Pinus longaeva (commonly referred to as the Great Basin bristlecone pine, intermountain bristlecone pine, or western bristlecone pine) is a long-living species of bristlecone pine tree found in the higher mountains of California, Nevada, and Utah. In 1987, the bristlecone pine was designated one of Nevada's state trees.

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

Description

It is a medium-size tree, reaching tall and with a trunk diameter of up to . The bark is bright orange-yellow, thin and scaly at the base of the trunk. The needles are in fascicles of five, stout, long, deep green to blue-green on the outer face, with stomata confined to a bright white band on the inner surfaces. The leaves show among the longest persistence of any plant, with some remaining green for 45 years.

The cones are ovoid-cylindrical, long and broad when closed, green or purple at first, ripening orange-buff when 16 months old, with numerous thin, fragile scales, each scale with a bristle-like spine long. The cones open to broad when mature, releasing the seeds immediately after opening. The seeds are long, with a wing; they are mostly dispersed by the wind, but some are also dispersed by Clark's nutcrackers.

These ancient trees have a gnarled and stunted appearance, especially those found at high altitudes, As the tree ages, much of its vascular cambium layer may die. In very old specimens, often only a narrow strip of living tissue connects the roots to a handful of live branches.

The Great Basin bristlecone pine differs from the Rocky Mountain bristlecone pine in that the needles of the former always have two uninterrupted resin canals, so it lacks the characteristic small white resin flecks appearing on the needles of the latter. The Great Basin bristlecone pine differs from the foxtail pine because the cone bristles of the former are over long, and the cones have a more rounded (not conic) base. The green pine needles give the twisted branches a bottle-brush appearance. The name 'bristlecone pine' refers to the dark purple female cones that bear incurved prickles on their surface.

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File:Inyo Bristlecone bcp tree (5632371665).jpg|Tree in Inyo National Forest

File:Pinus longaeva young cone Patriarch Grove.jpg|Young Cone

File:Pinus longaeva mature cone Patriarch Grove.jpg| Mature Cone

File:2015-07-13 07 39 32 Foliage and pollen cones on a Great Basin Bristlecone Pine along the North Loop Trail about 5.4 miles west of the trailhead in the Mount Charleston Wilderness, Nevada.jpg|pollen cones

File:Bristlecone Pinus longaeva new growth.jpg|New growth

File:White Mtns Ancient Bristlecone Pines Park - grainy (11226427796).jpg|Bark

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Distribution and ecology

[[File:GBBP_distribution_map.png|thumb|left|upright|Pinus longaeva distribution map

The tree grows in large open stands, unlike the related foxtail pine, which sometimes form dense forests. Pinus longaeva trees generally do not form closed canopies, usually covering only 15-50%. These areas prohibit the cutting or gathering of wood. The nutcrackers use conifer seeds as a food resource, storing many for later use in the ground, and some of these stored seeds are not used and are able to grow into new plants; these trees often exhibit a "multi-trunk" growth form from several seeds germinating at the same time. The prevalence of multi-trunk P. longaeva individuals in areas in which Clark's Nutcrackers are present has been used as evidence that the birds disperse P. longaeva seeds.

Age

thumb|Needles and cones, [[Snake Range, Nevada]]

A specimen located in the White Mountains of California was measured by Tom Harlan, a researcher with the Laboratory of Tree-Ring Research, to be 5,062 years old as of 2010. Harlan died in 2013, and neither the tree nor the core Harlan studied have been found, making the age or existence of this tree unable to be confirmed.

The confirmed oldest tree of this species, "Methuselah", is also located in the Ancient Bristlecone Pine Forest of the White Mountains. Methuselah is years old, as measured by annual ring count on a small core taken with an increment borer.

Among the White Mountain specimens, the oldest trees are found on north-facing slopes, with an average of 2,000 years, as compared to the 1,000 year average on the southern slopes. The climate and the durability of their wood can preserve them long after death, with dead trees as old as 7,000 years persisting next to live ones.

See also

  • List of superlative trees

References

  • The ancient bristlecone pine
  • Photo of cone (scroll to bottom of page)
  • High elevation white pine educational website: Pinus longaeva
  • Aeon Magazine longform article on Bristlecone pines