Abstract. Devillers, P. & Devillers-Terschuren, J.- Habitats of orchids of Wallonia [Natural. belges 79 (Orchid. 11) (1998): 219-240]. The habitats of the orchids of the Walloon region, one of the federated entities of Belgium, are reviewed in terms of the typology of Palaearctic habitats developed in the CORINE-Biotopes project of the European Union and the Emerald project of the Council of Europe. Allocation of species to precise habitat units is relatively easy and a fairly small number of units is characteristic of most species. Semidry grasslands, oligotrophic humid meadows, limestone beech forests and their substitution communities, transition fens, acidic fens and rich fens are the most significant habitats.

Key-Words: Orchidaceae, habitats, CORINE, Emerald, Belgium, Wallonia.