Fungi

 

Description

The Pteridophytes or Ferns and allies are an ancient and widespread plant group comprised of some 12,000 species. They are amongst the most successful plants in the world with plants such as Bracken (Pteridium aquilinum) having a genuinely global distribution. It is obvious to the naked eye that Ferns are dramatically different from Flowering plants and Conifers with their graceful arching fronds. What is not at all obvious however is that their life-cycle is dramatically different with the reproductive cycle occurring in two distinct phases, part of which is underground. They are for this reason called Cryptogametophytes which is a bit of a mouthful but accurate. I should know as I once failed an exam question on the meaning of the word.

Other than their reproductive differences, Ferns are morphologically distinct too, some having papery scales rather than hairs, but the most obvious distinction are their fronds which are frequently divided into minute pinnae, which are then further subdivided.

The Pteridophytes evolved in the Carboniferous and there are extensive fossil records. Giant Horsetails (Equisetopsida) formed some of the earliest forests and their 30m tall stems must have been an amazing sight.

The Taxonomy of the Pteridophytes is presently at a crossroads. There is no current consensus and much more work needs to be done to resolve issues of classification.

What is not at issue however is that ferns are some of the most beautiful plants as in the Tree-Fern Dicksonia antartica  or delicate as in Athyrium felix-femina, the beautiful Lady Fern

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All text & Images ©Andrew Brown 2003-2014