The former is concerned with the division of the earths surface into major districts characterized by particular plants or taxonomic groups of plants, with the subdivision of these floristic districts, and with the geographical distribution (both past and present) of the various taxonomic units, such as species, genera, and families.
In a general way, floristic plant geography is concerned with species, ecological plant geography with vegetation.
This mattel- is bound up with the centres of origin and with the past migrations of species; and such questions are usually treated as a part of floristic plant geography.
