A pine is any conifer in the genus Pinus (
Pines are widely distributed in the Northern Hemisphere; they occupy large areas of taiga (boreal forest), but are found in many habitats, including the Mediterranean Basin, and dry tropical forests in southeast Asia and Central America. Some are fire-resistant or fire-dependent.
Pine trees provide one of the most extensively used types of timber. The seeds are used to make dishes such as pesto, while retsina wine is flavoured with pine resin.
Description
Tree
Pine trees are
evergreen, coniferous
(or, rarely,
) growing tall, with the majority of species reaching tall.
The smallest are Siberian dwarf pine and
Potosi pinyon, and the tallest is an tall
sugar pine (
Pinus lambertiana) located in Yosemite National Park.
Pines are long lived and typically reach ages of 100–1,000 years, some even more. The longest-lived is the Great Basin bristlecone pine ( Pinus longaeva). One individual in the White Mountains of California, dubbed "Methuselah", is among the world's oldest living organisms at around 4,800-years old.
The spirals of branches, needles, and Conifer cone scales Phyllotaxis in Fibonacci number ratios.
File:Pinus lambertiana ProspectOR.jpg| Pinus lambertiana is the tallest pine species.
File:Pinus culminicola.jpg| Pinus culminicola is a low-growing shrub, among the shortest pines.
File:Big bristlecone pine Pinus longaeva.jpg|Ancient Pinus longaeva, among the oldest of all trees
Bark
The bark of most pines is thick and scaly, but some species have thin, flaky bark. The branches are produced in "pseudo-whorls", actually a very tight spiral but appearing like a ring of branches arising from the same point. Many pines are uninodal, producing just one such whorl of branches each year, from
at the tip of the year's new
plant stem, but others are multinodal, producing two or more whorls of branches per year.
File:Tree Types and Barks 004.jpg|Many pines, like Pinus taeda, have thick bark that flakes into scales.
File:Pinus bungeana— bark at Morris Arboretum 01 (cropped).jpg|Some species, like Pinus bungeana, have thin bark.
Foliage
Pines have four types of
leaf:
-
Seed leaves () on seedlings are borne in a whorl of 4–24.
-
Juvenile leaves, which follow immediately on seedlings and young plants, are long, single, green or often blue-green, and arranged spirally on the shoot. These are produced for six months to five years, rarely longer.
-
Scale leaves, similar to bud scales, are small, brown and not photosynthetic, and arranged spirally like the juvenile leaves.
-
Needles, the adult leaves, are green (photosynthetic) and bundled in clusters called fascicles. The needles can number from one to seven per fascicle, but generally number from two to five. Each fascicle is produced from a small bud on a dwarf shoot in the axil of a scale leaf. These bud scales often remain on the fascicle as a basal sheath. The needles persist for 1.5–40 years, depending on species. If a shoot's apical meristem is damaged (e.g. eaten by an animal), the needle fascicles just below the damage generate a stem-producing bud, which can then replace the lost growth tip.
File:Seekiefer (Pinus halepensis) 14d 1.jpg| Pinus halepensis seed leaf
File:Spontaneous Pinus seedling D171003.jpg|Juvenile leaves of seedling
Pinus pinaster, single and arranged spirally
File:Scale leaves of Austrian pine.jpg| Pinus nigra growth candles covered with thin brownish scale leaves
File:Pine needles in bunches of five.jpg| Pinus parviflora needles, in bunches of five in this species
Cones
Pines are
monoecious, having the male and female cones on the same tree.
The male cones are small, typically 1–5 cm long, and only present for a short period (usually in spring, though autumn in a few pines), falling as soon as they have shed their
pollen. The female cones take 1.5–3 years (depending on species) to mature after
pollination, with actual fertilisation delayed one year. At maturity, the female cones are 3–60 cm long. Each cone has numerous spirally-arranged scales, with two seeds on each fertile scale; the scales at the base and tip of the cone are small and sterile without seeds.
