Fern Ally - Classification

Classification

There were originally three or four groups of plants considered to be fern allies. In various classification schemes, these may be grouped as classes or divisions within the plant kingdom. Fern allies and ferns were sometimes grouped together as division Pteridophyta. Another traditional classification scheme of living plants is as follows (here, the first three classes are the "fern allies"):

• Kingdom: Plantae
  • Division Tracheophyta (vascular plants)
    • Class Lycopsida, clubmosses and related plants (fern-allies)
    • Class Sphenopsida or Equisetopsida, horsetails and scouring-rushes (fern-allies)
    • Class Psilopsida, whisk ferns (fern-allies)
    • Class Filices or Pteropsida, true ferns
    • Class Spermatopsida (or sometimes as several different classes of seed-bearing plants)

More recent evidence shows that the class Filices, as described above, is not monophyletic. The following classification represents a consensus view (although different authors may use different names for the various groups):

• Kingdom Plantae
  Subkingdom Tracheobionta
  • Division Lycopodiophyta
    • Class Lycopodiopsida, clubmosses
    • Class Selaginellopsida, spikemosses
    • Class Isoetopsida, quillworts and scale trees
  • Division Pteridophyta
    • Class Equisetopsida, horsetails and scouring-rushes
    • Class Psilotopsida, whisk ferns, adders'-tongues and moonworts
    • Class Marattiopsida, marattioid ferns
    • Class Pteridopsida, leptosporangiate ferns (also called Polypodiopsida or Filicopsida)
  • Division Spermatophyta (or as several different divisions of seed-bearing plants)

Note that in either scheme, the same basic groups are recognized (Lycopodiophyta, Equisetopsida, Psilotopsida), but in the most recent scheme only the Lycopodiophyta is not classified with the ferns.