Carex buxbaumii is a circumboreal species, rather rare in Fennoscandia and C.-Europe, very rare and scattered in Western Europe. It is characteristic of sedge swamps in succession to litter fen with oscillating phreatic level. Its ecological amplitude however seems not to be quite similar all over Europe. For an analysis of such differences vegetation tables (method of Braun-Blanquet) from E.-France, S.-Germany, Poland, the Netherlands and Sweden are summarised and compared in table I. Going from S to N and from E to W the species shows a tendency of preferring a more oligotrophic and moister habitat with a less oscillating water table. The dynamic and ecological position of the species within the Netherlands has been studied more in detail (table II).