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 known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All ex ...

cycad Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or f ...

s, ''

Ginkgo ''Ginkgo'' is a genus of non-flowering seed plants. The scientific name is also used as the English name. The order to which it belongs, Ginkgoales, first appeared in the Permian, 270 million years ago, and is now the only living genus withi ...

'', and

gnetophyte Gnetophyta () is a division of plants (alternatively considered the subclass Gnetidae or order Gnetales), grouped within the gymnosperms (which also includes conifers, cycads, and ginkgos), that consists of some 70 species across the three rel ...

s, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in el, γυμνόσπερμος ( el, γυμνός, translit=gymnos, lit=naked, label=none and el, σπέρμα, translit=sperma, lit=seed, label=none), literally meaning 'naked seeds'. The name is based on the unenclosed condition of their seeds (called

ovule In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the '' integument'', forming its outer layer, the ''nucellus'' (or remnant of the megasporangium), and the f ...

s in their unfertilized state). The non-encased condition of their seeds contrasts with the seeds and ovules of flowering plants (

angiosperms Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of br ...

), which are enclosed within an

ovary The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the bod ...

. Gymnosperm seeds develop either on the surface of scales or leaves, which are often modified to form

cones A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines co ...

, or solitary as in

yew Yew is a common name given to various species of trees. It is most prominently given to any of various coniferous trees and shrubs in the genus ''Taxus'': * European yew or common yew (''Taxus baccata'') * Pacific yew or western yew (''Taxus b ...

, ''

Torreya ''Torreya'' is a genus of conifers comprising six or seven species placed in the family Taxaceae, though sometimes formerly placed in Cephalotaxaceae. Four species are native to eastern Asia; the other two are native to North America. They ...

'', ''

''. Gymnosperm lifecycles involve alternation of generations. They have a dominant

diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respecti ...

sporophyte phase and a reduced haploid

gametophyte A gametophyte () is one of the two alternation of generations, alternating multicellular organism, multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has on ...

phase which is dependent on the sporophytic phase. The term "gymnosperm" is often used in

paleobotany Paleobotany, which is also spelled as palaeobotany, is the branch of botany dealing with the recovery and identification of plant remains from geological contexts, and their use for the biological reconstruction of past environments (paleogeog ...

to refer to all non-angiosperm seed plants. In that case, to specify the modern

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic ...

group of gymnosperms, the term Acrogymnospermae is sometimes used. The gymnosperms and

together comprise the

spermatophyte A spermatophyte (; ), also known as phanerogam (taxon Phanerogamae) or phaenogam (taxon Phaenogamae), is any plant that produces seeds, hence the alternative name seed plant. Spermatophytes are a subset of the embryophytes or land plants. They inc ...

s or seed plants. The gymnosperms are subdivided into five Divisions, four of which, the

Cycadophyta Cycads are seed plants that typically have a stout and woody ( ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or ...

Ginkgophyta Ginkgoales are a gymnosperm order containing only one extant species: ''Ginkgo biloba'', the ginkgo tree. It is monotypic, (the only taxon) within the class Ginkgoopsida, which itself is monotypic within the division Ginkgophyta . The order incl ...

Gnetophyta Gnetophyta () is a division of plants (alternatively considered the subclass Gnetidae or order Gnetales), grouped within the gymnosperms (which also includes conifers, cycads, and ginkgos), that consists of some 70 species across the three Reli ...

, and

Pinophyta 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 single extant class, Pinopsida. All ex ...

(also known as Coniferophyta) are still in existence while the

Pteridospermatophyta The term Pteridospermatophyta (or "seed ferns" or "Pteridospermatopsida") is a polyphyletic group of extinct seed-bearing plants (spermatophytes). The earliest fossil evidence for plants of this type is the genus ''Elkinsia'' of the late Devonian ...

are now extinct. Newer classification place the gnetophytes among the conifers. By far the largest group of living gymnosperms are the conifers (pines, cypresses, and relatives), followed by cycads, gnetophytes (''

Gnetum ''Gnetum'' is a genus of gymnosperms, the sole genus in the family Gnetaceae within the Gnetophyta. They are tropical evergreen trees, shrubs and lianas. Unlike other gymnosperms, they possess vessel elements in the xylem. Some species have bee ...

'', '' Ephedra'' and ''

Welwitschia ''Welwitschia'' is a monotypic gymnosperm genus, comprising solely the distinctive ''Welwitschia mirabilis'', endemic to the Namib desert within Namibia and Angola. ''Welwitschia'' is the only living genus of the family Welwitschiaceae and order ...

