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Conifers are a group of cone-bearing
seed plants The spermatophytes (; ), also known as phanerogams (taxon Phanerogamae) or phaenogams (taxon Phaenogamae), comprise those plants that produce seeds, hence the alternative name seed plants. They are a subset of the embryophytes or land plants. Th ...
, a subset of
gymnosperm The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also ...
s. Scientifically, they make up the
division Division or divider may refer to: Mathematics *Division (mathematics), the inverse of multiplication *Division algorithm, a method for computing the result of mathematical division Military *Division (military), a formation typically consisting o ...
Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant
class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differently f ...
, Pinopsida. All
extant Extant is the opposite of the word extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the endling, last individual o ...
conifers are
perennial A perennial plant or simply perennial is a plant Plants are predominantly photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and incl ...
woody plant A woody plant is a plant Plants are predominantly photosynthetic Photosynthesis is a process used by plants and other organisms to Energy transformation, convert light energy into chemical energy that, through cellular respiration, ca ...
s with
secondary growth In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Anc ...
. The great majority are
tree In botany, a tree is a perennial plant with an elongated Plant stem, stem, or trunk (botany), trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only wood plants with se ...

tree
s, though a few are
shrub A shrub (often called a bush) is a small- to medium-sized perennial A perennial plant or simply perennial is a plant Plants are predominantly photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the p ...

shrub
s. Examples include
cedars Cedars may refer to: * Cedar (plant), including a list of trees and plants known as cedar * Cedars (album), ''Cedars'' (album), an album released in 2003 by English band Clearlake * Cedars (immigration detention), facility in the UK * Cedars-Sinai ...
, Douglas-firs,
cypresses
cypresses
,
fir Firs (''Abies'') are a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology Biology is the natural science that studies life and living organisms, including ...

fir
s,
juniper Junipers are conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The divi ...

juniper
s,
kauri ''Agathis'', commonly known as kauri or dammara, is a genus Genus (plural genera) is a taxonomic rank Taxonomy (general) is the practice and science of classification of things or concepts, including the principles that underlie such class ...
,
larch Larches are deciduous In the fields of horticulture Horticulture is the art of cultivating plants in gardens to produce food and medicinal ingredients, or for comfort and ornamental purposes. Horticulturists grow flowers, fruits and nuts, v ...

larch
es,
pine A pine is any conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The divi ...

pine
s, hemlocks,
redwoods Sequoioideae, popularly known as redwoods, is a subfamily of Pinophyta, coniferous trees within the family (biology), family Cupressaceae. It includes the List of superlative trees#Largest, largest and tallest trees in the world. Description T ...

redwoods
,
spruce A spruce is a tree of the genus ''Picea'' , a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal ecosystem, boreal (taiga) regions of the Earth. ''Picea'' is the sole genus ...

spruce
s, and
yews
yews
.Campbell, Reece, "Phylum Coniferophyta". Biology. 7th. 2005. Print. P. 595 As of 1998, the division Pinophyta was estimated to contain eight families, 68 genera, and 629 living species. Although the total number of species is relatively small, conifers are
ecologically Ecology (from el, οἶκος, "house" and el, -λογία, label=none, "study of") is the study of the relationships between living organisms, including humans, and their physical environment. Topics of interest include the biodiversity ...
important. They are the dominant plants over large areas of land, most notably the
taiga Taiga (; rus, тайга́, p=tɐjˈɡa; relates to Mongolic and Turkic Turkic may refer to: * anything related to the country of Turkey * Turkic languages, a language family of at least thirty-five documented languages ** Turkic alphabets (di ...

taiga
of the
Northern Hemisphere The Northern Hemisphere is the half of Earth Earth is the third planet from the Sun and the only astronomical object known to harbour and support life. 29.2% of Earth's surface is land consisting of continents and islands. The remain ...

Northern Hemisphere
,Campbell, Reece, "Phylum Coniferophyta". Biology. 7th. 2005. Print. P. 595 but also in similar cool climates in mountains further south. Boreal conifers have many wintertime adaptations. The narrow conical shape of northern conifers, and their downward-drooping limbs, help them shed snow. Many of them seasonally alter their biochemistry to make them more resistant to freezing. While
tropical rainforest Tropical rainforests are rainforest Rainforests are characterized by a closed and continuous tree canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape ...

tropical rainforest
s have more
biodiversity Biodiversity is the biological variety and of . Biodiversity is a measure of variation at the , , and level. Terrestrial biodiversity is usually greater near the , which is the result of the warm and high . Biodiversity is not distributed ev ...

biodiversity
and turnover, the immense conifer forests of the world represent the largest terrestrial
carbon sink A carbon sink is any reservoir, natural or otherwise, that accumulates and stores some carbon Carbon (from la, carbo "coal") is a chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic tabl ...
. Conifers are of great economic value for
softwood file:Pinus sylvestris wood ray section 1 beentree.jpg, Scots Pine, a typical and well-known softwood Softwood is wood from gymnosperm trees such as conifers. The term is opposed to hardwood, which is the wood from angiosperm trees. Characterist ...
lumber Lumber, also known as timber, is wood Wood is a porous and fibrous structural tissue found in the Plant stem, stems and roots of trees and other woody plants. It is an organic materiala natural composite material, composite of cellulos ...
and
paper Paper is a thin sheet material Material is a substance Substance may refer to: * Substance (Jainism), a term in Jain ontology to denote the base or owner of attributes * Chemical substance, a material with a definite chemical composition * ...

paper
production.


Evolutionary history

The earliest conifers appear in the fossil record during the Late
Carboniferous The Carboniferous ( ) is a geologic period A geological period is one of the several subdivisions of geologic time enabling cross-referencing of rocks and geologic events from place to place. These periods form elements of a hierarchy of divisi ...
( Pennsylvanian), over 300 million years ago. Conifers have been suggested to be most closely related to the
Cordaitales Cordaitales are an extinct order of woody plants that may have been early conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyt ...
'','' a group of Carboniferous-Permian trees and clambering plants whose reproductive structures have some similarities to those of conifers. The most primitive conifers belong to the paraphyletic assemblage of "", which were small trees, and probably originated in dry upland habitats. The range of conifers expanded during the Early
Permian The Permian ( ) is a and which spans 47 million years from the end of the Period million years ago (Mya), to the beginning of the Period 251.902 Mya. It is the last period of the Era; the following Triassic Period belongs to the Era. The c ...
(
Cisuralian The Cisuralian is the first series/ epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the western slopes of the Ural Mountains in Russia and Kazakhstan ...
) to lowlands due to increasing aridity. Walchian conifers were gradually replaced by more advanced voltzialean or "transition" conifers. Conifers were largely unaffected by the
Permian–Triassic extinction event The Permian–Triassic extinction event, also known as the P–Tr extinction, the P–T extinction, the End-Permian Extinction, and colloquially as the Great Dying, formed the boundary between the Permian The Permian ( ) is a geologic period ...
, and were dominant land plants of the
Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles and the Age of Conifers, is the second-to-last era of Earth's geological history, lasting from about and comprising the Triassic The Triassic ( ) is a geologic period and system A system ...
era. Modern groups of conifers emerged from the Voltziales during the Late Permian through
Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...
. Conifers underwent a major decline in the
Late Cretaceous The Late Cretaceous (100.5–66 Year#SI prefix multipliers, Ma) is the younger of two epoch (geology), epochs into which the Cretaceous geological period, Period is divided in the geologic time scale. Stratum, Rock strata from this epoch form the ...
corresponding to the explosive
adaptive radiation In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, alters biotic inte ...
of
flowering plant Flowering plants include multiple members of the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greec ...

flowering plant
s.


