Murgia is a tabular mountain range of low altitude and elongated in shape stretching WNW-EE, located in central Apulia (Italy). Its North-Western part (with maximum elevations of 700 m a.s.l.), also known as Alta Murgia or North-West Murgia, is covered by a wide steppic grassland dominated by in Stipa austroitalica Martinovsky and Festuca circummediterranea Patzke. The richness of vascular flora (more than 390 species) recorded here is related to the heterogeneous conditions of the area determined by the regional geographic context, the physiography of the range, the pedological substrate and by natural and anthropic disturbances. The vegetation and phytoclimatic analyses of this steppic grassland have allowed to evaluate the habitat heterogeneity: this study is a basic step for the working out of conservation programmes of Murgia biodiversity.