Limber Pine
Encyclopedia
The Limber Pine, Pinus flexilis, is a species of pine
tree
-the family Pinaceae
that occurs in the mountains of the Western United States
, Mexico
, and Canada
. It is also called Southwestern White Pine and Rocky Mountain White Pine. A Limber Pine in Eagle Cap Wilderness
, Oregon
has been documented as over 2000 years old, and another one was confirmed at 1140 years old.
areas of the Rocky Mountains
from southwest Alberta
Canada south through Colorado
and New Mexico
into the northern states of Mexico
; from mountains in the eastern Pacific Northwest
states through the Great Basin
states of Nevada
and Utah
. It is also found in California
: in the Eastern Sierra Nevadas; the eastern California White Mountains
; and the Southern California
San Bernardino Mountains
, San Gabriel Mountains
, and San Jacinto Mountains
of the Transverse Ranges
; and a small disjunct population in the Black Hills
in South Dakota
.
Pinus flexilis is typically a high-elevation pine, often marking the tree line either on its own, or with Whitebark Pine (Pinus albicaulis)
, either of the Bristlecone pine
s, or Lodgepole Pine (Pinus contorta)
. In favourable conditions, it makes a tree to 20 metres (65.6 ft), rarely 25 metres (82 ft) tall. However, on exposed treeline sites, mature trees are much smaller, reaching heights of only 5 metres (16.4 ft) - 10 metres (32.8 ft). In steeply-sloping, rocky and windswept terrain in the Rocky Mountains of southern Alberta, limber pine is even more stunted, occurring in old stands where mature trees are consistently less than 3m in height.
, New Mexico
, and Texas
, populations of the Limber Pine often known as Southwestern White Pine, differ from the populations farther north. These are sometimes treated as a variety, Pinus flexilis var. reflexa, but more often as a distinct species, either "accurately" under the name Pinus reflexa, or erroneously through confusion with the Mexican Chihuahua White Pine
under the name Pinus strobiformis, which correctly applies to the Chihuahua White Pine.
The 'Southwestern White Pine' differs from typical Limber Pine in being a larger tree, to 25 metres (82 ft) - 35 metres (114.8 ft) tall, with longer needles, 6 centimetres (2.4 in) - 11 centimetres (4.3 in) long, which have strongly white stomatal bands on the inner faces of the needles (inconspicuous in the type), and are slightly serrated towards the tips of the needles.
The cones are also larger, typically 10 centimetres (3.9 in) - 20 centimetres (7.9 in) long. 'Southwestern White Pine' differs from true Mexican Pinus strobiformis in that the needles are not fully serrated, and the cones being smaller 15 centimetres (5.9 in) - 25 centimetres (9.8 in) in P. strobiformis), the cone scales shorter and the seeds smaller.
It is possible that Pinus reflexa is a natural hybrid between Pinus flexilis and Pinus strobiformis. Type localities of the three taxa are:
Limber Pine - Pinus flexilis is a member of the white pine
group, Pinus subgenus Strobus, and like all members of that group, the leaves ('needles') are in fascicles (bundles) of five, with a deciduous sheath. This distinguishes it from the Lodgepole Pine
, with two needles per fascicle, and the bristlecone pine
s, which share five needles per fascicle but have a semi-persistent sheath.
Distinguishing Limber Pine from the related Whitebark Pine
, also a white pine, is very much more difficult, and can only easily be done by the cones. In Limber Pine, the cones are 6 centimetres (2.4 in) - 12 centimetres (4.7 in) long where the species overlap, green when immature, and open to release the seeds; the scales are not fragile. In Whitebark Pine, the cones are 4 centimetres (1.6 in) - 7 centimetres (2.8 in) long, dark purple when immature, and do not open on drying, but are fragile and are pulled apart by birds (see below) to release the seeds. A useful clue resulting is that Whitebark Pines almost never have intact old cones lying under them, whereas Limber Pines usually do.