Taxonomy and naming

''Conifer'' is a Latin word, a compound of ''conus'' (cone) and ''ferre'' (to bear), meaning "the one that bears (a) cone(s)". The division name Pinophyta conforms to the rules of the ''
International Code of Nomenclature for algae, fungi, and plants The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) is the set of rules and recommendations dealing with the formal botanical name A botanical name is a formal scientific name Science (from the Latin Latin (, ...
(ICN)'', which state (Article 16.1) that the names of higher
taxa In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular interactions, Physiology, physiological mechanism ...
in plants (above the rank of family) are either formed from the name of an included family (usually the most common and/or representative), in this case
Pinaceae The Pinaceae, pine family, are conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Con ...

Pinaceae
(the
pine A pine is any conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The divi ...

pine
family), or are descriptive. A descriptive name in widespread use for the conifers (at whatever rank is chosen) is Coniferae (Art 16 Ex 2). According to the ''ICN'', it is possible to use a name formed by replacing the termination ''-aceae'' in the name of an included family, in this case preferably
Pinaceae The Pinaceae, pine family, are conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Con ...

Pinaceae
, by the appropriate termination, in the case of this division ''-ophyta''. Alternatively, " descriptive botanical names" may also be used at any
rank Rank is the relative position, value, worth, complexity, power, importance, authority, level, etc. of a person or object within a ranking A ranking is a relationship between a set of items such that, for any two items, the first is either "ranked ...
above family. Both are allowed. This means that if conifers are considered a division, they may be called Pinophyta or Coniferae. As a class, they may be called Pinopsida or Coniferae. As an order they may be called Pinales or Coniferae or Coniferales. Conifers are the largest and economically most important component group of the gymnosperms, but nevertheless they comprise only one of the four groups. The division Pinophyta consists of just one class, Pinopsida, which includes both living and fossil taxa. Subdivision of the living conifers into two or more orders has been proposed from time to time. The most commonly seen in the past was a split into two orders,
Taxales The fleshy aril which surrounds each seed in the yew is a highly modified seed cone scale. The plant order Taxales was until recently treated as a distinct order in the division Pinophyta, class Pinopsida, and included only those species in the fam ...
(Taxaceae only) and
Pinales The order Order or ORDER or Orders may refer to: * Orderliness Orderliness is associated with other qualities such as cleanliness Cleanliness is both the abstract state of being clean and free from germs, dirt, trash, or waste, and the habit of ...

Pinales
(the rest), but recent research into
DNA sequences A nucleic acid sequence is a succession of bases signified by a series of a set of five different letters that indicate the order of nucleotides Nucleotides are organic molecules , CH4; is among the simplest organic compounds. In chemistry, ...
suggests that this interpretation leaves the Pinales without Taxales as
paraphyletic In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and all descendants of that ancestor excluding a few—typically only one or two—Monophyly, monophyletic subgroups. The group is said to be paraphyleti ...

paraphyletic
, and the latter order is no longer considered distinct. A more accurate subdivision would be to split the class into three orders, Pinales containing only Pinaceae, Araucariales containing Araucariaceae and Podocarpaceae, and Cupressales containing the remaining families (including Taxaceae), but there has not been any significant support for such a split, with the majority of opinion preferring retention of all the families within a single order Pinales, despite their antiquity and diverse
morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology) In archaeology, morphology is the study of the shape of Artifact (archaeology), artefacts and ecofacts. Morphology is a major consid ...
. , the conifers were accepted as composed of seven families, with a total of 65–70 genera and 600–630 species (696 accepted names). The seven most distinct families are linked in the box above right and phylogenetic diagram left. In other interpretations, the
Cephalotaxaceae Cephalotaxaceae is a small grouping of conifers, that included one to three genera closely allied to Taxaceae. However, members of Cephalotaxaceae are now included in Taxaceae by botanists, instead of as a distinct family, based on phylogenetic evi ...
may be better included within the Taxaceae, and some authors additionally recognize Phyllocladaceae as distinct from Podocarpaceae (in which it is included here). The family
Taxodiaceae Taxodiaceae is a formerly recognized conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains ...
is here included in family Cupressaceae, but was widely recognized in the past and can still be found in many field guides. A new classification and linear sequence based on molecular data can be found in an article by Christenhusz et al.Christenhusz, M.J.M., Reveal, J., Farjon, A., Gardner, M.F., Mill, R.R. & Chase, M.W. (2011) A new classification and linear sequence of extant gymnosperms. Phytotaxa 19: 55–70. The conifers are an ancient group, with a
fossil A fossil (from Classical Latin Classical Latin is the form of Latin language Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication used by humans, inc ...

fossil
record extending back about 300 million years to the
Paleozoic The Paleozoic (or Palaeozoic) Era ( ; from the Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Eu ...
in the late
Carboniferous The Carboniferous ( ) is a geologic period A geological period is one of the several subdivisions of geologic time enabling cross-referencing of rocks and geologic events from place to place. These periods form elements of a hierarchy of divisi ...
period; even many of the modern genera are recognizable from fossils 60–120 million years old. Other classes and orders, now long extinct, also occur as fossils, particularly from the late Paleozoic and
Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles and the Age of Conifers, is the second-to-last era of Earth's geological history, lasting from about and comprising the Triassic The Triassic ( ) is a geologic period and system A system ...
eras. Fossil conifers included many diverse forms, the most dramatically distinct from modern conifers being some
herb In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables Vegetables are parts of plants that are consumed by humans or other animals as food. The original meaning is still commonly used and is app ...

herb
aceous conifers with no woody stems. Major fossil orders of conifers or conifer-like plants include the
Cordaitales Cordaitales are an extinct order of woody plants that may have been early conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyt ...
, Vojnovskyales,
Voltziales Voltziales is an extinct order of conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains ...
and perhaps also the Czekanowskiales (possibly more closely related to the
Ginkgo ''Ginkgo'' is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (taxonomy), circums ...

Ginkgo
phyta).


Morphology

All living conifers are woody plants, and most are trees, the majority having monopodial growth form (a single, straight trunk with side branches) with strong
apical dominance In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Anc ...
. Many conifers have distinctly scented
resin In polymer chemistry Polymer chemistry is a sub-discipline of chemistry Chemistry is the study of the properties and behavior of . It is a that covers the that make up matter to the composed of s, s and s: their composition, stru ...

resin
, secreted to protect the tree against
insect Insects (from Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication Communication (from Latin ''communicare'', meaning "to share" or "to be in ...

insect
infestation and
fungal A fungus (plural The plural (sometimes list of glossing abbreviations, abbreviated ), in many languages, is one of the values of the grammatical number, grammatical category of number. The plural of a noun typically denotes a quantity great ...

fungal
infection of wounds. Fossilized resin hardens into
amber Amber is fossil A fossil (from Classical Latin Classical Latin is the form of Latin language Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communi ...

amber
. The size of mature conifers varies from less than one metre, to over 100 metres. The world's tallest, thickest, largest, and oldest living trees are all conifers. The tallest is a
Coast Redwood ''Sequoia sempervirens'' ''Sunset Western Garden Book,'' 1995:606–607 is the sole living species of the genus ''Sequoia (genus), Sequoia'' in the cypress family (biology), family Cupressaceae (formerly treated in Taxodiaceae). Common names i ...

Coast Redwood
(''Sequoia sempervirens''), with a height of 115.55 metres (although one Victorian mountain ash, ''
Eucalyptus regnans ''Eucalyptus regnans'', known variously as mountain ash, swamp gum, or stringy gum, is a species of medium-sized to very tall forest tree that is native to Tasmania and Victoria, Australia. It is a straight-trunked tree with smooth grey bark, bu ...
'', allegedly grew to a height of 140 metres, although the exact dimensions were not confirmed). The thickest, meaning the tree with the greatest trunk diameter, is a (''Taxodium mucronatum''), 11.42 metres in diameter. The largest tree by three-dimensional volume is a Giant Sequoia (''
Sequoiadendron giganteum ''Sequoiadendron giganteum'' (giant sequoia; also known as giant redwood, Sierra redwood, Sierran redwood, Wellingtonia or simply big treea nickname also used by John Muir) is the sole living species in the genus ''Sequoiadendron'', and one of th ...

