[5] Methuselah is a Great Basin bristlecone pine that is 4,856 years old and has been credited as the oldest known living non-clonal organism on Earth.

The needles are in fascicles of five, stout, 2.5 to 4 cm (1 to 1+1⁄2 in) long, deep green to blue-green on the outer face, with stomata confined to a bright white band on the inner surfaces.

[citation needed] These ancient trees have a gnarled and stunted appearance, especially those found at high altitudes,[4] and have reddish-brown bark with deep fissures.

Environmental niche modelling has been used to better map the distribution of Great Basin bristlecone pine using topographic and spectral variables calculated from a geographic information system (GIS).

[10] The tree grows in large open stands, unlike the related foxtail pine, which sometimes form dense forests.

[13] An introduced fungal disease known as white pine blister rust (Cronartium ribicola) is believed to affect some individuals.

[4] Historically, Pinus longaeva stands experienced low to high severity fires, and fuels structures changed considerably across elevational gradients.

In low elevation, mixed species stands, fuels are often heavy and in close proximity to anthropogenic ignition sources.

Yet at high elevations near treeline, Pinus longaeva typically grow on limestone outcroppings that provide little or no surface fuels to propagate a wildfire.

[16] The confirmed oldest tree of this species, "Methuselah", is also located in the Ancient Bristlecone Pine Forest of the White Mountains.

[18] This article incorporates text from the ARKive fact-file "Pinus longaeva" under the Creative Commons Attribution-ShareAlike 3.0 Unported License and the GFDL.