The Cyme and the Bract: Other Lindens on the Tree Tour

Bracts are found on many plants and come in many different forms.

During bloom time lindens are easy to distinguish by their aroma and the clusters of small yellow flowers which resemble open tulips. After the flowers bloom and the seed, or nutlet, forms the linden can still be identified by the remains of the cyme, or flower clusters, and the bracts hanging along the branches. While still on the tree, bracts and cymes look like an extra, lighter green frill hanging below the leaves. 

The term bract was new to me, although on investigation, most of us are probably familiar with them in some form and think of them as “flower petals.” Instead they are specialized structures which protect the actual flowers of various species. Often, as in the case of poinsettias and dogwoods, we mistake the colored bracts for the flowers.  

Most of my resources say little about the cymes and bracts of the lindens. One website did talk about the bracts on lime trees, the British name for lindens. An interesting tidbit is that along with the flowers, bracts are harvested to make linden tea, which is known to help digestive disorders. It is also used as a sleep aid. The bracts alone may be made into a “beauty lotion” for cleansing the skin

Later in the year you have a clue you are under a linden when you find thin yellow leaves, which are actually bracts, under a tree. This year at least, these seemed to fall and scatter sooner than the actual leaves, but even when they are mixed with other leaves, they are distinctive in their thin, oval shape, rather like a tongue. 

There are a number of other linden trees on the City Park Arboretum tour. Most of them are either hybrids or cultivars. I can’t begin to tell a Greenspire Linden from a Redmond, although the first is a Tilia cordata and the latter is Tilia americana. According to Michael Dirr and Keith Warren in The Tree Book: Superior Selections for Landscapes, Streetscapes, and Gardens, each of these two trees, along with the many other cultivars, has its uses. The other cultivars found on the Arboretum tour are listed below with information from The Tree Book mentioned above. Numbers correspond to those on the Arboretum map.

C126 Tilia americana Sentry is narrower than most other versions and may have some resistance to Japanese beetles.

 C171 Tilia americana Redmond (C171) is said to be more urban tolerant that other lindens. 

Redmond Linden

C148 Tilia cordata Greenspire has the best pyramidal shape.

Greenspire Linden

C177 Tilia cordata Norlin is both a fast grower and cold hardy.

A83 Tilia x flavescens Glenleven is a hybrid between the American linden and the littleleaf linden and is known at the fastest growing linden hybrid. 

Glenleven Linden

E22 Tilia cordata Prestige. It seems little is written about this variety but it may be pollution resistant. 

C178 Tilia x flavescens Dropmore  The Dropmore linden is another hybrid which is viable to zone 2.

Dropmore Linden in bloom

C 149 Tilia cordata Fairview is said to have larger leaves.

Fairview Linden

 

 

 

Tea and Chocolate–Products of the Linden?

Honey from linden flowers is said to be some of the lightest and best available.

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Profusions of yellowish white linden flowers

By far the easiest way to find linden trees is during and immediately after they bloom as the clusters of flowers (cymes) give the whole tree a distinctive look, as if the undersides of the leaves have been painted a lighter color. The flowers also give off a fragrance that can be discerned from a distance. Most of the trees are quite tall and if they are tagged, it may be difficult to find the tag, but there is little mistaking a linden in bloom. Also helpful in identification when they aren’t blooming are the heart-shaped, but saw-tooth-edged leaves. The straight trunk and bark also help identify the genus.

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Grooved bark of the American linden

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Cymes of the linden with a single bract

Lindens bloom between May and July, although many sources mention June as the primary bloom time. The very fragrant blossoms come with a single bract and hang down like lacy umbrellas. Others have described them as “fireworks.”

In the US the American linden (Tilia americana) is also know as American basswood or just basswood. The range of this native tree in North America is the East and Midwest. In England, its European relative (Tilia cordata) is known as a Lime tree or little leaf linden.

