Colorado native trees – What Tree Where

Piñon Pine: Tastiest tree in the Southwest

Euell Gibbons may have proclaimed the piñon nut “the most palatable wild food.”

As you approach Santa Fe, you may notice hillsides covered with shrubby piñon trees. Nothing quite says you are in the Southwest as the crisp air carrying the scent of piñon pine. The smell of it burning wafts across the plaza in downtown Santa Fe. Plenty of stores carry piñon pine specialties, like piñon brittle, candies, nuts roasted with chile, and piñon coffee.

This species features in the traditions, legends, and ceremonies of many Southwestern cultures as described in a 1930s pamphlet from the National Parks Service. It may have been a major source of protein for Native Americans, including the Utes. For a modern discussion of the significance of the piñon to the Apache, this short blog includes a video and mentions piñon branches as smudge sticks. According to the site Pinenut.com, the nuts have had an economic benefit to the Navajo and in the 1930’s provided “more than the combined value of both rugs and silver which they produced.”

Piñon pine, Pinus edulis, is also known as Colorado piñon, Pinyon, common pinyon, New Mexico pinyon, Colorado pinyon, mesa pinyon, two-leaf pinyon, two-needle pine, nut pine, Rocky Mountain pinon, and Pino dulce. The preferred spelling, piñon, is Spanish and is interchangeable with most of the variations above. Although the USDA shows the trees throughout the Southwest, other sources indicate they are found primarily in Colorado, Utah, Arizona, and New Mexico. This discrepancy could be related to the existence of related species such as the single-leaf piñon, Pinus monophylla. Sibley* and others note the various species hybridize, making identification difficult.

Pinus edulis, the state tree of New Mexico, are “bushy” trees. They are slow growing but long-lived, possibly living up to 1000 years. The oldest verified tree was dated at 973 years, while the largest is located near Santa Fe, NM. As an alternate name suggests, this pine has two leaves in a fascicle, with the needles usually between 0.6 and 2.0 inches in length. The cones of the piñon are small, about an inch in diameter, and very round.* This species may not produce any cones until the trees are a quarter century old, with good seed production not starting until the specimen is 75 to 100 years old. As the fertilized seeds are comparatively heavy and not disbursed far by the wind, the species is dependent on birds to sow the seeds. Four species are primarily involved in this task: Clark’s nutcracker, Steller’s jay, Mexican jay, and the pinyon jay.

Although the seeds are what this species is known for, it is hard to beat its wood for a fire. The aroma is distinctive and quite pleasant. According to many sources, it provides nearly as many BTUs as hardwoods and has been called the “hardwood of soft woods.” Unfortunately, most sources lump piñon in with other pines, which might make sense on the national level. The benefits of burning in areas where it is available should not be overlooked. It is often cited as the best wood for chimineas.

The sap, or pitch, of the piñon has been used by Native Americans in the Southwest for various tasks such as mending cracks in bowls, waterproofing baskets, and as an adhesive. The medical uses of piñon are, in general, lumped in with the properties of other pines. A tea of the needles is used to ward off scurvy** or for its expectorant effect***. The inner bark could be used to dress burns and other skin conditions. Piñon is said to have an antiseptic quality. These last two factors are why it is used to make natural salves today. Mother Earth News suggests the antiseptic qualities make it a good bathroom cleaner and air freshener.

Today the nuts themselves are the stars of the piñon tree. Multiple places proclaim their nutritional value, from saying they are as protein rich as beef, to suggesting they may be a good source of polyunsaturated and monosaturated oils.

My first encounter with piñon nuts involved the difficulty of shelling them. My friends who had gone to college in Santa Fe, insisted the best way to crack them was with your teeth. Although this method is okay if you are going to ingest them raw or roasted for yourself, the idea of cracking nuts with that method and cooking with them for others seemed objectionable to me!

According to an undated article in New Mexico Magazine, a secret shelling machine was invented by the founder of Buffett’s, an Albuquerque mainstay since 1956. The article also states you can purchase shelled piñon from them but I was not able to find any for sale on their site at this time, shelled or not. You ARE still able to buy piñon candy from them, including piñon brittle.

