The neotropical region as a whole is much more species diverse than the palaeotropics but no more diverse at the family and only slightly at the generic level. Only 6.4% of neotropical species belong to plant families that are confined to the region and there is a greater generic diversity in Africa than in the neotropics indicating that species are much better indicators of total diversity. The striking difference in species make up between the northern Andean region and Amazonia is important to recognize in conservation planning. In the northern Andean region, herbs and shrubs with Andean-centred distributions predominate whereas in Amazonia, trees and shrubs with Amazonian-centred distributions predominate. The analysis of species distributions show both centres of endemism and centres of diversity which are not apparent when only higher taxa are considered. The local demography of species varies considerably within the lowland rainforest regions and this is discussed using data from quantitative inventories. It is concluded that accurate assessment of the taxon component of biodiversity of the neotropics must be based at the species level rather than at that of higher taxa, and that species data are a valuable tool for conservation planning.