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What is a Bristlecone Pine Tree?

This is a mature bristlecone pine tree with a gnarled trunk.

Pinus Longaeva

It is almost certain that as soon as you learn about the bristlecone pine tree, it will become your favorite tree. This tree is one of the most incredible coniferous evergreen trees on the planet. Not because it’s the most beautiful, or resilient, or large, but because it is the oldest living specimen known to man.

The ancient bristlecone pine can thrive in places where other plants do not exist. They are the most resilient and adaptive tree there is. They are a first succession species, meaning that they are the ones who repopulate a new open ground — whether it be open because of lava run or glacial runoff, they will bring plant life back to the area.

These ancient trees are quite small, and so it may be hard to know that they could possibly be so old. Their average life span is over 3000 years old, which is double the life expectancy of a redwood tree. Yet, they only grow to be an average of 15 meters in height, often less at higher altitudes.

The name “bristlecone” comes from the stunning purple cones that this tree produces. The female seed cones have scales that come equipped with extremely sharp points right at the opening, protecting seeds from invaders.

Curious about other types of pine trees or trees in general? Head on over to 101 Types of Trees from around the world, or learn more about the Ponderosa Pine Tree, White Pine Tree, Red Pine Tree, or Scots Pine Tree.

What are the Different Types of Bristlecone Pines?

The bristlecone pine has 3 subspecies. They are all very similar in appearance but differ mainly by their growing regions and by how populous they are in those regions.

The Great Basin Bristlecone Pine (pinus longaeva

This is a close look at a The Great Basin Bristlecone Pine with gnarled branches and leaves.

Is the longest-lived species of a bristlecone pine tree. They grow in Utah, Nevada, and California.

The Rocky Mountain Bristlecone Pine (Pinus aristata)

This is a look at a The Rocky Mountain Bristlecone Pine in a field.

Is the most common species of a bristlecone pine tree. They grow in Colorado, New Mexico, and Arizona. They are capable of forming closed canopies and these are capable of cultivation, whereas the other 2 species are not.

The Foxtail Pine (pinus balfouriana

This species of bristlecone pine tree form the densest groves. There are outlying populations in southern Oregon, the Klamath Mountains, and the southern Sierra Nevada. It is also referred to as the intermountain bristlecone pine.

For the topic of this article, we will be describing the physical attributes and growing regions of the Great Basin Bristlecone Pine tree.

What do Bristlecone Pine Trees Look Like?

Root System

The bristlecone pine’s ability to adapt and maintain resilience throughout the harsh conditions and climate of their growing regions is entirely dedicated to their type of root system.

These trees have root systems that are comprised of shallow roots that are very highly branched. They also have several very large and deep growing roots to help maintain stability, and to access moisture reserves deep in the earth.

Since they tend to live at high altitudes with very little water, they need both of these types of root systems in order to obtain nutrients and to be stable against windthrow.


Bristlecone pine trees will only grow to be about 15 meters tall in their lifetime, with the tallest bristlecone reaching only 18 meters in height. When these trees grow at higher altitudes, their height will only be about half of that. But just because they are short, does not mean that they aren’t thriving!

Growth Pattern

It is difficult to determine the average trunk diameter of the bristlecone pine tree, as their growth is extremely irregular and stunted. Because of their low nutrient soil, almost no water access, and high altitude, they do not follow the same growth pattern as other trees do.

Their gnarled branches tend to grow in almost Dr. Seuss-looking patterns. Because bristlecone pine wood is so dense and resinous, the wood appears as though it has been shaped by the wind, like sandstone. These effects create very unique and dazzling shapes.


This is a close look at the bark of a bristlecone pine tree.

Bristlecone pine bark is a red/brown color with deep fissures, and irregular grooves and ridges. However, in most of the photos we see of bristlecone pines, the trees do not have bark and only show the deadwood. This is because as the tree ages, the vascular cambium layer dies. The only living strip of tissue is in the center of the tree, and that is the only life source for the tree.