Sequoiadendron giganteum
''), with a volume 1486.9 cubic metres. The smallest is the pygmy pine (''Lepidothamnus laxifolius'') of New Zealand, which is seldom taller than 30 cm when mature. The oldest is a Great Basin Bristlecone Pine (''
Pinus longaeva ''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 Califo ...

Pinus longaeva
''), 4,700 years old.


Foliage

Since most conifers are evergreens, the
leaves A leaf (plural leaves) is the principal lateral appendage of the vascular plant plant stem, stem, usually borne above ground and specialized for photosynthesis. The leaves, stem, flower and fruit together form the shoot system. Leaves are ...

leaves
of many conifers are long, thin and have a needle-like appearance, but others, including most of the
Cupressaceae Cupressaceae is a conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The ...

Cupressaceae
and some of the
Podocarpaceae Podocarpaceae is a large family In human society A society is a Social group, group of individuals involved in persistent Social relation, social interaction, or a large social group sharing the same spatial or social territory, ty ...
, have flat, triangular scale-like leaves. Some, notably ''
Agathis ''Agathis'', commonly known as kauri or dammara, is a genus Genus (plural genera) is a taxonomic rank Taxonomy (general) is the practice and science of classification of things or concepts, including the principles that underlie such class ...
'' in Araucariaceae and ''
Nageia ''Nageia'' is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (taxonomy), circumscr ...
'' in Podocarpaceae, have broad, flat strap-shaped leaves. Others such as ''
Araucaria columnaris ''Araucaria columnaris'', the coral reef araucaria, Cook pine, New Caledonia pine, Cook araucaria, or columnar araucaria, is a species of conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they ...

Araucaria columnaris
'' have leaves that are awl-shaped. In the majority of conifers, the leaves are arranged spirally, exceptions being most of Cupressaceae and one genus in Podocarpaceae, where they are arranged in decussate opposite pairs or whorls of 3 (−4). In many species with spirally arranged leaves, such as ''
Abies grandis ''Abies grandis'' (grand fir, giant fir, lowland white fir, great silver fir, western white fir, Vancouver fir, or Oregon fir) is a fir native to the Pacific Northwest and Northern California Northern California (colloquially known as NorCa ...
'' (pictured), the leaf bases are twisted to present the leaves in a very flat plane for maximum light capture. Leaf size varies from 2 mm in many scale-leaved species, up to 400 mm long in the needles of some pines (e.g. Apache Pine, ''
Pinus engelmannii ''Pinus engelmannii'', commonly known as the Apache pine, is a tree In botany, a tree is a perennial plant with an elongated Plant stem, stem, or trunk (botany), trunk, supporting branches and leaves in most species. In some usages, the d ...
''). The
stoma File:LeafUndersideWithStomata.jpg, The underside of a leaf. In this species (''Tradescantia zebrina'') the guard cells of the stomata are green because they contain chlorophyll while the epidermal cells are chlorophyll-free and contain red pigme ...

stoma
ta are in lines or patches on the leaves and can be closed when it is very dry or cold. The leaves are often dark green in colour, which may help absorb a maximum of energy from weak sunshine at high
latitude In geography Geography (from Greek: , ''geographia'', literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, and phenomena of the Earth and planets. The first person to use the ...

latitude
s or under forest canopy shade. Conifers from hotter areas with high sunlight levels (e.g. Turkish Pine ''
Pinus brutia ''Pinus brutia'', commonly known as the Turkish pine, is a species of pine A pine is any Pinophyta, conifer in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The Plant Li ...
'') often have yellower-green leaves, while others (e.g.
blue spruce The blue spruce (''Picea pungens''), also commonly known as green spruce, white spruce, Colorado spruce, or Colorado blue spruce, is a species In biology, a species is the basic unit of biological classification, classification and a taxono ...
, ''Picea pungens'') may develop blue or silvery leaves to reflect
ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior through Spacetime, ...

ultraviolet
light. In the great majority of genera the leaves are
evergreen In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Anc ...

evergreen
, usually remaining on the plant for several (2–40) years before falling, but five genera (''
Larix Larches are deciduous In the fields of horticulture Horticulture is the art of cultivating plants in gardens to produce food and medicinal ingredients, or for comfort and ornamental purposes. Horticulturists grow flowers, fruits and nuts, v ...

Larix
'', ''
Pseudolarix ''Pseudolarix'' is a genus Genus (plural genera) is a taxonomic rank Taxonomy (general) is the practice and science of classification of things or concepts, including the principles that underlie such classification. The term may also refer t ...
'', ''
Glyptostrobus ''Glyptostrobus'', is a small genus Genus (plural genera) is a taxonomic rank Taxonomy (general) is the practice and science of classification of things or concepts, including the principles that underlie such classification. The term may als ...
'', ''
Metasequoia ''Metasequoia'', or dawn redwoods, is a genus of fast-growing deciduous In the fields of horticulture Horticulture is the art of cultivating plants in gardens to produce food and medicinal ingredients, or for comfort and ornamental purpo ...

Metasequoia
'' and ''
Taxodium ''Taxodium'' is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology Biology is the natural science that studies life and living organisms, including thei ...
'') are
deciduous In the fields of horticulture Horticulture is the art of cultivating plants in gardens to produce food and medicinal ingredients, or for comfort and ornamental purposes. Horticulturists are agriculturists who grow flowers, fruits and nuts, ...
, shedding their leaves in autumn. The seedlings of many conifers, including most of the Cupressaceae, and ''Pinus'' in Pinaceae, have a distinct juvenile foliage period where the leaves are different, often markedly so, from the typical adult leaves.


Tree ring structure

Tree rings Dendrochronology (or tree-ring dating) is the scientific method The scientific method is an Empirical evidence, empirical method of acquiring knowledge that has characterized the development of science since at least the 17th century. It in ...

Tree rings
are records of the
influence Influence or influencer may refer to: *Social influence, in social psychology, influence in interpersonal relationships **Minority influence, when the minority affect the behavior or beliefs of the majority *Influencer marketing, through individua ...
of
environmental A biophysical environment is a life, biotic and Abiotic component, abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environ ...
conditions, their anatomical characteristics record growth rate changes produced by these changing conditions. The microscopic
structure A structure is an arrangement and organization of interrelated elements in a material object or system A system is a group of Interaction, interacting or interrelated elements that act according to a set of rules to form a unified whole. ...

structure
of conifer wood consists of two types of
cells Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Closed spaces * Monastic cell, a small room, hut, or cave in which a monk or religious recluse lives * Prison cell, a room used to hold peopl ...
: parenchyma, which have an oval or polyhedral shape with approximately identical dimensions in three directions, and strongly elongated tracheids. Tracheids make up more than 90% of timber volume. The tracheids of earlywood formed at the beginning of a
growing season A season A season is a division of the year based on changes in weather Weather is the state of the atmosphere An atmosphere (from the greek words ἀτμός ''(atmos)'', meaning 'vapour', and σφαῖρα ''(sphaira)'', meani ...
have large radial sizes and smaller, thinner
cell wall A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane cell membrane vs. Prokaryotes The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to a ...
s. Then, the first tracheids of the transition zone are formed, where the radial size of cells and thickness of their cell walls changes considerably. Finally, the latewood tracheids are formed, with small radial sizes and greater cell wall thickness. This is the basic
pattern A pattern is a regularity in the world, in human-made design, or in abstract ideas. As such, the elements of a pattern repeat in a predictable manner. A geometric pattern is a kind of pattern formed of geometric Geometry (from the grc, ...

pattern
of the internal cell structure of conifer tree rings.