''), and ''

Ginkgo biloba ''Ginkgo biloba'', commonly known as ginkgo or gingko ( ), also known as the maidenhair tree, is a species of tree native to China. It is the last living species in the order Ginkgoales, which first appeared over 290 million years ago. Fossils ...

'' (a single living species). About 65% of gymnosperms are

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproducti ...

, but conifers are almost all

monoecious Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system alongside gynomonoecy, andromonoecy and trimonoecy. Monoecy i ...

. Some genera have mycorrhiza, fungal associations with roots (''Pinus''), while in some others (''Cycas'') small specialised roots called coralloid roots are associated with nitrogen-fixing cyanobacteria.

Diversity and origin

Over 1000 living species of gymnosperm exist. It was previously widely accepted that the gymnosperms originated in the

Late Carboniferous Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effe ...

period, replacing the

lycopsid Lycopodiopsida is a class of vascular plants known as lycopods, lycophytes or other terms including the component lyco-. Members of the class are also called clubmosses, firmosses, spikemosses and quillworts. They have dichotomously branching s ...

rainforests of the tropical region, but more recent phylogenetic evidence indicates that they diverged from the ancestors of

during the

Early Carboniferous Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early ...

. The radiation of gymnosperms during the late Carboniferous appears to have resulted from a whole

genome duplication Polyploidy is a condition in which the cells of an organism have more than one pair of (homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contains ...

event around . Early characteristics of seed plants are evident in fossil progymnosperms of the late

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, w ...

period around 383 million years ago. It has been suggested that during the mid-Mesozoic era, pollination of some extinct groups of gymnosperms was by extinct species of scorpionflies that had specialized

proboscis A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elonga ...

for feeding on pollination drops. The scorpionflies likely engaged in pollination mutualisms with gymnosperms, long before the similar and independent coevolution of nectar-feeding insects on angiosperms. Evidence has also been found that mid-Mesozoic gymnosperms were pollinated by Kalligrammatid lacewings, a now-extinct family with members which (in an example of

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...

) resembled the modern butterflies that arose far later. Zamia integrifolia02

All gymnosperms are

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

woody plant A woody plant is a plant that produces wood as its structural tissue and thus has a hard stem. In cold climates, woody plants further survive winter or dry season above ground, as opposite to herbaceous plants that die back to the ground until s ...

s, apart from the cycads. The soft and highly

parenchymatous Parenchyma () is the bulk of functional substance in an animal organ or structure such as a tumour. In zoology it is the name for the tissue that fills the interior of flatworms. Etymology The term ''parenchyma'' is New Latin from the word π ...

wood in cycads is poorly lignified, and their main structural support comes from an armor of sclerenchymatous leaf bases covering the stem, with the exception of species with underground stems. There are no

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition ...

gymnosperms and compared to angiosperms they occupy fewer

ecological niche In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of resources and competitors (fo ...

s, but have evolved both parasites (

parasitaxus ''Parasitaxus usta'' is a rare species of conifer of the family Podocarpaceae, and the sole species of the genus ''Parasitaxus''. It is a woody shrub up to 1.8 m found only in the remote, densely forested areas of New Caledonia, first discove ...

), epiphytes ( Zamia pseudoparasitica) and

rheophyte A rheophyte is a plant that lives in fast moving water currents in an environment where few other organisms can survive. Rheophytes tend to be found in currents that move at rates of one to two meters per second and that are up to 1 to 2 m deep. Th ...

s ( Retrophyllum minus).

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 single extant class, Pinopsida. All ex ...

s are by far the most abundant extant group of gymnosperms with six to eight families, with a total of 65–70 genera and 600–630 species (696 accepted names).Catalogue of Life: 2007 Annual checklist – Conifer database
Most conifers are evergreens. The leaves of many conifers are long, thin and needle-like, other species, including most

Cupressaceae Cupressaceae is a conifer family, the cypress family, with worldwide distribution. The family includes 27–30 genera (17 monotypic), which include the junipers and redwoods, with about 130–140 species in total. They are monoecious, subdio ...

and some

Podocarpaceae Podocarpaceae is a large family of mainly Southern Hemisphere conifers, known in English as podocarps, comprising about 156 species of evergreen trees and shrubs.James E. Eckenwalder. 2009. ''Conifers of the World''. Portland, Oregon: Timber Pre ...

