The 'Altipiani di Colfiorito' catchment basin in central Italy features a wetland system of great interest for conservation, composed of seven plains. Considering that most of the relevés conducted in the past refer to one plain and date back to the 1960s, the research aim was to widen and update the vegetation knowledge in the whole wetland system. Two hundred and thirty-nine phytosociological relevés were carried out using the Braun-Blanquet method. On the basis of cluster analysis of the species data set and phytosociological interpretation, 39 vegetation types were classified, most of which of high conservation interest in central Italy, referred to the Potamogetonetea (6 communities), Bidentetea (2), Phragmito-Magnocaricetea (21), Molinio-Arrhenatheretea (9), and Epilobietea angustifolii (1) classes. The new subassociation Phalaridetum arundinaceae alopecuretosum bulbosi is also described. Twenty-two communities found in the past decades by other authors were confirmed, while 17 were new records for the study area. Ten communities were attributed to four habitats of community interest according to the 92/43/EEC Directive, coded as 3150, 3260, 3270, and 6510. Twenty-four communities were not confirmed (eight of Charetea, Lemnetea minoris, and Potamogetonetea, one of Bidentetea; seven of Phragmito-Magnocaricetea; three of Scheuchzerio-Caricetea fuscae, four of Molinio-Arrhenatheretea and one of Isoëto-Nanojuncetea). Three habitats of community interest (3140, 3170*, and 7230) were not confirmed.