In the absence of cones, Limber Pine can also be hard to tell from Western White Pine
where they occur together in the northern Rockies and the Sierra Nevada east slope. The most useful clue here is that Limber Pine needles are entire (smooth when rubbed gently in both directions), whereas Western White Pine needles are finely serrated (feeling rough when rubbed gently from tip to base). Limber Pine needles are also usually shorter, 4 centimetres (1.6 in) - 7 centimetres (2.8 in) long, to Western White Pine's 5 centimetres (2 in) - 10 centimetres (3.9 in) (though note the overlap).
, where it has not yet been found. However, there is no known way of controlling the blister rust in existing trees. Research is under way, locating and breeding from the occasional naturally resistant Limber Pines, and by studying the resistance mechanisms of the European and Asian white pines (e.g. Swiss Pine
, Macedonian Pine
), which are strongly resistant to the disease.
Pinus flexilis'Vanderwolf's Pyramid' is widely available as an ornamental tree for garden
s. 'Vanderwolf's Pyramid' derives from Pinus reflexa, though it is usually listed in nursery catalogs under Pinus flexilis.
s and Clark's Nutcracker
s. American Black Bear
s may raid squirrel caches for Limber Pine nuts. Squirrels, Northern Flicker
s, and Mountain Bluebird
s often nest in the trees.
Pine
Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
-the family Pinaceae
Pinaceae
Pinaceae are trees or shrubs, including many of the well-known conifers of commercial importance such as cedars, firs, hemlocks, larches, pines and spruces. The family is included in the order Pinales, formerly known as Coniferales. Pinaceae are supported as monophyletic by its protein-type sieve...
that occurs in the mountains of the Western United States
Western United States
.The Western United States, commonly referred to as the American West or simply "the West," traditionally refers to the region comprising the westernmost states of the United States. Because the U.S. expanded westward after its founding, the meaning of the West has evolved over time...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, and Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. It is also called Southwestern White Pine and Rocky Mountain White Pine. A Limber Pine in Eagle Cap Wilderness
Eagle Cap Wilderness
Eagle Cap Wilderness is a wilderness area located in the Wallowa Mountains of northeastern Oregon , within the Wallowa–Whitman National Forest. The Wilderness was established in 1940. In 1964, it was included in the National Wilderness Preservation System...
, Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
has been documented as over 2000 years old, and another one was confirmed at 1140 years old.
Distribution
Northwestern - Western form
Limber Pine - Pinus flexilis is specifically found in the subalpineSubalpine
The subalpine zone is the biotic zone immediately below tree line around the world. Species that occur in this zone depend on the location of the zone on the Earth, for example, Snow Gum in Australia, or Subalpine Larch, Mountain Hemlock and Subalpine Fir in western North America.Trees in the...
areas of the Rocky Mountains
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
from southwest Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
Canada south through Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
and New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
into the northern states of Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
; from mountains in the eastern Pacific Northwest
Pacific Northwest
The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...
states through the Great Basin
Great Basin
The Great Basin is the largest area of contiguous endorheic watersheds in North America and is noted for its arid conditions and Basin and Range topography that varies from the North American low point at Badwater Basin to the highest point of the contiguous United States, less than away at the...
states of Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
and Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
. It is also found in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
: in the Eastern Sierra Nevadas; the eastern California White Mountains
White Mountains (California)
The White Mountains of California are a triangular fault block mountain range facing the Sierra Nevada across the upper Owens Valley. They extend for approximately as a greatly elevated plateau about wide on the south, narrowing to a point at the north, with elevations generally increasing...
; and the Southern California
Southern California
Southern California is a megaregion, or megapolitan area, in the southern area of the U.S. state of California. Large urban areas include Greater Los Angeles and Greater San Diego. The urban area stretches along the coast from Ventura through the Southland and Inland Empire to San Diego...
