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Polypodiopsida Cronquist, Takht. & Zimmerm. 1966


Kathleen M. Pryer, Alan R. Smith, and Carl Rothfels
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taxon links [up-->]Equisetidae [up-->]Polypodiidae [up-->]Psilotales [up-->]Marattiidae [up-->]Ophioglossales extinct icon extinct icon Phylogenetic position of group is uncertainPhylogenetic position of group is uncertain[down<--]Embryophytes Interpreting the tree
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This tree diagram shows the relationships between several groups of organisms.

The root of the current tree connects the organisms featured in this tree to their containing group and the rest of the Tree of Life. The basal branching point in the tree represents the ancestor of the other groups in the tree. This ancestor diversified over time into several descendent subgroups, which are represented as internal nodes and terminal taxa to the right.

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Tree based on Smith et al., 2006.
Containing group: Embryophytes

What is the Name of this Clade?

Polypodiopsida historically did not include the horsetails or whiskferns, two clades now believed to fall within the ferns. The use of other potential names for this inclusive clade, such as Monilophyta or Moniliformopses, is complicated by the uncertain placement of extinct taxa; these clades may not correspond perfectly with the ferns as here defined.

Another set of names, including Pteridophyta and "pteridophyte," is inappropriate for a different reason. These names are commonly used to refer to all seed-free vascular plants, and thus include both the ferns and the lycophytes (Lycopodiopsida). While these two groups have some life-cycle similarities, they are not closely related. Ferns are more closely related to seed plants ("Spermatopsida"--the gymnosperms and angiosperms) than they are to lycophytes (see the Embryophytes page for the phylogenetic tree linking these taxa).

Other Names for Polypodiopsida Cronquist, Takht. & Zimmerm. 1966


Galtier, J. and A.C. Scott. 1985. Diversification of early ferns. Proc. Roy.Soc. Edinb. 86B:289-301.

Gensel, P.G. 1992. Phylogenetic relationships of the zosterphylls and lycopsids: Evidence from morphology, paleoecology, and cladistic methods of inference. Ann. Missouri Bot. Gard. 79: 450-473.

Hasebe, M., T. Omori, M. Nakazawa, T. Sano, M. Kato, and K. Iwatsuki. 1994. rbcL gene sequences provide evidence for the evolutionary lineages of leptosporangiate ferns. Proc. Natl. Acad. Sci. USA 91: 5730-5734.

Hasebe, M., P.G. Wolf, K.M. Pryer, K. Ueda, M. Ito, R. Sano, G.J. Gastony, J. Yokoyama, J.R. Manhart, N. Murakami, E.H. Crane, C.H. Haufler, W.D. Hauk. 1995. Fern phylogeny based on rbcL nucleotide sequences. Amer. Fern J. 85: 134-181.

Holttum, R.E. 1947. A revised classification of leptosporangiate ferns. J. Linn. Soc. (Bot.) 53: 23-159.

Holttum, R.E. 1949. The classification of ferns. Biol. Rev. 24: 267-296.

Holttum, R.E. 1973. Posing the problems. In A.C. Jermy, J.A. Crabbe, and B.A. Thomas.(eds.), The phylogeny and classification of the ferns, pp. 1-10. Bot. J. Linn. Soc. 67 (Suppl. 1).

Kenrick, P. and P.R. Crane. 1997a. The origin and early evolution of plants on land. Nature: in press.

Kenrick, P. and Crane, P.R. 1997b. The origin and early diversification of land plants: a cladistic study. Smithsonian Press (in press).

Kranz, H. D. and V. A. R. Huss. 1996. Molecular evolution of pteridophytes and relationships to seed plants: evidence from complete 18S rRNA gene sequences. Plant Systematics and Evolution (in press).

Kranz, H.D., D. Miks, M. Siegler, I. Capesius, C.W. Sensen, and V.A.R. Huss. 1995. The origin of land plants: phylogenetic relationships among charophytes, bryophytes, and vascular plants inferred from complete small-subunit ribosomal RNA gene sequences. J. Mol. Evol. 41: 74-84.

Kubitzki, K. (ed.). 1990. The families and genera of vascular plants. Vol. 1. Pteridophytes and gymnosperms. K.U. Kramer and P.S. Green (vol. eds.). Springer-Verlag, Berlin.

Lovis, J.D. 1977. Evolutionary patterns and processes in ferns. In R.D. Preston and H.W. Woolhouse (eds.), Advances in botanical research, Vol. 4, pp. 229-415. Academic Press, London.

Manton, I. 1950. Problems of cytology and evolution in the Pteridophyta. Cambridge University Press, London.

Manhart, J.R. 1995. Chloroplast 16S rDNA sequences and phylogenetic relationships of fern allies and ferns. Amer. Fern J. 85: 182-192.

Mickel, J.T. 1974. Phyletic lines in the modern ferns. Ann. Missouri Bot. Gard. 61: 474-482.

Pichi Sermolli, R.E.G. 1977. Tentamen pteridophytorum genera in taxonomicum ordinem redigendi. Webbia 31: 313-512.

Pryer, K.M., A.R. Smith, and J.E. Skog. 1995. Phylogenetic relationships of extant ferns based on evidence from morphology and rbcL sequences. Amer. Fern J. 85: 205-282.

Pryer, K. M., H. Schneider, et al. 2001. Horsetails and ferns are a monophyletic group and the closest living relatives to seed plants. Nature 409: 618-622.

Pryer, K. M., E. Schuettpelz, et al. 2004. Phylogeny and evolution of ferns (monilophytes) with a focus on the early leptosporangiate divergences. Amer. J. Bot. 91: 1582-1598.

