Over the past 250 years, the botanical community has developed an elaborate system of rules for the proper naming of plants. Members of this community meet every six years to discuss changes to the published code of botanical nomenclature. This means that it is permissible for a plant to have a name that is also used for an animal. Types Names are based on their types.
Every plant name is tied to a particular herbarium specimen called a type.
A type is a specimen that a botanist designates as typical of what he or she believes a new species to be. Another botanist may not be able to understand the classification proposed by the first botanist but can always examine the type specimen and use that as a guide to applying the name. There are also many examples of names that have had to be changed because the type, after it had been examined, was found to belong to a different species. For instance, the small-headed aster of eastern North America had been called Aster vimineus , but the type of this name was shown to be a specimen of the goblet aster, Aster lateriflorus . Therefore, Aster vimineus can no longer be used for the small-headed aster, which is now called Aster racemosa .