Numerous sites discuss the differences between “hard shell” nuts, those which are from Pinus edulis, and the soft shell nuts, Pinus monophylla, or Nevada nuts. The nuts of Pinus monophylla are larger, more resinous, and not considered as tasty. Euell Gibbons may have proclaimed the piñon nut “the most palatable wild food.” Many websites warn against buying Nevada nuts when you are after piñons. The New Mexico Piñon Nut Company ships nuts. Pinenut.com explained the 2021 supply is limited as the quarantine kept pickers out of the trees.

Not only the Native American population of the Southwest harvests piñon; many Hispanic families also gather the nuts in the fall. In many areas of New Mexico you see cars parked along the interstate and people scurrying amongst the trees. Harvesting your own nuts is the most economical. Although it is legal to gather nuts for your personal use in certain areas, it is best to know the laws. Some people shake the trees to remove the nuts or cones, but the traditional method is to pick off the ground as seen in this short video. Less traditional methods of picking and preparing nuts are discussed in this article where the author suggests breaking open the nuts with a rolling pin.

Although most articles mention eating the pine nuts raw or roasted, recipes for their use abound. Fancy recipes such as pine nut soup, pine-encrusted pork, and a chocolate tart are including in this article from New Mexico Magazine. A number of recipes including candy and cookies can be found here. Native American Feast Day cookies feature piñons.

The piñon pine has also been used as a Christmas tree, living or cut. As is true for other features of the piñon, most lists of best trees for Christmas neglect to mention the species. New Mexico State University recommends them as having a good shape and says they are easily available for residents to cut. Every once in a while another publication will mention this conifer as a holiday possibility such as this bulletin from Washington state, which seems a bit out of their natural range!

A recent article discusses threats against piñon nuts and the trees themselves: climate change and cheap imports from other countries. Recent droughts have weakened the trees, which then are attacked by the ips, or bark, beetle. A study from California found higher temperatures decreased the viability of piñon pollen., while other studies have implicated heat death as the cause of the loss of between 40 and 80 percent of the trees. Not only are the trees and nuts endangered, but up to three quarters of the bird population may have disappeared in a decade.

Although it does little to solve the larger problem of the demise of the trees, it is still possible to use the logs as firewood if measures are made to destroy remaining beetles. In another glimmer of hope, the study mentioned above about the effect of heat, mentions a fungus that often grows with piñons may confer some drought protection.

By some reports nut harvests have decreased in yield by nearly seventy-five percent in less than fifty years. Indeed not all of the decline in piñon economy can be assigned to the change in climate. More than one article mentions the penchant for bulldozing trees in favor of ranchland or mineral and oil development as another factor leading to the decrease in productive piñons. The lower cost of imports doesn’t help the case for gathering the increasingly scare native product, either. In 2020-21 the cost of the nuts soared due to Covid-19 keeping pickers away.

In a 2014 publication, Rocky Mountain Forests at Risk, the authors discuss the importance of iconic trees in the Rockies and show possible scenarios related to drought, heat, and wildfire. They state the piñon-juniper woodlands are the most extensive type of forest land in the United States. They also mention piñons cultural significance as well as its role in water quality.

The Colorado pinyon (or piñon) pine in Fort Collin’s City Park

The Colorado pinyon (Pinus Edulis) can be found in City Park just northwest of Club Tico and across the road, near a power box. There are only two conifers in that area, and both appear to be piñon pines.

* David Allen Sibley, The Sibley Guide to Trees (Alfred A. Knopf, 2009, p.12)

**Linda Kershaw, Edible & Medicinal Plants of the Rockies (Lone Pine Publishing, 2000, p.36)

*** Michael Moore, Medicinal Plants of the Mountain West (Museum of New Mexico Press, 2003, p. 196)

The Difficulty of Defining a Fruit Tree, featuring Plums.

A tomato is actually a fruit but legally it is a vegetable!

What exactly is a fruit? My unabridged Random House dictionary has five definitions including: the edible part of a plant developed from a flower; part of plant growth useful to humans or animals; the developed ovary of a seed plant. (Random House Dictionary of the English Language, Unabridged, 1987.) More than likely the average person would say something along the lines of “the part of a plant that we eat” or name a few examples, such as a banana, raspberries, or apples.