, have flat, triangular scale-like leaves. ''

Agathis ''Agathis'', commonly known as kauri or dammara, is a genus of 22 species of evergreen tree. The genus is part of the ancient conifer family Araucariaceae, a group once widespread during the Jurassic and Cretaceous periods, but now largely res ...

'' in Araucariaceae and ''

Nageia ''Nageia'' is a genus of conifers belonging to the podocarp family Podocarpaceae.Christopher N. Page. 1990. "Podocarpaceae" pages 332-346. In: Klaus Kubitzki (general editor); Karl U. Kramer and Peter S. Green (volume editors) ''The Families an ...

'' in Podocarpaceae have broad, flat strap-shaped leaves.

Cycad Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or f ...

s are the next most abundant group of gymnosperms, with two or three families, 11 genera, and approximately 338 species. A majority of cycads are native to tropical climates and are most abundantly found in regions near the equator. The other extant groups are the 95–100 species of Gnetales and one species of

. Today gymnosperms are the most threatened of all plant groups.

Classification

A formal classification of the living gymnosperms is the "Acrogymnospermae", which form a

monophyletic group A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

within the

s. The wider "Gymnospermae" group includes extinct gymnosperms and is thought to be

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

. The fossil record of gymnosperms includes many distinctive

taxa In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular n ...

that do not belong to the four modern groups, including seed-bearing trees that have a somewhat

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except ...

-like vegetative morphology (the so-called "seed ferns" or pteridosperms). When fossil gymnosperms such as these and the

Bennettitales Bennettitales (also known as cycadeoids) is an extinct order of seed plants that first appeared in the Permian period and became extinct in most areas toward the end of the Cretaceous. Bennettitales are among the most common Mesozoic seed plants ...

, glossopterids, and '' Caytonia'' are considered, it is clear that angiosperms are nested within a larger gymnospermae clade, although which group of gymnosperms is their closest relative remains unclear. The extant gymnosperms include 12 main families and 83 genera which contain more than 1000 known species. Subclass Cycadidae *Order

Cycadales Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or f ...

**Family

Cycadaceae ''Cycas'' is a genus of plants belonging to a very ancient lineage, the Cycadophyta, which are not closely related to palms, ferns, trees or any other modern group of plants. They are evergreen perennials which achieved their maximum diversity in ...

: ''

Cycas ''Cycas'' is a genus of plants belonging to a very ancient lineage, the Cycadophyta, which are not closely related to palms, ferns, trees or any other modern group of plants. They are evergreen perennials which achieved their maximum diversity in ...

'' **Family

Zamiaceae The Zamiaceae are a family of cycads that are superficially palm or fern-like. They are divided into two subfamilies with eight genera and about 150 species in the tropical and subtropical regions of Africa, Australia and North and South Americ ...

: ''

Dioon ''Dioon'' is a genus of cycads in the family Zamiaceae. It is native to Mexico and Central America. Their habitats include tropical forests, pine-oak forest, and dry hillsides, canyons and coastal dunes. Description Dioons are dioecious, palmli ...

'', ''

Bowenia The genus ''Bowenia'' includes two living and two fossil species of cycads in the family Stangeriaceae, sometimes placed in their own family Boweniaceae. They are entirely restricted to Australia. The two living species occur in Queensland. '' ...

'', ''

Macrozamia ''Macrozamia'' is a genus of around forty species of cycads, family Zamiaceae, all of which are endemic to Australia. Many parts of the plant have been utilised for food and material, most of which is toxic if not processed correctly. Descript ...

'', ''

Lepidozamia ''Lepidozamia'' is a genus of two species of cycad, both endemic to Australia. They are native to rainforest climates in eastern Queensland and eastern New South Wales. They have a diploid chromosome number of 2n = 18. Etymology The name is der ...

'', ''

Encephalartos ''Encephalartos'' is a genus of cycad native to Africa. Several species of ''Encephalartos'' are commonly referred to as bread trees, bread palms or kaffir bread, since a bread-like starchy food can be prepared from the centre of the stem. The ge ...

'', '' Stangeria'', ''

Ceratozamia ''Ceratozamia'' is a genus of New World cycads in the family Zamiaceae. The genus contains 27 known currently living species and one or two fossil species. Most species are endemic to mountainous areas of Mexico, while few species extend into the ...