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Tilia americana in bloom

Most sources state our native tree grows to a height of around 70′. The National Champion tree in a Kentucky cemetery, crowned in 2017, has a height of 102′. There is a tie for the largest American Linden in Colorado, with one tree in Fort Collins and the other in Denver. Both are listed at a height of 92′. Monumental Trees lists the tallest American Linden in Europe at 101 feet and the oldest specimen in the Netherlands as about 138 years old. Other sources have suggested the species can live for a thousand years!

Monumental Trees lists the tallest Tilia Cordata at 132.87 feet. This tree resides in the United Kingdom. One source states a tree in Britain is over 2000 years old, but Monumental Trees lists the oldest as a mere 820 years. In North America, the little leaf has been introduced in the most northeastern parts of the continent, where the normal height is said to be 50 to 60 feet. The US champion (height plus girth plus branch spread) is in the state of Maryland and only towers 83 feet. Colorado’s champion can be found in Denver at 89 feet, with the second place tree, 72′, found in Fort Collins.

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Tilia cordata

Native Americans made rope, netting, and baskets out of the inner bark, or bast, of the basswood tree. The wood is used for lightweight projects such as guitars and other instruments, carvings, yardsticks, and veneer. At one time basswood was the prime material for prosthetic limbs. The Iroquois carved the bark for ceremonial masks. The wood of the tree, being lightweight and fast-burning, may not be the best choice for heating.

According to the Kentucky Department of Horticulture, the American Linden was first cultivated in 1752. An oil derived from its seed pods was used as a replacement for olive oil, while the sap can be made into a drink or boiled into a syrup. Honey from linden flowers is said to be some of the lightest and best available. The preponderance of bees around the trees give rise to another of its nicknames, the bee tree, not to be confused with the Korean bee tree.

An usual product first made in the 19th century from the dried flowers and nutlets

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Nutlets on the little leaf linden

was a chocolate-like substance. Unfortunately this concoction did not keep well and production ceased. In a short article discussing this “chocolate” the author says it is still possible to make some for immediate consumption or to freeze and includes a recipe.

The flowers of the tree especially have many uses. In France the leaves were made into a tea (tilleul) and used as a mild sedative.

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Blooms on comes with a single bract

Cup of Linden tea
Cup of Linden tea. The tea bags are slimy but the taste is pleasant.

Since the middle ages, the tea has been used to cure headaches. Alternatively the flowers could be added to a hot bath to help insomnia. Even today the flowers may be used in the making of perfume, As an early variation of “forest bathing,” sitting under the trees was thought to be helpful to epileptics.

Usually made from the European species, Tilia Cordata, linden tea is a well known use of the trees’ flowers, leaves, and bark. Unlike many medicinal uses of plants, linden tea has had a number of scientific studies conducted and papers written. Many benefits, such as relieving hypertension, stomach issues, and pain, helping you sleep, and a reduction of inflammation are reported in alternative medicine articles. Along with benefits, most of these articles mention a few drawbacks, such as possible heart problems and drowsiness.

To find the trees in City Park, follow your nose! The American Linden (Tilia americanapictured in this blog is B98, which is across from the trolley station on S. Roosevelt Ave. There is another American Linden on the tree map at B101, which is located on north side of City Park Drive between fields 1 and 2. Tilia cordata, or the Little Leaf Linden (A 88), is also on the north side City Park Drive. It is the fourth stem in from the northwest corner of Roosevelt and City Park Drive, two down from the light post and near the little kids’ playground. These three trees almost form the points of an equilateral triangle.

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.

Bristlecone
Bristlecone in City Park

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)

 

 

Arizona Cypress: Drought Tolerant or a Fine Specimen Christmas Tree?

Its retained cones look like jingle bells

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An opened cone with another closed

Continue reading “Arizona Cypress: Drought Tolerant or a Fine Specimen Christmas Tree?”

A Rare Evergreen with a lot of Names: the Modoc Cypress

Modoc Cypress is listed as Vulnerable.

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The Modoc Cypress.

