The
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...
Pinales in the
division Pinophyta,
class Pinopsida, comprises all the
extant
Extant is the opposite of the word extinct. It may refer to:
* Extant hereditary titles
* Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English
* Extant taxon, a taxon which is not extinct, ...
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 division contains a single ...
s. The distinguishing characteristic is the reproductive structure known as a
cone produced by all Pinales. All of the extant conifers, such as
cedar,
celery-pine,
cypress
Cypress is a common name for various coniferous trees or shrubs of northern temperate regions that belong to the family Cupressaceae. The word ''cypress'' is derived from Old French ''cipres'', which was imported from Latin ''cypressus'', the ...
,
fir
Firs (''Abies'') are a genus of 48–56 species of evergreen coniferous trees in the family (biology), family Pinaceae. They are found on mountains throughout much of North America, North and Central America, Europe, Asia, and North Africa. The ...
,
juniper,
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 hemisphere, on lowlands in the north and high on mountains furt ...
,
pine
A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanic ...
,
redwood,
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 ( taiga) regions of the Earth. ''Picea'' is the sole genus in the sub ...
,
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 br ...
and ''
Araucaria araucana'' ("Monkey tail tree" or "Monkey puzzle tree") are included here. Some
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
conifers, however, belong to other distinct orders within the division
Pinophyta.
Multiple molecular studies indicate this order being
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 ...
with respect to
Gnetales, with studies recovering Gnetales as either a sister group to Pinaceae or being more derived than Pinaceae but sister to the rest of the group.
Taxonomy
History
Brown (1825) first discerned that there were two groups of seed plants, distinguished by the form of seed development, based on whether the
ovules
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 ...
were exposed, receiving pollen directly, or enclosed, which do not. Shortly afterwards,
Brongniart (1828) coined the term ''
Phanérogames
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 ...
gymnosperms'' to describe the former group. The distinction was then formalized by
Lindley (1830), dividing what he referred to as the subclass
Dicotyledons into two
tribes
The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to confl ...
, Gymnosperms and Angiosperms. In the gymnosperms (or Gymnospermae) Lindley included two orders, the Cycadeae and the Coniferae. In his final work (1853) he described Gymnogens as a class with four orders;
* Cycadeaceae (cycads)
* Pinaceae (conifers)
* Taxaceae (taxads)
* Gnetaceae
In contrast,
Bentham and Hooker (1880) included only three orders in the class Gymnospermeae, by including taxads within Coniferae;
* Gnetaceae
* Coniferae
* Cycadaceae
In the
Engler system
One of the prime systems of plant taxonomy, the Engler system was devised by Adolf Engler (1844–1930), and is featured in two major taxonomic texts he authored or co-authored. His influence is reflected in the use of the terms "Engler School" an ...
(1903) Gymnospermae is listed as a subdivision (''Unterabteilung'') and adopted more of a
splitter approach, including extinct taxa, with the following six classes;
*
Cycadales
*
Bennettitales
*
Cordaitales
*
Ginkgoales
* Coniferae
*
Gnetales
During this period,
Gorozhankin published his treatise on Gymnosperms (1895), for which he bears the
botanical authority
In botanical nomenclature, author citation is the way of citing the person or group of people who validly published a botanical name, i.e. who first published the name while fulfilling the formal requirements as specified by the ''International Cod ...
for Pinales,
Gorozh.. In his classification, Gymnospermae (alternatively named Archespermae) was a class of the division
Archegoniatae, divided into subclasses;
*
Cycadoideae
*
Peucideae
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 extant ...
(Coniferae)
A system of two groups was maintained by the most commonly used classification in the twentieth century, the revision of the Engler system by Pilger (1926), who grouped 12 families of the Gymnospermae subdivision into 2 classes;
* Coniferales (Coniferae)
* Gnetales
The treatment of Gymnosperms as two groups, though with varying composition and names, was followed for most of the twentieth century, including the systems of Chamberlain (1935), Benson (1957) and
Cronquist (1960).
In the latter, Cronquist divided Gymnospermae into two divisions;
* division Coniferophyta
** class Coniferae
** class
Chlamydospermae
''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 hav ...
