Pinus ponderosa, commonly known as the ponderosa pine or western yellow pine, is a very large pine tree species of variable habitat native to mountainous regions of western North America. It is the most widely distributed pine species in North America.

Pinus ponderosa grows in various erect forms in 16 western U.S. states as well as British Columbia in Canada and has been introduced in temperate regions of Europe and in New Zealand. It was first documented in modern science in 1826 in eastern Washington near present-day Spokane (of which it is the official city tree). On that occasion, David Douglas misidentified it as Pinus resinosa (red pine). In 1829, Douglas concluded that he had a new pine among his specimens and coined the name Pinus ponderosa for its heavy wood. In 1836, it was formally named and described by Charles Lawson, a Scottish nurseryman. It was adopted as the official state tree of Montana in 1949.

Other vernacular names that have been used for the species are "bull pine" and "blackjack pine", but these are general woodsmans terms applied to growth stages of several different pines, rather than specific to Pinus ponderosa.

The egg-shaped cones, which are often found in great number under trees, are long. Others state that it has no distinctive scent, while still others state that the bark smells like vanilla if sampled from a furrow. Sources agree that the Jeffrey pine is more strongly scented than the ponderosa pine. When carved into, pitch-filled stumps emit a scent of fresh pitch. In January 2011, a Pacific ponderosa pine in the Rogue River–Siskiyou National Forest in Oregon was measured with a laser to be high. The measurement was performed by Michael Taylor and Mario Vaden, a professional arborist from Oregon. The tree was climbed on 13 October 2011, by Ascending The Giants (a tree-climbing company in Portland, Oregon) and directly measured with tape-line at high. As of 2015, a Pinus lambertiana specimen was measured at , which surpassed the ponderosa pine previously considered the world's tallest pine tree.

Taxonomy

Pinus ponderosa was scientifically described and named by Charles Lawson working from information provided by David Douglas in 1836.

The taxonomy of the ponderosa pine is heavily disputed by botanists and foresters. In a pair of research papers in 2013 for the US Forest Service, Robert Z. Callaham concluded that it is a single species from the Rocky Mountains to the Pacific coast divided into five subspecies. In the World Plants database maintained by Michael Hassler only three varieties are recognized, one described in 2024. On the other hand the World Flora Online (WFO) lists just two varieties. The Plants of the World Online (POWO) lists four varieties, but separates out two other taxa recognized as varieties as species. Similarly to POWO Christopher J. Earle writes in the Gymnosperm Database that the ponderosa pine has three subspecies and recognizes two taxa as species. In the Flora of North America (FNA) three varieties are recognized.

Subspecies and varieties

  • Pinus ponderosa subsp. benthamiana (Hartw.) Silba, syn. Pinus benthamiana Hartw., Pinus ponderosa var. benthamiana (Hartw.) Vasey, Pinus ponderosa subsp. critchfieldiana Callaham (nom. superfl.), Pinus ponderosa var. pacifica J.R.Haller & Vivrette (nom. superfl.) – Pacific ponderosa pine

:: The Olympic Peninsula in Washington State, Oregon west of the Cascade Range, the whole of California, and far western Nevada, at on coastal-draining slopes of major mountain ranges. This is recognized by GRIN and PLANTS as the correct name for Callaham's subspecies critchfieldiana. It is also accepted by POWO but at varietal rank, Both Callaham, cited Hartweg's older name benthamiana in the synonymies of their new names, thus making them both invalid nomina superflua under Article 52 of the ICN. Despite this, POWO currently accepts var. pacifica.

