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Pinus ponderosa

Pinus ponderosa, commonly known as the ponderosa pine, bull pine, blackjack pine, or western yellow-pine, is a very large pine tree species of variable habitat native to the western United States and Canada. It is the most widely distributed pine species in North America.
Pinus ponderosa grows in various erect forms from British Columbia southward and eastward through 16 western U.S. states and has been successfully introduced in temperate regions of Europe. 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 is the official state tree of Montana.
Pinus ponderosa is a dominant tree in the Kuchler plant association, the ponderosa shrub forest. Like most western pines, the ponderosa generally is associated with mountainous topography. However, it is found on banks of the Niobrara River in Nebraska. Scattered stands occur in the Willamette Valley of Oregon and in the Okanagan Valley and Puget Sound areas of Washington. Stands occur throughout low level valleys in British Columbia reaching as far north as the Thompson, Fraser and Columbia watersheds. In its Northern limits, it only grows below 1,300m (4,200ft) elevation, but is most common below 800m (2,600ft). Ponderosa covers 1 million acres (4,000 km2), or 80%, 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. It does not extend into Mexico.
Modern forestry research has identified five different taxa of P. ponderosa, with differing botanical characters and adaptations to different climatic conditions. Four of these have been termed "geographic races" in forestry literature. Some botanists historically treated some races as distinct species. In modern botanical usage, they best match the rank of subspecies and have been formally published.
Before the distinctions between the North Plateau race and the Pacific race were fully documented, most botanists assumed that ponderosa pines in both areas were the same. When a botanist and a geneticist from California found in 1948 a distinct tree on Mt. 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. Subsequent research determined this to be one of the southern-most outliers of the typical North Plateau race of ponderosa pine. Its current classification is Pinus ponderosa var. washoensis.
An additional variety, tentatively named P. p. var. willamettensis, found in the Willamette Valley in western Oregon, 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.