Reproduction

Most conifers are
monoecious Monoecy (; adjective form: monoecious ) is a sexual system A sexual system is a pattern of sex allocationSex allocation is the allocation of resources to male versus female reproduction in sexual species.Charnov EL. (1982). ''The Theory of Sex A ...

monoecious
, but some are or
dioecious Dioecy (; Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is approximately 1 ...

dioecious
; all are
wind-pollinated Anemophily or wind pollination is a form of pollination Pollination is the transfer of pollen Pollen Tube Diagram Pollen is a powdery substance consisting of pollen grains which are male microgametophytes of seed plants, which produce mal ...
. Conifer seeds develop inside a protective cone called a
strobilus A strobilus (plural: strobili) is a structure present on many land plant Plants are predominantly photosynthetic Photosynthesis is a process used by plants and other organisms to Energy transformation, convert light energy into chemical ...
. The cones take from four months to three years to reach maturity, and vary in size from 2 mm to 600 mm long. In
Pinaceae The Pinaceae, pine family, are conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Con ...

Pinaceae
,
Araucariaceae Araucariaceae – also known as araucarians – is a very ancient family of conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinop ...
,
Sciadopityaceae ''Sciadopitys verticillata'', the or Japanese umbrella-pine, is a unique conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyt ...
and most
Cupressaceae Cupressaceae is a conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The ...

Cupressaceae
, the cones are
wood Wood is a porous and fibrous structural tissue found in the stems and roots of tree In botany, a tree is a perennial plant with an elongated Plant stem, stem, or trunk (botany), trunk, supporting branches and leaves in most species. ...

wood
y, and when mature the scales usually spread open allowing the seeds to fall out and be dispersed by the
wind Wind is the natural movement of air or other gases relative to a planet's surface. Wind occurs on a range of scales, from thunderstorm A thunderstorm, also known as an electrical storm or a lightning storm, is a storm characterized by th ...

wind
. In some (e.g.
fir Firs (''Abies'') are a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology Biology is the natural science that studies life and living organisms, including ...

fir
s and cedars), the cones disintegrate to release the seeds, and in others (e.g. the
pine A pine is any conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The divi ...

pine
s that produce
pine nut Pine nuts, also called piñón (), pinoli (), or pignoli, are the edible seed A seed is an embryonic plant enclosed in a protective outer covering. The formation of the seed is part of the process of reproduction Reproduction (or procr ...
s) the nut-like seeds are dispersed by
bird Birds are a group of warm-blooded vertebrate Vertebrates () comprise all species of animal Animals (also called Metazoa) are multicellular eukaryotic organisms that form the Kingdom (biology), biological kingdom Animalia. With ...

bird
s (mainly
nutcracker A nutcracker is a designed to open by cracking their shells. There are many designs, including levers, screws, and ratchets. The lever version is also used for cracking and shells. A decorative version portrays a person whose mouth forms the ...
s, and
jay A jay is any of several species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of ...

jay
s), which break up the specially adapted softer cones. Ripe cones may remain on the plant for a varied amount of time before falling to the ground; in some fire-adapted pines, the seeds may be stored in closed cones for up to 60–80 years, being released only when a fire kills the parent tree. In the families
Podocarpaceae Podocarpaceae is a large family In human society A society is a Social group, group of individuals involved in persistent Social relation, social interaction, or a large social group sharing the same spatial or social territory, ty ...
,
Cephalotaxaceae Cephalotaxaceae is a small grouping of conifers, that included one to three genera closely allied to Taxaceae. However, members of Cephalotaxaceae are now included in Taxaceae by botanists, instead of as a distinct family, based on phylogenetic evi ...
,
Taxaceae Taxaceae (), commonly called the yew family, is a conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Co ...

Taxaceae
, and one
Cupressaceae Cupressaceae is a conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The ...

Cupressaceae
genus (''
Juniper Junipers are conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The divi ...

Juniper
us''), the scales are soft, fleshy, sweet, and brightly colored, and are eaten by fruit-eating birds, which then pass the seeds in their droppings. These fleshy scales are (except in ''Juniperus'') known as
aril An aril (pronounced ), also called an arillus, is a specialized outgrowth from a seed that partly or completely covers the seed. An arillode or false aril is sometimes distinguished: whereas an aril grows from the attachment point of the seed ...

aril
s. In some of these conifers (e.g. most Podocarpaceae), the cone consists of several fused scales, while in others (e.g. Taxaceae), the cone is reduced to just one seed scale or (e.g. Cephalotaxaceae) the several scales of a cone develop into individual arils, giving the appearance of a cluster of berries. The male cones have structures called
microsporangia Microsporangia are sporangia that produce microspores that give rise to male gametophytes when they germinate. Microsporangia occur in all vascular plants that have Heterospory, heterosporic life cycles, such as Spermatophyte, seed plants, Selagin ...
that produce yellowish pollen through meiosis. Pollen is released and carried by the wind to female cones. Pollen grains from living pinophyte species produce pollen tubes, much like those of angiosperms. The
gymnosperm The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also ...
male gametophytes (pollen grains) are carried by wind to a female cone and are drawn into a tiny opening on the ovule called the
micropyleMicropyle may refer to: * Micropyle (botany) a minute opening in the integument of an ovule of a seed plant. * Micropyle (zoology), a differentiated area of surface in an egg, through which a sperm enters {{Disambiguation ...
. It is within the ovule that pollen-germination occurs. From here, a pollen tube seeks out the female gametophyte, which contains archegonia each with an egg, and if successful, fertilization occurs. The resulting
zygote A zygote (, ) is a eukaryotic Eukaryotes () are organism In biology, an organism () is any organic, life, living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are ...

zygote
develops into an
embryo An embryo is the early stage of development of a multicellular organism A multicellular organism is an organism In biology, an organism () is any organic, life, living system that functions as an individual entity. All organisms ar ...

embryo
, which along with the female gametophyte (nutritional material for the growing embryo) and its surrounding integument, becomes a
seed A seed is an embryonic ''Embryonic'' is the twelfth studio album by experimental rock band the Flaming Lips released on October 13, 2009, on Warner Bros. Records, Warner Bros. The band's first double album, it was released to generally positi ...

seed
. Eventually, the seed may fall to the ground and, if conditions permit, grow into a new plant. In
forestry Forestry is the science and craft of creating, managing, planting, using, conserving and repairing forest A forest is an area of land dominated by tree In botany, a tree is a perennial plant with an elongated Plant stem, ste ...
, the terminology of
flowering plant Flowering plants include multiple members of the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greec ...

flowering plant
s has commonly though inaccurately been applied to cone-bearing trees as well. The male cone and unfertilized female cone are called ''male flower'' and ''female flower'', respectively. After fertilization, the female cone is termed ''fruit'', which undergoes ''ripening'' (maturation). It was found recently that the
pollen Pollen is a powdery substance consisting of pollen grains which are microsporophytes of seed plants The spermatophytes (; ), also known as phanerogams (taxon Phanerogamae) or phaenogams (taxon Phaenogamae), comprise those plant Plant ...

pollen
of conifers transfers the
mitochondria A mitochondrion (; ) is a double-membrane A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Biological membranes include cell membranes ...

mitochondria
l
organelle In cell biology Cell biology (also cellular biology or cytology) is a branch of biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, ...
s to the
embryo An embryo is the early stage of development of a multicellular organism A multicellular organism is an organism In biology, an organism () is any organic, life, living system that functions as an individual entity. All organisms ar ...

embryo
, a sort of
meiotic Meiosis (; , because it is a reductional division) is a special type of cell division of germ cells in Sexual reproduction, sexually-reproducing organisms used to produce the gametes, such as sperm or egg cells. It involves two rounds of divi ...

meiotic
drive that perhaps explains why ''
Pinus A pine is any conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The di ...