Modoc cypress does not have a widespread natural range and is found naturally only in northern California and southern Oregon. At least one source calls this species the northernmost and hardiest of its genus, but its need for sunlight and susceptibility to fire seem to contradict the hardiness designation.

In 1898 this species was discovered in Modoc County, California by the botanist Milo Samuel Baker, an important collector and teacher during the early years of the last century. Not only is this tree known as Baker Cypress, Modoc Cypress, or Siskiyou Cypress but there appears to be controversy as to its scientific name. Proposed Latin names are Callitropsis bakeri, Hesperocyparis bakeri, Cupressus macnabiana, or Neocupressus bakeri. The second name is currently used in the USDA plants database. The nomenclature used on the tree tour map and often on the web, is a fifth destination, Cupresses bakeri, one of the older names given in the Gymnosperm Database.

Modoc Cypress is listed in Threatened Conifers of the World and on the Red List as Vulnerable. This may have to do with fire suppression practices as the cones do not normally open to spread seed unless subjected to heat, but the tree can be susceptible to fire damage. The thin, curling bark of the younger trees may also be detrimental in a forest fire. OLYMPUS DIGITAL CAMERAThe reproduction cycle of this species is discussed on the above site. When the small, hard cones open, the seed is distributed by wind or rain.

Modoc detail
Cone and leaves of the Modoc Cypress

The tree may grow to fifty feet, but as one nursery website put it, “not in your lifetime, maybe your kids or grand kids.” No tree of this species is listed in Champion Trees, but the Gymnosperm Database lists a specimen in Oregon at 127′ as being the biggest known.

Although there is some information about the medicinal use of cypress, it is also classified as a neurotoxin and is often associated with death. The same website mentions some species are planted in church yards and cemeteries. In the correct dosage some species of cypress may have medicinal and cosmetic properties, but no specific mention is made of the Modoc Cypress.

In City Park Modoc Cypress (D197) may be found near the frog sculptures, closer to Sheldon Drive. To me the cypresses can be identified by a hazy aura around them, probably an illusion from their interesting leaves.

 

 

 

 

 

Chinkapin oak, including the Story Behind its Latin Name

The Latin name for this tree features a misspelling.

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Acorn growing on the chinkapin oak.

Once again, like many other species of oak, the chinkapin oak is native to most of the United States east of Colorado as well as in two states sharing a border with the Centennial state, New Mexico and Oklahoma. This species, Quercus muehlenbergii, is also known as chestnut oak, yellow oak, common chinquapin oak, rock oak, rock chestnut oak, and yellow chestnut oak. It is one of those oaks whose leaves the uninitiated might not consider to be oak leaves. Instead, with their ragged or sawtooth-like edges, they could be mistaken for elm or chestnut leaves .

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Shiny chinkapin oak leaves

The acorns of this species of white oak are considered of the best eating quality. They are an important food for a variety of birds including woodpeckers and turkeys, as well as black bears and many small mammals and deer. The Chinkapin oak could be considered instrumental in the mobility of this country as the logs were once used as fuel in steamships. Later, logs were used as railroad ties. The wood is often fashioned into cabinets and furniture. The tree also has a few medicinal uses as an antiemetic and astringent.

In the wild the trees grow to 60-80′. Cultivated, they may only reach about fifty feet. The current champion tree in the U.S. grows in Virginia. It stands 66′ tall with a crown spread of 113′. The four trees listed as Colorado champions, all of which are in Denver, range from 62 to 66 feet in height but the largest tree has an overall point value (height plus crown spread plus trunk circumference) of less than half that of the national champion.The oldest recorded tree in the US is around 343 years old and can be found in Springfield, Ohio.

Where did this species get its common name? It bears a similarity to a tree in the same family (Beech) but a different genus and species, Castanea pumila, which has an overlapping  range with the oak species. The Allegheny chinkapin, also called a drawf chestnut, is a small tree or shrub with a single burr containing a nut. The leaves of this species look very similar to those of the Chinkapin oak, but the lack of an acorn should be a distinguishing feature.

