Pteridophyte
| Pteridophyte Informal paraphyletic group of vascular plants that reproduce by spores
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| Lycopodiella inundata | |
Scientific classification
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Division: | Pteridophyta |
| Included | |
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| Excluded | |
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A pteridophyte is a vascular plant (with xylem and phloem) that reproduces by means of spores. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as "cryptogams", meaning that their means of reproduction is hidden.
monophyletic group because ferns (and horsetails) are more closely related to seed plants than to lycophytes. "Pteridophyta" is thus no longer a widely accepted taxon, but the term pteridophyte remains in common parlance, as do pteridology and pteridologist as a science and its practitioner, for example by the International Association of Pteridologists and the Pteridophyte Phylogeny Group
.
Description
Pteridophytes (ferns and lycophytes) are free-sporing
Taxonomy
Phylogeny
Of the pteridophytes, ferns account for nearly 90% of the extant diversity.molecular phylogenetic era, considered the ferns as monilophytes, as follows:[3]
- Tracheophyta(tracheophytes) - vascular plants
- Subdivision Lycopodiophyta(lycophytes) - less than 1% of extant vascular plants
- Euphyllophytina(euphyllophytes)
- Infradivision Moniliformopses(monilophytes)
- Infradivision Spermatophyta- seed plants, ~260,000 species
- Infradivision
- Subdivision
where the monilophytes comprise about 9,000 species, including
Filicopsida was already in use.[6] By comparison "lycopod" or lycophyte (club moss) means wolf-plant. The term "fern ally" included under Pteridophyta generally refers to vascular spore-bearing plants that are not ferns, including lycopods, horsetails, whisk ferns and water ferns (Marsileaceae, Salviniaceae and Ceratopteris). This is not a natural grouping but rather a convenient term for non-fern, and is also discouraged, as is eusporangiate for non-leptosporangiate ferns.[7]
However both Infradivision and Moniliformopses are also invalid names under the
families, without assigning a higher taxonomic rank.[3]
Furthermore, within the Polypodiopsida, the largest grouping, a number of informal clades were recognised, including leptosporangiates, core leptosporangiates,
Eupolypods II).[3]
In 2014
Chase, summarising the known knowledge at that time, treated this group as two separate unrelated taxa in a consensus classification;[7]
- Lycopodiophyta(lycopods) 1 subclass, 3 orders, each with one family, 5 genera, approx. 1,300 species
- Polypodiophyta(ferns) 4 subclasses, 11 orders, 21 families, approx. 212 genera, approx. 10,535 species
- Subclass Equisetidae Warm.
- Subclass Ophioglossidae Klinge
- Subclass MarattiidaeKlinge
- Subclass PolypodiidaeCronquist, Takht. & Zimmerm.
These subclasses correspond to Smith's four classes, with Ophioglossidae corresponding to Psilotopsida.
The two major groups previously included in Pteridophyta are
|
Pteridophyta |
Subdivision
Pteridophytes consist of two separate but related classes, whose nomenclature has varied.[3][10] The system put forward by the Pteridophyte Phylogeny Group in 2016, PPG I, is:[2]
- Class Lycopodiopsida Bartl. – lycophytes: clubmosses, quillworts and spikemosses; 3 extant orders
- Order LycopodialesDC. ex Bercht. & J.Presl – clubmosses; 1 extant family
- Order Isoetales Prantl – quillworts; 1 extant family
- Order SelaginellalesPrantl – spikemosses; 1 extant family
- Order
- Class PolypodiopsidaCronquist, Takht. & W.Zimm. – ferns; 11 extant orders
- Subclass Equisetidae Warm. – horsetails; 1 extant order, family and genus (Equisetum)
- Order Equisetales DC. ex Bercht. & J.Presl – 1 extant family
- Subclass Ophioglossidae Klinge – 2 extant orders
- Order PsilotalesPrant – whisk ferns; 1 extant family
- Order OphioglossalesLink – grape ferns; 1 extant family
- Order
- Subclass MarattiidaeKlinge – marattioid ferns; 1 extant order
- Order MarattialesLink – 1 extant family
- Order
- Subclass PolypodiidaeCronquist, Takht. & W.Zimm. – leptosporangiate ferns; 7 extant orders
- Order OsmundalesLink – 1 extant family
- Order HymenophyllalesA.B.Frank – 1 extant family
- Order Gleicheniales Schimp – 3 extant families
- Order Schizaeales Schimp. – 3 extant families
- Order Salviniales Link – 2 extant families
- Order Cyatheales A.B.Frank – 8 extant families
- Order Polypodiales Link – 26 extant families
- Order
- Subclass Equisetidae Warm. – horsetails; 1 extant order, family and genus (Equisetum)
In addition to these living groups, several groups of pteridophytes are now
Progymnospermopsida
.
