oldest known plants is a simple blue-green algae.They were a single-celled organisms to function with one devoid of the cell nucleus.Among the blue-green algae found both unicellular and multicellular organisms capable of photosynthesis.The process of photosynthesis contributed entering the Earth's atmosphere of oxygen.

about 2600 million years ago, in the Proterozoic era, the Earth filled red and green algae.In the Late Paleozoic (Silurian) having the oldest higher plants called Rhyniophyta or psilophytes.They were shoots, but no leaves and roots.Rhyniophyta reproduce by spores.They grew partly on land or in water.

appearance of higher spore plants

about 400-360 million years ago, there are first spread Moss fami
ly ferns and plants belonging to the higher spore plants.On land begins the process of separation plant to the root, stem and leaf, having supporting tissue and vascular conduction system.

first land plants were small in size.Gradually there were more major forms of plants - ferns, having roots with root hairs.In the Paleozoic era ferns were huge plants that filled the land.But due to the fact that their propagation needed water, they grew only in areas having high humidity.

gymnosperms and angiosperms

360-280 million years ago (Carboniferous period) were seed ferns, which became the ancestor of all gymnosperms.Dominated while huge tree ferns gradually die off and form deposits of coal.

In the Permian period of the Paleozoic appear ancient gymnosperms.In place of an endangered tree-ferns and grass seed come ferns.

About 240 million years ago came the Mesozoic Era.Its Triassic any modern gymnosperms, and in the Jurassic - early angiosperms.They have a flower, inside which the pollination, fertilization and the formation of the fetus.It should include angiosperms herbaceous plants, trees and shrubs.

About 70 million years ago, begins Cenozoic era, the planet fill existing today angiosperms and gymnosperms.

evolution of plants - a very difficult and lengthy process, in which the world appears all the modern variety of plants, including algae, ferns, bryophytes and flowering plants.