Schematic transect of the xeric geosigmetum of the Monte Pellegrino road system (via Pietro Bonanno, on the slopes of Arenella before the hairpin bend overlooking Palermo, 120 m a.s.l.): 1) grassland vegetation with Pennisetum setaceum (Penniseto setacei-Hyparrhenietum hirtae); 2) thermo-chasmophytic wall vegetation with Capparis spinosa (Capparidetum rupestris); 3) road margin hemicryptophytic, nitrophilous vegetation with Pennisetum setaceum (Olopto miliacei-Pennisetetum setacei ass. nov.); 4) chasmophytic cliff vegetation with Lomelosia cretica (Scabioso-Centauretum ucriae); 5) artificial forest plantations with Eucalyptus camaldulensis and Pinus halepensis.