Definitions

stomium

Polypodiales

The order Polypodiales encompasses the major lineages of polypod ferns, which comprise more than 80% of today's fern species. They are found in many parts of the world including tropical, semitropical and temperate areas. The characteristics of this group include: sporangia with a vertical annulus interrupted by the stalk and stomium; indusia laterally or centrally attached (or lost); gametophytes green, chordate, and surficial.

Polypodiales may be regarded as one of the most evolutionarily advanced orders of monilophytes (ferns), based on recent genetic analysis. They arose and diversified about 100 million years ago, probably subsequent to the diversification of the angiosperms.

The 15 families of Polypodiales are listed here from those considered most basal to those considered most derived:

Now-obsolete families of Polypodiales:

  • Drynariaceae - now in Polypodiaceae
  • Grammitidaceae - now in Polypodiaceae
  • Gymnogrammitidaceae - now in Polypodiaceae
  • Loxogrammaceae - now in Polypodiaceae
  • Nephrolepidaceae - now in Lomariopsidaceae
  • Platyceriaceae - now in Polypodiaceae
  • Pleursoriopsidaceae - now in Polypodiaceae

References

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