Gymnosperms are a group of plants that hold the seeds. Their ovules are not enclosed in an ovary, so these plants do not bear fruits. The botanical Classification of Gymnosperms can be of four types: Cycads, conifers, ginkgo and gnetophyta.
- Cycads: Cycads are the seed plants which were popular during the dinosaur period of earth. They are the primitive gymnosperms. These kind of trees have thick trunks, large compounded leaves i.e. they contain many small leaflets which are attached to a single central stem. The smallest gymnosperms found today are the zamia pygmae. They are about 25 cm in height. Cycads are the dioecious plants i.e. they have separate male and female plants. The male plant have the cones filled with pollen grains. Whereas the female plants produce the seeds. Sago palm is the most popular cycad plant.
- Gnetophyta: They are another genus of gymnosperms which commonly consist of tropical evergreen trees, shrubs and woody vines from the three different genera namely Ephedra, Gnetum and Welwitschia. They have a soft coating which gives them a flowery look. This coating gives gnetophyta an ancestral connection with the angiosperms.
- Ginkgo: The only species of Ginkgophyta present till now is Gingkgo, also known as maidenhair tree. It has a sturdy leaf-like structure. These plants were saved by the Chinese people as they use it for various medicines and it is believed that its fan type leaves and seeds help in improving the memory and sharpening the thinking level.
- Conifers: Conifers or the Corniferopsida are characterized by their male and female cones. They are known for their smaller male and bigger female cones as well as the needle like structures of the leaves. For about 200 million years they have dominated the world’s major forests, but now only 630 species of them are left. They are present at places having a temperate climate. Hence they consist of medium, tall sized trees and even small shrubs. One of the example of conifers is Sequia Sempervines also known as Red Douglas or Caliphornia.
Sequia is the tallest gymnosperm and it can live for 1800 years and its height is about 110m.