Gnetales: An Overview
Gnetales is an order of the gymnospermic seed plants. This order is composed of three genera- Gnetum, Ephedra, and Welwitschia. Chamberlain (1935) has placed all three genera in a single-family…
Gymnosperms
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Coniferales: An Overview
Coniferales is a group of gymnospermic plants. The members of this group form the common conifers. It includes both fossil and present-day living genera. Coniferales reached their maximum development probably…
Ginkgoales: An Overview
Ginkgoales is a gymnospermic order having one living genus (Ginkgo biloba). The members of this order once had an almost worldwide distribution in the Jurassic period. The fossil members of…
Cycadales: An Overview
Cycadales is a gymnospermic order. Members of this order are mostly inhabitants of tropical and subtropical regions. It includes both living and fossil genera. They originated in the Mesozoic era…
Pteridospermales (Cycadofilicales): An Overview
The Pteridospermales or Cycadofilicales are characteristic gymnospermous plants that bore fern-like foliage, which in turn bore seeds that were unprotected. Hence, they are known as seed ferns. Pteridospermales is a…
Bennettitales (Cycadeoidales): An Overview
The Bennettitales (Cycadeoidales) are a fossil group found from the Triassic to the lower Cretaceous, but were predominant in the Jurassic period of the Mesozoic era in South America, North…
Evolution of Female Gametophyte in Gymnosperms
The female gametophyte of gymnosperms is a multicellular structure serving the functions of bearing the archegonia and nourishing the developing embryo. It exhibits a progressive series of significant changes leading…