The pteridophytes are vascular plants (plants with xylem and phloem) that neither flower nor produce seeds. Instead, they reproduce and disperse only via spores. Divisions Non-seed-bearing plants Equisetophyta Lycopodiophyta Psilotophyta Pteridophyta Superdivision Spermatophyta Pinophyta Cycadophyta Ginkgophyta Gnetophyta Magnoliophyta The vascular plants are plants in the Kingdom Plantae (also called Viridiplantae) that have specialized tissues for conducting water. ... In vascular plants, xylem is one of the two types of transport tissue in plants, phloem being the other one. ... In vascular plants, phloem is the living tissue that carries organic nutrients, particularly sucrose, to all parts of the plant where needed. ... A Phalaenopsis flower A flower, (<Old French flo(u)r<Latin florem<flos), also known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Magnoliophyta, also called angiosperms). ... A ripe red jalapeño cut open to show the seeds For other uses, see Seed (disambiguation). ... This article is about a biological reproductive structure; for the video game, see Spore (video game). ...

Pteridophyte classification

The pteridophytes do not form a monophyletic group but consist of several groups, the Lycopodiophyta (club mosses, spike mosses, and quillworts), the Equisetophyta (horsetails), the Psilotophyta (whisk ferns), the Ophioglossophyta (adder's tongues and grape ferns), and the Pteridophyta (true ferns). In phylogenetics, a group is monophyletic (Greek: of one race) if it consists of a common ancestor and all its descendants. ... Classes Lycopodiopsida - clubmosses Selaginellopsida - spikemosses Isoetopsida - quillworts The Division Lycopodiophyta (sometimes called Lycophyta) is a tracheophyte subdivision of the Kingdom Plantae. ... Classes Equisetopsida The division Equisetophyta is a taxon in the kingdom Plantae containing primitive land plants. ... Families Psilotaceae Tmesipteridaceae Psilotophyta (the whisk ferns; also sometimes as Psilophyta) is a division (i. ... Families and Genera Family Ophioglossaceae Ophioglossum Cheiroglossa Family Botrychiaceae Botrychium Botrypus Sceptridium Family Helminthostachiaceae Helminthostachys zeylanica The Ophioglossophyta are a small group of plants. ... Classes Marattiopsida Osmundopsida Gleicheniopsida Pteridopsida A fern is any one of a group of about 20,000 species of plants classified in the phylum or division Pteridophyta, also known as Filicophyta. ...

In addition to these living groups of pteridophytes are several groups now extinct and known only from fossils. These groups include the Rhyniophyta, Zosterophyllophyta, Trimerophytophyta, and the progymnosperms. In biology and ecology, extinction is the ceasing of existence of a species or group of species. ... An ammonite fossil Eocene fossil fish of the genus Knightia Petrified wood fossil formed through permineralization. ... Archaeopteris is an extinct genus of tree-like ferns that many scientists believe to be the first tree. ...

Modern studies of the land plants agree that all the pteridophytes share a single common ancestor. However, they are not a clade (monophyletic group) because the seed plants are also descended from within this group -- probably close relatives of the progymnosperms. A clade is a term belonging to the discipline of cladistics. ... The spermatophytes comprise those plants that produce seeds. ...

Pteridophyte sexuality

These plants are generally sporophyte-oriented; that is, the normal plant is the diploid sporophyte, with the only haploid structure being the gametophyte (prothallium) in season. This basic pattern is like that found in the seed plants but with an important exception. Unlike the seed plants, the pteridophytes have a gametophyte stage that is free-living. As a result, pteridophyte sexuality is more complicated than that of the seed plants. There are several basic categories of sexuality in pteridophytes. Theterms distinguish between types of gametophyte sexuality: In plants that undergo alternation of generations, a sporophyte is the structure, or phase of life, that contains a total complement of chromosomes: The sporophyte produces spores, in a process called meiosis. ... Diploid (meaning double in Greek) cells have two copies (homologs) of each chromosome (both sex- and non-sex determining chromosomes), usually one from the mother and one from the father. ... Haploid (meaning simple in Greek) cells have only one copy of each chromosome. ... In plants that undergo alternation of generations, a gametophyte is the structure, or phase of life, that contains only half of the total complement of chromosomes: The sporophyte produces spores, in a process called meiosis. ... A prothallium, or prothallus, is a fern in gametophyte stage in the alternation of generations cycle. ...