Rather than rotting away, the durability and longevity of the wood come from its resinous content. Bark will die away, but the heartwood remains. As we just described, the inner wood becomes shaped and molded by the wind, rain, and freezing.


This is a close look at the bristlecone pine tree foliage.

Bristlecone pine trees are coniferous evergreens, meaning that they possess needles and cones that do not shed seasonally. This tree is particularly impressive in this sense as bristlecone pine needles can remain on the tree for over 40 years.

This is rather incredible, seeing as the average coniferous foliage will only remain on a tree for about 5 years. The bristlecone pine does this in order to conserve enough energy to stay alive, rather than by growing new foliage.

These needle-like leaves grow in bundles of 5. They grow on the tree’s terminal branches in a spiral pattern, creating a long bottle brush appearance. Needles are dark green, short, and very stiff.

How do Bristlecone Pine Trees Reproduce?


This is a close look at the cluster of pine cones of a bristlecone pine tree.

Bristlecone pine trees are monoecious, meaning that both female cones and male cones occur on the same tree. However, they do not engage in self-pollination to ensure the genetic diversity of the species, which is part of the reason why these trees are so old and successful.

Seed cones (ovule producing – female characteristics) are a very dark purple color and are covered in glistening sap. Their color and sheen help the cone to absorb more heat, enabling it to grow faster.

Seed cones have incurved prickles on top of their scales, which is where the name is derived from. Mature cones will be 2-4 inches long, and maturation takes about 2 years.

Pollen cones (pollen-producing – male characteristics) are of similar shape, size, and color. Upon maturity their scales will dry out and open, releasing the pollen. Bristlecone pine trees are wind-pollinated.

Reproductive Rates

Because of the impossibly harsh living conditions of the bristlecone pine tree, their seed crop production is erratic at best — it is difficult to say how often they produce seeds, or when they begin doing so.

Under the current climatic and environmental changes, their population is not growing but remains stable. They are currently on the red list of the International Union for Conservation of Nature (IUCN), but are fortunately of “least concern”. Their population is stable for now, as long as citizens abide by the “no cutting or wood gathering” protection laws.

Where do Bristlecone Pine Trees Grow?

The bristlecone pine does not occur naturally in very many places. They can be found in isolated groves growing in subalpine groves and very high altitude arid regions in the western United States. The three subspecies of bristlecone pine only occur in Arizona, California, Colorado, New Mexico, Nevada, Oregon, and Utah.

Bristlecone pine groves can be found right at the treeline, and often are the only tree present in those areas, as no other species could survive those kinds of conditions. They occur most commonly at 1700-3400m above sea level.

What are the Growing Conditions of Bristlecone Pine Trees?


This is a look at a single bristlecone pine tree growing on a dry soil.

The key thing to note about the bristlecone pine is that it can grow in areas that no other plant species would dream of going. They grow in soil that is derived from dolomite, limestone, sandstone, or quartzite.

They can tolerate either alkaline or acidic soil, as long as it is very well-drained — they will not exist in clay-like soil conditions. The soil they grow in is usually high in calcium and magnesium as well, and low in phosphorous. These soil contents exclude almost all other plant species.

Sun Exposure

Bristlecone pine trees completely shade intolerant, and they can only survive if they have full sun, all day, every day. Lucky for them, the regions they grow in don’t usually have any other sort of tree competition, and so their canopy is completely their own.

Water Level

The bristlecone pine is possibly one of the most drought-tolerant of all tree species They live in areas that only receive 25cm of rain per year.

How are Bristlecone Pine Trees Used?

This is a close look at the inner bark of a bristlecone pine tree.


There is only one way in which the bristlecone pine tree should be used, and that is for pure admiration. These extremely unique and rare trees are thankfully protected by the IUCN. Lots of testing is done on bristlecones because of their extremely impressive life expectancy.

By cross-dating bristlecone pine debris, dendroclimatologists are able to use specific information in order to reconstruct chronologies of precipitation patterns in the long-ago past.