Pinus
'' and other conifers are so productive, and perhaps also has bearing on observed sex-ratio bias. File:Abies lasiocarpa 6972.JPG, Pinaceae: unopened female cones of
subalpine fir ''Abies lasiocarpa'', the subalpine fir or Rocky Mountain fir, is a western North America North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere. It can also be described as the ...
(''Abies lasiocarpa'') Taxus baccata MHNT.jpg, Taxaceae: the fleshy aril that surrounds each seed in the (''Taxus baccata'') is a highly modified seed cone scale Immature fir cone.jpg, Pinaceae: pollen cone of a
Japanese Larch ''Larix kaempferi'', the Japanese larch or karamatsu () in Japanese, is a species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A ...
(''Larix kaempferi'')


Life cycle

Conifers are
heterosporous Heterospory is the production of spores )'', growing on a thinning, thinned hybrid black poplar ''(populus, Populus x canadensis)''. The last stage of the moss#Life cycle, moss lifecycle is shown, where the sporophytes are visible before dispe ...
, generating two different types of spores: male
microspore Microspores are land plant The Embryophyta (), or land plants, are the most familiar group of green plant Plants are predominantly photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encomp ...
s and female
megaspore Megaspores, also called macrospores, are a type of spore )'', growing on a thinned hybrid black poplar ''(Populus x canadensis)''. The last stage of the moss lifecycle is shown, where the sporophytes are visible before dispersion of their sp ...

megaspore
s. These spores develop on separate male and female
sporophylls A sporophyll is a leaf that bears sporangia. Both microphylls and megaphylls can be sporophylls. In heterosporous plants, sporophylls (whether they are microphylls or megaphylls) bear either megasporangia and thus are called megasporophylls, or mic ...
on separate male and female cones. In the male cones, microspores are produced from microsporocytes by
meiosis Meiosis (; , because it is a reductional division) is a special type of of in organisms used to produce the , such as or . It involves two rounds of division that ultimately result in four cells with only one copy of each (). Additionall ...

meiosis
. The microspores develop into pollen grains, which are male gametophytes. Large amounts of pollen are released and carried by the wind. Some pollen grains will land on a female cone for pollination. The generative cell in the pollen grain divides into two
haploid Ploidy () is the number of complete sets of chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. Most eukaryotic chromosomes include packaging proteins called histones which, aided by ...
sperm cells by
mitosis In cell biology Cell biology (also cellular biology or cytology) is a branch of biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical proce ...

mitosis
leading to the development of the pollen tube. At fertilization, one of the sperm cells unites its haploid nucleus with the haploid nucleus of an egg cell. The female cone develops two ovules, each of which contains haploid megaspores. A megasporocyte is divided by meiosis in each ovule. Each winged pollen grain is a four celled male
gametophyte A gametophyte () is one of the two alternating multicellular phases in the life cycles of plant Plants are predominantly photosynthetic Photosynthesis is a process used by plants and other organisms to Energy transformation, convert ...
. Three of the four cells break down leaving only a single surviving cell which will develop into a female
multicellular A multicellular organism is an organism In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular ...

multicellular
gametophyte. The female gametophytes grow to produce two or more
archegonia Image:Archegonium.jpg, 240px, Diagram of archegonium anatomy An archegonium (pl: archegonia), from the ancient Greek ''ἀρχή'' ("beginning") and ''γόνος'' ("offspring"), is a multicellular structure or organ of the gametophyte phase of cert ...
, each of which contains an egg. Upon fertilization, the
diploid Ploidy () is the number of complete sets of chromosomes in a cell (biology), cell, and hence the number of possible alleles for Autosome, autosomal and Pseudoautosomal region, pseudoautosomal genes. Sets of chromosomes refer to the number of mate ...
egg will give rise to the embryo, and a seed is produced. The female cone then opens, releasing the seeds which grow to a young
seedling A seedling is a young sporophyte 350px, Sporophytes of moss during spring A sporophyte () is the diploid Ploidy () is the number of complete sets of chromosome A chromosome is a long DNA molecule with part or all of the genetic ...

seedling
. # To fertilize the ovum, the male cone releases
pollen Pollen is a powdery substance consisting of pollen grains which are microsporophytes of seed plants The spermatophytes (; ), also known as phanerogams (taxon Phanerogamae) or phaenogams (taxon Phaenogamae), comprise those plant Plant ...

pollen
that is carried on the wind to the female cone. This is
pollination Pollination is the transfer of pollen Pollen is a powdery substance consisting of pollen grains which are Sporophyte, microsporophytes of spermatophyta, seed plants, which produce male gametes (sperm cells). Pollen grains have a hard coat ...

pollination
. (Male and female cones usually occur on the same plant.) # The pollen fertilizes the female gamete (located in the female cone). Fertilization in some species does not occur until 15 months after pollination. # A fertilized female gamete (called a
zygote A zygote (, ) is a eukaryotic Eukaryotes () are organism In biology, an organism () is any organic, life, living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are ...

zygote
) develops into an
embryo An embryo is the early stage of development of a multicellular organism A multicellular organism is an organism In biology, an organism () is any organic, life, living system that functions as an individual entity. All organisms ar ...

embryo
. # A
seed A seed is an embryonic ''Embryonic'' is the twelfth studio album by experimental rock band the Flaming Lips released on October 13, 2009, on Warner Bros. Records, Warner Bros. The band's first double album, it was released to generally positi ...

seed
develops which contains the embryo. The seed also contains the integument cells surrounding the embryo. This is an evolutionary characteristic of the
Spermatophyta The spermatophytes, also known as phanerogams (taxon Phanerogamae) or phaenogams (taxon Phaenogamae), comprise those plant Plants are mainly multicellular organisms, predominantly photosynthetic Photosynthesis is a process used by plan ...

Spermatophyta
. # Mature seed drops out of cone onto the ground. # Seed germinates and seedling grows into a mature plant. # When the plant is mature, it produces cones and the cycle continues.


Female reproductive cycles

Conifer reproduction is synchronous with seasonal changes in temperate zones. Reproductive development slows to a halt during each winter season and then resumes each spring. The male
strobilus A strobilus (plural: strobili) is a structure present on many land plant Plants are predominantly photosynthetic Photosynthesis is a process used by plants and other organisms to Energy transformation, convert light energy into chemical ...
development is completed in a single year. Conifers are classified by three reproductive cycles that refer to the completion of female strobilus development from initiation to seed maturation. All three types of reproductive cycle have a long gap between
pollination Pollination is the transfer of pollen Pollen is a powdery substance consisting of pollen grains which are Sporophyte, microsporophytes of spermatophyta, seed plants, which produce male gametes (sperm cells). Pollen grains have a hard coat ...

pollination
and
fertilization Fertilisation or fertilization (see American and British English spelling differences#-ise.2C -ize .28-isation.2C -ization.29, spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes ...

fertilization
. One year reproductive cycle:The genera include ''
Abies Firs (''Abies'') are a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, vi ...

Abies
'', ''
Picea A spruce is a tree of the genus ''Picea'' , a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal ecosystem, boreal (taiga) regions of the Earth. ''Picea'' is the sole genus ...