• Dioicous pteridophytes produce only antheridia (male organs) or archegonia (female organ) on a single gametophyte body.
• Monoicous pteridophytes produce both antheridia and archegonia on the same gametophyte body.

  Protandrous pteridophytes produce the male antheridia first, and then their female argchegonia.

  Protogynous pteridophytes produce the archegonia first, followed by the antheridia.

Notice that these terms are not the same as monoecious and dioecious, which refer to whether or not a sporophyte plant bears one or both kinds of gametophyte. Those terms apply only to seed plants. This article is in need of attention from an expert on the subject. ... Diagram of antheridium anatomy An antheridium (plural: antheridia) is a structure or organ of the gametophyte phase of certain plants producing and containing the spermatids or male gametes. ... An archegonium (pl: archegonia) (from the Greek arche = beginning and gonos = born) is a multicellular structure or organ of the gametophyte phase of certain plants producing and containing the ovum or female gamete. ... This page is a candidate to be copied to Wiktionary. ... Diagram of antheridium anatomy An antheridium (plural: antheridia) is a structure or organ of the gametophyte phase of certain plants producing and containing the spermatids or male gametes. ... An archegonium (pl: archegonia) (from the Greek arche = beginning and gonos = born) is a multicellular structure or organ of the gametophyte phase of certain plants producing and containing the ovum or female gamete. ... Protogynous animals are sequential hermaphrodites, where that animal is first biologically female, having only female sexual organs, then changes to be biologically male. ... In plants that undergo alternation of generations, a sporophyte is the structure, or phase of life, that contains a total complement of chromosomes: The sporophyte produces spores, in a process called meiosis. ... The spermatophytes (also known as phanerogams) comprise those plants that produce seeds. ...

See also

• Embryophyte
• Lycopodiophyta
• Equisetophyta
• Psilotophyta
• Ophioglossophyta
• Pteridophyta
• Plant sexuality

Divisions Non-vascular plants (bryophytes) Marchantiophyta - liverworts Anthocerotophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adders-tongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta - flowering plants The embryophytes are the most familiar... Classes Lycopodiopsida - clubmosses Selaginellopsida - spikemosses Isoetopsida - quillworts The Division Lycopodiophyta (sometimes called Lycophyta) is a tracheophyte subdivision of the Kingdom Plantae. ... Classes Equisetopsida The division Equisetophyta is a taxon in the kingdom Plantae containing primitive land plants. ... Families Psilotaceae Tmesipteridaceae Psilotophyta (the whisk ferns; also sometimes as Psilophyta) is a division (i. ... Families and Genera Family Ophioglossaceae Ophioglossum Cheiroglossa Family Botrychiaceae Botrychium Botrypus Sceptridium Family Helminthostachiaceae Helminthostachys zeylanica The Ophioglossophyta are a small group of plants. ... Classes Marattiopsida Osmundopsida Gleicheniopsida Pteridopsida A fern is any one of a group of about 20,000 species of plants classified in the phylum or division Pteridophyta, also known as Filicophyta. ... Plant sexuality deals with the wide variety of sexual reproduction systems found across the plant kingdom. ...

References

• Gifford, Ernest M. & Foster, Adriance S. (1988). Morphology and Evolution of Vascular Plants, (3rd ed.). New York: W. H. Freeman and Company. ISBN 0-7167-1946-0.
• Raven, Peter H., Evert, Ray F., & Eichhorn, Susan E. (2005). Biology of Plants (7th ed.). New York: W. H. Freeman and Company. ISBN 0-7167-1007-2.