The main objective of the project is to carry out a first phase of general inventory of the vascular flora of the Massif Central de Midi-Pyrénées (2019-2022). The French Massif Central, in its natural meaning, particularly topographical, geological and phytogeographical benefits from considerable inventory pressure over a large part of its area, notably in the context of the work carried out by the CBN of the Massif Central, which led in particular in 2006 to the publication of an atlas of the vascular flora of Auvergne followed in 2013 by that of the Loire and Rhône. This project proposes to extend this work to the mid-Pyrenean part of the Massif Central, in continuity with that of the Auvergne-Rhône-Alpes and Nouvelle-Aquitaine regions. The methodology consists of distributing a reasoned sampling pressure by 5x5 km mesh according to a method proven in other territories. The data will be transferred to SINP Occitanie and can be mobilised for analysis and synthesis at the scale of the massif or other units of the territory. A second action specifically concerns the Aubrac Regional Natural Park, on the theme of open herbaceous environments and will be carried out in partnership with the Park and the other two CBNs concerned (network of pilot farms, prairial typology, ecological diagnostics, participation in technical days and juries of agricultural practices).