This provides people world-wide, a way to refer to a distinctly identified and classified plant using the same accepted name. A genus refers to a group of species of plants that share certain structural characteristics as determined by botanical study. The genus name, a noun, may come from mythology, literature, or other sources which refer to something the plant resembles. This is why plants with distinctively different foliage or other characteristics can be classified as the same species.
Species is abbreviated sp.
A subdivision of species which describes naturally occurring changes, sports, or mutations that create a distinctively different plant in appearance. The same plant may grow on two different continents but grow taller on one than the other or have identical flowers forms but different colors. These would would be an example of different forms or varieties. These are sometimes abbreviated cv. Examples are variegations, growth forms, foliage or flower color, etc.