Picea
'', ''
Cedrus ''Cedrus'', common English name cedar, is a genus of conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as ...
'', ''
Pseudotsuga ''Pseudotsuga'' is a genus of evergreen In botany Botany, also called , plant biology or phytology, is the science Science (from the Latin word ''scientia'', meaning "knowledge") is a systematic enterprise that Scientific method, ...
,'' ''
Tsuga ''Tsuga'' (, from Japanese Japanese may refer to: * Something from or related to Japan , image_flag = Flag of Japan.svg , alt_flag = Centered deep red circle on a white rectangle , image_coat ...
'', '' Keteleeria'' ''(
Pinaceae The Pinaceae, pine family, are conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Con ...

Pinaceae
)'' and ''
Cupressus ''Cupressus'' is one of several genera Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (tax ...
,
Thuja ''Thuja'' ( ) is a genus of conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a sing ...

Thuja
,
Cryptomeria ''Cryptomeria'' (literally "hidden parts") is a monotypic In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biol ...

Cryptomeria
,
Cunninghamia ''Cunninghamia'' is a genus of one or two living species of evergreen In botany Botany, also called , plant biology or phytology, is the science Science (from the Latin word ''scientia'', meaning "knowledge") is a systematic enterp ...

Cunninghamia
'' and '' Sequoia (
Cupressaceae Cupressaceae is a conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The ...

Cupressaceae
)''. Female strobili are initiated in late summer or fall in a year, then they overwinter. Female strobili emerge followed by pollination in the following spring. Fertilization takes place in summer of the following year, only 3–4 months after pollination. Cones mature and seeds are then shed by the end of that same year. Pollination and fertilization occur in a single growing season.Singh, H. 1978. Embryology of gymnosperms. Berlin, Gebruder Borntraeger. Two-year reproductive cycle:The genera includes ''
Widdringtonia ''Widdringtonia'' is a genus of conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a ...
'', ''
Sequoiadendron ''Sequoiadendron'' is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (taxonomy), ci ...

Sequoiadendron
'' (''
Cupressaceae Cupressaceae is a conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The ...

Cupressaceae
'') and most species of ''Pinus''. Female
strobilus A strobilus (plural: strobili) is a structure present on many land plant Plants are predominantly photosynthetic Photosynthesis is a process used by plants and other organisms to Energy transformation, convert light energy into chemical ...
initials are formed in late summer or fall then overwinter. Female strobili emerge and receive pollen in the first year spring and become conelets. The conelet goes through another winter rest and, in the spring of the 2nd year
archegonia Image:Archegonium.jpg, 240px, Diagram of archegonium anatomy An archegonium (pl: archegonia), from the ancient Greek ''ἀρχή'' ("beginning") and ''γόνος'' ("offspring"), is a multicellular structure or organ of the gametophyte phase of cert ...
form in the conelet. Fertilization of the
archegonia Image:Archegonium.jpg, 240px, Diagram of archegonium anatomy An archegonium (pl: archegonia), from the ancient Greek ''ἀρχή'' ("beginning") and ''γόνος'' ("offspring"), is a multicellular structure or organ of the gametophyte phase of cert ...
occurs by early summer of the 2nd year, so the pollination-fertilization interval exceeds a year. After fertilization, the conelet is considered an immature cone. Maturation occurs by autumn of the 2nd year, at which time seeds are shed. In summary, the 1-year and the 2-year cycles differ mainly in the duration of the pollination- fertilization interval. Three-year reproductive cycle: Three of the conifer species are
pine A pine is any conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The divi ...

pine
species (''
Pinus pinea The stone pine, botanical name ''Pinus pinea'', also known as the Italian stone pine, umbrella pine and parasol pine, is a tree from the pine family (''Pinaceae''). The tree is native plant, native to the Mediterranean region, occurring in Sout ...

Pinus pinea
'', ''
Pinus leiophylla ''Pinus leiophylla'', commonly known as Chihuahua pine, smooth-leaf pine,''Pinus leiophylla'' was originally described and published in ''Linnaea'' 6:354. 1831. and yellow pine (in Mexico Mexico ( es, México ; Nahuan languages: ), officia ...
'', ''
Pinus torreyana The Torrey pine, ''Pinus torreyana'', is a rare pine A pine is any Pinophyta, conifer in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The Plant List compiled by the Ro ...

Pinus torreyana
'') which have pollination and fertilization events separated by a 2-year interval. Female strobili initiated during late summer or autumn in a year, then overwinter until the following spring. Female
strobili A strobilus (plural: strobili) is a structure present on many land plant species consisting of sporangia-bearing structures densely aggregated along a stem. Strobili are often called cones, but some botanists restrict the use of the term cone to t ...
emerge then pollination occurs in spring of the 2nd year then the pollinated
strobili A strobilus (plural: strobili) is a structure present on many land plant species consisting of sporangia-bearing structures densely aggregated along a stem. Strobili are often called cones, but some botanists restrict the use of the term cone to t ...
become conelets in the same year (i.e. the second year). The female
gametophytes A gametophyte () is one of the two alternating multicellular phases in the life cycles of plant Plants are mainly multicellular organisms, predominantly photosynthetic Photosynthesis is a process used by plants and other organisms ...
in the conelet develop so slowly that the
megaspore Megaspores, also called macrospores, are a type of spore )'', growing on a thinned hybrid black poplar ''(Populus x canadensis)''. The last stage of the moss lifecycle is shown, where the sporophytes are visible before dispersion of their sp ...

megaspore
does not go through free-nuclear divisions until autumn of the 3rd year. The conelet then overwinters again in the free-nuclear female
gametophyte A gametophyte () is one of the two alternating multicellular phases in the life cycles of plant Plants are predominantly photosynthetic Photosynthesis is a process used by plants and other organisms to Energy transformation, convert ...
stage. Fertilization takes place by early summer of the 4th year and seeds mature in the cones by autumn of the 4th year.


Tree development

The growth and form of a forest tree are the result of activity in the primary and secondary
meristem The meristem is a type of tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a species of geometer moth found in North America * ''Triphosa du ...
s, influenced by the distribution of photosynthate from its needles and the hormonal gradients controlled by the apical meristems (Fraser et al. 1964).Fraser, D.A.; Belanger, L.; McGuire, D.; Zdrazil, Z. 1964. Total growth of the aerial parts of a white spruce tree at Chalk River, Ontario, Canada. Can. J. Bot. 42:159–179. External factors also influence growth and form. Fraser recorded the development of a single white spruce tree from 1926 to 1961. Apical growth of the stem was slow from 1926 through 1936 when the tree was competing with
herb In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables Vegetables are parts of plants that are consumed by humans or other animals as food. The original meaning is still commonly used and is app ...

herb
s and
shrub A shrub (often called a bush) is a small- to medium-sized perennial A perennial plant or simply perennial is a plant Plants are predominantly photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the p ...

shrub
s and probably shaded by larger trees. Lateral branches began to show reduced growth and some were no longer in evidence on the 36-year-old tree. Apical growth totaling about 340 m, 370 m, 420 m, 450 m, 500 m, 600 m, and 600 m was made by the tree in the years 1955 through 1961, respectively. The total number of needles of all ages present on the 36-year-old tree in 1961 was 5.25 million weighing 14.25 kg. In 1961, needles as old as 13 years remained on the tree. The ash weight of needles increased progressively with age from about 4% in first-year needles in 1961 to about 8% in needles 10 years old. In discussing the data obtained from the one 11 m tall white spruce, Fraser et al. (1964) speculated that if the photosynthate used in making apical growth in 1961 was manufactured the previous year, then the 4 million needles that were produced up to 1960 manufactured food for about 600,000 mm of apical growth or 730 g dry weight, over 12 million mm3 of wood for the 1961 annual ring, plus 1 million new needles, in addition to new tissue in branches, bark, and roots in 1960. Added to this would be the photosynthate to produce energy to sustain respiration over this period, an amount estimated to be about 10% of the total annual photosynthate production of a young healthy tree. On this basis, one needle produced food for about 0.19 mg dry weight of apical growth, 3 mm3 wood, one-quarter of a new needle, plus an unknown amount of branch wood, bark and roots. The order of priority of photosynthate distribution is probably: first to apical growth and new needle formation, then to buds for the next year's growth, with the cambium in the older parts of the branches receiving sustenance last. In the white spruce studied by Fraser et al. (1964), the needles constituted 17.5% of the over-day weight. Undoubtedly, the proportions change with time.