  • Pinus ponderosa subsp. brachyptera (Engelm.) Silba, syn. Pinus brachyptera Engelm., Pinus ponderosa var. brachyptera (Engelm.) Lemmon – southwestern ponderosa pine

:: Four corners transition zone, including southern Colorado, southern Utah, northern and central New Mexico and Arizona, westernmost Texas, and a single small population in the far northwestern Oklahoma panhandle. The Gila Wilderness contains one of the largest and healthiest forests. Hot with bimodal monsoonal rainfall; wet winters and summers contrast with dry springs and falls; mild to cold winters. This taxon is recognized by Callaham and GRIN as a subspecies, and in PLANTS at varietal rank, of var. ponderosa by World Plants, its range is from southeast British Columbia south through Washington and Oregon east of the Cascade Range to northeast California and western Nevada east of the Sierra Nevada, and in Idaho and western Montana. As combined with subsp. benthamiana as in FNA it extends further south into California, but their treatment excludes western Montana.

  • Pinus ponderosa subsp. scopulorum (Engelm.) A.E.Murray, syn. Pinus ponderosa var. scopulorum Engelm., Pinus scopulorum (Engelm.) Lemmon – Rocky Mountains ponderosa pine

:: This is recognized by Callaham and GRIN as a subspecies, and by WFO as a variety, World Plants,

:: This is recognized by Callaham and GRIN as a subspecies, but not accepted by any of the other authorities, who all include its distribution mapped by Callaham within subsp./var. scopulorum. It includes the populations in southern South Dakota, Nebraska, and southeast Wyoming at lower altitudes on drier sites than typical of scopulorum.

Before the distinctions between the North Plateau and Pacific taxa were fully documented, most botanists assumed that ponderosa pines in both areas were the same. In 1948, when a botanist and a geneticist from California found a distinct tree on Mount Rose in western Nevada with some marked differences from the ponderosa pine they knew in California, they described it as a new species, Washoe pine Pinus washoensis H.Mason & Stockw. Subsequent research determined this to be one of the southernmost outliers of the typical North Plateau race of ponderosa pine. Trees of the North Plateau ponderosa indistinguishable from washoensis can be found as far north as Promontory Hill near Merritt in British Columbia in Canada. Some authors accept it as a valid variety Pinus ponderosa var. washoensis (H.Mason & Stockw.) J.R. Haller & Vivrette, It has been reported from , in upper mixed-conifer to lower subalpine habitats.

An additional possible variety, not formally described but colloquially named Willamette Valley ponderosa pine, is found in the Willamette Valley in western Oregon, where it is rare. This is likely just one of the many islands of Pacific subspecies of ponderosa pine occurring in the Willamette Valley and extending north to the southeast end of Puget Sound in Washington.

The closely related five-needled Arizona pine (Pinus arizonica) extends southward into Mexico. It was formerly often treated as another variety, as Pinus ponderosa var. arizonica (Engelm.) Shaw,

Distinguishing subspecies

The subspecies of P. ponderosa can be distinguished by measurements along several dimensions:

|  apple green to yellow green

|  red-brown to dark purple

| &nbsp;green; "above 2,500 to 3,000 m,<br/>some trees have distinctly purple cones" of the Black Hills of South Dakota. It is found on foothills and mid-height peaks of the northern, central, and southern Rocky Mountains, in the Cascade Range, in the Sierra Nevada, and in the maritime-influenced Coast Range. In Arizona, it predominates on the Mogollon Rim and is scattered on the Mogollon Plateau and on mid-height peaks () in Arizona and New Mexico. Arizona pine (P. arizonica), found in the mountains of extreme southwestern New Mexico, southeastern Arizona, and northern Mexico, is sometimes classified as a variety of ponderosa pine, but is presently recognized as a separate species. Ponderosa pine are also found in the Chisos, Davis, and Guadalupe Mountains of Texas, at elevations between .

Ecology

The fire cycle for ponderosa pine is 5 to 10 years, in which a natural ignition sparks a low-intensity fire. Low, once-a-decade fires are known to have helped specimens live for half a millennium or more. The tree has thick bark, and its buds are protected by needles, allowing even some younger individuals to survive weaker fires. Blue stain fungus, Grosmannia clavigera, is introduced in sapwood of P. ponderosa from the galleries of all species in the genus Dendroctonus (mountain pine beetle), which has caused much damage. Western pine and other beetles can be found consuming the bark. The seeds are eaten by squirrels, chipmunks, quail, grouse, and Clark's nutcracker, while mule deer browse the seedlings.