Saying a fruit is the part of plants that we eat does not distinguish a fruit from a vegetable, but then some botanists would say there is no such thing as a vegetable. Instead they might identify what we call vegetables as the specific non-fruit part of a plant which we eat, for example, the stem (rhubarb, celery) or leaf (kale, spinach) or root (beets, carrots). The botanical definition of a fruit is simply an organ which contains seeds, but complicating matters is the legal case defining a tomato as a vegetable. Nix vs Hedden was settled in 1893.Yes, a tomato is actually a fruit but legally it is a vegetable!

The purpleleaf plum leaves at their greenest later in the year

All flowering trees (angiosperms) produce fruit, not all of which we eat. According to Gollner, there are between 70,000 to 80,000 plant species which produce edible fruits. Of these, only about twenty species provide the majority of what we consume.* Other sources are even more pessimistic and say the human species relies mostly on TWELVE species of plant.

Excluding citrus trees, nearly all trees producing the common fruits we eat are members of Rosaceae, or the rose family. Genus Prunus includes plums, cherries, apricots, peaches, and almonds, all of which are drupes or stone fruits. Apples and crabapples fall into genus Malus. Their fruits are collectively known as pomes. Pears, in the genus Pyrus, are also pomes. Fruit cultivation probably began somewhere between 6000 to 3000 BCE, primarily in the Fertile Crescent and Eygpt. Some of the earliest domesticated fruits included figs, dates, and olives.

For eons, fruits eaten raw were suspect, with Pliny stating pears were not digestible and Galen suggesting fruits were “troublesome in everyway.”** Early crops looked little like what we now consume. This link provides a few pictures of early fruits.

Prunus is the largest genus in family Rosaceae with the cherries and plums representing the most species. We do have native plums in North America, but information on all the species, often merely labeled “wild plums,” is difficult to come by. Some internet sources allude to many species, but the only place I found multiple species, about 30, enumerated was on a comprehensive map of wild plums throughout the United States. The accompanying blog post explains wild plums are becoming endangered due to the loss of animals (bears) to disperse the seeds.

The list of trees in City Park includes one native American plum (Prunus americana) tree. For nearly a year I have passed by where this tree is said to be located but have not been able to find a tag or determine any definitive characteristics (like evidence of fruit). It either isn’t there or is hidden in plain sight. Most sources list this species as being either a small tree, usually no taller than 25′ or a shrub with prickly twigs. The leaves, like others in this genre are serrated. The bark becomes scaly with age. The white flowers bloom prior to the leaves as early as March. Fruit is 1″ and turns reddish.***

Purple leaf plum was introduced to this county from Asia, is found mostly on the east and west coasts, although older literature shows a swath of the middle of the US as suitable habitat.

There are three purpleleaf plum trees in City Park, Prunus cerasifera Atropurpurea, also known as cherry plum, myrobalan or Pissardii. According to Dirr and Warren, the Atropurpurea variety is from the 1880s and may be the forerunner of many more recent cultivars. Although I have been observing these dark-leafed trees for a number of years, I have not noticed any fruit on them. This could be because, like the American plum, the fruit is only about an inch long. They do have beautiful pinkish white blossoms early in the spring. The foliage changes over the summer from deep purple to a dark green.

The plum trees from their deep purple to later green

To find the purpleleaf plums (C123), walk along City Park Drive from the exit on Jackson Street until you find a cluster of trees in a space encircled with rocks. When they are in bloom, they are easily identifiable by the color of their leaves.

If you want to try and find the American plum, walk along the ditch between Oak Street and Mountain Avenue and see if anything looks similar to a plum.

Dirr, Michael and Warren, Keith. The Tree Book: Superior Selections for Landscapes, Streetscapes, and Gardens, Timber Press, 2019.

*Gollner, Adam Leith. The Fruit Hunters: A story of Nature, Adventure, Commerce and Obsession, Schriber, 2008. p 23

**Ibid. p. 48

***Sibley, David Allen. The Sibley Guide to Trees.Knopf. 2015

Bristlecone Pine–Cursed Tree or one That Changed History?

They are slow growers and may add as little as one 1/100 an inch of girth in a year

There are two species of bristlecone pine, both native to the southwestern United States. Pinus aristata, known as the Rocky Mountain bristlecone, hickory pine, or Colorado bristlecone, grows in the mountains of Colorado, New Mexico, and Arizona.