Modern studies of the land plants agree that seed plants emerged from
paraphyletic
grade.
Lifecycle
Just as with
gametes
). Pteridophytes differ from bryophytes in that the sporophyte is branched and generally much larger and more conspicuous, and from seed plants in that both generations are independent and free-living. The sexuality of pteridophyte gametophytes can be classified as follows:
- egg cells).
- Monoicous: each individual gametophyte produces both antheridia and archegonia and can function both as a male and as a female.
- Protandrous: the antheridia mature before the archegonia (male first, then female).
- Protogynous: the archegonia mature before the antheridia (female first, then male).
These terms are not the same as
dioecious
, which refer to whether a seed plant's sporophyte bears both male and female gametophytes, i. e., produces both pollen and seeds, or just one of the sexes.
See also
- Embryophyte
- Fern ally
- Plant sexuality
References
Bibliography
- Cantino, Philip D.; Doyle, James A.; Graham, Sean W.; JSTOR 25065865.
- .
- PMID 24532607.
- Clark, James; Hidalgo, Oriane; Pellicer, Jaume; Liu, Hongmei; Marquardt, Jeannine; Robert, Yannis; Christenhusz, Maarten; Zhang, Shouzhou; Gibby, Mary; Leitch, Ilia J.; Schneider, Harald (May 2016). "Genome evolution of ferns: evidence for relative stasis of genome size across the fern phylogeny". PMID 26756823.
- .
- Gifford, Ernest M.; Foster, Adriance S. (1996). Morphology and evolution of vascular plants (3rd ed.). New York: Freeman. ISBN 0-7167-1946-0.
- Kenrick, Paul; Crane, Peter (1996). "Embryophytes: Land plants". Tree of Life Web Project. Retrieved 19 April 2017.
- Kenrick, Paul; Crane, Peter R. (4 September 1997). "The origin and early evolution of plants on land" (PDF). S2CID 3866183.
- Kenrick, Paul; Crane, Peter (1997). The Origin and Early Diversification of Land Plants: A Cladistic Study. Washington, D.C.: ISBN 9781560987291.
- Pryer, K. M.; Schuettpelz, E.; Wolf, P. G.; Schneider, H.; Smith, A. R.; Cranfill, R. (1 October 2004). "Phylogeny and evolution of ferns (monilophytes) with a focus on the early leptosporangiate divergences". PMID 21652310.
- Pteridophyte Phylogeny Group (November 2016). "A community-derived classification for extant lycophytes and ferns". Journal of Systematics and Evolution. 54 (6): 563–603. S2CID 39980610.
- Ranker, Tom A.; Haufler, Christopher H. (2008). Biology and Evolution of Ferns and Lycophytes. ISBN 978-0-521-87411-3.
- ISBN 0-7167-1007-2.
- Schneider, Harald; Schuettpelz, Eric (November 2016). "Systematics and evolution of lycophytes and ferns". Journal of Systematics and Evolution. 54 (6): 561–562. S2CID 90542414.
- Smith, Alan R.; Kathleen M. Pryer; Eric Schuettpelz; Petra Korall; Harald Schneider; Paul G. Wolf (2006). "A classification for extant ferns" (PDF). JSTOR 25065646.
- Walkowiak, Radoslaw Janusz (2017). "Classification of Pteridophytes - Short classification of the ferns" (PDF). IEA Paper. .
External links
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