Raubeson, L.A. and D.B. Stein. 1995. Insights into fern evolution from mapping chloroplast genomes. Amer. Fern J. 85: 193-204.

Rothwell, G.W. 1987. Complex Paleozoic filicales in the evolutionary radiation of ferns. Amer. J. Bot. 74: 458-461.

Rothwell, G.W. 1994. Phylogenetic relationships among ferns and gymnosperms; an overview. J. Plant Res. 107: 411-416.

Rothwell, G.W. 1995. The fossil history of branching: Implications for the phylogeny of land plants. Pp 71-86 in: P.C. Hoch and A.G. Stevenson (eds.). Experimental and molecular approaches to Plant Biosystematics. Missouri Botancial Garden, St. Louis.

Rothwell, G.W. 1996. Pteridophytic evolution: an often underappreciated phytological success story. Rev. Palaeobot. Palynol. 90: 209-222.

Rothwell, G.W. and R.A. Stockey. 1994. The role of Hydropteris pinnata gen. et sp. nov. in reconstructing the cladistics of heterosporous ferns. Amer. J. Bot. 81: 479-492.

Schneider, H. 1996. Vergleichende Wurzelanatomie der Farne. Ph.D. Dissertation, Zurich University.

Schuettpelz, E., P. Korall, et al. 2006. Plastid atpA data provide improved support for deep relationships among ferns. Taxon 55: 897-906.

Schuettpelz, E. and K. M. Pryer. 2007. Fern phylogeny inferred from 400 leptosporangiate species and three plastid genes. Taxon 56: 1037-1050.

Smith, A.R. 1995. Non-molecular phylogenetic hypotheses for ferns. Amer. Fern J. 85: 104-122.

Smith, A. R., K. M. Pryer, et al. 2006. A classification for extant ferns. Taxon 55: 705-731.

Stewart, W.N. and G.W. Rothwell. 1993. Paleobotany and the evolution of plants, ed. 2. Cambridge University Press, Cambridge.

Taylor, T.N. and E.L. Taylor. 1993. The biology and evolution of fossil plants. Prentice-Hall, Inc., Englewood Cliffs, NJ.

Thomas, B.A. 1991. The study of fossil ferns. British Pteridology 1891-1991: 7-16.

Tryon, A.F. and B. Lugardon. 1991. Spores of the Pteridophyta. Springer-Verlag, New York.

Tryon, R.M. and A. Tryon. 1982. Ferns and allied plants, with special reference to tropical America. Springer-Verlag, New York.

Wagner, W. H., Jr. 1974a. Pteridology, 1947--1972. Ann. Missouri Bot. Gard. 61: 86--111.

Wagner, W. H., Jr. 1974b. Structure of spores in relation to fern phylogeny. Ann. Missouri Bot. Gard. 61: 332--353.

Wagner, W.H., Jr. and A.R. Smith. 1993. Pteridophytes. Pp. 247-266 in Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico. Oxford University Press, New York.

Wolf, P.G. 1995. Phylogenetic analyses of rbcL and nuclear ribosomal RNA gene sequences in Dennstaedtiaceae. Amer. Fern J. 85: 306-327.

Wolf, P.G., P.S. Soltis, D.E. Soltis. 1994. Phylogenetic relationships of dennstaedtioid ferns: evidence from rbcL sequences. Mol. Phylog. Evol. 3: 383-392.

Wolf, P. G., K. M. Pryer, A. R. Smith, and M. Hasebe. in press. Phylogenetic studies of extant pteridophytes. In: Molecular Systematics of Plants, 2nd edition. P. S. Soltis, D. E. Soltis, J. J. Doyle (eds). Chapman and Hall, New York.

Information on the Internet

Title Illustrations
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Scientific Name Psilotum nudum
Specimen Condition Live Specimen
Body Part Close view of the stem, showing immature sporangia
Copyright © 1997 Brian R. Speer
Scientific Name Cyathea
Comments young leaf of a tree fern
Body Part young leaf (crozier)
Copyright © 1997
Scientific Name Equisetum pratense
Specimen Condition Live Specimen
Source Meadow Horsetail
Source Collection Flickr
Image Use creative commons This media file is licensed under the Creative Commons Attribution-ShareAlike License - Version 2.0.
Copyright © 2008 Miika Silfverberg
Scientific Name Cheiroglossa palmata
Comments a tropical fern growing on tree bark
Copyright © 1997
Scientific Name Osmunda regalis
Location Massachusetts, USA
Comments The royal fern in Julia Child's yard
Copyright © 1997 Nan Crystal Arens
About This Page
We are grateful to Brian R. Speer (Dept. of Integrative Biology, University of California at Berkeley); for his patient technical assistance.

Kathleen M. Pryer
Duke University, Durham, North Carolina, USA

University of California, Berkeley, California, USA

Carl Rothfels
Duke University, Durham, North Carolina, USA

Correspondence regarding this page should be directed to Kathleen M. Pryer at and Carl Rothfels at

All Rights Reserved.

Citing this page:

Pryer, Kathleen M., Alan R. Smith, and Carl Rothfels. 2009. Polypodiopsida Cronquist, Takht. & Zimmerm. 1966. Ferns. Version 14 January 2009 (under construction). http://tolweb.org/Polypodiopsida/20615/2009.01.14 in The Tree of Life Web Project, http://tolweb.org/

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For a more detailed explanation of the different ToL page types, have a look at the Structure of the Tree of Life page.

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