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Pteridopsida ~ Modern Ferns
Tree fern
Tree fern
Scientific classification
Kingdom: Plantae
Division: Pteridophyta
Class: Pteridopsida/Polypodiopsida
Orders

The Pteridopsida is a class of plants in the Division Pteridophyta that includes all the leptosporangiate ferns. Plants are living Organisms belonging to the kingdom Plantae. A fern is any one of a group of about 20000 Species of Plants classified in the phylum or division Pteridophyta, also known as Filicophyta Osmundaceae is the only Fern family of the order Osmundales; an order in the class Polypodiopsida or in some classifications the only order in the The Hymenophyllaceae ( filmy ferns and bristle ferns) is a family of seven genera and over 600 species of Ferns with a subcosmopolitan distribution Schizaeales is an order of fern (class Pteridopsida) The ferns in this order were once all lumped into the family Schizaeaceae in the old order Filicales The order Salviniales (formerly known as the Hydropteridales and including the former Marsileales) is an order of Ferns in the Division Pteridophyta The order Cyatheales is a Taxonomic division of the Fern subclass Cyatheatae, which includes the tree ferns. The order Polypodiales encompasses the major lineages of polypod Ferns which comprise more than 80% of today's fern species Blechnales is a order of Fern. Some authors include the Blechnales in a more broadly defined Polypodiales. Plants are living Organisms belonging to the kingdom Plantae. A fern is any one of a group of about 20000 Species of Plants classified in the phylum or division Pteridophyta, also known as Filicophyta Leptosporangiate ferns are vascular spore plants whose Sporangia arose from a single epidermal cell and not from a group of cells as in Eusporangiate ferns In the recent 2006 classification by Smith et al. the class is renamed Polypodiopsida. This recent reclassification of Monilophyte (ferns) is based on multiple molecular studies published since 1994 that have clarified some of the confusion of the placement and relations among fern families. Monilophyte refers to the monophyletic group of Ferns defined in a broad sense which is sister group to the Spermatophytes within the Subdivision Euphyllophytes [1] Polypodiopsida is one of four classes of Monilophytes (an Infradivision, this rank is not recognized by the International Code of Botanical Nomenclature), the other three being Marattiopsida, Equisetopsida, and Psilotopsida. Class Marattiopsida is a group of Ferns containing a single order Marattiales, and family Marattiaceae. Equisetopsida, or Sphenopsida, is a class of Plants with a fossil record going back to the Devonian. Psilotopsida is a class of Fern -like plants As circumscribed by Smith et al [1]

Classification

The classification scheme proposed by Smith et al. (alternative names in brackets):



Discussion of Molecular Classification

There has been some challenge to the recent molecular studies, claiming that these provide a skewed view of the phylogenetic order because the studies don't take into account fossil representatives[2]. Polypodiaceae is a family of polypod Ferns which includes more than 60 Genera divided into several tribes and containing around 1000 Polypodiaceae is a family of polypod Ferns which includes more than 60 Genera divided into several tribes and containing around 1000 Polypodiaceae is a family of polypod Ferns which includes more than 60 Genera divided into several tribes and containing around 1000 Polypodiaceae is a family of polypod Ferns which includes more than 60 Genera divided into several tribes and containing around 1000 Polypodiaceae is a family of polypod Ferns which includes more than 60 Genera divided into several tribes and containing around 1000 Polypodiaceae is a family of polypod Ferns which includes more than 60 Genera divided into several tribes and containing around 1000 However, the molecular studies have clarified relations among families that were thought to be non-monophyletic before the advent of molecular information, which were left in their non-monophyletic ranks because there was not enough information to do otherwise[3]. The reclassification of ferns using multiple molecular studies, which have generally supported each other, is not any different from classifications of the past--it is the definition of the relations utilizing the all the information available. It does not discourage the further study and clarification of the groups, and does not mean that if further study proves the classification wrong, it will not be changed.

References

  1. ^ a b Smith, A. R. , K. M. Pryer, et al. (2006). "A classification for extant ferns. " Taxon 55(3): 705-731
  2. ^ Rothwell, G. W. and K. C. Nixon (2006). "How does the inclusion of fossil data change our conclusions about the phylogenetic history of euphyllophytes. " Int. J. Plant Sci 167(3): 737-749
  3. ^ Kramer, K. U. (1990). Notes on the Higher Level Classification of the Recent Ferns. The Families and Genera of Vascular Plants: Pteridophytes and Gymnosperms. K. Kubitzki, K. U. Kramer and P. S. Green. New York, Springer-Verlag. 1: 49-52
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