We analysed and interpreted ecologically a part of classic peatland vegetation material of prof. Rauno Ruuhijärvi dating from 1960. Sample plots formed a compositional gradient along NMDS 1 across three traditionally recognized peatland subzones of Finnish Lapland, and Cajanderian site types showed a poor—rich gradient along NMDS 2. Analysis-based major vegetation groups were related to the regional and the mire-expanse-to-margin gradient. Southerly-focused Eriophorum gracile—Potentilla palustris—Straminergon stramineum major group was interpreted as an indication of a more voluminous spring flood in a more oceanic climate, while northerly-focused Carex rotundata—Trichophorum cespitosum m. g. was interpreted as a reflection of a minor spring flood in a more continental climate. Regional communities were compatible with Cajanderian site types and showed new regional and vegetation-ecological features for site types. They were related to three European fen alliances, which represented boreal (Stygio-Caricion limosae), arcto-boreal-alpine (Drepanocladion exannulati) and widespread (Scheuchzerion palustris) vegetation.