The first plants appeared about 2.5 billion years ago, and since then has come a long evolutionary path.
Who on Earth about 400 thousand species of plants, which are dominated by gymnosperms and flowering.
The first plant scientists say blue-greenAlgae - the major bacteria that provide themselves with energy through photosynthesis, the process that releases oxygen. They appeared not later than 2.5 billion years ago and are still in existence. Blue-green algae is significantly influenced the development of life on Earth, as they have led to a sharp saturation of oxygen in the atmosphere. Currently they produce according to various estimates from 20 to 40% of all the oxygen on the planet.
During the Proterozoic era (2700-570 million yearsago) Wildlife finally split into heterotrophic (animal kingdom) and autotrophic (plant kingdom) organisms. Along with the blue-green algae, a host of other bacteria-autotrophs - green algae, red algae, iron bacteria, etc.
About 450 million years ago, the first plantsappeared on land, these were higher plants, which in contrast to algae have differentiated tissues. The first plants on land are called Rhyniophyta, they grow up to 20 cm in height and covered with vast tracts of land with a continuous carpet. At the moment, these primitive plants are completely extinct. In these special cells first appeared - tracheids, which provided the movement of nutrients and water within the plant. At the same time, there were mosses and lichens.
After 50 million years there were the firstfern, which is the same as the Rhyniophyta, reproduce by spores, but were more advanced. Some ferns reached enormous proportions. Formed fern forest. Wet hot climate of the period contributed to the prosperity of spore.
Fern and other spore graduallygymnosperms evolved. During the Permian period (230-280 million years ago) spore virtually disappeared from the face of the earth, and they were replaced by coniferous and ginkovye that thrived during the Triassic and Jurassic. At this time, there was a huge number of species of gymnosperms, some of them even had yagodovidnye fruit.
At the beginning of the Cretaceous period, which is about 137millions of years ago, the first angiosperms, which is actively developing during this period. These plants, like grapes, beech, willow, poplar, ficus, eucalyptus, board, laurel, magnolia, appeared at a time.
Cenozoic Era, which began 67 millionyears ago and continues to this day, it was the era of angiosperms, already at the beginning of the earth landscapes were similar to modern. During the ice age species of angiosperms appeared sensitive to the cold.