Seed-dispersal mechanism

Wind and animal dispersals are two major mechanisms involved in the dispersal of conifer seeds. Wind born seed dispersal involves two processes, namely; local neighborhood dispersal (LND) and long-distance dispersal (LDD). Long-distance dispersal distances range from from the source. Birds of the crow family,
Corvidae Corvidae is a cosmopolitan Cosmopolitan may refer to: Food and drink * Cosmopolitan (cocktail), also known as a "Cosmo" History * Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic campaign of 1949–1953 ...

Corvidae
, are the primary distributor of the conifer seeds. These birds are known to
cache Cache, caching, or caché may refer to: Places * Cache (Aosta) Cache is a frazione of the city of Aosta, in the Aosta Valley region of Italy. Frazioni of Aosta Valley Aosta {{Aosta-geo-stub ..., a frazione in Italy * Cache Creek (disambi ...
32,000 pine seeds and transport the seeds as far as from the source. The birds store the seeds in the soil at depths of under conditions which favor
germination Germination is the process by which an organism In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biolog ...

germination
.


Invasive species

A number of conifers originally introduced for forestry have become
invasive species An invasive species is an introduced organism that becomes overpopulated and negatively alters its new environment. Although their spread can have beneficial aspects, invasive species adversely affect the invaded habitat Ibex in an ...
in parts of
New Zealand New Zealand ( mi, Aotearoa ''Aotearoa'' (; commonly pronounced by English English usually refers to: * English language English is a West Germanic languages, West Germanic language first spoken in History of Anglo-Saxon Engl ...

New Zealand
, including radiata pine (''
Pinus radiata ''Pinus radiata'' ( syn. ''Pinus insignis''), the Monterey pine, insignis pine or radiata pine, is a species of pine A pine is any conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnos ...
''), lodgepole pine (''''),
Douglas fir The Douglas fir (''Pseudotsuga menziesii'') is an evergreen In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who ...
(''Pseudotsuga mensiezii'') and European larch (''
Larix decidua ''Larix decidua'', the European larch, is a species of larch Larches are deciduous conifers in the genus ''Larix'', of the family Pinaceae (subfamily Laricoideae). Growing from tall, they are native to much of the cooler temperate northern he ...

Larix decidua
''). In parts of
South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. With over 60 million people, it is the world's 23rd-most populous nation and covers an area of . South Africa has three capital citie ...

South Africa
, maritime pine (''
Pinus pinaster ''Pinus pinaster'', the maritime pine or cluster pine, is a pine A pine is any Pinophyta, conifer in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The Plant List compile ...

Pinus pinaster
''), patula pine ('' P. patula'') and radiata pine have been declared invasive species. These wilding conifers are a serious environmental issue causing problems for pastoral farming and for
conservation Conservation is the preservation or efficient use of resources, or the conservation of various quantities under physical laws. Conservation may also refer to: Environment and natural resources * Nature conservation, the protection and manageme ...
. Radiata pine was introduced to Australia in the 1870s. It is "the dominant tree species in the Australian plantation estate""Fauna conservation in Australian plantation forests: a review"
, May 2007, D.B. Lindenmayer and R.J. Hobbs
– so much so that many Australians are concerned by the resulting loss of native wildlife habitat. The species is widely regarded as an environmental weed across southeastern and southwestern Australia and the removal of individual plants beyond plantations is encouraged.


Predators

At least 20 species of roundheaded borers of the family feed on the wood of
spruce A spruce is a tree of the genus ''Picea'' , a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal ecosystem, boreal (taiga) regions of the Earth. ''Picea'' is the sole genus ...

spruce
,
fir Firs (''Abies'') are a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology Biology is the natural science that studies life and living organisms, including ...

fir
, and
hemlock Hemlock may refer to: Plants *Several poisonous plants in the family Apiaceae **''Cicuta'' (water hemlock) **''Conium'', four species, of which ''maculatum'' is the only endemic outside of southern Africa; in history given to poison and execute p ...
(Rose and Lindquist 1985).Rose, A.H.; Lindquist, O.H. 1985. Insects of eastern spruces, fir and, hemlock, revised edition. Gov’t Can., Can. For. Serv., Ottawa, For. Tech. Rep. 23. 159 p. (cited in Coates et al. 1994, cited orig ed 1977) Borers rarely bore tunnels in living trees, although when populations are high, adult beetles feed on tender twig bark, and may damage young living trees. One of the most common and widely distributed borer species in North America is the (''Monochamus scutellatus''). Adults are found in summer on newly fallen or recently felled trees chewing tiny slits in the bark in which they lay eggs. The eggs hatch in about 2 weeks and the tiny
larva A larva (plural larvae ) is a distinct juvenile form many animal Animals (also called Metazoa) are multicellular A multicellular organism is an organism In biology, an organism () is any organic, life, living system that f ...
e tunnel to the wood and score its surface with their feeding channels. With the onset of cooler weather, they bore into the wood making oval entrance holes and tunnel deeply. Feeding continues the following summer when larvae occasionally return to the surface of the wood and extend the feeding channels generally in a U-shaped configuration. During this time, small piles of frass extruded by the larvae accumulate under logs. Early in the spring of the second year following egg-laying, the larvae, about 30 mm long,
pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insect Insects (from Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communicat ...

pupa
te in the tunnel enlargement just below the wood surface. The resulting adults chew their way out in early summer, leaving round exit holes, so completing the usual 2-year life cycle.


Cultivation

Conifers – notably ''
Abies Firs (''Abies'') are a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, vi ...

Abies
'' (fir), ''
Cedrus ''Cedrus'', common English name cedar, is a genus of conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as ...
'', ''
Chamaecyparis lawsoniana ''Chamaecyparis lawsoniana'', known as Port Orford cedar or Lawson cypress, is a species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodivers ...

Chamaecyparis lawsoniana
'' (Lawson's cypress), ''
Cupressus ''Cupressus'' is one of several genera Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (tax ...
'' (cypress),
juniper Junipers are conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The divi ...

juniper
, ''
Picea A spruce is a tree of the genus ''Picea'' , a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal ecosystem, boreal (taiga) regions of the Earth. ''Picea'' is the sole genus ...

Picea
'' (spruce), ''
Pinus A pine is any conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The di ...

Pinus
'' (pine), ''
Taxus ''Taxus'' is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (taxonomy), circumscri ...

Taxus
'' (yew), ''
Thuja ''Thuja'' ( ) is a genus of conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a sing ...

Thuja
'' (cedar) – have been the subject of selection for ornamental purposes (for more information see the
silviculture Silviculture is the practice of controlling the growth, composition/structure, and quality of forest A forest is an area of land dominated by tree In botany, a tree is a perennial plant with an elongated Plant stem, stem, or trunk ...
page). Plants with unusual growth habits, sizes, and colours are propagated and planted in parks and gardens throughout the world.