'', ''

Microcycas ''Microcycas'' is a genus of cycads in the family Zamiaceae containing only one species, ''Microcycas calocoma'', endemic to a small area in western Cuba in Pinar del Río Province. Description The plant grows up to 10 m tall with an upright, so ...

'', ''

Zamia ''Zamia'' is a genus of cycad of the family Zamiaceae, native to North America from the United States (in Georgia and Florida) throughout the West Indies, Central America, and South America as far south as Bolivia. The genus is considered to be ...

'' Subclass

Ginkgoidae Ginkgoidae is a subclass of Equisetopsida in the sense used by Mark W. Chase and James L. Reveal in their 2009 article "A phylogenetic classification of the land plants to accompany APG III." This subclass contains the single extant genus ''Ginkg ...

*Order

Ginkgoales Ginkgoales are a gymnosperm order containing only one extant species: ''Ginkgo biloba'', the ginkgo tree. It is monotypic, (the only taxon) within the class Ginkgoopsida, which itself is monotypic within the division Ginkgophyta . The order inclu ...

**Family Ginkgoaceae: ''

'' Subclass

Gnetidae Gnetophyta () is a division of plants (alternatively considered the subclass Gnetidae or order Gnetales), grouped within the gymnosperms (which also includes conifers, cycads, and ginkgos), that consists of some 70 species across the three ...

*Order

Welwitschiales Welwitschiaceae is a family of plants of the order Gnetales with one living species, '' Welwitschia mirabilis'', found in southwestern Africa. Three fossil genera have been recovered from the Crato Formation – late Aptian ( Lower Cretaceous) ...

**Family

Welwitschiaceae Welwitschiaceae is a family of plants of the order Gnetales with one living species, '' Welwitschia mirabilis'', found in southwestern Africa. Three fossil genera have been recovered from the Crato Formation – late Aptian ( Lower Cretaceous) ...

: ''

'' *Order

Gnetales Gnetophyta () is a division of plants (alternatively considered the subclass Gnetidae or order Gnetales), grouped within the gymnosperms (which also includes conifers, cycads, and ginkgos), that consists of some 70 species across the three rel ...

**Family Gnetaceae: ''

'' *Order Ephedrales **Family

Ephedraceae Ephedraceae is a family of gymnosperms belonging to Gnetophyta, it contains only a single extant genus, '' Ephedra'', as well as a number of extinct genera from the Early Cretaceous. Taxonomy File:Eamesia chinensis.png, '' Eamesia'' File:Chengi ...

: '' Ephedra'' Subclass

Pinidae Pinidae is a subclass of Equisetopsida in the sense used by Mark W. Chase and James L. Reveal in their 2009 article "A phylogenetic classification of the land plants to accompany APG III." This subclass comprises the conifers. The Pinidae subcl ...

*Order

Pinales The order Pinales in the division Pinophyta, class Pinopsida, comprises all the extant conifers. The distinguishing characteristic is the reproductive structure known as a cone produced by all Pinales. All of the extant conifers, such as ce ...

**Family

Pinaceae The Pinaceae, or pine family, are conifer trees or shrubs, including many of the well-known conifers of commercial importance such as cedars, firs, hemlocks, larches, pines and spruces. The family is included in the order Pinales, formerly know ...

: ''

Cedrus ''Cedrus'', common English name cedar, is a genus of coniferous trees in the plant family Pinaceae (subfamily Abietoideae). They are native to the mountains of the western Himalayas and the Mediterranean region, occurring at altitudes of 1,500� ...

'', ''

Pinus A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden a ...

'', ''

Cathaya ''Cathaya'' is a genus in the pine family, Pinaceae, with one known living species, ''Cathaya argyrophylla''. ''Cathaya'' is a member of the subfamily Laricoideae, most closely related to ''Pseudotsuga'' and ''Larch, Larix''. A second species, ' ...

'', ''

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 (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfam ...

'', ''

Pseudotsuga ''Pseudotsuga'' is a genus of evergreen coniferous trees in the family Pinaceae (subfamily Laricoideae). Common names for species in the genus include Douglas fir, Douglas-fir, Douglas tree, Oregon pine and Bigcone spruce. ''Pseudotsuga menzie ...

'', ''

Larix 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 hemisphere, on lowlands in the north and high on mountains furth ...

'', ''

Pseudolarix ''Pseudolarix'' is a genus of coniferous trees in the pine family Pinaceae containing three species, the extant '' Pseudolarix amabilis'' and the extinct species ''Pseudolarix japonica'' and ''Pseudolarix wehrii''. ''Pseudolarix'' species are c ...

