In this article we will discuss about Gnetum. After reading this article you will learn about: 1. Distribution of Gnetum 2. Habit of Gnetum 3. Anatomy 4. Reproduction 5. Relationships. Contents: Distribution of Gnetum Habit of Gnetum Anatomy of Gnetum Reproduction of Gnetum Relationships of Gnetum 1. Distribution of Gnetum: Gnetum, represented by about 40 species is confined to the [...]
Learn about the comparison of Embryogeny and Seed of Cycas and Embryogeny and Seed of Pinus. Comparison # Embryogeny and Seed of Cycas: 1. The wall formation of cycas in the oospore starts only when numerous nuclei have been formed. 2. Pro-embryo in cycas, has no clear tiers in the young stage. 3 Only one potential embryo develops in cycas, [...]
In this article we will discuss about the Origin of Secondary Wood, Primary Vasculature and Leaf in Gymnosperms. Origin of Secondary Wood in Gymnosperms: Under-mentioned are some of the studies which indicate that the secondary wood of the modern gymnosperms might have originated in the Progymnospermopsida of Upper Devonian period: (1) The frond-genus Archaeopteris of Progymnospermopsida had very large fern-like [...]