The Plantae Kingdom includes a great number of plant species that presently inhabit the planet – from the primitive ferns to the more evolved flowering plants. This gives origin to a huge variety of life forms, modeling every ecosystem on earth. With more than 250 000 species, plants are the second more diverse group of higher living organisms, being only out passed by arthropods.
On of the most important plant characteristics is their green colour, which is due to the presence of a pigment called chlorophyll, which absorbs sunlight and uses its energy to synthesize carbohydrates from CO2 and water through a process called photosynthesis.