Biodiversity is the total variability within and among species of all living organisms and their habitats.
It is estimated that there are between 300,000 and 500,000 species of higher plants (i.e flowering and cone bearing plants), of which approximately 250,000 have been identified or described.
The diversity of plant life exists for many reasons - a key factor being adaptive changes which allow different species to thrive in the many varied environments of the world. Plants have developed adaptations for different soil types, methods of pollination, daylight hours, temperature, altitude, competition with other plants. The list is endless, even two plants of the same species, separated by geography will have a different genetic make-up.