San Bernardino Mountains
San Bernardino Mountains
The San Bernardino Mountains are a short transverse mountain range north and east of San Bernardino in Southern California in the United States. The mountains run for approximately 60 miles east-west on the southern edge of the Mojave Desert in southwestern San Bernardino County, north of the...
, San Gabriel Mountains
San Gabriel Mountains
The San Gabriel Mountains Range is located in northern Los Angeles County and western San Bernardino County, California, United States. The mountain range lies between the Los Angeles Basin and the Mojave Desert, with Interstate 5 to the west and Interstate 15 to the east...
, and San Jacinto Mountains
San Jacinto Mountains
The San Jacinto Mountains are a mountain range east of Los Angeles in southern California in the United States. The mountains are named for Saint Hyacinth . The Pacific Crest Trail runs along the spine of the range.The range extends for approximately from the San Bernardino Mountains southeast to...
of the Transverse Ranges
Transverse Ranges
The Transverse Ranges are a group of mountain ranges of southern California, in the Pacific Coast Ranges physiographic region that runs along the Pacific coast from Alaska to Mexico in North America. The Transverse Ranges begin at the southern end of the California Coast Ranges and lie between...
; and a small disjunct population in the Black Hills
Black Hills
The Black Hills are a small, isolated mountain range rising from the Great Plains of North America in western South Dakota and extending into Wyoming, USA. Set off from the main body of the Rocky Mountains, the region is something of a geological anomaly—accurately described as an "island of...
in South Dakota
South Dakota
South Dakota is a state located in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux American Indian tribes. Once a part of Dakota Territory, South Dakota became a state on November 2, 1889. The state has an area of and an estimated population of just over...
.
Pinus flexilis is typically a high-elevation pine, often marking the tree line either on its own, or with Whitebark Pine (Pinus albicaulis)
Whitebark Pine
Pinus albicaulis, known commonly as Whitebark Pine, Pitch Pine, Scrub Pine, and Creeping Pine occurs in the mountains of the Western United States and Canada, specifically the subalpine areas of the Sierra Nevada, the Cascade Range, the Pacific Coast Ranges, and the northern Rocky Mountains –...
, either of the Bristlecone pine
Bristlecone pine
The bristlecone pines are a small group of pine trees that are thought to reach an age far greater than that of any other single living organism known, up to nearly 5,000 years....
s, or Lodgepole Pine (Pinus contorta)
Lodgepole Pine
Lodgepole Pine, Pinus contorta, also known as Shore Pine, is a common tree in western North America. Like all pines, it is evergreen.-Subspecies:...
. In favourable conditions, it makes a tree to 20 metres (65.6 ft), rarely 25 metres (82 ft) tall. However, on exposed treeline sites, mature trees are much smaller, reaching heights of only 5 metres (16.4 ft) - 10 metres (32.8 ft). In steeply-sloping, rocky and windswept terrain in the Rocky Mountains of southern Alberta, limber pine is even more stunted, occurring in old stands where mature trees are consistently less than 3m in height.
Southwestern form
In ArizonaArizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
, and Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
, populations of the Limber Pine often known as Southwestern White Pine, differ from the populations farther north. These are sometimes treated as a variety, Pinus flexilis var. reflexa, but more often as a distinct species, either "accurately" under the name Pinus reflexa, or erroneously through confusion with the Mexican Chihuahua White Pine
Chihuahua White Pine
The Chihuahua White Pine, Pinus strobiformis, family Pinaceae, is a species of pine tree that occurs in the Sierra Madre Occidental mountains of Northern Mexico, from a short distance south of the United States border south through Chihuahua and Durango to Jalisco.It is typically a high-elevation...
under the name Pinus strobiformis, which correctly applies to the Chihuahua White Pine.
The 'Southwestern White Pine' differs from typical Limber Pine in being a larger tree, to 25 metres (82 ft) - 35 metres (114.8 ft) tall, with longer needles, 6 centimetres (2.4 in) - 11 centimetres (4.3 in) long, which have strongly white stomatal bands on the inner faces of the needles (inconspicuous in the type), and are slightly serrated towards the tips of the needles.