The American Gotthilf Henry Ernst Muhlenberg (1753-1815) is credited with describing this variety of oak along with the German botanist, Carl Ludwig Willdenow. Muhlenberg was an ordained minister, college president, and botanist who published at least two influential books. A genus of grasses, Muhlenburgia, was named after him. He also discovered a turtle, which was called the Muhlenberg’s tortoise until the name was changed in 1956 to the bog turtle.

The Latin name of the chinkapin oak has a convoluted history, complete with a misspelling. In the past this species was considered to contain three varieties of trees, but on reclassifying and renaming, the species was given the Latin name Quercus muehlenbergii by George Engelmann, which would account for the full name Quercus muehlenbergii Engelm.

And the misspelling? When Engelmann honored Muhlenberg, he used the German spelling with an umlaut, which when transcribed resulted in the muehlenbergii spelling. Both spellings are now sometimes used.

There are two chinkapin oaks identified on the Fort Collins City Park Tree Tour. One  is located in the quadrant bordered by Jackson and W. Mulberry. This specimen (C159) is in a group of trees and may have lost its identifying tag. The second tree (E16), located behind the fire station in the southwest corner of the park, was planted in 1996. It also appears to have lost its tag. The tree can be found on the peninsula between the parking lot and the roadway, near a fake rock.

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Chinkapin oak near the Parks Department parking lot

 

 

 

 

Bur Oak: largest native acorns

In Texas the acorns may be the size of golf balls!

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Looking up through the bur oak

While the spelling of bur oak is sometimes burr oak, according to Sibley* it is also called a mossy-cup oak or blue oak. The Lady Bird Johnson Wildlife Center adds more names to this list, including Savanna oak, overcup oak, prairie oak, mossy-overcup oak. To add to the confusion, in certain terrains it can be referred to as scrub oak.  It would appear some of its names are related to the various habitats in which this species, Quercus macrocarpa, grows. Alternatively, it refers to the appearance of its acorns.

This white oak is native to much of the eastern and midwestern United States and Canada, although its characteristics vary depending on its location. According to Iowa State University, this tree has the most variable characteristics of any of the oaks. For example, its acorns are large in its southernmost growth area while they can be about a fifth the size in the northern regions.

The overall height of the tree also varies by its habitat. In northern climates it may only grow to half the size of the same species in southern latitudes.  This year saw a new national champion bur oak be honored in West Virginia. This specimen is a bit over 107 feet tall and has a trunk circumference of more than 278 inches. Models of climate change have predicted  bur oak may have an increase in its range, but the locations where it thrives may also shift. Due to its long taproot it may be able to withstand drought conditions.OLYMPUS DIGITAL CAMERA

Its acorns can be the largest of the native oak species and are well fringed, hence its mossy-cup moniker. Its Latin name is related to the acorns; marco means large in Greek and carpa refers to fruit. One author states burr oak acorns in Texas are golf-ball sized! Iowas State University allows the trees do not bear fruit until they are 35 years old. Most sources state the trees can live 300 to 400 years. The university site also states the lumber of the tree can be used like white oak, but isn’t as valuable due to its many branches. The USDA mentions  the most valuable bur oak trees for lumber come from Iowa and Illinois where it is usually marketed generically as white oak.

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Bark of the bur oak

The trees provide food to 96 or more species of wildlife, including black bears. According to this article, acorns are the primary high quality food source for black bears in northeastern Minnesota. Cattle and other livestock may ingest seedlings and acorns even though this material may prove poisonous in large quantities. This same source specifically mentions the Cheyenne of Montana as having eaten a mixture of acorns and buffalo fat.

Like other trees in general, and other oaks in particular, parts of the bur oak have been used medicinally. A unique mention is made of tree galls used to treat intestinal problems and as an antiseptic.

The tagged Quercus macrocarpa in Fort Collins City Park was planted in 1979. It is located between the reservable shelter and the road to the golf course. Look for the electrical box painted with a black cat. If you point to the east at a diagonal from the box, you should be in line with the tree. OLYMPUS DIGITAL CAMERA

  • Sibley, David Allen. The Sibley Guide to Trees, 2009.