The seeds () are mostly small and winged, and are Anemochory (wind-dispersed). Some are larger, have only a vestigial wing, and are bird-dispersed. Female cones are woody and sometimes armed to protect developing seeds from foragers. At maturity, the cones usually open to release the seeds. In some of the bird-dispersed species, for example whitebark pine,Keith Rushforth (1987). 074702801X, Christopher Helm Publishers. 074702801X
File:Pinus radiata cone.jpg| Pinus radiata female (seed) cone
File:2021-04-18 11 01 55 Pollen cones on a Loblolly Pine along a walking path in the Franklin Farm section of Oak Hill, Fairfax County, Virginia.jpg| Pinus taeda male (pollen) cones
File:KoreanPineSeeds.jpg| Pinus koraiensis seeds
File:Pitch pine cones exposed to fire.jpg| Pinus rigida cones open when exposed to fire. (left to right: before; after; 24 hours later)
Naming
The modern English name "pine" derives from Latin
pinus, traced to the Indo-European base
*pīt- 'resin'.
Before the 19th century, pines were often called firs, a name now applied to another genus,
Fir. In some European languages, Germanic cognates of the Old Norse name are still in use for pines, as in
Danish language fyr and
German language Föhre.
The genus
Pinus was named by
Carl Linnaeus in 1753.
Pinus sylvestris, the Scots pine, was later chosen as the
type species.
Evolution
Fossil history
The
Pinaceae, the pine family, first appeared in the
Jurassic period.
The genus
Pinus first appeared during the
Early Cretaceous; the oldest verified fossil is
Pinus yorkshirensis from the
Hauterivian-
Barremian boundary (~130-125 million years ago) from the Speeton Clay, England.
However, there are possible records of the genus from the
Jurassic.
File:Pinus yorkshirensis holotype (straight).jpg|Oldest pine fossil: Pinus yorkshirensis cone. Early Cretaceous, 131–129 mya
File:Pinus johndayensis Fossil High School Cove Creek.jpg|Fossil cone and needles of Pinus johndayensis, Oligocene, 33 mya
External phylogeny
Based on
transcriptome analysis,
Pinus is most closely related to the genus
Cathaya, which in turn is closely related to the genus
Picea, the spruces. These genera, with
and
, form the pinoid
clade of the Pinaceae.
Internal phylogeny
The evolutionary history of the genus
Pinus has been complicated by hybridisation. Pines are prone to inter-specific breeding. Wind pollination, long life spans, overlapping generations, large population size, and weak reproductive isolation make breeding across species more likely. As the pines have diversified, gene transfer between different species has created a complex history of genetic relatedness.
Research using large genetic datasets has clarified these relationships.
Two 21st century phylogenies are given below; the differences between them demonstrate these complications:
Taxonomy
Pines are
. The genus is divided into two subgenera based on the number of
Vascular bundle in the needle, and the presence or absence of a resin seal on the scales of the mature cones before opening. The subgenera can be distinguished by cone, seed, and leaf characters:
-
Pinus subg. Pinus, the yellow, or hard pine group, with cones with a resin seal on the scales, and generally with harder wood; the needle fascicles mostly have a persistent sheath (two exceptions, Pinus leiophylla and Pinus lumholtzii, have deciduous sheaths).
-
Strobus, syn. Pinus subg. Ducampopinus, the white or soft pine, and pinyon pine groups, with cones without a resin seal on the scales, and usually have softer wood; the needle fascicles mostly have a deciduous sheath (one exception, Pinus nelsonii, has a persistent sheath).
Phylogenetic evidence indicates that the subgenera diverged anciently from one another.
World Flora Online accepts 134 species-rank taxa (119 species and 15 nothospecies) of pines as current, with additional synonyms,
Distribution
Pines are native to the Northern Hemisphere, with the most species in North America, some in Asia, and a few in Europe. Only two species,
Pinus sylvestris and
Pinus sibirica, occur in more than one of those regions (Asia and Europe).
They occupy large areas of
boreal forest (taiga) in latitudes between 50° and 60° N; about a third of this
biome is in North America and
Scandinavia, the rest in
Siberia.
The northernmost species is
Pinus sylvestris, reaching just north of 70° N in Stabbursdalen National Park in Norway;
One species,
Pinus merkusii, crosses the equator in
Sumatra to 2°S.
In North America, various species occur in regions at latitudes from as far north as 66° N
to as far south as 12°N.
