''Pinus flexilis'', the limber pine, is a species of
pine
A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanic ...
tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...
-the family
Pinaceae that occurs in the mountains of the
Western United States
The Western United States (also called the American West, the Far West, and the West) is the region comprising the westernmost states of the United States. As American settlement in the U.S. expanded westward, the meaning of the term ''the We ...
,
Mexico
Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...
, and
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by to ...
. It is also called Rocky Mountain white pine.
A limber pine in
Eagle Cap Wilderness
Eagle Cap Wilderness is a wilderness area located in the Wallowa Mountains of northeastern Oregon (United States), within the Wallowa–Whitman National Forest. ,
Oregon
Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...
, has been documented as over 2,000 years old, and another one was confirmed at 1,140 years old. Another candidate for the oldest limber pine was identified in 2006 near the
Alta Ski Area in Utah; called "Twister", the tree was confirmed to be at least 1,700 years old and thought to be even older.
Description
Its pliant branches gives it the common name "limber" and specific epithet ''flexilis''. Its needles are about long and a dark, blueish green.
Its bark is heavily creased and dark grey. Its pale wood is lightweight and soft.
''Pinus flexilis'' is typically a high-elevation pine, often marking the tree line either on its own, or with
whitebark pine
''Pinus albicaulis'', known by the common names whitebark pine, white bark pine, white pine, pitch pine, scrub pine, and creeping pine, is a conifer tree native to the mountains of the western United States and Canada, specifically subalpine ...
(''Pinus albicaulis''), either of the
bristlecone pines, or
lodgepole pine (''Pinus contorta''). In favorable conditions, it makes a tree to , rarely tall. On exposed tree line sites, mature trees are much smaller, reaching heights of only .
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 in height.
One of the world's oldest living limber pine trees grows on the banks of the upper North Saskatchewan River at Whirlpool Point in Alberta.
Recent measurements give a maximum girth of 185". In 1986, a core sample 10 cm was retrieved by two researchers who counted 400 rings.
Extrapolating this data gives an age close to 3,000 years.
Similar species
''Pinus flexilis'' is a member of the
white pine group, ''
Pinus
A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden ...
'' 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 pines, which share five needles per fascicle but have a semi-persistent sheath.
''Pinus albicaulis''
Distinguishing limber pine from the related whitebark pine (''P. albicaulis''), also a white pine, is very much more difficult, and can only easily be done by the cones. In limber pine, the cones are 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 long, dark purple when immature, and do not open on drying, but are fragile and are pulled apart by birds to release the seeds. A useful clue is that whitebark pines almost never have intact old cones lying under them, whereas limber pines usually do.
''Pinus monticola''
In the absence of cones, limber pine can also be hard to tell from
Western white pine
Western white pine (''Pinus monticola''), also called silver pine and California mountain pine, is a species of pine in the family Pinaceae. It occurs in mountain ranges of northwestern North America. It is the state tree of Idaho.
Description ...
(''P. monticola'') 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, long, while western white pine needles are , though the ranges overlap.
Distribution
The largest part of the limber pine's range is in the
Rocky Mountains
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico ...
, from southwest
Alberta
Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest T ...
and southeastern
British Columbia
British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...
south through
Colorado
Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of the ...
and
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe, New Mexico, Santa Fe
, LargestCity = Albuquerque, New Mexico, Albuquerque
, LargestMetro = Albuquerque metropolitan area, Tiguex
, Offi ...
into the northern states of
Mexico
Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...
. It is also found through the
Great Basin
The Great Basin is the largest area of contiguous endorheic watersheds, those with no outlets, in North America. It spans nearly all of Nevada, much of Utah, and portions of California, Idaho, Oregon, Wyoming, and Baja California. It is noted fo ...
states of
Nevada
Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...
and
Utah
Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to its ...
, in the eastern
Sierra Nevada
The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primar ...
and
White Mountains of
Northern California
Northern California (colloquially known as NorCal) is a geographic and cultural region that generally comprises the northern portion of the U.S. state of California. Spanning the state's northernmost 48 counties, its main population centers incl ...
, and in the
San Bernardino and
San Gabriel Mountains
The San Gabriel Mountains ( es, Sierra de San Gabriel) are a mountain range located in northern Los Angeles County and western San Bernardino County, California, United States. The mountain range is part of the Transverse Ranges and lies betw ...
of the
Transverse Ranges
The Transverse Ranges are a group of mountain ranges of southern California, in the Pacific Coast Ranges physiographic region in North America. The Transverse Ranges begin at the southern end of the California Coast Ranges and lie within Santa ...
in
Southern California
Southern California (commonly shortened to SoCal) is a geographic and cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most populous urban ...
. Continuing south the species is found in the
San Jacinto Mountains,
Santa Rosa Mountains, and
Hot Springs Mountain of the
Peninsular Ranges
The Peninsular Ranges (also called the Lower California province) are a group of mountain ranges that stretch from Southern California to the southern tip of the Baja California peninsula; they are part of the North American Coast Ranges, which ...
. There are small disjunct populations in eastern
Oregon
Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...
, in western
North Dakota
North Dakota () is a U.S. state in the Upper Midwest, named after the indigenous Dakota Sioux. North Dakota is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minnesota to the east, ...
and
Nebraska
Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the sout ...
,
and in the
Black Hills
The Black Hills ( lkt, Ȟe Sápa; chy, Moʼȯhta-voʼhonáaeva; hid, awaxaawi shiibisha) is an isolated mountain range rising from the Great Plains of North America in western South Dakota and extending into Wyoming, United States. Black ...
of
South Dakota
South Dakota (; Sioux: , ) is a U.S. state in the North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota and Dakota Sioux Native American tribes, who comprise a large po ...