'', ''

Tsuga ''Tsuga'' (, from Japanese (), the name of ''Tsuga sieboldii'') is a genus of conifers in the subfamily Abietoideae of Pinaceae, the pine family. The common name hemlock is derived from a perceived similarity in the smell of its crushed foliage ...

'', '' Nothotsuga'', ''

Keteleeria ''Keteleeria'' is a genus of three species of coniferous trees in the family Pinaceae first described as a genus in 1866. The genus name ''Keteleeria'' honours J.B. Keteleer (1813–1903), a French nurseryman. The group is related to the gener ...

'', ''

Abies Firs (''Abies'') are a genus of 48–56 species of evergreen coniferous trees in the family Pinaceae. They are found on mountains throughout much of North and Central America, Europe, Asia, and North Africa. The genus is most closely related to ...

'' *Order

Araucariales Araucariaceae – also known as araucarians – is an extremely ancient family of coniferous trees. The family achieved its maximum diversity during the Jurassic and Cretaceous periods and the early Cenozoic, when it was distributed almost world ...

**Family

Araucariaceae Araucariaceae – also known as araucarians – is an extremely ancient family of coniferous trees. The family achieved its maximum diversity during the Jurassic and Cretaceous periods and the early Cenozoic, when it was distributed almost world ...

: ''

Araucaria ''Araucaria'' (; original pronunciation: .ɾawˈka. ɾja is a genus of evergreen coniferous trees in the family Araucariaceae. There are 20 extant species in New Caledonia (where 14 species are endemic, see New Caledonian ''Araucaria ...

'', '' Wollemia'', ''

'' **Family

: ''

Phyllocladus ''Phyllocladus'', the celery pines, is a small genus of conifers, now usually treated in the family Podocarpaceae.James E. Eckenwalder. 2009. ''Conifers of the World''. Timber Press: Portland, OR, USA. .'' ''Species occur mainly in New Zealand, ...

'', '' Lepidothamnus'', ''

Prumnopitys ''Prumnopitys'' is a genus of conifers belonging to the family Podocarpaceae. The nine recognized species of ''Prumnopitys'' are densely branched, dioecious evergreen trees up to 40 metres in height. Etymology The name ''Prumnopitys'' comes fr ...

'', ''

Sundacarpus ''Sundacarpus'' is a monotypic genus of conifers containing a single species ''Sundacarpus amarus'', belonging to the family Podocarpaceae. ''Sundacarpus'' was designated a genus by C.N.Page in 1989; formerly it had been classified variously as ...

'', ''

Halocarpus ''Halocarpus'' is a genus of conifers of the family Podocarpaceae.Christopher N. Page. 1990. "Podocarpaceae" pages 332-346. In: Klaus Kubitzki (general editor); Karl U. Kramer and Peter S. Green (volume editors) ''The Families and Genera of Vascu ...

'', ''

Parasitaxus ''Parasitaxus usta'' is a rare species of conifer of the family Podocarpaceae, and the sole species of the genus ''Parasitaxus''. It is a woody shrub up to 1.8 m found only in the remote, densely forested areas of New Caledonia, first discove ...

'', ''

Lagarostrobos ''Lagarostrobos franklinii'' is a species of conifer native to the wet southwestern corner of Tasmania, Australia. It is often known as the Huon pine or Macquarie pine, although it is actually a podocarp (Podocarpaceae), not a true pine (Pinac ...

'', ''

Manoao ''Manoao'' is a monotypic genus in the family ''Podocarpaceae.'' The single species, ''M. colensoi'', known as manoao ( Māori), silver pine, Westland pine, or white silver pine, is endemic to New Zealand. Before 1996 it was classified in gen ...

'', ''

Saxegothaea ''Saxegothaea'' is a genus comprising a single species, ''Saxegothaea conspicua''. It is a conifer in the podocarp family Podocarpaceae, native to southern South America. It grows in Chile and Argentina from 35° to 46° South latitude; in its no ...

'', '' Microcachrys'', ''

Pherosphaera ''Pherosphaera'' is a genus of conifers belonging to the family Podocarpaceae. Its native range is Southeastern Australia. Both species are evergreen shrubs. They are dioecious, with male and female flowers on separate plants. Species Specie ...

