A seed plant or spermatophyte (; New Latin ''spermat-'' and Greek ' (phytón), plant), also known as a phanerogam (taxon Phanerogamae) or a phaenogam (taxon Phaenogamae), is any
plant
Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...
that produces
seed
In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...
s. It is a category of
embryophyte
The embryophytes () are a clade of plants, also known as Embryophyta (Plantae ''sensu strictissimo'') () or land plants. They are the most familiar group of photoautotrophs that make up the vegetation on Earth's dry lands and wetlands. Embryophy ...
(i.e. land plant) that includes most of the familiar land plants, including the
flowering plants
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...
and the
gymnosperms
The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetoph ...
, but not
ferns
The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissue ...
,
mosses
Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta ('' sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and ho ...
, or
algae
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...
.
The term ''phanerogam'' or ''phanerogamae'' is derived from the
Greek
Greek may refer to:
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group
*Greek language, a branch of the Indo-European language family
**Proto-Greek language, the assumed last common ancestor of all kno ...
(), meaning "visible", in contrast to the term "cryptogam" or "
cryptogamae" (, and (), 'to marry'). These terms distinguish those plants with hidden sexual organs (cryptogamae) from those with visible ones (phanerogamae).
Description
The extant spermatophytes form five divisions, the first four of which are classified as
gymnosperm
The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetoph ...
s, plants that have unenclosed, "naked seeds":
*
Cycadophyta, the cycads, a subtropical and tropical group of plants,
*
Ginkgophyta
Ginkgoopsida is a proposed class of gymnosperms defined by Sergei V. Meyen in 1984 to encompass Ginkgoales (which contains the living ''Ginkgo'') alongside a number of extinct seed plant groups, which he considered to be closely related based ...
, which includes a single living species of tree in the genus ''
Ginkgo
''Ginkgo'' is a genus of non-flowering seed plants, assigned to the gymnosperms. The scientific name is also used as the English common name. The order to which the genus belongs, Ginkgoales, first appeared in the Permian, , and ''Ginkgo'' is n ...
'',
*
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 ...
, the conifers, which are
cone-bearing trees and shrubs, and
*
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 relict ...
, the gnetophytes, various woody plants in the relict genera ''
Ephedra'', ''
Gnetum'', and ''
Welwitschia
''Welwitschia'' is a monotypic genus of gnetophytes containing only the species ''Welwitschia mirabilis''. It is named after the Austrian botanist Friedrich Welwitsch, who documented the plant in the 1850s. In common use, it is sometimes ref ...
''.
The fifth extant division is the
flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...
s, also known as angiosperms or magnoliophytes, the largest and most diverse group of spermatophytes:
*
Angiosperms
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed within a fruit. T ...
, the flowering plants, possess seeds enclosed in a
fruit
In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering.
Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...
, unlike gymnosperms.
In addition to the five living taxa listed above, the fossil record contains evidence of many
extinct
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...
taxa of seed plants, among those:
*
Pteridospermae, the so-called "seed ferns", were one of the earliest successful groups of land plants, and forests dominated by seed ferns were prevalent in the late
Paleozoic
The Paleozoic ( , , ; or Palaeozoic) Era is the first of three Era (geology), geological eras of the Phanerozoic Eon. Beginning 538.8 million years ago (Ma), it succeeds the Neoproterozoic (the last era of the Proterozoic Eon) and ends 251.9 Ma a ...
.
* ''
Glossopteris'' was the most prominent tree genus in the ancient southern supercontinent of
Gondwana
Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zea ...
during the
Permian
The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...
period.
By the
Triassic
The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...
period, seed ferns had declined in ecological importance, and representatives of modern gymnosperm groups were abundant and dominant through the end of the
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
, when the
angiosperms
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed within a fruit. T ...
radiated.
Evolutionary history

A series of evolutionary changes began with
a whole genome duplication event in the ancestor of seed plants occurred about .
A middle
Devonian
The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...
(385-million-year-old)
precursor to seed plants from
Belgium
Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeas ...
has been identified predating the earliest seed plants by about 20 million years. ''
Runcaria'', small and radially symmetrical, is an integumented
megasporangium
A sporangium (from Late Latin, ; : sporangia) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other groups form sporangia at some point in their lif ...
surrounded by a cupule. The
megasporangium
A sporangium (from Late Latin, ; : sporangia) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other groups form sporangia at some point in their lif ...
bears an unopened distal extension protruding above the mutlilobed
integument
In biology, an integument is the tissue surrounding an organism's body or an organ within, such as skin, a husk, Exoskeleton, shell, germ or Peel (fruit), rind.
Etymology
The term is derived from ''integumentum'', which is Latin for "a coverin ...
. It is suspected that the extension was involved in anemophilous (wind)
pollination
Pollination is the transfer of pollen from an anther of a plant to the stigma (botany), stigma of a plant, later enabling fertilisation and the production of seeds. Pollinating agents can be animals such as insects, for example bees, beetles or bu ...
. ''Runcaria'' sheds new light on the sequence of character acquisition leading to the seed. ''Runcaria'' has all of the qualities of seed plants except for a solid
seed coat
In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be sown, which may include seed and husk or tuber. Seeds are the ...
and a system to guide the pollen to the seed.
''Runcaria'' was followed shortly after by plants with a more condensed cupule, such as ''
Spermasporites'' and ''
Moresnetia''. Seed-bearing plants had diversified substantially by the
Famennian
The Famennian is the later of two faunal stages in the Late Devonian epoch. The most recent estimate for its duration is that it lasted from around 371.1 to 359.3 million years ago. An earlier 2012 estimate, still used by the International Commis ...