.
It is found at a wide range of altitudes depending on the latitude, from . In the northern half of its range, it grows in the
montane zone near the lower
tree line
The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures, extreme snow ...
; in the middle of its range between the
45th and
40th parallels, it grows on windswept sites in the montane and
subalpine zone
Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...
s; and in the southern part of its range, it grows mainly at high elevations in the subalpine zone near the upper tree line.
It can more often be found at the outer fringes of a forest than in the forest itself.
Ecology
''Pinus flexilis'' is an important source of food for several species, including
red squirrels and
Clark's nutcracker
Clark's nutcracker (''Nucifraga columbiana''), sometimes referred to as Clark's crow or woodpecker crow, is a passerine bird in the family Corvidae, native to the mountains of western North America. The nutcracker is an omnivore, but subsists mai ...
s, the latter being an important distributor of seeds.
There is evidence that limber pines co-evolved with Clark's nutcrackers, which are the primary dispersers of the seeds.
In a relic, low elevation population, seeds are also dispersed by small rodents.
American black bear
The American black bear (''Ursus americanus''), also called simply a black bear or sometimes a baribal, is a medium-sized bear endemic to North America. It is the continent's smallest and most widely distributed bear species. American black bear ...
s and
grizzly bear
The grizzly bear (''Ursus arctos horribilis''), also known as the North American brown bear or simply grizzly, is a population or subspecies of the brown bear inhabiting North America.
In addition to the mainland grizzly (''Ursus arctos horri ...
s may raid squirrel caches for limber pine nuts.
Squirrels,
Northern flicker
The northern flicker or common flicker (''Colaptes auratus'') is a medium-sized bird of the woodpecker family. It is native to most of North America, parts of Central America, Cuba, and the Cayman Islands, and is one of the few woodpecker spec ...
s, and
mountain bluebirds often nest in the trees. There is some evidence that ''P. flexilis'' has a symbiotic relationship with nitrogen-fixing bacteria that inhabit the needles.
The species is generally
shade tolerant
In ecology, shade tolerance is a plant's ability to tolerate low light levels. The term is also used in horticulture and landscaping, although in this context its use is sometimes imprecise, especially in labeling of plants for sale in commercial ...
and resistant to fire, but does not thrive in dense habitats, instead occurring in areas relatively hostile to other species.
Threats
Limber pine is susceptible to
white pine blister rust,
caused by ''Cronartium ribicola'', a fungus that was introduced accidentally from Europe. Limber pine mortality is high in many areas throughout its range, except
Arizona
Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...
, where it has not yet been found. However, there is little hope 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.
The tree has also been damaged by
bark beetle
A bark beetle is the common name for the subfamily of beetles Scolytinae. Previously, this was considered a distinct family (Scolytidae), but is now understood to be a specialized clade of the "true weevil" family (Curculionidae). Although the ...
epidemics, particularly at drought-affected low elevations.
Cultivation
The popular
cultivar
A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture ...
''P. flexilis'' 'Vanderwolf's Pyramid' is widely available as an
ornamental tree
Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that ...
for
garden
A garden is a planned space, usually outdoors, set aside for the cultivation, display, and enjoyment of plants and other forms of nature. The single feature identifying even the wildest wild garden is ''control''. The garden can incorporate bot ...
s. 'Vanderwolf's Pyramid' derives from ''P. reflexa'', though it is usually listed in nursery catalogs under ''P. flexilis''.
The Southwestern white pine is popular as a windbreak tree or an ornamental tree due to its drought tolerance. It is also grown as a
Christmas tree
A Christmas tree is a decorated tree, usually an evergreen conifer, such as a spruce, pine or fir, or an artificial tree of similar appearance, associated with the celebration of Christmas. The custom was further developed in early modern ...
, liked for the soft needles but with stiffer branches than an
Eastern white pine
''Pinus strobus'', commonly called the eastern white pine, northern white pine, white pine, Weymouth pine (British), and soft pine is a large pine native to eastern North America. It occurs from Newfoundland, Canada west through the Great Lake ...
.
Uses
The large seeds are edible,
and were reportedly consumed by Native Americans in Montana.
See also
*
Burmis Tree
References
Further reading
*
*
External links
Gymnosperm Database: ''Pinus flexilis''''Pinus flexilis'', Jepson Manual*
ttps://web.archive.org/web/20140508151347/http://www.opb.org/programs/ofg/segment/old-tree/ Old Tree Documentary produced by
Oregon Field Guide
''Oregon Field Guide'' is a weekly television program produced by Oregon Public Broadcasting focusing on recreation, the outdoors, and environmental issues in the state of Oregon. The show has become part of the Oregon zeitgeist. Steve Amen i ...
{{Authority control
flexilis
Trees of the Western United States
Trees of Northeastern Mexico
Trees of Northwestern Mexico
Trees of the Great Basin
Flora of the West Coast of the United States
Trees of Alberta
Trees of the Southwestern United States
Trees of Baja California
Trees of British Columbia
Trees of Chihuahua (state)
Trees of Coahuila
Trees of the Northwestern United States
Trees of the South-Central United States
Trees of Nuevo León
Trees of Sonora
Trees of the North-Central United States
Flora of the California desert regions
Flora of the Sierra Nevada (United States)
Flora of California
Natural history of the Peninsular Ranges
~Pinus
~Pinus
Least concern flora of North America
Least concern flora of the United States
Flora of the Rocky Mountains