Pinophyta 68085 225245592 2008-07-12T17:47:25Z Krasanen 1798064 [[WP:UNDO|Undid]] revision 225236855 by [[Special:Contributions/Lisasmall|Lisasmall]] ([[User talk:Lisasmall|talk]]);kauri is the common name,Agathis the scientific;other [[taxa]] listed with common n {{redirect|Conifer}} {{Unreferenced|date=December 2007}} {{Taxobox | name = Pinophyta | fossil_range = [[Late Carboniferous]] - Recent | image = Araucaria heterophylla 01.jpg | image_width = 250px | image_caption = Trees of a Pinophyta species: <br>''[[Araucaria heterophylla]]'' ([[Araucariaceae]]) | regnum = [[Plant]]ae | divisio = '''Pinophyta''' | classis = '''Pinopsida''' | subdivision_ranks = Orders & Families | subdivision = [[Cordaitales]] †<br> [[Pinales]]<br> &nbsp;&nbsp;[[Pinaceae]] - Pine family<br> &nbsp;&nbsp;[[Araucariaceae]] - Araucaria family<br> &nbsp;&nbsp;[[Podocarpaceae]] - Yellow-wood family<br> &nbsp;&nbsp;[[Sciadopitys|Sciadopityaceae]] - Umbrella-pine family<br> &nbsp;&nbsp;[[Cupressaceae]] - Cypress family<br> &nbsp;&nbsp;[[Cephalotaxaceae]] - Plum-yew family<br> &nbsp;&nbsp;[[Taxaceae]] - Yew family<br> [[Vojnovskyales]] †<br> [[Voltziales]] † }} The '''conifers''', division '''Pinophyta''', also known as division '''Coniferae''', are one of 13 or 14 [[division (botany)|division]] level [[taxon|taxa]] within the [[Plant|Kingdom Plantae]]. They are [[Conifer cone|cone]]-bearing seed [[plant]]s with [[Vascular plant|vascular]] tissue; all extant conifers are [[woody plant]]s, the great majority being [[tree]]s with just a few being [[shrub]]s. Typical examples of conifers include [[cedar]]s, [[douglas-fir]]s, [[Cupressaceae|cypresses]], [[fir]]s, [[juniper]]s, [[Agathis|kauris]], [[larch]]es, [[pine]]s, [[Sequoia|redwood]]s, [[spruce]]s, and [[Taxaceae|yew]]s. Species of conifers can be found growing naturally in almost all parts of the world, and are frequently dominant plants in their [[habitat (ecology)|habitats]], as in the [[taiga]], for example. Conifers are of immense economic value, primarily for [[timber]] and [[paper]] production; the wood of conifers is known as [[softwood]]. The division contains approximately 630 living species.<ref name=Catalogue> [http://www.catalogueoflife.org/show_database_details.php?database_name=Conifer+Database Catalogue of Life: 2007 Annual checklist - Conifer database] </ref> ==Evolution== The earliest Conifers date back to the late [[Carboniferous]] ([[Pennsylvanian]]) period. {{Sectstub|date=May 2008}} ==Taxonomy and naming== The division name Pinophyta conforms to the rules of the ''[[ICBN]]'', which state (Article 16.1) that the names of higher [[taxon|taxa]] 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 [[pine]] family), or are descriptive. In the latter case the name for the conifers (at whatever rank is chosen) is '''Coniferae''' (Art 16 Ex 2), which is also in widespread use. Older scientific names (no longer allowed) are Coniferophyta and Coniferales. According to the ''[[ICBN]]'' 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]], by the appropriate termination, in the case of this division ''-ophyta''. Alternatively, "[[descriptive botanical names]]" may also be used at any [[rank (botany)|rank]] above family. Both are allowed. This means that if the conifers are regarded to be a division they may be called Pinophyta or Coniferae (if regarded as a class they may be called Pinopsida or Coniferae; if regarded as an order they may be called Pinales or Coniferae (but see also [[Coniferales]])). Commonly the conifers are considered equivalent to the [[Gymnosperms]], particularly in areas with a temperate climate where they may be the only commonly occurring gymnosperms. However, these are two different levels of grouping: 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]] (Taxaceae only) and [[Pinales]] (the rest), but recent research into [[molecular biology|DNA sequences]] suggests that this interpretation leaves the Pinales without Taxales as [[paraphyletic]], and the latter order is no longer regarded as 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 (biology)|morphology]]. [[Image:Pinophyta.png|left|thumb|380px|Phylogeny of the Pinophyta based on [[cladistic]] analysis of [[molecular biology|molecular data]]. Derived from papers by A. Farjon and C. J. Quinn & R. A. Price in the Proceedings of the Fourth International Conifer Conference, ''Acta Horticulturae'' 615 (2003)]] The conifers are now accepted as comprising six to eight families, with a total of 65-70 genera and 600-630 species (696 accepted names).