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

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

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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.**

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Trunk of a Gambel Oak

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.

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Looking through the branches

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.

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The Gambel oak on the west side of the stone wall

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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Quirky Quercus and the Leaves of its Genus

Old Ironsides was built out of a species of white oak.

Legislation was passed in November, 2004 proclaiming the oak tree the national tree of the United States. I suspect most of us think of oaks as large trees with majestic canopies and easily distinguishable leaves. Probably we think the leaves look like this:

But the number of trees in the oak genus, all of which are members of the Beech family, are reported to be between 400* and 600 worldwide. Michael A. Dirr and Keith S. Warren in their The Tree Book (2019) list the number as 530, including both deciduous and evergreen species. The outdated The Plant List includes at least 605 species and Tree Names lists 605 plants under Quercus.

There seems to be some question as to the number of oak species in North America, too. Many sources suggest there are about 90 species in the US and Canada (Dirr and Warren) while Sibley includes only 69 native species. There are at least nineteen species of oak in California alone. Many sources list the number of  varieties in the US at about 90, but state there are at least 160 species in Mexico. The USDA map for Quercus shows all states except Idaho and all Canadian providences have native or introduced oaks.

On top of the large number of species, the various species easily hybridize, often making classification difficult. Within the two broad classifications of red oak or white oak, though, the trees do not interbreed. Some recognize an intermediate form of Quercus called golden oak. This subgroup may consist of only five species, although other sources state that there are none in North America.

Both red and white oak trees are used for furniture, flooring, cabinets, veneers and paneling. Historically only three species of white oak have been used in cooperage and for aging whiskies and wines.White oak is more often considered for outdoor uses as it has greater rot resistance. Live oak, a type of white oak, was used to build what is currently the oldest commissioned warship in the world, the U.S.S. Constitution. “Old Ironsides” was launched in 1797! Some of the ways to tell the difference between red and white oak trees, as well as their respective lumber, are discussed here.

Acorns give a clue as to whether a tree belongs to the group of red or white oaks, as well as a way to identify the various species. Acorns are also much more variable than I believed as a kid. Some are hairy, others elongated, a few tiny and some huge.

Red Oak with acorn
Note the large size of the cap of the red oak’s acorn.

Unfortunately, we have a lot of squirrels in our park and it is difficult to come across an intact acorn, but if you have an area with an abundance of acorns, this article discusses the foraging and processing of them for use in recipes such as Acorn Mousse and Acorn shortbread cookies. Guidebooks such as Sibley and the National Audubon Society Field Guide to North American Trees will usually include a picture or description of the nut to help with identification. While many species forage for acorns, other animals apparently can be poisoned when ingesting acorns, oak leaves, and bark. Acorns contain tannins and may be bitter. This can be remedied by repeated rinsing of the mashed meal.

Another reason acorns may be hard to come by in our park is the trees may not produce until they are twenty years old and the crop might not be considered a full one until the tree reaches fifty. According to this same source and others, the more bitter the acorn, the longer it will store.

An easy way to tell if an oak is a red or a white is by the leaf. White oak leaves generally have rounded lobes while red oaks have pointy tips. In many cases you have to look very closely as the tip is as thin as a hair.

Red oak tips
Leaves from three species of red oak

With the large number of oak species, it might be of little surprise that not all oak leaves look like you might expect. Some do not resemble that typical sketch above in the least. To complicate matters, the same tree may have leaves of distinctly different shapes! (Sibley, P

There are twenty-six tagged oak trees in City Park, although a number of these are hybrids or varietals. For this first post in a series on Quercus, we look at variations in leaf form. I have ignored the leaves of the hybrids.

Burr, others
The Oregon mountain oak has a small leaf while the burr (or bur) oak has larger leaves with many lobes. The typical leaf might have a more indented mid-section.

English Oaks
All English oaks, which are native to England, are white oaks. This can be seen in these three varieties rounded leaf lobes.

