The present study evaluated the floristic diversity and biological spectrum of Muscat Governorate, Sultanate of Oman. Heterogeneity of geology, topography and climatic conditions create a diverse array of habitats across the 3,500 km2 study area, supporting a range of vegetation types. Floristic studies were conducted across 42 sites spread across various habitats such as sand dunes, alluvial plains, gravel plains, wadis, saline dunes, coastal areas, farms and plantations. A total of 264 species belonging to 183 genera and 54 families of angiosperm were documented during sampling the vegetation from different wilayats of the Governorate. Maximum number of species belonged to family Fabaceae (14%), followed by Poaceae (12%), Asteraceae (9%), Apocyanaceae and Convolvulaceae (3.66% each), Boraginaceae, Euphorbiaceae, Zygophylaceae (3% each). The biological spectrum was represented almost equally by therophytes and chamaephytes (30% each), followed by phanerophytes (19%), hemicryptophytes (13%), geophytes (4%), liana (3%), and helophytes (1%). The dominance of therophytes and chamaephytes reveals a thero-chamaephytic phytoclimate for the area. Different habitats are characterized by specific plant assemblages, but some species such as Acacia tortilis, Prosopis cineraria, Tetraena quaterense, Dipterygium gluacum, Aerva javanica, due to their broad ecological tolerance and adaptations, inhabit more than one habitats, while some species are just confined to certain parts of a single habitat.