What are the Damaging Agents of the Bristlecone Pine Tree?

Specifically, the subspecies of rocky mountain bristlecone pine species is highly threatened by a fungal disease called white pine blister rust, which is caused by the mountain pine beetle.

White pine blister rust is an infection that starts in the tree’s needles and causes yellow spots. The infection eventually seeps into the twigs, branches, and heart of the tree. The fungus sporulates and continues spreading throughout the tree. Eventually, cankers are formed which provide a port of entry for decaying fungus.

What Happened to the Oldest Living Tree – Bristlecone Pine?

This is a look at Methuselah, the oldest living tree in the world.

The oldest known living specimen on earth was called Prometheus, and it was a bristlecone pine tree. This tree was said to have 4862 growth rings.

A young dendrologist (tree scientist) (whose name is not usually disclosed) contacted the local forest association to ask if he had permission to do some testing in a local bristlecone pine forest, filled with old trees. He received permission and began doing his testing.

A very expensive piece of equipment became stuck in the trunk of the tree because of its high density. He then asked the local forest association if he had permission to cut down the tree and do testing at his school lab. They consented, and so the tree was cut down.

Once the Prometheus tree was cut and brought to the lab, it was only then that the young dendrologist started counted the tree rings and came to discover that he had just cut down the oldest tree on the planet.

A devastating accident, especially coming from a lover of trees.


Why are bristlecone pine trees special?

The bristlecone pine tree is considered as being very special because it has the longest life expectancy of any living thing on earth. Their average life span is about 3000 years old, whereas the oldest known tree is almost 5000.

They are also special because they can grow in the harshest growing conditions, where no other plant species could possibly survive. Because of this harsh climate, the tree is formed by the wind, rain, and snow, creating very irregular and gnarled growth patterns.

How old do bristlecone pine trees get?

The average life expectancy of the bristlecone pine tree is 3000-4000 years old. That is over double the life expectancy of a California redwood tree.

How tall do bristlecone pine trees grow?

The tallest known bristlecone pine is only 18 meters in height. If a tree is growing at a very high elevation, it may only grow to be half of that height. These trees need to conserve all of the energy they can just to stay alive, and that is why they don’t experience large sizes.

How fast do bristlecone pine trees grow?

The growing rate of the bristlecone pine tree is so slow that it is almost comical. They only grow 0.025cm per year.

Where is the oldest bristlecone pine tree located?

The oldest bristlecone pine was 4862 years old and went by the name Prometheus and was the oldest living organism. That tree was accidentally cut down recently, and so the current oldest bristlecone pine tree is now found in the Inyo National Forest of southeastern Sierra of California. This tree’s name is Methuselah tree, it is 4852 years old. The exact location of this tree is a very well kept secret.

Where is the tallest bristlecone pine tree located?

The tallest bristlecone pine tree is located in a place called Patriarch grove. It is found in the White Mountain of the Inyo National Forest in the southeastern Sierra of California.

Why is Nevada’s state tree the bristlecone pine?

Some of the oldest living specimens of the bristlecone pine tree can be found in eastern Nevada, and for this reason, it is the official state tree of Nevada.

How do you age a bristlecone pine tree?

You can only determine the age of a bristlecone pine tree through its number of tree rings.

What is a limber pine tree?

The limber pine tree is another name used to refer to the rocky mountain bristlecone pine tree.

Are there bristlecone pine trees in Colorado?

The rocky mountain bristlecone pine trees grow in Colorado, whereas the other two subspecies do not.

Are there bristlecone pines in Yosemite?

The foxtail pine is a subspecies of bristlecone pine that grows in Yosemite Valley, eastern California. The other two subspecies of bristlecone do not occur there.

Where does the name bristlecone come from?

Bristlecone pine trees get their name from very sharp bristles that grow on the outside of the cone scales to help protect the cones from scavengers.

The tree also develops very short and densely clustered needles that make a twig resemble a bristle brush!