Phylum

Polypodiophyta

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The phylum Pterophyta is a group of non-seed plants with a fossil record dating back to the lower Devonian. The phylum consists of about 11,000 living species.

Vegetatatively,the Pterophyta are a diverse group of plants with true leaves, roots and stems. Leaves are macrophylls and, in many families, demonstrate circinate vernation (a pattern of uncoiling of a crozier-like structure due to uneven growth). While arborescent species exist, no living fern demonstrates true secondary growth. Roots are adventitious.

Reproductively, the Pterophyta also vary; they may be either homosporous and exosporic or heterosporous and endosporic. Homospory with the production of photosythetic free-living gametophytes is the most common pattern. The structure of the spore, sporangium and sorus are all important taxonomic features.

 

Links to Family Directories:

 Aspleniaceae  Dryopteridaceae  Polypodiaceae
 Athyriaceae  Gleicheniaceae  Pteridaceae
 Azollaceae  Hymenophyllaceae  Salviniaceae
 Blechnaceae  Marattiaceae  Schizeaceae
 Cyathaceae  Marsileaceae  Thelypteridaceae
 Dennstaeditaceae  Ophioglossaceae  
 Dicksoniaceae  Osmundaceae