Tag: phanerogams

In Gymnosperms the fertilized ovule does not develop into a fruit as it would in an angiosperm. Because gymnosperms have no ovary, they can never produce fruit. Seeds develop from the ovules that are found in the developed ovaries or fruit, but in the case of gymnosperms, the ovules are located directly on the surface of the flower or cone. Yews and ginkgoes develop fruit like structures, but their seed is not inside these organs, which makes them Gymnosperms.

Gymnosperms are seed bearing non flowering plants. Since gymnosperms have no ovaries, they do not produce real fruits, at least not in the botanical sense. Because no fruit tissue surrounds gymnosperm seeds, the seeds are said to be "naked." 
In Gymnosperms vascular tissues are arranged into vascular bundles just like Angiosperms. However, xylem does not possess vessels and phloem is without companion cells, like pteridophytes.

A perennial plant or simply perennial is a plant that lives for more than two years. 

The gymnosperm is represented by a perennial, evergreen, woody plant. Most of them are trees and some are shrubs. A few gymnosperms may be lianas or climbers. There are no herbs. Gymnosperms include one of the world's tallest trees, Sequoia sempervirens.

Megasporangium or ovule is borne on adaxial or upper surface of megasporophyll or ovuliferous scale and are generally orthotropous and unitegmic in gymnosperms but are bitegmic in the Gnetales.

The gymnosperms are a group of seed-producing plants that do not produce flowers. These include conifers, cycads, Ginkgo, and gnetales. Though they are seed bearing their seeds are not enclosed in ovary they make up for about 700 species of woody plants with most of them being trees and some shrubs. A few gymnosperms however may lianas or climbers. However, there are no herbs in the group.

Fruits are not formed in gymnosperms due to absence of ovary. The ovules of a gymnosperm do not develop in an ovary but are "naked". Seeds develop from the ovules that are found in the developed ovaries but in the case of gymnosperms, the ovules are located directly on the surface of the flower or cone. 

Gymnosperms and angiosperms are the phenerogames or spermatophytes. 

Gymnosperms are the most primitive of the seed plants. A seed comprises two parts: an endosperm, which nourishes the embryo, and the embryo itself, which is fed by the endosperm.

The sporophyte (2n) phase is the longest phase. The gametophytes (1n), microspores and megaspores, are reduced in size. This phase may take more than one year between pollination and fertilization, while the pollen tube grows towards the megasporocyte (2n), which undergoes meiosis into megaspores. The megaspores will mature into eggs (1n) .
Gymnosperm seed is made up of three generations of tissues. 
1) maternal sporophyte tissue (seed coat and nucellus), 
2) gametophyte 
3) daughter sporophyte (embryo)