'', '' Acmopyle'', ''

Dacrycarpus ''Dacrycarpus'' is a genus of conifers belonging to the family Podocarpaceae.Christopher N. Page. 1990. "Podocarpaceae" pages 332-346. In: Klaus Kubitzki (general editor); Karl U. Kramer and Peter S. Green (volume editors) ''The Families and Gene ...

'', ''

Dacrydium ''Dacrydium'' is a genus of conifers belonging to the podocarp family Podocarpaceae. Sixteen species of evergreen dioecious trees and shrubs are presently recognized. The genus was first described by Solander in 1786, and formerly included many ...

'', '' Falcatifolium'', '' Retrophyllum'', ''

'', ''

Afrocarpus ''Afrocarpus'' is a genus of conifers of the family Podocarpaceae. Two to six species are recognized. They are evergreen trees native to Africa. ''Afrocarpus'' was designated a genus in 1989, when several species formerly classified in '' Podoca ...

'', ''

Podocarpus ''Podocarpus'' () is a genus of conifers, the most numerous and widely distributed of the podocarp family, the Podocarpaceae. The name comes from Greek πούς (poús, “foot”) + καρπός (karpós, “fruit”). ''Podocarpus'' speci ...

'' *Order

Cupressales Cupressaceae is a conifer family, the cypress family, with worldwide distribution. The family includes 27–30 genera (17 monotypic), which include the junipers and redwoods, with about 130–140 species in total. They are monoecious, subdioe ...

**Family

Sciadopityaceae ''Sciadopitys verticillata'', the or Japanese umbrella-pine, is a unique conifer endemic to Japan. It is the sole member of the family Sciadopityaceae and genus ''Sciadopitys'', a living fossil with no close relatives. The oldest fossils of '' ...

: '' Sciadopitys'' **Family

: ''

Cunninghamia ''Cunninghamia'' is a genus of one or two living species of evergreen coniferous trees in the cypress family Cupressaceae. They are native to China, northern Vietnam and Laos, and perhaps also Cambodia. They may reach in height. In vernacular u ...

'', '' Taiwania'', ''

Athrotaxis ''Athrotaxis'' is a genus of two to three species (depending on taxonomic opinion) of conifers in the cypress family, Cupressaceae. The genus is endemic to western Tasmania, where they grow in high altitude temperate rainforests.Farjon, A. (20 ...

'', ''

Metasequoia ''Metasequoia'', or dawn redwoods, is a genus of fast-growing deciduous trees, one of three species of conifers known as redwoods. The living species ''Metasequoia glyptostroboides'' is native to Lichuan county in Hubei province, China. Altho ...

'', '' Sequoia'', ''

Sequoiadendron ''Sequoiadendron'' is a genus of evergreen trees, with two species, only one of which survives to the present: * ''Sequoiadendron giganteum'', extant, commonly known as wellingtonia, giant redwood and giant sequoia, growing naturally in the Sier ...

'', ''

Cryptomeria ''Cryptomeria'' (literally "hidden parts") is a monotypic genus of conifer in the cypress family Cupressaceae, formerly belonging to the family Taxodiaceae. It includes only one species, ''Cryptomeria japonica'' (syn. ''Cupressus japonica'' ...

'', '' Glyptostrobus'', ''

Taxodium ''Taxodium'' is a genus of one to three species (depending on taxonomic opinion) of extremely flood-tolerant conifers in the cypress family, Cupressaceae. The generic name is derived from the Latin word ''taxus'', meaning "yew", and the Greek ...

'', ''

Papuacedrus ''Papuacedrus papuana'' is a species in the conifer family Cupressaceae, the sole species in the genus ''Papuacedrus''. Some botanists do not consider this species as forming a distinct genus, but include it in the related genus ''Libocedrus''. I ...

'', ''

Austrocedrus ''Austrocedrus'' is a genus of conifer belonging to the cypress family (Cupressaceae). It has only one species, ''Austrocedrus chilensis'', native to the Valdivian temperate rain forests and the adjacent drier steppe-forests of central-southern C ...

'', ''

Libocedrus ''Libocedrus'' is a genus of five species of coniferous trees in the cypress family Cupressaceae, native to New Zealand and New Caledonia. The genus is closely related to the South American genera '' Pilgerodendron'' and '' Austrocedrus'', and ...

'', ''

Pilgerodendron ''Pilgerodendron'' is a genus of conifer belonging to the cypress family Cupressaceae. It has only one species, ''Pilgerodendron uviferum'', which is endemic to the Valdivian temperate rain forests and Magellanic subpolar forests of southern Chi ...