Pinus longaeva, native to Utah, Nevada, and California, is called either Great Basin bristlecone or Intermountain bristlecone. Both species are long-lived, but the Intermountain Bristlecone holds the record as possibly the oldest living specimen on earth. At first glance the name bristlecone seems to be due to the small branches with their short, stiff leaves which cause them to look a bit like bottle brushes. A third moniker for the Colorado Bristlecone is foxtail pine due to branches resembling those of foxes.

Close up of a branch — Small branches looking somewhat like a bottle brush

Originally both species were classified as foxtail pines (Pinus balfouriana) but were reclassified in the 1800s and the two types of bristlecone were further distinguished in the the 1960s. The actual reason longaeva and aristata are called bristlecone pines is due to a bristle on the young cone.

Both species belong to the five-needled or white pine group of Pinus. In Colorado, bristlecones typically grow from an altitude of 8300 to 13000 feet (Ackerfield.**) At higher altitudes they are slow growers. According to one source they may add as little as 1/100th of girth in a year. Often bristlecones grow with both limber pines and Engelmann spruce and sometimes near treeline with common juniper. Their seeds are tiny. Unlike most other pine species, they are winged. The trees do not produce seeds until they are between ten and forty years old, but may continue to reproduce throughout their extremely long lives. Most references mention these evergreens retain their needles for many years, with one article stating the needles may persist for decades. Often the needles are sprinkled with white resin spots, making the tree look like it has suffered a case of dandruff.

Bristlecone closeup — Close up of a branchlet of a bristlecone pine

When discussing edibility or medicinal use of the bristlecone, sources such as Edible & Medicinal Plants of the Rockies (Kershaw, Linda, 2000) and Medicinal Plants of the Mountain West (Moore, Michael, 2003) tend to lump them in with other five-needled pines. Both sources mention pine needle teas to enjoy or use for coughs and fevers. Both sources warn an excess of the tea may be detrimental, especially to pregnant women. Pines may also provide resin and be used for firewood, although in national parks, all bristlecone pines are protected.

Dirr and Warren* mention the bristlecone for the landscape, especially in dry areas with poor soil. They do need full sun and are usually sold as cultivars. In the yard they may have the look of whimsical holiday trees. At higher altitudes they have the appearance of large pieces of misplaced driftwood.

Although Pinus aristata has evolved numerous survival mechanisms, and the ability to adapt to hardships may be part of the secret to its longevity, climate change may be playing a part in new dangers to these old trees. In the early 2000s, bristlecone pines were documented to have died from mountain pine beetle infestations. White pine blister rust and dwarf mistletoe are also known to endanger these long-lived trees.

A Pinus longaeva specimen known as Prometheus was counted as nearing 4900 years when it was cut down by graduate student Don Currey. There are various stories about how exactly this tree was destroyed with the exact facts in dispute. A full reckonning of the acrimony and confusion surrounding the Great Basin bristlecone pine designated as WPN-114 has many facets of today’s fights about climate change. To make the death of this tree a greater tragedy, when the pith of the tree was sent to the University of Arizona’s Laboratory of Tree Ring Research after Don Currey’s death, a more precise dating of the tree was determined. Now some estimate Prometheus may have been 5100 years old.

In a piece developed for Radiolab, the hosts play a recording of Don Currey telling part of the story of WPN-114’s demise. The piece on Prometheus begins around 15:00 minutes. Although interesting, there appears to be at least one mistake in the update. Prometheus lived in the Snake Mountains in what is now Great Basin National Park, while the White Mountains and the disputed new oldest tree is in California.

In 2014 the artist Jeff Weiss produced an exhibit, or as he calls it “a thing,” to mark the 50th anniversary of the cutting down of this great tree. (There is a film about this “thing” discussing the history of the tree and the art; the story starts around 9:48. Although the information is overall interesting, there are a lot of extraneous comments.)

Another Pinus longaeva, Methuselah, is a mere fifty years younger and still living. And a third, even older tree is rumored to have been located by the same man (Edmund Shulman) who found Methuselah, but this has not been verified. The tree is said to be living in an undisclosed area of the White Mountains and was 5067 years old in 2019. The oldest Rocky Mountain bristlecone, which is located in Colorado, is a mere 2436 (in 2020) years of age.