Various species have been introduced to temperate and subtropics regions of both hemispheres, where they are grown as timber or cultivated as ornamental plants in parks and gardens. A number of such introduced species have become naturalised, and species such as Pinus radiata are considered invasive species in some regions.
File:Pinus sylvestris - Furu Stabbursdalen.jpg|Most northerly: Pinus sylvestris in Stabbursdalen National Park, Norway, at 70° North
File:Lake Baikal, Siberian mixed forest, Taiga, Siberia, Russia.jpg|Pines and in the Siberian taiga by Lake Baikal
File:Pines plant.jpg| Pinus merkusii in Sumatra: the only pine whose range extends south of the equator
File:Prospectsydneypineforest.jpg| Pinus radiata in Australia, where it was introduced in the late 19th century.
Ecology
Environmental factors
Pines grow in a very large variety of environments, ranging from semi-arid desert to rainforests, from sea level up to , from the coldest to the hottest environments on Earth. They often occur in mountainous areas with favourable soils.
Pinus contorta is a Fire ecology, requiring to maintain healthy populations of diverse ages.
File:Бор кривул 01.JPG| Pinus mugo, a dwarf mountain species at altitude in Macedonia
File:Prescribed burn in a Pinus nigra stand in Portugal.JPG|A controlled burn in a Pinus nigra stand, Portugal
File:Lodgepole pine Yellowstone 1998 near firehole.jpg|A stand of Pinus contorta regenerating 10 years after a major fire at Yellowstone National Park
Species interactions
Pine needles serve as food for the
caterpillar larvae of several
moth species including the
pine beauty, a pest of mature stands of pine trees,
and the
pine hawk-moth, a large species which causes only occasional damage.
Some moths, notably the pine processionary, whose caterpillars can completely defoliate pine trees,
[ ] and the
Dendrolimus pini, are serious pests of commercial forestry.
File:Panolis.flammea.7102.jpg|Pine beauty moth ( Panolis flammea)
File:Sphinx pinastri 03.JPG|Pine hawk-moth ( Sphinx pinastri) caterpillar feeding on pine needles
File:Treviño - Cerro de Treviño - Nido de procesionaria 01 (cropped).jpg|Tent of pine processionary moth ( Thaumetopoea pityocampa) caterpillars
File:Dendrolimus pini larva.jpg|Dendrolimus pini ( Dendrolimus pini) caterpillars on Scots pine with damage to needles
Several species of pine are attacked by nematodes, causing pine wilt disease, which can quickly kill trees.[ Bursaphelenchus xylophilus, Pine Wilt Nematode. Nematology. University of Nebraska, Lincoln.][ Bursaphelenchus xylophilus. Nemaplex. UC Davis.]
The sawfly Diprion pini is likewise a serious commercial pest of pine forestry, especially of Pinus sylvestris. (2025). 022638263X, University of Chicago Press. 022638263X
File:Diprion pini 2 beentree.jpg|Mass of Diprion pini sawfly caterpillars on pine tree
File:Spotted nutcracker with pine nut (cropped).jpg|Northern nutcracker with nut of Pinus sibirica
File:Pinus pumila cone eaten by Nucifraga caryocatactes.JPG| Pinus pumila cone opened by nutcrackers
File:Boletus pinophilus3.JPG|The pine bolete Boletus pinophilus forms an ectomycorrhizal association with several pines.
Uses
Timber
Pines are among the most commercially important tree species, valued for their timber and wood pulp throughout the world.
In temperate and tropical regions, they are fast-growing
that grow in relatively dense stands. Commercial pines are grown in
for timber that is denser and therefore more durable than spruce (
Picea). Pine wood is widely used in high-value carpentry items such as furniture, window frames, panelling, floors, and roofing due to its abundance and low cost.
[Wiemann, M. C. (2010). Characteristics and Availability of Commercially Important Woods. In Wood handbook: Wood as an engineering material
]
/ref>
As pine wood has little resistance to insects or decay after logging, in its untreated state it is generally recommended for indoor construction purposes only, such as indoor drywall framing. It is commonly used in Canadian Lumber Standard graded wood.
