''Pinus monophylla'', the single-leaf pinyon, (alternatively spelled piñon) is a

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 ...

in the

pinyon pine The pinyon or piñon pine group grows in southwestern North America, especially in New Mexico, Arizona, and Utah. The trees yield edible nuts, which are a staple food of Native Americans, and widely eaten as a snack and as an ingredient in ...

group, native to

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

. The range is in southernmost

Idaho Idaho ( ) is a U.S. state, state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Monta ...

, western

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 ...

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 ...

, southwest

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 ...

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 ...

, eastern and southern

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

and northern

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

. It occurs at moderate altitudes from , rarely as low as and as high as . It is widespread and often abundant in this region, forming extensive open woodlands, often mixed with

juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' () of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere, from the Arc ...

s in the Pinyon-juniper woodland

plant community A plant community is a collection or association of plant species within a designated geographical unit, which forms a relatively uniform patch, distinguishable from neighboring patches of different vegetation types. The components of each plant ...

. Single-leaf pinyon is the world's only one-needled pine.Gerry Moore et al. 2008

Description

Species

''Pinus monophylla'' is a small to medium size

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 ...

, reaching tall and with a trunk diameter of up to rarely more. The bark is irregularly furrowed and scaly. The

leaves A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...

('needles') are, uniquely for a pine, usually single (not two or more in a fascicle, though trees with needles in pairs are found occasionally), stout, long, and grey-green to strongly glaucous blue-green, with

stomata In botany, a stoma (from Greek ''στόμα'', "mouth", plural "stomata"), also called a stomate (plural "stomates"), is a pore found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange. The pore is b ...

over the whole needle surface (and on both inner and outer surfaces of paired needles). The cones are acute-globose, the largest of the true pinyons, long and broad when closed, green at first, ripening yellow-buff when 18–20 months old, with only a small number of very thick scales, typically 8–20 fertile scales. The cones thus grow over a two-year (26-month) cycle, so that newer green and older, seed-bearing or open brown cones are on the tree at the same time. Pinyon with pine nuts in cone

The

seed cone A conifer cone (in formal botanical usage: strobilus, plural strobili) is a seed-bearing organ on gymnosperm plants. It is usually woody, ovoid to globular, including scales and bracts arranged around a central axis, especially in conifers an ...

s open to broad when mature, holding the

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosper ...

s on the scales after opening. The seeds are long, with a thin shell, a white

endosperm The endosperm is a tissue produced inside the seeds of most of the flowering plants following double fertilization. It is triploid (meaning three chromosome sets per nucleus) in most species, which may be auxin-driven. It surrounds the embryo an ...

, and a vestigial wing. Empty pine nuts with undeveloped seeds (self-pollinated) are a light tan color, while the "good" ones are dark brown.Ronald M. Lanner 1981 The pine nuts are dispersed by the pinyon jay, which plucks the seeds out of the open cones, choosing only the dark ones and leaving the light ones (as in image at right). The jay, which uses the seeds as a food resource, stores many of the seeds for later use by burying them. Some of these stored seeds are not used and are able to grow into new trees. Indeed, Pinyon seeds will rarely germinate in the wild unless they are cached by jays or other animals.

Subspecies and genetics

There are three subspecies: * ''Pinus monophylla'' subsp. ''monophylla''. Most of the range, except for the areas below. Needles more stout, bright blue-green, with 2–7 resin canals and 8–16 stomatal lines. Cones are long, often longer than broad. * ''Pinus monophylla'' subsp. ''californiarum'' (D. K. Bailey) Zavarin. Southernmost Nevada, southwest through southeastern California (northwest only as far as the

San Jacinto Mountains The San Jacinto Mountains (''Avii Hanupach''Munro, P., et al. ''A Mojave Dictionary''. Los Angeles: UCLA. 1992. in Mojave) are a mountain range in Riverside County, located east of Los Angeles in southern California in the United States. The mo ...

) to 29°N in northern Baja California. Needles less stout, gray-green, with 8–16 resin canals and 13–18 stomatal lines. Cones are long, broader than long. * ''Pinus monophylla'' subsp. ''fallax'' (E. L. Little) D.K. Bailey. Slopes of the lower

Colorado River The Colorado River ( es, Río Colorado) is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and northern Mexico. The river drains an expansive, arid watershed that encompasses parts of seven U.S. s ...

valley and adjacent tributaries from St. George, Utah to the

Hualapai Mountains The Hualapai Mountains are a mountain range located in Mohave County, east of Kingman, Arizona. Rising up to 8,417 feet at its highest peak, the higher elevations of the Hualapai Mountains support Madrean Sky Island habitats, and are host to ...