(Gnetales)
* division Cycadophyta
** class Cycadae
Benson,(1957) who introduced the term Pinales, divided gymnosperms into four classes;
* Conopsida (conifers, including Pinales)
*
Ephedropsida
*
Gnetopsida
*
Cycadopsida
In a later revision, in collaboration with two other taxonomists (1966), Cronquist merged all the gymnosperms into a single division, Pinophyta, with three subdivisions reflecting the main lineages;
* Cycadicae
* Pinicae
* Gneticae
In the era of
molecular phylogenetics
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
, De-Zhi and colleagues (2004) once again proposed a division of 12 gymnosperm families into two classes;
* Cycadopsida
** order Cycadales
* Coniferopsida
** subclass Multinervidae (6 orders)
** subclass Taxidae
*** order Taxales
*** order Pinales
With the development of the
Angiosperm Phylogeny Group came a major realignment of the linear classification of the
land plants, by
Chase and
Reveal (2009). In this system, the land plants form a class,
Equisetopsida ''s.l.'' (''sensu lato'') or ''
sensu
''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular c ...
''
Chase &
Reveal, also known as embryophytes or Embryophyceae ''
nom. illeg.''. Class Equisetopsida ''s.l.'' is divided into 14
subclades as subclasses, including Magnoliidae (
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 ...
). The gymnosperms are represented by four of these subclasses, placing them in a
sister group
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree.
Definition
The expression is most easily illustrated by a cladogram:
Taxon A and ...
relationship to angiosperms. Subclasses (number of orders);
* subclass Cycadidae
Pax (1)
* subclass Ginkgooidae
Engl. Engl or Engl. may refer to:
*England, a country that is part of the United Kingdom
*English
*Engl (surname), a German surname
*Engl., taxonomic abbreviation for botanist Adolf Engler
Heinrich Gustav Adolf Engler (25 March 1844 – 10 October 193 ...
(1)
* subclass Gnetidae
Pax (3)
* subclass Pinidae
Cronquist, Takht.
Armen Leonovich Takhtajan or Takhtajian ( hy, Արմեն Լևոնի Թախտաջյան; russian: Армен Леонович Тахтаджян; surname also transliterated Takhtadjan, Takhtadzhi︠a︡n or Takhtadzhian, pronounced takh-tuh-JA ...
& Zimmerm.
Walter Max Zimmermann (May 9, 1892 – June 30, 1980) was a German botanist and systematist. Zimmernann’s notions of classifying life objectively based on phylogenetic methods and on evolutionarily important characters were foundational for moder ...
(conifers) (1)
Controversies
Gymnosperm (Acrogymnospermae)
taxonomy has been considered controversial, and lacks consensus. As
taxonomic classification transformed from being based solely on
plant morphology
Phytomorphology is the study of the physical form and external structure of plants.Raven, P. H., R. F. Evert, & S. E. Eichhorn. ''Biology of Plants'', 7th ed., page 9. (New York: W. H. Freeman, 2005). . This is usually considered distinct from ...
to
molecular phylogenetics
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
, the number of taxonomic publications increased considerably after 2008, however, these approaches have not been uniform. A taxonomic classification has been complicated by the relationship of
extant to extinct
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 ...
, and within extinct taxa, and particularly the placement of
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 ...
. The latter have been variously classified as
basal
Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''.
Science
* Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure
* Basal (medicine), a minimal level that is nec ...
to all gymnosperms,
sister group
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree.
Definition
The expression is most easily illustrated by a cladogram:
Taxon A and ...
to conifers (‘gnetifer’ hypothesis) or sister to Pinaceae (‘gnepine’ hypothesis) in which they are classified within the conifers. The extant conifers most likely form a
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.. In 2018, the Gymnosperm Phylogeny Group was established, analogous to the
Angiosperm Phylogeny Group and
Pteridophyte Phylogeny Group, with the intention of reaching a consensus.
Phylogeny
Gymnosperms form a group of four subclasses among the
spermatophytes
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 ...
(seed bearing plants). In turn, the seed plants together with the
monilophyte 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 ...
subclasses make up the
tracheophytes (vascular plants), part of the class
Equisetopsida (embryophytes or land plants), as opposed to the
green algae
The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( Embryophytes) have emerged deep in the Charophyte alg ...
. Among the seed plants, the gymnosperms are a sister group to the subclass
Magnoliidae (angiosperms or flowering plants).
There are about 1000 extant gymnosperm
species
In biology, a species is the basic unit of Taxonomy (biology), 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 organisms in which any two individuals of ...
, distributed over about 12
families and 83
genera. Many of these genera are
monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...