The cones are also larger, typically 10 centimetres (3.9 in) - 20 centimetres (7.9 in) long. 'Southwestern White Pine' differs from true Mexican Pinus strobiformis in that the needles are not fully serrated, and the cones being smaller 15 centimetres (5.9 in) - 25 centimetres (9.8 in) in P. strobiformis), the cone scales shorter and the seeds smaller.
It is possible that Pinus reflexa is a natural hybrid between Pinus flexilis and Pinus strobiformis. Type localities of the three taxa are:
- Pinus flexilis: Pikes PeakPikes PeakPikes Peak is a mountain in the Front Range of the Rocky Mountains, west of Colorado Springs, Colorado, in El Paso County in the United States of America....
, ColoradoColoradoColorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains... - Pinus reflexa: Santa Catalina MountainsSanta Catalina MountainsThe Santa Catalina Mountains, commonly referred to as the Catalina Mountains, are located north, and northeast of Tucson, Arizona, United States, on Tucson's north perimeter. The mountain range is the most prominent in the Tucson area, with the highest average elevation...
40 kilometres (40,000 m) east of Tucson, ArizonaArizonaArizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix... - Pinus strobiformis: Cusihuiráchic, 90 km southwest of the city of ChihuahuaChihuahua, ChihuahuaThe city of Chihuahua is the state capital of the Mexican state of Chihuahua. It has a population of about 825,327. The predominant activity is industry, including domestic heavy, light industries, consumer goods production, and to a smaller extent maquiladoras.-History:It has been said that the...
, in the south of the Mexican state of Chihuahua
Related species
Pinus classification
There are three main subgenera of Pinus, the subgenus Strobus , the subgenus Ducampopinus , and the subgenus Pinus...
group, Pinus subgenus Strobus, and like all members of that group, the leaves ('needles') are in fascicles (bundles) of five, with a deciduous sheath. This distinguishes it from the Lodgepole Pine
Lodgepole Pine
Lodgepole Pine, Pinus contorta, also known as Shore Pine, is a common tree in western North America. Like all pines, it is evergreen.-Subspecies:...
, with two needles per fascicle, and the bristlecone pine
Bristlecone pine
The bristlecone pines are a small group of pine trees that are thought to reach an age far greater than that of any other single living organism known, up to nearly 5,000 years....
s, which share five needles per fascicle but have a semi-persistent sheath.
Distinguishing Limber Pine from the related Whitebark Pine
Whitebark Pine
Pinus albicaulis, known commonly as Whitebark Pine, Pitch Pine, Scrub Pine, and Creeping Pine occurs in the mountains of the Western United States and Canada, specifically the subalpine areas of the Sierra Nevada, the Cascade Range, the Pacific Coast Ranges, and the northern Rocky Mountains –...
, also a white pine, is very much more difficult, and can only easily be done by the cones. In Limber Pine, the cones are 6 centimetres (2.4 in) - 12 centimetres (4.7 in) long where the species overlap, green when immature, and open to release the seeds; the scales are not fragile. In Whitebark Pine, the cones are 4 centimetres (1.6 in) - 7 centimetres (2.8 in) long, dark purple when immature, and do not open on drying, but are fragile and are pulled apart by birds (see below) to release the seeds. A useful clue resulting is that Whitebark Pines almost never have intact old cones lying under them, whereas Limber Pines usually do.
In the absence of cones, Limber Pine can also be hard to tell from Western White Pine
Western White Pine
Western White Pine, Pinus monticola in the family Pinaceae, is a species of pine that occurs in the mountains of the western United States and Canada, specifically the Sierra Nevada, the Cascade Range, the Coast Range, and the northern Rocky Mountains. The tree extends down to sea level in many...
where they occur together in the northern Rockies and the Sierra Nevada east slope. The most useful clue here is that Limber Pine needles are entire (smooth when rubbed gently in both directions), whereas Western White Pine needles are finely serrated (feeling rough when rubbed gently from tip to base). Limber Pine needles are also usually shorter, 4 centimetres (1.6 in) - 7 centimetres (2.8 in) long, to Western White Pine's 5 centimetres (2 in) - 10 centimetres (3.9 in) (though note the overlap).