'', ''

Widdringtonia ''Widdringtonia'' is a genus of coniferous trees in the Cupressaceae (cypress family). The name was Austrian botanist Stephan Endlicher's way of honouring an early expert on the coniferous forests of Spain, Capt. Samuel Edward Widdrington (1787– ...

'', '' Diselma'', ''

Fitzroya ''Fitzroya'' is a Monotypic taxon, monotypic genus in the Cupressaceae, cypress family. The single living species, ''Fitzroya cupressoides'', is a tall, long-lived Pinophyta, conifer native to the Andes mountains and coastal of southern Chile, a ...

'', ''

Callitris ''Callitris'' is a genus of coniferous trees in the Cupressaceae (cypress family). There are 16 recognized species in the genus, of which 13 are native to Australia and the other three (''C. neocaledonica, C. sulcata'' and ''C. ...

'', ''

Actinostrobus ''Actinostrobus'' is a genus of coniferous trees in the Cupressaceae (cypress family). Common names include cypress, sandplain-cypress and cypress-pine, the last of these shared by the closely related genus ''Callitris''. Species There are three ...

'', '' Neocallitropsis'', '' Thujopsis'', ''

Thuja ''Thuja'' ( ) is a genus of coniferous tree or shrub in the Cupressaceae (cypress family). There are five species in the genus, two native to North America and three native to eastern Asia. The genus is monophyletic and sister to '' Thujopsis'' ...

'', ''

Fokienia ''Fokienia'' is a genus of conifer tree belonging to the cypress family. In its characteristics, ''Fokienia'' is intermediate between the genera of ''Chamaecyparis'' and '' Calocedrus''. Genetically ''Fokienia'' is much closer to ''Chamaecyparis' ...

'', ''

Chamaecyparis ''Chamaecyparis'', common names cypress or false cypress (to distinguish it from related cypresses), is a genus of conifers in the cypress family Cupressaceae, native to eastern Asia ( Japan and Taiwan) and to the western and eastern margins of ...

'', ''

Cupressus ''Cupressus'' is one of several genera of evergreen conifers within the family Cupressaceae that have the common name cypress; for the others, see cypress. It is considered a polyphyletic group. Based on genetic and morphological analysis, the ge ...

'', ''

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

'', ''

Calocedrus ''Calocedrus'', the incense cedar (alternatively spelled incense-cedar), is a genus of coniferous trees in the cypress family Cupressaceae first described as a genus in 1873. It is native to eastern Asia and western North America. The generic ...

'', '' Tetraclinis'', '' Platycladus'', ''

Microbiota Microbiota are the range of microorganisms that may be commensal, symbiotic, or pathogenic found in and on all multicellular organisms, including plants. Microbiota include bacteria, archaea, protists, fungi, and viruses, and have been fou ...

'' **Family

Taxaceae Taxaceae (), commonly called the yew family, is a coniferous family which includes six extant and two extinct genera, and about 30 species of plants, or in older interpretations three genera and 7 to 12 species. Description They are many-bran ...

: ''

Austrotaxus ''Austrotaxus spicata'', the New Caledonia yew or southern yew, is a species of yew, the sole species in the genus ''Austrotaxus''. It is related to the other yews in the genera ''Taxus'' and '' Pseudotaxus''. It is endemic to New Caledonia, oc ...

'', ''

Pseudotaxus ''Pseudotaxus chienii'', the whiteberry yewThomas, P. & Yang, Y. 2013''Pseudotaxus chienii''.The IUCN Red List of Threatened Species. Version 2015.2. Downloaded on 04 September 2015. (), is a species of plant in the yew family, Taxaceae. It is th ...

'', ''

Taxus ''Taxus'' is a genus of coniferous trees or shrubs known as yews in the family Taxaceae. They are relatively slow-growing and can be very long-lived, and reach heights of , with trunk girth averaging . They have reddish bark, lanceolate, flat, ...

'', ''

Cephalotaxus ''Cephalotaxus'', commonly called plum yew or cowtail pine, is a genus of conifers comprising 11 species, treated in either the Cephalotaxaceae, or in the Taxaceae when that family is considered in a broad sense. The genus is endemic to eastern ...

'', ''

Amentotaxus ''Amentotaxus'' is a genus of conifers (catkin-yews) comprising five species, treated in either the Cephalotaxaceae, or in the Taxaceae when that family is considered in a broad sense. The genus is endemic to subtropical Southeast Asia, from ...