, the last stage of the Devonian. Examples include ''
Elkinsia'', ''
Xenotheca'', ''
Archaeosperma'', "''
Hydrasperma''", ''
Aglosperma'', and ''
Warsteinia''. Some of these Devonian seeds are now classified within the order
Lyginopteridales
The Lyginopteridales are an extinct group of seed plants known from the Paleozoic. They were the first plant fossils to be described as Pteridospermatophyta, pteridosperms (a polyphyletic group sometimes referred to as "seed ferns") and, thus, th ...
.
Phylogeny
Seed-bearing plants are a
clade
In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...
within the
vascular plants
Vascular plants (), also called tracheophytes (, ) or collectively tracheophyta (; ), are plants that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue ( ...
(tracheophytes).
Internal phylogeny
The spermatophytes were traditionally divided into
angiosperm
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed within a fruit ...
s, or flowering plants, and
gymnosperm
The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetoph ...
s, which includes the gnetophytes, cycads,
ginkgo, and conifers. Older morphological studies believed in a close relationship between the gnetophytes and the angiosperms,
in particular based on
vessel element
A vessel element or vessel member (also called a xylem vessel) is one of the cell types found in xylem, the water conducting tissue of plants. Vessel elements are found in most angiosperms (flowering plants) and in some gymnosperms such as cyca ...
s. However, molecular studies (and some more recent morphological and fossil papers) have generally shown a
clade
In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...
of
gymnosperm
The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetoph ...
s, with the gnetophytes in or near the conifers. For example, one common proposed set of relationships is known as the ''gne-pine hypothesis'' and looks like:
However, the relationships between these groups should not be considered settled.
Other classifications
Other classifications group all the seed plants in a single
division, with
classes for the five groups:
* Division Spermatophyta
**
Cycad
Cycads are seed plants that typically have a stout and woody (ligneous) trunk (botany), trunk with a crown (botany), crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants o ...
opsida, the cycads
**
Ginkgoopsida, the
ginkgo
''Ginkgo'' is a genus of non-flowering seed plants, assigned to the gymnosperms. The scientific name is also used as the English common name. The order to which the genus belongs, Ginkgoales, first appeared in the Permian, , and ''Ginkgo'' is n ...
**
Pinopsida
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 e ...
, the conifers, ("Coniferopsida")
**
Gnetopsida
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 relict ...
, the gnetophytes
**
Magnoliopsida, the
flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...
s, or Angiospermopsida
A more modern classification ranks these groups as separate divisions (sometimes under the Superdivision Spermatophyta):
*
Cycad
Cycads are seed plants that typically have a stout and woody (ligneous) trunk (botany), trunk with a crown (botany), crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants o ...
ophyta, the cycads
*
Ginkgophyta
Ginkgoopsida is a proposed class of gymnosperms defined by Sergei V. Meyen in 1984 to encompass Ginkgoales (which contains the living ''Ginkgo'') alongside a number of extinct seed plant groups, which he considered to be closely related based ...
, the ginkgo
*
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 ...
, the conifers
*
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 relict ...
, the gnetophytes
*
Magnoliophyta
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed within a fruit. Th ...
, the flowering plants

Unassigned extinct spermatophyte orders, some of them formerly grouped as "
Pteridospermatophyta", the polyphyletic "seed ferns".
* †
Cordaitales
Cordaitales are an extinct order of gymnosperms, known from the early Carboniferous to the late Permian. Many Cordaitales had elongated strap-like leaves, resembling some modern-day conifers of the Araucariaceae and Podocarpaceae. They had co ...
* †
Calamopityales
* †
Callistophytales
* †
Caytoniales
* †
Gigantopteridales
* †
Glossopteridales
* †
Lyginopteridales
The Lyginopteridales are an extinct group of seed plants known from the Paleozoic. They were the first plant fossils to be described as Pteridospermatophyta, pteridosperms (a polyphyletic group sometimes referred to as "seed ferns") and, thus, th ...
* †
Medullosales
* †
Peltaspermales
* †
Umkomasiales (corystosperms)
* †
Czekanowskiales
* †
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 were amongst the most common seed plants of th ...
* †
Erdtmanithecales
* †
Pentoxylales
* †
Petriellales Taylor et al. 1994
* †
Avatiaceae Anderson & Anderson 2003
* †
Axelrodiopsida Anderson & Anderson
* †
Alexiales Anderson & Anderson 2003
* †
Hamshawviales Anderson & Anderson 2003
* †
Hexapterospermales Doweld 2001
* †
Hlatimbiales Anderson & Anderson 2003
* †
Matatiellales Anderson & Anderson 2003
* †
Arberiopsida Doweld 2001
* †
Iraniales E. Taylor et al. 2008
* †
Vojnovskyales E. Taylor et al. 2008
* †
Hermanophytales E. Taylor et al. 2008
* †
Dirhopalostachyaceae E. Taylor et al. 2008
References
Further reading
* Thomas N. Taylor, Edith L. Taylor, and Michael Krings. 2008. ''Paleobotany: The Biology and Evolution of Fossil Plants'', 2nd edition. Academic Press (an imprint of Elsevier): Burlington, MA; New York, NY; San Diego, CA, USA, London, UK. 1252 pages. .
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Superphyla
Devonian first appearances
Plants