Scientific name: Pinus contorta var. latifolia Engelmann 1871
Synonyms: Pinus bourcieri Carrière, Pinus boursieri Carrière, Pinus contorta subsp. latifolia (Engelm.) Critchf., Pinus contorta var. bourcieri (Carrière) House, Pinus contorta var. hendersonii Lemmon, Pinus contorta var. yukonensis W.L.Strong, Pinus divaricata var. hendersonii (Lemmon) B.Boivin, Pinus divaricata var. latifolia (Engelm.) B.Boivin, Pinus divaricata var. musci B.Boivin, Pinus murrayana var. sargentii Mayr, Pinus tamrac A.Murray bis, Pinus tenuis Lemmon
Common names: Rocky Mountain lodgepole pine
Description
Tall, spirelike trees, exceptionally to 50 m. Bark remaining predominantly scaly, even on large trunks. 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 (4-)5-8 cm long, 1-2(-3) mm wide, 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 solitary or in pairs, 4-6 cm long, strongly asymmetric and recurved on branches, persistent and variously serotinous. 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.
Mountains in western North America from the central Yukon and southern Northwest Territories (Canada), south in the Cascade Range to Washington and in the Rocky Mountains to central Utah, southern Colorado, and southwestern South Dakota; 100-3,500 m.
Conservation Status
Red List Category & Criteria: Least Concern
Pinus contorta var. latifolia is widespread and abundant in many parts of its range and is therefore assessed as Least Concern.
Pinus contorta var. latifolia Engelm. tends to be more inland and occurs from the Yukon south to Colorado. Rocky Mountain 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.
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. 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 var. latifolia is sometimes planted as a shelter tree on barren sites, but is otherwise uncommon in cultivation; only a limited number of cultivars are known.
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
Copyright © Aljos Farjon, James E. Eckenwalder, IUCN, Conifers Garden. All rights reserved.