, and along the lower flank of the Mogollon Rim to

Silver City, New Mexico Silver City is a town in Grant County, New Mexico, United States. It is the county seat and the home of Western New Mexico University. As of the 2010 census the population was 10,315. As of the 2020 census, the population was 9,704. History ...

. Needles less stout, gray-green, with 2–3 resin canals and 8–16 stomatal lines. Cones are long, broader than long. It is most closely related to the

Colorado pinyon ''Pinus edulis'', the Colorado pinyon, two-needle piñon, pinyon pine, or simply piñon, is a pine in the pinyon pine group whose ancestor was a member of the Madro-Tertiary Geoflora (a group of drought resistant trees) and is native to the Unite ...

, which hybridises with it (both subsps. ''monophylla'' and ''fallax'') occasionally where their ranges meet in western Arizona and Utah. It also (subsp. ''californiarum'') hybridises extensively with

Parry pinyon ''Pinus quadrifolia'', the Parry pinyon, is a pine in the pinyon pine group native to southernmost California in the United States and northern Baja California in Mexico, from 33° 30' N south to 30° 30' N. The Parry pinyon has a lifespan of aro ...

. This classification of pinyon species based only upon the presence of single-needle fascicles is brought into doubt by the reporting of trees from both the Pinus monophylla/Pinus edulis and the Pinus monophylla subsp. fallax/Pinus edulis zones as growing more single needle fascicles after dry years and more two-needled fascicles after wet years. Pinus monophylla x edulis needles

Mojave National Preserve

An isolated population of single-leaf pinyon trees in the

Mojave Desert The Mojave Desert ( ; mov, Hayikwiir Mat'aar; es, Desierto de Mojave) is a desert in the rain shadow of the Sierra Nevada mountains in the Southwestern United States. It is named for the indigenous Mojave people. It is located primarily ...

New York Mountains The New York Mountains are a small mountain range found in northeastern San Bernardino County in California, USA. The range's northeastern area lies in southeastern Nevada. The range lies just south of the small community of Ivanpah, and nor ...

, within the

Mojave National Preserve Mojave National Preserve is a United States National Preserve located in the Mojave Desert of San Bernardino County, California, USA, between Interstate 15 and Interstate 40. The preserve was established October 31, 1994, with the passage of ...

of southeast

, has needles mostly in pairs and was previously thought to be Colorado pinyons. They have recently been shown to be a two-needled variant of single-leaf pinyon from chemical and genetic evidence. Occasional two-needled pinyons in northern

are hybrids between single-leaf pinyon and

Prehistoric occurrence

''Pinus monophylla'' has been studied with regard to prehistoric occurrence based upon fossil needles found in packrat middens and fossil pollen records. All three of these sub-types of single-needled pinyon have maintained distinctive ranges over the last 40,000 years, although the northerly species (''Pinus monophylla'') expanded greatly throughout Utah and Nevada since the end of the Pleistocene, 11,700 years ago. The southern California variety has been found to occur within Joshua Tree National Park throughout the last 47,000 years.

Uses and symbolism

The edible seeds,

pine nut Pine nuts, also called piñón (), pinoli (), pignoli or chilgoza (), are the edible seeds of pines (family Pinaceae, genus ''Pinus''). According to the Food and Agriculture Organization, only 29 species provide edible nuts, while 20 are trad ...

s, are collected throughout its range; Native American of the Great Basin region commonly ate them. Various birds and mammals eat the seeds as well. The roasted cones are also edible. The

Shoshoni The Shoshone or Shoshoni ( or ) are a Native American tribe with four large cultural/linguistic divisions: * Eastern Shoshone: Wyoming * Northern Shoshone: southern Idaho * Western Shoshone: Nevada, northern Utah * Goshute: western Utah, e ...

name for the plant is Ai'-go-û-pi. Individuals may harvest the seed for personal use on BLM and Forest Service land. Single-leaf pinyon is also cultivated 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

native plant In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution (though often popularised as "with no human intervention") during history. The term is eq ...

drought tolerant Drought tolerance is the ability to which a plant maintains its biomass production during arid or drought conditions. Some plants are naturally adapted to dry conditions'','' surviving with protection mechanisms such as desiccation tolerance, deto ...