'', ''

Extinct groupings

* Division

* Order

** Family Cycadeoidaceae ** Family Williamsoniaceae * Order Erdtmanithecales *Order Pentoxylales *Order Czekanowskiales

Life cycle

Gymnosperms, like all

vascular plants Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They a ...

, have a sporophyte-dominant life cycle, which means they spend most of their life cycle with diploid cells, while the

(gamete-bearing phase) is relatively short-lived. Like all

seed plants A spermatophyte (; ), also known as phanerogam (taxon Phanerogamae) or phaenogam (taxon Phaenogamae), is any plant that produces seeds, hence the alternative name seed plant. Spermatophytes are a subset of the embryophytes or land plants. They inc ...

, they are

heterosporous Heterospory is the production of spores of two different sizes and sexes by the sporophytes of land plants. The smaller of these, the microspore, is male and the larger megaspore is female. Heterospory evolved during the Devonian period from ...

, having two spore types, microspores (male) and megaspores (female) that are typically produced in pollen cones or ovulate cones, respectively. The exception is the females in the cycad genus

, which form a loose structure called megasporophylls instead of cones. As with all heterosporous plants, the gametophytes develop within the spore wall. Pollen grains (microgametophytes) mature from microspores, and ultimately produce sperm cells. Megagametophytes develop from megaspores and are retained within the ovule. Gymnosperms produce multiple

archegonia An archegonium (pl: archegonia), from the ancient Greek ''ἀρχή'' ("beginning") and ''γόνος'' ("offspring"), is a multicellular structure or organ of the gametophyte phase of certain plants, producing and containing the ovum or female ga ...

, which produce the female gamete. During pollination, pollen grains are physically transferred between plants from the pollen cone to the ovule. Pollen is usually moved by wind or insects. Whole grains enter each ovule through a microscopic gap in the ovule coat (

integument In biology, an integument is the tissue surrounding an organism's body or an organ within, such as skin, a husk, shell, germ or rind. Etymology The term is derived from ''integumentum'', which is Latin for "a covering". In a transferred, or ...

) called the micropyle. The pollen grains mature further inside the ovule and produce sperm cells. Two main modes of fertilization are found in gymnosperms. Cycads and ''

'' have

flagellated A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide Motility#Cellular level, motility. Many protists with flagella are termed as flagellates. A m ...

motile sperm that swim directly to the egg inside the ovule, whereas conifers and

s have sperm with no flagella that are moved along a

pollen tube A pollen tube is a tubular structure produced by the male gametophyte of seed plants when it germinates. Pollen tube elongation is an integral stage in the plant life cycle. The pollen tube acts as a conduit to transport the male gamete cells fr ...

to the egg. After

syngamy Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Pro ...

(joining of the sperm and egg cell), the zygote develops into an embryo (young sporophyte). More than one embryo is usually initiated in each gymnosperm seed. The mature seed comprises the embryo and the remains of the female

, which serves as a food supply, and the

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

Genetics

The first published sequenced genome for any gymnosperm was the genome of ''

Picea abies ''Picea abies'', the Norway spruce or European spruce, is a species of spruce native to Northern, Central and Eastern Europe. It has branchlets that typically hang downwards, and the largest cones of any spruce, 9–17 cm long. It is very clo ...

'' in 2013.

Uses

Gymnosperms have major economic uses. Pine, fir, spruce, and cedar are all examples of conifers that are used for

lumber Lumber is wood that has been processed into dimensional lumber, including beams and planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, w ...

, paper production, and resin. Some other common uses for gymnosperms are

soap Soap is a salt of a fatty acid used in a variety of cleansing and lubricating products. In a domestic setting, soaps are surfactants usually used for washing, bathing, and other types of housekeeping. In industrial settings, soaps are used ...

varnish Varnish is a clear transparent hard protective coating or film. It is not a stain. It usually has a yellowish shade from the manufacturing process and materials used, but it may also be pigmented as desired, and is sold commercially in vario ...

, nail polish, food, gum, and

perfume Perfume (, ; french: parfum) is a mixture of fragrant essential oils or aroma compounds (fragrances), fixatives and solvents, usually in liquid form, used to give the human body, animals, food, objects, and living-spaces an agreeable scent. ...

References

General bibliography

External links

Gymnosperm DatabaseGymnosperms on the Tree of Life
* {{Authority control 01 Extant Late Devonian first appearances