Fern ally is a general term covering a somewhat diverse group of vascular plants that are not flowering plants and not true ferns. Like ferns, these plants reproduce by shedding spores to initiate an alternation of generations. There are 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. The more traditional classification scheme is as follows (here, the first three classes are the "fern allies"):

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

A more modern or newer classification scheme is:

• Kingdom Plantae
  Subkingdom Tracheobionta
  • Division Lycopodiophyta
    • Class Lycopodiopsida, the clubmosses
    • Class Selaginellopsida, the spikemosses
    • Class Isoëtopsida, the quillworts
  • Division Equisetophyta, the horsetails and scouring-rushes
  • Division Psilotophyta, the whisk ferns
  • Division Ophioglossophyta, the adders-tongues and moonworts
  • Division Pteridophyta, the ferns
  • Division Spermatophyta (or as several different divisions of seed-bearing plants)

Note that in either scheme, the basic subdivision of the fern allies is preserved, with the exception that the Ophioglossophyta (Ophioglossopsida), once thought to be true ferns, are now generally regarded by many to be a distinct group of fern allies.

External links

• Common Ferns and Fern-Ally Species
• A Classification of the Ferns and Fern-Allies (uses frames)