A literature study on the plant geography of West European soft-water macrophyte species was carried out. The purpose of this study was to find an explanation for the specific composition of the Dutch softwater flora. In The Netherlands, soft-water macrophyte species with very different geographical ranges coexist. With respect to species distribution, four geographical groups could be distinguished: (1) a group with a boreal distribution; (2) a group with an atlantic distribution; (3) a group with a distribution that extends over the boreal and the atlantic area; and (4) a group with a wider distribution. Boreal and atlantic species favour different soft-water microhabitats and are ecologically not similar. Littorella uniflora (L.) Aschers., both boreal and atlantic, combines the ecological characteristics of both groups of species.