According to the Gymnosperm Database, the largest specimen of Pinus aristata is located in New Mexico. The tree may be of dwarf stature at high elevations but may reach 40′ at lower altitudes. The 2018 champion tree in Colorado was found in the San Isabel forest and reached a height of 59′, about twenty feet higher than the next candidate. Lower altitude trees may not reach the great ages of their counterparts closer to treelike. They may become victims of heart-rot, decreasing their longevity to around 300 years.

Bristlecone bark — Bark of the Rocky Mountain Bristlecone Pine

The Rocky Mountain bristlecone’s relative, the Great Basin bristlecone pine has also played a part in calibrating carbon dating techniques and helped correct the historical record. This was done by overlapping tree ring patterns from living tree core samples and intact patterns of deadwood. This technique has enabled dendrochronologists, archeologists, and historians to examine climatic and other patterns over 10,000 years and has earned the Intermountain bristlecone pine the moniker the Tree that Rewrote History. Here is a link to a 2009 poetic documentary, The Oldest Tree on Earth: The Curse of the Methuselah Tree. It includes a clip of Don Currey discussing the cutting of Prometheus and information from the person who claims to have found an even older specimen.

The curse of the bristlecones implies those who touch/cut the trees will have brief lives. Edmund Shulman who cored Methuselah in the 1950s died at 49, while a 32-year-old Forest Service employ who helped carry a slab of Prometheus off the mountain suffered a heart attack on the way down and died. Currey, who one would assume would be the most cursed, died at 70, diminishing the likelihood of a curse in my mind. A highly recommended 2020 New Yorker article by Alex Ross, “The Past and Future of the Earth’s Oldest Trees,” discusses the curse, dendrochronology, the controversy over the bristlecone’s possible submission to climate change, and other aspects of this species.

bristlecone against the sky — Colorado Bristlecone pine hiding amongst the spruces.

To find C170 Pinus aristata in City Park, go to the intersection of Mulberry Street and Sheldon Drive. On the northeast corner is a small grove of trees including some spruce and deciduous trees. The shortest of the conifers should be the Colorado Bristlecone pine. Last I looked, I did not see its tag. This tree was planted in 1978 when it had a diameter of eight inches.

*The Tree Book:Superior Selections for Landscapes, Streetscapes, and Gardens (Dirr, Michael and Warren, Keith, 2019)

**Flora of Colorado (Ackerfield, Jennifer, 2015)

Native Oaks of Colorado–the Ubiquitous and Dichotomous Gambel’s Oak

Quercus gambelii is a tree native to the Southwest, including Colorado.

OLYMPUS DIGITAL CAMERA — Gambel oak leaves

On the Fort Collins City Park Self-guided tree tour two oaks are listed as native to Colorado, the bur and the Gambel. Jennifer Ackerfield, Flora of Colorado, 2015, lists the Gambel oak as well as two shrubby oaks with which it hybridizes as native to this state. The USDA map shows the Gambel oak being native to states of the west and southwest, including Colorado, Wyoming and South Dakota. The USDA map shows the Bur oak as native to most of the Canadian provinces and the eastern United States as well as states north, south, and east of Colorado, but not Colorado itself.

According to the passage in Western Explorers and other sources, Gambel oak may also be called scrub oak. Ackerman agrees Quercus gambelli Nutt. can be either shrubby or a small tree*, but other authors call different species of Quercus scrub oak. Some of these also may be native to the region, and all of them do appear to be mostly shrubs. To add to the confusion, other plant databases also call Gambel Oak Rocky Mountain White Oak or Utah White Oak. This short article says Gambel oaks are well-suited to Colorado by their smaller form as they require less water than many of their relatives. The smaller size also helps them withstand wind and snow. This species is common in Grand Canyon National Park.**

Nearly all sources agree the wood from Gambel oak is mostly only good for fuel, although it might also have been used for equipment handles and furniture such as cradle.

Many concoctions of oaks in general (Medicinal Plants of the Mountain West, Michael Moore, 2003) and Gambel Oak in particular, have been used for gum inflammation, diarrhea and other intestinal conditions. Another use mentioned in the book is a chewed bolus of the leaves applied to insect bites. Other uses include as an analgesic for postpartum pain. Acorns have been eaten to increase sexual potency.

The acorns of this oak have very short or nearly nonexistent stems. The hairy cap covers less than half of the actual nut.*** Properly prepared acorn meal can be added to breads or soups to increase protein content. Some use acorns as a coffee substitute that does not contain caffeine. You can make your own or even buy it!