File:John Deere 2054 DHSP forestry swing machine, Kaibab National Forest 1.jpg|Logging Pinus ponderosa, Arizona
File:100 mm furu.jpg|100 mm (4 inch) thick pine timber sawn in sawmill, Sweden
File:Arquitectura en madera.jpg|Pine as an architectural material, Spain
File:Interior of the IKEA Băneasa 14.jpg|Pine furniture, 2019
Ornamental uses
Many pine trees make attractive ornamental plantings for and larger , while dwarf are suitable for smaller spaces. There are at least 818 named (or trinomials) recognised by the American Conifer Society ACS.
File:Pinus parviflora Miyajima 2zz.jpg| Pinus parviflora 'Miyajima' ornamental cultivar
File:JBP_Kotobuki.jpg| Pinus thunbergii 'Kotobuki'
as a 65-year-old bonsai
Food
The seeds (pine nuts) are generally edible; the young male cones can be cooked and eaten, as can the bark of young twigs.
The soft, moist, white inner bark (vascular cambium) beneath the woody outer bark is edible and very high in vitamins vitamin A and vitamin C.
A herbal tea is made by steeping young, green pine needles in boiling water (known as tallstrunt in Sweden).
File:Christmas pinioli cookies.jpg|Pinolate biscuits with
File:BasilPesto.JPG|Pesto with basil and pine nuts
File:Retsina.JPG|A bottle of retsina,
a Greek wine flavoured with Pinus halepensis resin
Other uses
Turpentine oil, traditionally used as a solvent in , and , is extracted from pine resin
File:Chipping a turpentine tree.jpg|Extracting resin to make turpentine and rosin (before 1920)
File:TianguisArtesanalPatzcuaro2016 113.jpg|Pine needle baskets, Pátzcuaro, Mexico, 2016
File:胡开文龙翔凤舞柱形墨.jpg|Chinese ink sticks can be made of pine soot.
Culture
In ancient Egypt, the god Osiris was honoured with an image placed in a cavity inside a pine tree. In ancient Greece, the goddess Pitthea was linked with pines, while in ancient Rome, the tree was worshipped in the festival of the god Attis and the goddess Cybele.
In 1924, the Italian composer Ottorino Respighi completed his tone poem Pines of Rome. Each of its four movements depicts a pine-clad setting in the city of Rome, namely the Villa Borghese gardens, near a catacomb, on the Janiculum, and along the Appian Way.
Pines are often featured in paintings. A 2021 study lists over a hundred works: many are by artists from the Mediterranean region, such as Paul Cézanne and Jean-Baptiste-Camille Corot; Northern Europe, such as Akseli Gallen-Kallela and James William Giles; and North America, with works by Tom Thomson and others. The paintings often depict Pinus pinea by the Mediterranean sea; other species include P. sylvestris and P. pinaster.[Wolfram Eberhard (2003 1986), A Dictionary of Chinese Symbols: Hidden Symbols in Chinese Life and Thought. London, New York: Routledge. , sub "Pine".]
File:Ménade relieve romano (Museo del Prado) 04b.jpg|A maenad (follower of Dionysus) holding a thyrsus topped with a pine cone. Roman, 120–140 AD
File:Ikeno Taiga 池大雅 - Pines on Mount Tai (after Gao Qian (after Tang Yin)) - 1985.203 - Arthur M. Sackler Museum.jpg| Pines on Mount Tai, Ike no Taiga, Japan, 18th century
File:Pissarro - the-pine-trees-of-louveciennes-1870.jpg| The Pine Trees of Louveciennes, Camille Pissarro, 1870
File:Le pin à l'Estaque (P. Cézanne, Musée de l'Orangerie) (4619406661).jpg| Le pin à l'Estaque,
Paul Cézanne, 1875
File:Under the Pines PMA(15) (16982300531).jpg| Under the Pines, Evening, Claude Monet, 1888
File:'Pine Clouds', 1903 painting by Wu Ku-hsiang.jpg|"Pine Clouds", fan painting by Wu Ku-hsiang, China, 1903
File:Tom Thomson - The West Wind - Google Art Project.jpg| The West Wind,
Tom Thomson, 1917,
depicting Pinus resinosa
See also
-
El Pino (The Pine Tree)
-
Pine barrens
-
Pine-cypress forest
-
Pine Tree Flag
-
Tree of Peace
Bibliography
External links
