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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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.

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Trunk of the limber pine

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.

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Leaves of the limber pine

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.