Gymnosperma (Pine)

Gymnosperma (Pine) Characteristics of the life cycle The female and male inflorescence of the pine tree develop as cones on the sporophyte. The female cones (female strobili, singular strobilus) consist of megasporophylls that carry uncovered (Gymno = naked / exposed, hence Gymnosperms) ovules. Inside the ovule the megasporocyte undergoes meiosis, producing four haploid cells. One of these cells survive as a megaspore. The megaspore goes through mitotic divisions and forms a small female gametophyte, in which two or three...

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Cycadofilicales: Features and Classification | Gymnosperms

Cycadofilicales: Features and Classification | Gymnosperms | Origin of Cycadofilicales: The Cycadofilicales or Pteridosperms are popularly known as ‘seed ferns’. They were trees or small plants bearing fern-like foliage. They flourished greatly in the Carboniferous and the period was so very rich in fossil fern leaves that it was thought to be the ‘Age of Ferns’. Owing to the presence of fern-like leaves they were formerly believed to be a kind of fern, but subsequently when fossil leaves with attached seeds were discovered (1903) the Cycadofilicales...

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Bennettitales: Classification and Features | Gymnosperms

Bennettitales: Classification and Features | Gymnosperms  Contents: Origin of Bennettitales The Sporophyte and the Flower of Bennettitales Characteristic Features of Bennettitales Classification of Bennettitales Comparison between Williamsoniaceae and Cycadeoideaceae Genera of Bennettitales Indian Bennettitales  Affinity of Bennettitales 1. Origin of Bennettitales: Bennettitales resembled modern Cycads but had...

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