Although the Gambel Oak provides food and cover for wildlife such as deer and squirrels, it is considered poisonous for many domestic species, such as cattle and sheep. Gambel oak holds a similar dichotomous place in fire management. Under moderate conditions it may act as a firebreak, but in severe conditions it can be explosive and deadly.

Thomas Nuttall, one of the most famous naturalist of his time, named this species after a young naturalist. William Gambel was only 15 when he began working under Nuttall. Soon he ventured out to the Southwest and discovered a new species of oak near Santa Fe. Also on his journeys he found numerous new bird species, some of which also bear his name. Gambel named one of these, a woodpecker, after Nuttall. Eventually he returned to Philadelphia where he earned his medical degree and married a childhood friend. Shortly after this, he packed his bags and headed back to California for the gold rush and to set up his medical practice. During his trip, he contacted typhoid and died at age twenty-six.

To find the Gambel Oak (Quercus gambelii) specimen in City Park look for E59 on the map.

This tree is near the intersection of City Park and Bryan Avenue’s NW corner in a small cluster of trees. You can locate this cluster with the Gambel in the middle on the west side of the stone wall located between the derelict miniature train station and the road.

*Ackerfield, Jennifer, Flora of Colorado, 2015 p. 486

**Little, Elbert National Audubon Society Field Guide to North American Trees, Western Region, 1994 p.398

***Preston and Braham, North American Trees, 5th edition, 2002 p. 303

Limber Pine—Branches Flexible Enough You can Tie them in Knots

The tree grows under conditions which may prove too harsh for other species.

Limber pine (Pinus flexilis) is another species which may be susceptible to damage from the pine beetle. Like most other trees, this species has a number of alternate names, including Rocky Mountain pine. This conifer is native to the western states as well as the two westernmost Canadian providences.

In Colorado, it is found from elevations of 5000′ to 12,000′. It is also native to Utah where it is reported to grow from elevations of 4000′ to 11000′. Limber pine in North Dakota grow below 3000′. The groves of trees in North Dakota are thought to have arisen from seeds carried to the area by various Native Americans.

Limber pine survive stressors which may prove too harsh for other species. For instance, it is able to grow under dry conditions. The bendable property of its branches may allow it to survive in avalanche prone areas and this trait may help with slope stabilization as well as runoff control. Limber pines also have deep taproots, which help with resistance to wind. This species provide food for rodents and birds, such as the Clark’s Nutcracker. In turn the seeds are too large to be blown far by the wind; birds, then are a means of distribution. OLYMPUS DIGITAL CAMERA

Although lumber from Pinus flexilis is of little commercial value today, in the past it was used in mines, as railroad ties, and as firewood. In herbal medicine the resin may be used like that of other pines—as an antiseptic and to help with respiratory conditions. The seeds can also serve as a food source for humans.

Limber pines are a long-lived species, which may not reach maturity until 200 years. (North American Trees, Preston and Braham.) Some of the oldest trees may be well over 1500 years. Even though some members of this species grow on windy ridges causing twisting and stunting, others may approach sixty feet in height.

Pinus flexilis belongs to the the group of pines with their needles in bundles of five. These leaves grow to be between 2.5 and 3.5 inches in length. The female cones are green prior to maturity and may grow as long as seven inches.

Like many conifers of the mountain west, the limber pine may be affected by climate change and damage by various pests, including mountain pine beetles; a fungus which causes white pine blister rust; and drawf mistletoe. The fungus spread from Asia to Europe in the 1860s. It made its appearance in Wyoming on limber pines in 1970 and by the late 1990s was found in Colorado as well.

To find the tagged LIMBER PINE (Pinus flexilis) in the arboretum, C182, start near the SE corner of Sheldon Drive and City Park. A row of trees, including ashes and conifers, runs more or less parallel to City Park Drive. The limber pine is in the middle of a small cluster of conifers. In the middle of an open area is a park bench which is west of this small grove of trees. Another landmark might be the exercise station near this same corner. You could walk from there along the row of trees to find the pine.

This specimen was planted in 1981 when it had a diameter of 8″. In the flesh it does not appear quite as scraggly as it does in the winter photo.

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Limber pine in the snow