Various animals nest in the ponderosa pines, such as the pileated woodpecker.

Pathology

Pinus ponderosa is affected by Armillaria, Phaeolus schweinitzii, Fomes pini, Atropellis canker, dwarf mistletoe, Polyporus anceps, Verticicladiella, Elytroderma needle cast, and western gall rust. It is also considered a "weed" in parts of Australia.

Uses

Native Americans consumed the seeds and sweet inner bark. They chewed the dried pitch, which was also used as a salve. They used the limbs and branches as firewood and building material, and the trunks were carved into canoes. The needles and roots were made into baskets. The needles were also boiled into a solution to treat coughs and fevers. Old-growth trees were widely used by settlers as lumber, including for railroads. The wood is pale yellow to light brown, straight-grained, and moderately soft, making it suitable for a wide range of applications in construction and manufacturing. Younger trees are of poor quality for lumber due to the tendency to warp.

Blue stained pine

thumb|[[Grosmannia clavigera (blue stain fungus).]]

Blue-stained pine is wood marked by blue-gray streaks caused by fungi spread by the mountain pine beetle (Dendroctonus ponderosae). As the beetles infest trees like ponderosa and lodgepole pine, they introduce blue-stain fungi (Grosmannia spp.), which colonize the sapwood but do not weaken the wood structurally. Although often discounted in the marketplace due to its appearance, blue-stained pine is gaining popularity in sustainable and rustic design, where its distinct color is embraced as a natural and decorative feature.

Engineered Wood and Paper Products

Ponderosa pine is widely used in the production of engineered wood and pulp products. A large share of harvested logs goes into plywood, particleboard, fiberboard, and paper. Ponderosa pine peeler logs are rotary-cut to produce veneer, which is used in plywood panels. The wood's light color and pleasant pine scent add to its appeal for interior use.

Notable uses and structures

thumb|Ponderosa pine ceiling in the historic [[Grand Canyon Lodge.]]

Because of its abundance and warm appearance, ponderosa pine has been used in many notable western U.S. buildings, often contributing to a rustic, parkitecture aesthetic. One iconic example is the Grand Canyon Lodge where architect Gilbert Stanley Underwood used massive ponderosa beams for the sloped roof and expansive interiors. Another example is Fuller Lodge in Los Alamos, New Mexico, using more than 700 locally harvested ponderosa logs in its log-style design.

Cultivation

thumb|Pinus ponderosa as [[bonsai. This tree is estimated to be over 40 years old. The long length of the needles is the main challenge when training this species as bonsai.]]

Cultivated as a bonsai, ponderosas are prized for their rough, flaky bark, contorted trunks, flexible limbs, and dramatic deadwood. Collected specimens can be wildly sculpted by their environment, resulting in beautiful twisted trunks, limbs and deadwood. In the mountains they can be found growing in pockets in the rock, stunting their growth. The main challenge for this species in bonsai cultivation is the natural long length of its needles, which takes years of training and care to reduce.

This species is grown as an ornamental plant in parks and large gardens.

Culture

Pinus ponderosa is the official state tree of Montana. In a 1908 poll to determine the state tree, Montana schoolchildren chose the tree over the Douglas fir, American larch, and cottonwood. However, the tree was not officially named the state tree until 1949.

The Ponderosa Ranch in the classic TV series Bonanza was named after the ponderosa pine, commonly found in the Lake Tahoe region where the fictional Cartwright family's ranch was set. Bonanza was one of the first Westerns to be filmed in color and made frequent visual use of scenic pine forests to emphasize the ranch's size and frontier beauty.

See also

  • Southern yellow pine

References

General references

  • USDA Plants Profile for Pinus ponderosa (ponderosa pine)
  • Gymnosperm Database: Pinus ponderosa
  • Calflora Database: Pinus ponderosa (ponderosa pine, western yellow pine)
  • Jepson Manual eFlora (TJM2) treatment of Pinus ponderosa