Pinus ponderosa
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. On that occasion, David Douglas misidentified it as Pinus resinosa. 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.
Description
Pinus ponderosa is a large coniferous pine tree. The bark helps distinguish it from other species. Mature to overmature individuals have yellow to orange-red bark in broad to very broad plates with black crevices. Younger trees have blackish-brown bark, referred to as "blackjacks" by early loggers. The five varieties or subspecies, as classified by some botanists, can be identified by their characteristically bright-green needles. The Pacific subspecies has the longest at and most flexible needles in plume-like fascicles of three, and green immature cones. The North Plateau or Columbia ponderosa pine has long and relatively flexible needles in fascicles of three, and purple immature cones. The Rocky Mountains subspecies has shorter and stouter needles growing in bushy, tuft-like fascicles of two or three, and usually green immature cones. The southwestern subspecies has stout needles long, in fascicles of three. The central High Plains subspecies is characterized by the fewest branches for the species.The egg-shaped cones, which are often found in great number under trees, are long. Each scale has a sharp point.
Sources differ on the scent of P. ponderosa. Some state that the bark smells of turpentine, which could reflect the dominance of terpenes. 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.
Size
The National Register of Big Trees lists a ponderosa pine that is tall and in circumference. 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 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. However, the USDA Natural Resources Conservation Service PLANTS database lists these as varieties as of 2025. 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 lists just two varieties. The Plants of the World Online 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 three varieties are recognized.
Subspecies and varieties
- Pinus ponderosa subsp. benthamiana Silba, syn. Pinus benthamiana Hartw., Pinus ponderosa var. benthamiana Vasey, Pinus ponderosa subsp. critchfieldiana Callaham, Pinus ponderosa var. pacifica J.R.Haller & Vivrette – Pacific ponderosa pine
- Pinus ponderosa subsp. brachyptera Silba, syn. Pinus brachyptera Engelm., Pinus ponderosa var. brachyptera Lemmon – southwestern ponderosa pine
- Pinus ponderosa subsp. ponderosa Douglas ex C. Lawson – North plateau ponderosa pine, Columbia ponderosa pine
- Pinus ponderosa subsp. scopulorum A.E.Murray, syn. Pinus ponderosa var. scopulorum Engelm., Pinus scopulorum Lemmon – Rocky Mountains ponderosa pine
- Pinus ponderosa subsp. readiana Callaham – Central High Plains ponderosa pine
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 J.R. Haller & Vivrette, while others treat it without distinction as a synonym of subsp./var. ponderosa. 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 extends southward into Mexico. It was formerly often treated as another variety, as Pinus ponderosa var. arizonica Shaw, but is now generally recognized as a separate species.
Distinguishing subspecies
The subspecies of P. ponderosa can be distinguished by measurements along several dimensions:| Common name | Pacific | North Plateau | Rocky Mountains | Southwestern | Central High Plains |
| Scientific name | P. p. benthamiana | P. p. ponderosa | P. p. scopulorum | P. p. brachyptera | P. p. readiana |
| Years needles remain green | 3.9±0.25, N=30 | 4.7±0.14, N=50 | 5.7±0.28, N=23 | 4.3±0.18, N=24 | 4.7±0.18, N=5 |
| Foliage length on branch | 25.1±2.4, N=30 | 26.2±2.2, N=50 | 21.1±1.7, N=23 | 21.8±2.7, N=24 | 42.2±6.7, N=5 |
| Needle length | 19.8±0.44, N=30 | 16.8±0.29, N=48 | 11.2±0.27, N=23 | 14.7±0.45, N=24 | 15.6±0.57, N=5 |
| Needles per fascicle | 3.0±0.00, N=30 | 3.0±0.00, N=48 | 2.6±0.06, N=23 | 3.0±0.03, N=24 | 2.4±0.11, N=5 |
| Needle thickness | 45.9±0.49, N=30 | 47.8±0.51, N=48 | 46.4±0.68, N=23 | 44.8±0.87, N=24 | 49.7±0.61, N=5 |
| Branches per whorl | 4.4±0.13, N=30 | 3.7±0.11, N=50 | 3.0±0.17, N=23 | 3.4±0.25, N=23 | 2.3±0.11, N=5 |
| Branch angle | 56±1.8, N=30 | 51±1.7, N=50 | 50±2.3, N=23 | 48±3.1, N=24 | 36±1.9, N=5 |
| Seed cones length | 101.4±2.48, N=25 | 88.7±1.24, N=36 | 70.7±2.20, N=22 | 74.9±2.51, N=20 | 71.1±2.46, N=5 |
| Seed cones width | 77.1±1.35, N=25 | 71.6±0.73, N=36 | 61.5±1.08, N=22 | 62.6±1.77, N=20 | 63.3±2.18, N=5 |
| Seed cone form W/L | 0.80±0.03, N=25 | 0.84±0.03, N=36 | 0.90±0.02, N=22 | 0.86±0.02, N=20 | 0.90±0.03, N=5 |
| Seed length | 7.5±0.08, N=23 | 7.6±0.16, N=14 | 6.3±0.09, N=17 | 6.4±0.18, N=16 | 7.0±0.12, N=5 |
| Seed width | 4.9±0.05, N=23 | 4.9±0.08, N=14 | 4.1±0.05, N=17 | 4.3±0.09, N=16 | 4.5±0.10, N=5 |
| Seed + wing length | 32.3±0.58, N=23 | 24.8±0.62, N=14 | 22.9±0.63, N=17 | 23.3±0.68, N=15 | 23.1±0.78, N=5 |
| Immature cone color | apple green to yellow green | red-brown to dark purple | green; "above 2,500 to 3,000 m, some trees have distinctly purple cones" | green | green |
Notes
Names of taxa and transition zones are on the map.
Numbers in columns were derived from multiple measurements of samples taken from 10 trees on a varying number of geographically dispersed plots.
Numbers in each cell show calculated mean ± standard error and number of plots.