<ref name=Catalogue /> The seven most distinct families are linked in the box above right and phylogenetic diagram left. In other interpretations, the Cephalotaxaceae may be better included within the Taxaceae, and some authors additionally recognise [[Phyllocladus|Phyllocladaceae]] as distinct from Podocarpaceae (in which it is included here). The family [[Taxodiaceae]] is here included in family Cupressaceae, but was widely recognised in the past and can still be found in many field guides. The conifers are an ancient group, with a [[fossil]] record extending back about 300 million years to the [[Paleozoic]] in the late [[Carboniferous]] period; even many of the modern genera are recognisable 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]] eras. Fossil conifers included many diverse forms, the most dramatically distinct from modern conifers being some [[herb]]aceous conifers with no woody stems. Major fossil orders of conifers or conifer-like plants include the [[Cordaitales]], [[Vojnovskyales]], [[Voltziales]] and perhaps also the [[Czekanowskiales]] (possibly more closely related to the [[Ginkgo]]phyta). <br clear = left> ==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]]. The size of mature conifers varies from less than one meter, to over 100 metres. The world's tallest, largest, thickest and oldest living things are all conifers. The tallest is a [[Sequoia|Coast Redwood]] (''Sequoia sempervirens''), with a height of 115.55 metres. The largest is a [[Giant Sequoia]] (''Sequoiadendron giganteum''), with a volume 1486.9 cubic metres. The thickest, or tree with the greatest trunk diameter, is a [[Taxodium mucronatum|Montezuma Cypress]] (''Taxodium mucronatum''), 11.42 metres in diameter. The oldest is a [[Great Basin Bristlecone Pine]] (''Pinus longaeva''), 4,700 years old. ===Foliage=== [[Image:Douglas fir leaves and bud.jpg|left|thumb|[[Pinaceae]]: needle leaves and bud of [[Coast Douglas-fir]] (''Pseudotsuga menziesii'')]] [[Image:C lawsoniana Lge.jpg|right|thumb|[[Cupressaceae]]: scale leaves of [[Chamaecyparis lawsoniana|Lawson's Cypress]] (''Chamaecyparis lawsoniana''); scale in mm]] The [[leaf|leaves]] of many conifers are long, thin and have a needle like look about them, but others, including most of the [[Cupressaceae]] and some of the [[Podocarpaceae]], have flat, triangular scale-like leaves. Some, notably ''[[Agathis]]'' in Araucariaceae and ''[[Nageia]]'' in Podocarpaceae, have broad, flat strap-shaped leaves. 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, the leaf bases are twisted to present the leaves in a flat plane for maximum light capture (see e.g. photo of [[Grand Fir]] ''Abies grandis''). 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''). The [[stomata]] 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]]s or under forest canopy shade. Conifers from hotter areas with high sunlight levels (e.g. [[Turkish Pine]] ''Pinus brutia'') often have yellower-green leaves, while others (e.g. [[Blue Spruce]] ''Picea pungens'') have a very strong glaucous wax bloom to reflect [[ultraviolet light]]. In the great majority of genera the leaves are [[evergreen]], usually remaining on the plant for several (2-40) years before falling, but five genera (''[[larch|Larix]]'', ''[[Pseudolarix]]'', ''[[Glyptostrobus]]'', ''[[Metasequoia]]'' and ''[[Taxodium]]'') are [[deciduous]], shedding the leaves in autumn and leafless through the winter. 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. ===Reproduction=== [[Image:Picea abies cone USFWS.jpg|right|thumb|Pinaceae: cone of a [[Norway Spruce]] (''Picea abies'')]] [[Image:TXbaccata.jpg|left|thumb|180px|Taxaceae: the fleshy aril which surrounds each seed in the [[Taxus baccata|European Yew]](''Taxus baccata'') is a highly modified seed cone scale]] [[Image:Immature fir cone.jpg|thumb|right|Pinaceae: pollen cone of a [[Japanese Larch]] (''Larix kaempferi'')]] ''See [[conifer cone]]s for a more detailed discussion.'' Most conifers are [[Plant sexuality|monoecious]], but some are [[Plant sexuality|subdioecious]] or [[Plant sexuality|dioecious]]; all are [[wind]]-[[pollination|pollinated]]. Conifer seeds develop inside a protective cone called a ''strobilus'' (or, very loosely, "pine cones", which technically occur only on pines, not other conifers!). 