Rocky Mountains Bristlecone Pine
Encyclopedia
Pinus aristata, the Rocky Mountain Bristlecone Pine, is a species of pine
native to the United States
. It appears in the Rocky Mountains
in Colorado
and northern New Mexico
, with an isolated population in the San Francisco Peaks
in Arizona
. It is usually found at very high altitudes, from 2500-3700 m, in cold, dry subalpine climate conditions, often at the tree line, although it also forms extensive closed-canopy stands at somewhat lower elevations.
Pinus aristata is a medium-size tree
, reaching 5-15 m tall and with a trunk diameter of up to 1.5 m. The bark is grey-brown, thin and scaly at the base of the trunk. The leaves
('needles') are in fascicles of five, stout, 2.5-4 cm long, deep green to blue-green on the outer face, with stomata confined to a bright white band on the inner surfaces. The cones
are ovoid-cylindrical, 5-10 cm long and 3-4 cm broad when closed, purple at first, ripening yellow-buff when 16 months old, with numerous thin, fragile scales, each scale with a bristle-like spine 4-8 mm long.
The cones open to 4-6 cm broad when mature, releasing the seed
s immediately after opening. The seeds are 5 mm long, with a 10-20 mm wing; they are mostly dispersed by the wind, but some are also dispersed by Clark's Nutcracker
s, which pluck the seeds out of the opening cones. The nutcrackers use the seeds as a food resource, storing many for later use, and some of these stored seeds are not used and are able to grow into new plants.
It differs most conspicuously from the two other bristlecone pine species in that the needles usually have only one, (only rarely two) resin canals, and these are commonly interrupted and broken, leading to highly characteristic small white resin flecks appearing on the needles. This character, which looks a bit like 'dandruff
' on the needles, is diagnostic of Pinus aristata; no other pine shows it (though sometimes, scale insect
infestations can look superficially similar).
It is a long-lived tree, though not attaining the longevity of Pinus longaeva. The oldest known tree, which grows high on Black Mountain
in Colorado, was found to have at 2,435-year tree ring record (and overall estimated age of 2,480 years, per Craig Brunstein) in 1992. However, trees rarely live over 1,500 years.
This species was previously described as a subspecies of Pinus balfouriana (Pinus balfouriana aristata). Pinus aristata is currently regarded as one of three closely related species known as bristlecone pine
s and is sometimes named as the Rocky Mountains, or Colorado, bristlecone pine .
In addition to its informal and regional names, the trees are referred to as the Bristlecone, Foxtail or Hickory pine.
s in cold climates. Even so, it is never as long-lived as in the wild, typically living less than 100 years before it succumbs to root decay in the warmer, moister conditions prevalent in most inhabited places.
Pine
Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
native to the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. It appears in the Rocky Mountains
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
in Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
and northern New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
, with an isolated population in the San Francisco Peaks
San Francisco Peaks
The San Francisco Peaks are a volcanic mountain range located in north central Arizona, just north of Flagstaff.The highest summit in the range, Humphreys Peak, is the highest point in the state of Arizona at in elevation. The San Francisco Peaks are the remains of an eroded stratovolcano...
in Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
. It is usually found at very high altitudes, from 2500-3700 m, in cold, dry subalpine climate conditions, often at the tree line, although it also forms extensive closed-canopy stands at somewhat lower elevations.
Description
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
, reaching 5-15 m tall and with a trunk diameter of up to 1.5 m. The bark is grey-brown, thin and scaly at the base of the trunk. The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
('needles') are in fascicles of five, stout, 2.5-4 cm long, deep green to blue-green on the outer face, with stomata confined to a bright white band on the inner surfaces. The cones
Conifer cone
A cone is an organ on plants in the division Pinophyta that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity...
are ovoid-cylindrical, 5-10 cm long and 3-4 cm broad when closed, purple at first, ripening yellow-buff when 16 months old, with numerous thin, fragile scales, each scale with a bristle-like spine 4-8 mm long.
The cones open to 4-6 cm broad when mature, releasing the seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s immediately after opening. The seeds are 5 mm long, with a 10-20 mm wing; they are mostly dispersed by the wind, but some are also dispersed by Clark's Nutcracker
Clark's Nutcracker
Clark's Nutcracker , sometimes referred to as Clark's Crow or Woodpecker Crow, is a passerine bird in the family Corvidae. It is slightly smaller than its Eurasian relative the Spotted Nutcracker . It is ashy-grey all over except for the black-and-white wings and central tail feathers...
s, which pluck the seeds out of the opening cones. The nutcrackers use the seeds as a food resource, storing many for later use, and some of these stored seeds are not used and are able to grow into new plants.
Dandruff
Dandruff is the shedding of dead skin cells from the scalp . Dandruff is sometimes caused by frequent exposure to extreme heat and cold. As it is normal for skin cells to die and flake off, a small amount of flaking is normal and common; about 487,000 cells/cm2 get released normally after...
' on the needles, is diagnostic of Pinus aristata; no other pine shows it (though sometimes, scale insect
Scale insect
The scale insects are small insects of the order Hemiptera, generally classified as the superfamily Coccoidea. There are about 8,000 species of scale insects.-Ecology:...
infestations can look superficially similar).
It is a long-lived tree, though not attaining the longevity of Pinus longaeva. The oldest known tree, which grows high on Black Mountain
Black Mountain
-Australia:*Black Mountain , a mountain in Canberra*Black Mountain, New South Wales, a village in Guyra Shire, New South Wales*Black Mountain, Queensland, a small town in Queensland...
in Colorado, was found to have at 2,435-year tree ring record (and overall estimated age of 2,480 years, per Craig Brunstein) in 1992. However, trees rarely live over 1,500 years.
This species was previously described as a subspecies of Pinus balfouriana (Pinus balfouriana aristata). Pinus aristata is currently regarded as one of three closely related species known as bristlecone pine
Bristlecone pine
The bristlecone pines are a small group of pine trees that are thought to reach an age far greater than that of any other single living organism known, up to nearly 5,000 years....
s and is sometimes named as the Rocky Mountains, or Colorado, bristlecone pine .
In addition to its informal and regional names, the trees are referred to as the Bristlecone, Foxtail or Hickory pine.
Cultivation
Pinus aristata is by far the most common of the bristlecone pines in cultivation, where it is a very attractive slow-growing small tree suitable for small gardenGarden
A garden is a planned space, usually outdoors, set aside for the display, cultivation, and enjoyment of plants and other forms of nature. The garden can incorporate both natural and man-made materials. The most common form today is known as a residential garden, but the term garden has...
s in cold climates. Even so, it is never as long-lived as in the wild, typically living less than 100 years before it succumbs to root decay in the warmer, moister conditions prevalent in most inhabited places.