Conditions for growth

Conifers can absorb nitrogen in either the
ammonium The ammonium cation An ion () is an atom An atom is the smallest unit of ordinary matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects t ...

ammonium
(NH4+) or
nitrate Nitrate is a polyatomic ion A polyatomic ion, also known as a molecular ion, is a covalently bonded A covalent bond is a chemical bond A chemical bond is a lasting attraction between atoms, ions or molecules that enables the format ...

nitrate
(NO3) form, but the forms are not physiologically equivalent. Form of nitrogen affected both the total amount and relative composition of the soluble nitrogen in white spruce tissues (Durzan and Steward 1967).Durzan, D.J.; Steward, F.C. 1967. The nitrogen metabolism of ''Picea glauca'' (Moench) Voss and ''Pinus banksiana'' Lamb. as influenced by mineral nutrition. Can. J. Bot. 45:695–710. Ammonium nitrogen was shown to foster
arginine Arginine, also known as -arginine (symbol Arg or R), is an α-amino acid Amino acids are organic compound , CH4; is among the simplest organic compounds. In chemistry, organic compounds are generally any chemical compounds that contain car ...

arginine
and
amide In organic chemistry Organic chemistry is a branch of chemistry Chemistry is the study of the properties and behavior of . It is a that covers the that make up matter to the composed of s, s and s: their composition, structure, ...

amide
s and lead to a large increase of free
guanidine Guanidine is the compound with the formula HNC(NH2)2. It is a colourless solid that dissolves in polar solvents. It is a strong base that is used in the production of plastics and explosives. It is found in urine Urine is a liquid by-product ...
compounds, whereas in leaves nourished by nitrate as the sole source of nitrogen guanidine compounds were less prominent. Durzan and Steward noted that their results, drawn from determinations made in late summer, did not rule out the occurrence of different interim responses at other times of the year. Ammonium nitrogen produced significantly heavier (dry weight) seedlings with higher nitrogen content after 5 weeks (McFee and Stone 1968)McFee, W.W.; Stone, E.L. 1968. Ammonium and nitrate as nitrogen sources for ''Pinus radiata ''and ''Picea glauca''. Soil Sci. Soc. Amer. Proc. 32(6):879–884. than did the same amount of nitrate nitrogen. Swan (1960)Swan, H.S.D. 1960. The mineral nutrition of Canadian pulpwood species. 1. The influence of nitrogen, phosphorus, potassium, and magnesium deficiencies on the growth and development of white spruce, black spruce, jack pine, and western hemlock seedlings grown in a controlled environment. Pulp Paper Res. Instit. Can., Montreal QC, Woodlands Res. Index No. 116, Tech. Rep. 168. 66 p. found the same effect in 105-day-old white spruce. The general short-term effect of nitrogen fertilization on coniferous seedlings is to stimulate shoot growth more so than root growth (Armson and Carman 1961).Armson, K.A.; Carman, R.D. 1961. Forest tree nursery
soil managementSoil management is the application of operations, practices, and treatments to protect soil and enhance its performance (such as soil fertility or soil mechanics). It includes soil conservation, soil conditioner, soil amendment, and optimal soil heal ...
. Ont. Dep. Lands & Forests, Timber Branch, Ottawa ON. 74 p.
Over a longer period, root growth is also stimulated. Many
nursery Nursery may refer to: Childcare * Nursery (room), a room within the house designed for the care of a young child or children. * Nursery school, a daycare facility for preschool-age children * Prison nursery, for imprisoned mothers with their young ...
managers were long reluctant to apply nitrogenous
fertilizer A fertilizer (American English American English (AmE, AE, AmEng, USEng, en-US), sometimes called United States English or U.S. English, is the set of varieties of the English language native to the United States. Currently, American E ...

fertilizer
s late in the growing season, for fear of increased danger of frost damage to succulent tissues. A presentation at the North American Forest Tree Nursery Soils Workshop at Syracuse in 1980 provided strong contrary evidence: Bob Eastman, President of the Western Maine Forest Nursery Co. stated that for 15 years he has been successful in avoiding winter “burn” to
Norway spruce ''Picea abies'', the Norway spruce or European spruce, is a species of spruce native to Northern Europe, Northern, Central Europe, Central and Eastern Europe. It has branchlets that typically hang downwards, and the largest cones of any spruce, 9 ...

Norway spruce
and white spruce in his nursery operation by fertilizing with 50–80 lb/ac (56–90 kg/ha) nitrogen in September, whereas previously winter burn had been experienced annually, often severely. Eastman also stated that the overwintering storage capacity of stock thus treated was much improved (Eastman 1980).Eastman, B. 1980. The Western Maine Forest Nursery Company. pp. 291–295 In Proc. of the North American Forest Tree Nursery Soils Workshop, July 28 – August 1, 1980, Syracuse, New York. Environment Canada, Canadian Forestry Service, USDA For. Serv. The concentrations of nutrients in plant tissues depend on many factors, including growing conditions. Interpretation of concentrations determined by analysis is easy only when a nutrient occurs in excessively low or occasionally excessively high concentration. Values are influenced by environmental factors and interactions among the 16 nutrient elements known to be essential to plants, 13 of which are obtained from the soil, including
nitrogen Nitrogen is the chemical element upright=1.0, 500px, The chemical elements ordered by link=Periodic table In chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science ...

nitrogen
,
phosphorus Phosphorus is a chemical element In chemistry, an element is a pure Chemical substance, substance consisting only of atoms that all have the same numbers of protons in their atomic nucleus, nuclei. Unlike chemical compounds, chemical el ...

phosphorus
,
potassium Potassium is a chemical element In chemistry Chemistry is the study of the properties and behavior of . It is a that covers the that make up matter to the composed of s, s and s: their composition, structure, properties, b ...

potassium
,
calcium Calcium is a chemical element In chemistry, an element is a pure Chemical substance, substance consisting only of atoms that all have the same numbers of protons in their atomic nucleus, nuclei. Unlike chemical compounds, chemical elem ...

calcium
,
magnesium Magnesium is a chemical element upright=1.0, 500px, The chemical elements ordered by link=Periodic table In chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science ...

magnesium
, and
sulfur Sulfur (in nontechnical British English: sulphur) is a chemical element In chemistry Chemistry is the study of the properties and behavior of . It is a that covers the that make up matter to the composed of s, s and s: th ...

sulfur
, all used in relatively large amounts (Buckman and Brady 1969).Buckman, H.O.; Brady, N.C. 1969. The Nature and Properties of Soils, 7th ed. Macmillan NY. 653 p. Nutrient concentrations in conifers also vary with season, age, and kind of tissue sampled, and analytical technique. The ranges of concentrations occurring in well-grown plants provide a useful guide by which to assess the adequacy of particular nutrients, and the ratios among the major nutrients are helpful guides to nutritional imbalances.


Economic importance

The
softwood file:Pinus sylvestris wood ray section 1 beentree.jpg, Scots Pine, a typical and well-known softwood Softwood is wood from gymnosperm trees such as conifers. The term is opposed to hardwood, which is the wood from angiosperm trees. Characterist ...
derived from conifers is of great economic value, providing about 45% of the world's annual lumber production. Other uses of the timber include the production of paper and plastic from chemically treated wood pulp. Some conifers also provide foods such as
pine nuts Pine nuts, also called piñón (), pinoli (), or pignoli, 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 traded locally or ...

pine nuts
and
Juniper berries A juniper berry is the female seed cone produced by the various species of juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' of the cypress family Cupressaceae. Depending on taxonomic viewpoint, between 50 and 67 spec ...
, the latter used to flavor
gin , United States, 2010) Gin is a Liquor, distilled alcoholic drink that derives its predominant flavour from juniper berries (''Juniperus communis''). Gin originated as a medicinal liquor made by monks and alchemists across Europe, particularly ...
.


References


Bibliography

*


External links

* *
tolweb.org
Conifers


World list of conifer species from Conifer Database by A. Farjon in the Catalogue of Life

Tree browser for conifer families and genera via the Catalogue of Life

Royal Horticultural Society Encyclopedia of Conifers: A Comprehensive Guide to Cultivars and Species

DendroPress: Conifers Around the World
* {{Authority control Plant divisions Extant Pennsylvanian first appearances