Suvarna Garge (Editor)

Schizaeales

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Kingdom
  
Plantae

Rank
  
Order

Division
  
Pteridophyta

Schizaeales tolweborgtreeToLimages31065763151747d9c5o25

Class
  
Polypodiopsida /  Pteridopsida (disputed)

Similar
  
Gleicheniales, Lygodium, Schizaeaceae, Osmundales, Water ferns

Schizaeales is an order of fern (class Pteridopsida).

Contents

Classification

In the molecular phylogenetic classification of Smith et al. in 2006, the Schizaeales were placed in the leptosporangiate ferns, class Polypodiopsida. Three families, Anemiaceae, Lygodiaceae, and Schizaeaceae were recognized. The linear sequence of Christenhusz et al. (2011), intended for compatibility with the classification of Chase and Reveal (2009) which placed all land plants in Equisetopsida, reclassified Smith's Polypodiopsida as subclass Polypodiidae and placed the Schizaeales there, with the same three families. The classification of Christenhusz and Chase (2014) placed all members of the Schizaeales in a more broadly defined Schizaeaceae, reducing the three existing families to subfamilies as Anemioideae, Lygodioideae, and Schizaeoideae. The PPG I classification (2016) returned to the three-family definition of the order.

Historically, the ferns in this order were once all lumped into the family Schizaeaceae in the old order Filicales. However, although they are demonstrably related, these ferns differ markedly, and so three groups have now been elevated to family status:

  • The family Schizaeaceae are generally small ferns with forking fronds and a distinctive, somewhat non-fern-like, appearance.
  • The family Anemiaceae look very fern-like and are typically terrestrial or epipetric.
  • The family Lygodiaceae, or Climbing Ferns, look very ferny but are highly distinctive in their growth habit: the rachis of the frond is long and flexible, with indeterminate growth, so that the fronds form climbing or trailing vines.

    • At one time some workers believed the water ferns (order Salviniales) to be allied to this order because of certain structural similarities, but modern cladistic studies have ruled out any special alliance.

    Evolution

    Schizaeales had a northern hemisphere concentration as late as the Mesozoic, but by the Quaternary, there was a clear shift to a southern hemisphere distribution

    References

    Schizaeales Wikipedia
    (Text) CC BY-SA