, and

wildlife garden A wildlife garden (or wild garden) is an environment created by a gardener that serves as a sustainable haven for surrounding wildlife. Wildlife gardens contain a variety of habitats that cater to native and local plants, birds, amphibians, ...

s, and for

natural landscaping Natural landscaping, also called native gardening, is the use of native plants and adapted species, including trees, shrubs, groundcover, and grasses which are local to the geographic area of the garden. Benefits Maintenance Natural land ...

. It is used regionally 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 ...

. It is rarely seen in nurseries, because it is difficult to germinate. In 1959, it was designated Nevada's

state tree This is a list of U.S. state, federal district, and territory trees, including official trees of the following of the states, of the federal district, and of the territories. Table See also * List of U.S. state, district, and territorial insign ...

, later to be joined by the

Great Basin Bristlecone Pine ''Pinus longaeva'' (commonly referred to as the Great Basin bristlecone pine, intermountain bristlecone pine, or western bristlecone pine) is a long-living species of bristlecone pine tree found in the higher mountains of California, Nevada, an ...

. Its discovery, by White people, is attributed to American politician and explorer

John C. Frémont John Charles Frémont or Fremont (January 21, 1813July 13, 1890) was an American explorer, military officer, and politician. He was a U.S. Senator from California and was the first Republican nominee for president of the United States in 1856 ...

Deforestation

During the mid-nineteenth century, many pinyon groves were cut down to make

charcoal Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, ...

for ore-processing, threatening the traditional lifestyle of the Native Americans who depended on them for food. When the

railroad Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a prep ...

s penetrated these areas, imported

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when ...

supplanted locally produced charcoal. Following the resulting re-establishment of pinyon woodlands after the charcoal era, many

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Adult females are referred to as cows and adult ...

ranchers became concerned that these woodlands provided decreased

livestock Livestock are the domesticated animals raised in an agricultural setting to provide labor and produce diversified products for consumption such as meat, eggs, milk, fur, leather, and wool. The term is sometimes used to refer solely to ani ...

forage Forage is a plant material (mainly plant leaves and stems) eaten by grazing livestock. Historically, the term ''forage'' has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also use ...

grazing In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to roam around and consume wild vegetations in order to convert the otherwise indigestible (by human gut) cellulose within grass and ot ...

rangeland Rangelands are grasslands, shrublands, woodlands, wetlands, and deserts that are grazed by domestic livestock or wild animals. Types of rangelands include tallgrass and shortgrass prairies, desert grasslands and shrublands, woodlands, sava ...

. Efforts to clear these woodlands, often using a surplus

battleship A battleship is a large armour, armored warship with a main artillery battery, battery consisting of large caliber guns. It dominated naval warfare in the late 19th and early 20th centuries. The term ''battleship'' came into use in the late 1 ...

chain dragged between two

bulldozer A bulldozer or dozer (also called a crawler) is a large, motorized machine equipped with a metal blade to the front for pushing material: soil, sand, snow, rubble, or rock during construction work. It travels most commonly on continuous track ...

s, peaked in the 1950s, but were subsequently abandoned when no long term forage increase resulted. The

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

of large areas of Pinyon woodlands in the interests of

mining Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the econom ...

and cattle ranching is seen by some as an act of ecological and cultural vandalism.

References

Sources

* C. Michael Hogan (2009)
''Elephant Tree: Bursera microphylla'', GlobalTwitcher.com, ed. N. Stromberg
* * Ronald M. Lanner (1981). ''The Piñon Pine: A Natural and Cultural History''. University of Nevada Press. .

External links

USDA Plants Profile: ''Pinus monophylla''
{{Authority control monophylla Edible nuts and seeds Trees of the Southwestern United States Trees of the Northwestern United States Trees of the South-Central United States Trees of Baja California Trees of the Great Basin North American desert flora Flora of the California desert regions Flora of Baja California Flora of Arizona Flora of California Flora of Nevada Flora of Utah Flora of Idaho Flora of New Mexico Flora of the Western United States Flora of the Southwestern United States Mojave National Preserve Natural history of the Mojave Desert Plants used in Native American cuisine Taxa named by John Torrey Taxa named by John C. Frémont Least concern flora of the United States Garden plants of North America Ornamental trees Drought-tolerant plants