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]], [[Araucariaceae]], [[Sciadopityaceae]] and most [[Cupressaceae]], the cones are [[wood]]y, and when mature the scales usually spread open allowing the seeds to fall out and be dispersed by the [[wind]]. In some (e.g. [[fir]]s and [[cedar]]s), the cones disintegrate to release the seeds, and in others (e.g. the [[pine]]s that produce [[pine nut]]s) the nut-like seeds are dispersed by [[bird]]s (mainly [[Nutcracker (bird)|nutcracker]]s and [[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]], [[Cephalotaxaceae]], [[Taxaceae]], and one [[Cupressaceae]] genus (''[[Juniper]]us''), the scales are soft, fleshy, sweet and brightly coloured, 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]]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 [[sporangium|microsporangia]] which 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. When a [[pollen]] grain lands near a female [[gametophyte]], it undergoes fertilisation of the female gametophyte. Alternatively, the [[gymnosperm]] male gametophytes are carried by wind to a female cone and are drawn into a tiny opening on the ovule called the [[micropyle]]. It is within the ovule that germination occurs. From here, a pollen tube seeks out the female gametophyte and if successful, fertilisation will occur. In both cases, the resulting [[zygote]] develops into an [[embryo]], which along with its surrounding integument, becomes a [[seed]]. Eventually the seed may fall to the ground and, if conditions permit, grows into a new plant. In [[forestry]], the terminology of [[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). ===Life cycle=== # To fertilize the ovum, the male cone releases [[pollen]] that is carried on the wind to the female cone. # A fertilized female gamete (called a [[zygote]]) develops into an [[embryo]]. # Along with integument cells surrounding the embryo, a [[seed]] develops containing the embryo. # Mature seed drops out of cone onto the ground. # Seed germinates and seedling grows into a mature plant. # When mature, the adult plant produces cones. ==Other facts== Although the total number of species is relatively small, conifers are of immense [[ecology|ecological]] importance. They are the dominant plants over huge areas of land, most notably the [[boreal forest]]s of the [[northern hemisphere]], but also in similar cool climates in mountains further south. Many conifers have distinctly scented [[resin]], secreted to protect the tree against [[insect]] infestation and [[fungus|fungal]] infection of wounds. Fossilised resin hardens into [[amber]]. [[They Might Be Giants]] recorded a song about conifers called ''[[C Is for Conifers]]'' on their 2005 album [[Here Come The ABCs]]. == Notes == {{reflist}} == Image Gallery == <gallery> Image:Young_pine_trees.jpg|Longleaf Pine </gallery> == External links == * [http://tolweb.org/tree?group=Conifers&contgroup=Spermatopsida ToLweb: Conifers] * [http://www.conifers.org/zz/pinales.htm Pinophyta - The Gymnosperm Database] * [http://www.livescience.com/animals/070504_chicago_cave.html 300 million-year-old conifer in Illinois - 4/2007] * [http://www.catalogueoflife.org/annual-checklist/2008/search_results.php?search_type=browse_by_classification&kingdom=Plantae&phylum=Pinophyta&tax_class=&order=&superfamily=&family=&genus=&species=&infraspecies=&match_whole_words=on&Submit=Search+%3E%3E List of all Pinophyta species from Conifer Database by A Farjon in the 2008 Catalogue of Life] {{Pinophyta}} [[Category:Conifers| ]] [[bg:Иглолистни]] [[ca:Pinòpsid]] [[cs:Jehličnany]] [[cy:Conwydden]] [[da:Nåletræ]] [[et:Paljasseemnetaimed]] [[es:Pinophyta]] [[eo:Pinofitoj]] [[fa:مخروطیان]] [[fr:Pinophyta]] [[ko:구과식물]] [[id:Tumbuhan runjung]] [[it:Pinophyta]] [[he:מחטניים]] [[lv:Kailsēkļi]] [[lt:Pušūnai]] [[hu:Fenyők]] [[mk:Четинар]] [[nl:Coniferen]] [[ja:球果植物門]] [[pl:Iglaste]] [[pt:Conífera]] [[ro:Pinophyta]] [[qu:Akwayuq]] [[ru:Хвойные (отдел)]] [[sk:Borovicorasty]] [[sl:Iglavci]] [[fi:Paljassiemeniset]] [[sv:Barrväxter]] [[vi:Ngành Thông]] [[to:ʻakau paini]] [[uk:Хвойні]]