Species diversity of the tree flora of 38 districts in the Greater Cairo city was studied with reference to landscape differentiation of species make-up. Three main habitats including 14 sites with 263 sample plots were considered [35 urban parks, 76 road islands and 152 street verges] . In total, 378 of vascular plant species belonging to 264 genera and 79 families were recorded in urban areas of the Greater Cairo city. The most species-rich [44.7%] families were Fabaceae [36 spp.] , Asparagaceae, Poaceae [21 spp.] , Moraceae [19 spp.] , Asteraceae [17 spp.] , Euphorbiaceae and Malvaceae [15 spp.] , Arecaceae [14 spp.] , Lamiaceae [11 spp.] , whereas the remaining families [70] constituted together 193 species. Ficus [18 spp.] was the highest among the species-rich genera, followed by Euphorbia [11 spp.] , Asparagus, Brachychiton, Callistemon, Citrus and Pinus [4 spp, each] . 257 genera contained only 1-3 species e. g. Cereus, Koelreuteria, Strelitzia, Terminalia, Carica and Toona. Growth form spectra revealed that, the recorded trees [139 spp.] belonged to 32 families; shrubs [79 spp.] to 30 families, herbs and others [160 spp,] to 48 families