(41%), and another 27% are oligotypic (2–5 species). The four subclasses have also been treated as
divisions of the Spermatophytes. Alternative names and the approximate number of genera and species in each are;
* Cycadidae (Cycadophyta, cycads 10, 300)
* Ginkgooidae (Ginkgophyta, gingko 1, 1)
* Gnetidae (Gnetophyta 3, 100)
* Pinidae (Pinophyta, conifers 70, 600)
The term Pinophyta has also been used to include all conifers, extinct and extant, with Pinales representing all the extant conifers.
Christenhusz
Dr Maarten Joost Maria Christenhusz (born 27 April 1976) is a Dutch botanist, natural historian and photographer.
Career
He was born in Enschede, the Netherlands, received his undergraduate and master's degrees from Utrecht University in Bi ...
and colleagues extended the system of Chase and Reveal to provide a revised classification of gymnosperms in 2011, based on the above four
subclades. In this scheme, the Pinidae comprise three orders, including Pinales, and 6 families;
* Pinales
Gorozh. (
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 ...
)
*
Araucariales Gorozh. (
Araucariaceae,
Podocarpaceae)
*
Cupressales Link (
Sciadopityaceae,
Cupressaceae,
Taxaceae)
However, the exact phylogeny remained a topic that was 'hotly debated", in particular whether the main lineages were best represented by the four subclasses of Christenhusz and colleagues or the more traditional five clades (cycads, ginkgos, cupressophytes, Pinaceae and gnetophytes). In 2014 the first complete molecular phylogeny was published, based on 90 species representing all extant genera. This established cycads as the basal group, followed by Ginkgoaceae, as sister to the remaining gymnosperms, and supporting the ‘gnepine’ hypothesis. This analysis favours the five clade hypothesis, the remaining clade following divergence of the Pinidae, are referred to as the conifer II clade, or cupressophytes, in distinction from the conifer I clade (Gnetidae, Pinidae). This clade, in turn, has two lineages. The first consisting of Sciadopityaceae and the Araucariales, the second being the Cupressales. In the Christenhusz scheme, the Sciadopityaceae were considered to be within Cupressales. The term Cupressaceae ''s.l.'' refers to the inclusion of Taxodiaceae. These relationships are shown in this
cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...
, although no formal taxonomic revision was undertaken.
A more comprehensive analysis was undertaken by Ran and colleagues in 2018, as part of a detailed phylogeny of all seed plants. This forms the basis of the Tracheophyte Phylogeny Poster and the Angiosperm Phylogeny Website.
Subdivision
Historically conifers, in the order Pinales have been considered to consist of six to seven extant families, based on the classification of class Coniferae by
Pilger (1926), considered the standard through most of the twentieth century. These families were treated as a single order, in distinction to some earlier systems. His families were;
*
Araucariaceae
*
Cupressaceae (
cypresses
Cypress is a common name for various coniferous trees or shrubs of northern temperate regions that belong to the family Cupressaceae. The word ''cypress'' is derived from Old French ''cipres'', which was imported from Latin ''cypressus'', the la ...
,
juniper,
redwood)
*
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 ...
(
firs,
pines,
cedars,
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 hemisphere, on lowlands in the north and high on mountains furt ...
,
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 ( taiga) regions of the Earth. ''Picea'' is the sole genus in the sub ...
)
*
Podocarpaceae
*
Taxaceae (
yews)
*
Cephalotaxaceae
*
Taxodiaceae
Subsequent revisions merged the Taxodiaceae and Cupressaceae, and placed ''
Sciadopitys'', formerly in Cupressaceae, into a separate family (Sciadopityaceae). Cephalotaxaceae had previously been recognized as a separate family, but was subsequently included in Taxaceae. Similarly
Phyllocladaceae were included in Podocarpaceae. Yews (Taxaceae) have sometimes been treated as a separate order (Taxales).
Christenhusz and colleagues (2011) included only one family in Pinales, Pinaceae, a practice subsequently followed by the
Angiosperm Phylogeny Website and the Gymnosperm Database. In this restricted model Pinales (Pinaceae) comprisea 11 genera and about 225 species, all of the other conifers originally included in this order, being included in other orders such as Cupressales.
Notes
References
Bibliography
Books
*
*
**
*
*
*
*
* , see also
Die Natürlichen Pflanzenfamilien
** , in vol. 13 Gymnospermae
*
*
*
*
* , ''see also''
*
*
*
** , in
Encyclopaedias
*
*
Articles
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
Websites
*
* (''see also''
Angiosperm Phylogeny Website)
*
*
*
External links
*
*
{{Authority control
Plant orders