so Pinus contorta does not attain dominance. As a component of the mixed conifer forest it can attain 50 m in height, with one metre d.b.h., and live to a considerable age. In other areas, such as large tracts of Yellowstone Park in Wyoming, Lodgepole Pine appears to be self-perpetuating as the only tree species capable of growing in a more dynamic environment characterized by frequent fires. No range wide threats have been identified. Bark beetles and changes in fire frequencies may be locally problematic. Lodgepole Pine is a major timber tree in western North America. Its geographical varieties differ apart from minor botanical characters also in growth performance and maximum size, which is at least in part due to environmental factors. As with other conifers, it attains greatest size in Oregon and California (var. murrayana) with trees over 50 m tall and 2 m diam. In the interior, the tall, thin stems of densely grown pines provided the 'lodgepoles', i.e. tent poles for the bison-hide covered conical tents of the Plains Indians with such famous tribes or 'nations' as the Dakota ('Sioux') and Blackfeet. Today Lodgepole Pine is put to all traditional (European) uses common to pine wood, but mass production is for the pulp industry or increasingly the manufacture of so-called structural particleboard, where chips are glued into boards for interior construction. Pinus contorta is sometimes planted as a shelter tree on barren sites, but is otherwise uncommon in cultivation; only a limited number of cultivars are known. Hybrids between Pinus contorta and Pinus banksiana have been generated by foresters in the USA in attempts to produce trees suitable for plantations. This species is present in many protected areas throughout its range.

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