Diseases
Unfortunately, Limber Pine is afflicted with White Pine Blister Rust (Cronartium ribicola), a fungus that was introduced accidentally from Europe. Limber Pine mortality is high in many areas throughout its range, except ArizonaArizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, where it has not yet been found. However, there is no known way of controlling the blister rust in existing trees. Research is under way, locating and breeding from the occasional naturally resistant Limber Pines, and by studying the resistance mechanisms of the European and Asian white pines (e.g. Swiss Pine
Swiss Pine
The Swiss Pine or Arolla Pine, Pinus cembra, is a species of pine tree that occurs in the Alps and Carpathian Mountains of central Europe, in Poland , Switzerland, France, Italy, Austria, Germany, Slovenia, Slovakia, Ukraine and Romania. It typically grows at to altitude. It often reaches the...
, Macedonian Pine
Macedonian Pine
Pinus peuce is a species of pine native to the mountains of Macedonia, Bulgaria, Albania, Montenegro, Kosovo, the extreme southwest of Serbia, and the extreme north of Greece, growing typically at 1,000-2,200 m altitude. It often reaches the alpine tree line in this area...
), which are strongly resistant to the disease.
Cultivation
The popular cultivarCultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...
Pinus flexilis
Garden
A garden is a planned space, usually outdoors, set aside for the display, cultivation, and enjoyment of plants and other forms of nature. The garden can incorporate both natural and man-made materials. The most common form today is known as a residential garden, but the term garden has...
s. 'Vanderwolf's Pyramid' derives from Pinus reflexa, though it is usually listed in nursery catalogs under Pinus flexilis.
Wildlife
Limber Pine is an important source of food for several species, including Red SquirrelPine squirrel
Pine squirrels are squirrels of the genus Tamiasciurus. This genus includes three species, the American Red Squirrel T. hudsonicus, the Douglas Squirrel T. douglasii and Mearns's Squirrel T. mearnsi...
s and Clark's Nutcracker
Clark's Nutcracker
Clark's Nutcracker , sometimes referred to as Clark's Crow or Woodpecker Crow, is a passerine bird in the family Corvidae. It is slightly smaller than its Eurasian relative the Spotted Nutcracker . It is ashy-grey all over except for the black-and-white wings and central tail feathers...
s. American Black Bear
American black bear
The American black bear is a medium-sized bear native to North America. It is the continent's smallest and most common bear species. Black bears are omnivores, with their diets varying greatly depending on season and location. They typically live in largely forested areas, but do leave forests in...
s may raid squirrel caches for Limber Pine nuts. Squirrels, Northern Flicker
Northern Flicker
The Northern Flicker is a medium-sized member of the woodpecker family. It is native to most of North America, parts of Central America, Cuba, the Cayman Islands, and is one of the few woodpecker species that migrate. There are over 100 common names for the Northern Flicker...
s, and Mountain Bluebird
Mountain Bluebird
The Mountain Bluebird is a medium-sized bird weighing about 2-5 ounces, with a length from 15–20 cm . They have light underbellies and black eyes. Adult males have thin bills are bright turquoise-blue and somewhat lighter beneath. Adult females have duller blue wings and tail, grey breast,...
s often nest in the trees.
External links
- USDA Plants Profile: Pinus flexilis
- Gymnosperm Database: Pinus flexilis
- Flora of North America: profile and map - Pinus flexilis
- Pinus flexilis cone photos - & "Pinus reflexa" and "Pinus strobiformis" comparison: scroll ¼ way down page.
- High Elevation White Pine Educational Website: Pinus flexilis