The Kingdom of Saudi Arabia is one of the countries with the most biological diversity. The flora of the northeast of Makkah, which included some valleys and the Harrat area (Lava Field), was studied between January 2021 and April 2023. The present work focused on analyzing life forms, habits, and chorotypes. A total of 253 species have been identified, belonging to 161 genera and 46 families. Magnoliopsida (Dicots) has 205 species spread among 131 genera and 40 families. In comparison, Liliopsida (Monocots) has 46 species spread across 29 genera and five families, besides two species belonging to one genus of Gymnosperms (Ephedra foeminea and Ephedra foliata). The most prominent families in the studied area were Poaceae (37 species), Fabaceae (29 species), and Asteraceae (24 species). The study found six rare species in the flora of Saudi Arabia: Atriplex farinosa, Cyperus rotundus, Datura innoxia, Kohautia caespitosa, Launaea nudicaulis, and Plantago ciliata.