Graves and MOngolian
Note the rounded ends of the Mongolian and Chinkapin Oak, indicating they belong to the white oak group.

Red and Swamp
The swamp oak is a white oak although it is difficult to tell its lobes are rounded. The tips of the northern red oak, though, are decidedly pointed!

The photo below shows the Oriental White oak leaves growing on the tree. I would never have picked out either of these two leaves to belong to the oak family!

 

Although I do not have a photograph, as this tree is not on tree tour, there is a species called the Maple-leaf Oak. This endangered tree currently numbers only about 600. According to Sibley this oak is related to the Shumard, although the pictures of the leaves look  more similar to maple leaves than the skinny Shumard leaf pictured below.

Shumard and Gambel
Shumard Oak (Quercus shumardii) a red oak on the left with its acorn and a Gambel Oak (Quercus gambelii) on the right.

*The Sibley Guide to Trees, David Sibley, 2009

 

 

 

 

 

 

 

 

The Shellbark Hickory; A Tough Nut to Crack

Hickory ice cream is delicious

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Hickory nut on the Shellbark hickory

The taxonomy for the hickory tree is a little nutty. Members of  the walnut family, Carya (hickories) represent about 25 species worldwide. Eleven are native to North America. Also a member of the walnut family, and of the same species as hickories, are the the trees which produce pecans.

The SHELLBARK Hickory (Carya laciniosa) is native to most of the eastern United States and Ontario. Like many other species, it has many alternate names including; big shellbark, bottom shellbark, kingnut, and thick shellbark.

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The compound leaves of the Shellbark hickory

Another moniker, bigleaf shagbark, may cause some confusion between the two types of hickory tree. Even though some say the flavor of the shellbark’s nut, with its difficult shell to crack, isn’t as good as that of the shagbark, a few plantations of shellbark trees have been established. The shellbark hickory can hybridize with pecans to produce a larger nut. It may crossbreed with shagbarks as well.

The wood of the shellbark, as with most hickories, is considered one of the hardest of the American native trees and is difficult to work as it tends to blunt edges. Because of the strength of the wood, it may be used to make chairs and rockers.  The lumber also has a high BTU output, making it desirable as firewood. It is also used for smoking meats, such as in this recipe for hickory smoked turkey. 

When in Portland, ME, I had the pleasure of eating a blueberry crumble with hickory ice cream at the Portland Harbor Hotel. I must admit while I was enjoying the very woody flavor I had no idea there was more than one kind of hickory tree. I include this recipe for hickory ice cream, which does call for shagbark chips, as well as one for hickory nut shortbread cookies.

Native peoples had numerous uses for the parts of the shellback tree, including the

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The shaggy bark of the shellbark hickory

innerbark for snowshoe rims and baskets and the wood for arrow shafts and blow darts. The shellbark hickory had numerous uses in traditional medicine including as an abortifacient, cold remedy, analgesic, an emetic, and a digestive system  aid. Other uses included gun stocks and tool handles. The species has also been used to produce dyes and make soap.

Due to the large and long taproot, the trees may be difficult to transplant. They are slow growing as well. The nuts are food for many small mammals as well as turkeys and deer. There are many husks on the ground near the specimen tree, but none are intact, verifying their use as squirrel food.

The champion tree, crowned in 2018, is 109′ tall and found in Virginia. Although the height of the tree may depend on environmental conditions, Carya laciniosa are said to usually be about 60′ to 80′ tall. The specimen in Fort Collin’s City Park was planted in 1991 and had a trunk diameter of 3.5″.

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The shellbark hickory

Find D198 Shellbark Hickory (Carya laciniosa) along Sheldon Drive. The best way to describe where to find it is south of the intersection with City Park Drive. The tree is east of the shelter near the lake and almost directly west of the exercise station on the east side of Sheldon Drive. The nut husks are the give away as I don’t think this tree is labeled.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Carya laciniosa was used extensively by the Cherokee, according to Moerman (1998)