The main objective of this study is to quantify the floral richness and diversity of Tetraclinis ecosystem in the Moroccan Central Plateau. The approach was based on over 300 floristic surveys covering the different parts of the Moroccan Central Plateau forests. It also entails the analysis and processing of data from studies in the region. The results indicate that there are 233 taxa belonging to 56 families. Keywords: Floral richness, Tetraclinis ecosystem, Moroccan Central Plateau IntroductionDue to its typical and geographical position between the Atlantic Ocean to the west and the Mediterranean Sea to the north, Morocco is characterized by high vascular plant diversity with approximately 4200 species and subspecies belonging to 135 families and 940 genera (Benabid, 2000). The endemic flora includes 951 species and subspecies, representing 21 % of the Moroccan vascular plants. The richest floristic regions for endemic species are located at the top of high mountains.By its geographical position, its varied topography, geology, ecoregion and climate, the Central Plateau of Morocco includes a large area of forest ecosystems with an important floristic diversity. However, this flora richness is still not well known and botanical studies within the zone still remains limited.

The current study aims to quantify and evaluate the Tetraclinis stands (Tetraclinis articulata (Vahl.) Masters) richness and floristic diversity at Kharouba Site of Biological and Ecological Interest (SBEI). The 150 floristic surveys conducted in the site allowed us to inventory 143 species distinguished with rare taxa majority that are distributed over 54 families and 123 genera. This reduced number of taxa reflects the alarming biodiversity deterioration of the SBEI. The study also enabled us to define the biological spectrum of the study area that is characterized by a significant abundance of Therophytes.