Know All About Pteridophytes

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                    Pteridophytes :- 

The pteridophytes include horsetails and ferns. 

• The first terrestrial plants to possess vascular tissue – xylem and phloem. 

• In bryophytes the dominant phase in the life cycle is the gamethophytic plant body. However. In pteridophytes , the main plant body is a sporophytes. 

• in forns. 

• Distinct compact structures called strobli or cones (Selaginella, Equisetum). 

• Inconspious , small bet multicellular.

• Free – living mostly photosynthetic thalloid gametophytes called prothallus. 

• Need for water for fertillisation. 

• Fussion of male gamete with an egg present in archegonium result in the formation of zygotes. 

• Selaginella and Salvinia which produce two kinds of spores, macro (large) and micro (small) spores, are known and Heterospores .

The Female gametophytes in these plants are retained on the parents sporophytes for variable periods. The developments of the zygote into young embryo take place within in the female gametophytes. This events is a precursor to the seed habit consided and important step in evolution. 


   Pteridophytes further classified into fear classes. 

• Psilopsida (Psilotum).

• Lycospida ( Selaginella , Lycopodium) 

• Sphenopsida (Equistum) 

• Pteropsida ( Dryopteries , Pteris , Adiantum). 


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