Systematic composition, species diversity and plant chorology at Wadi Tashar, Jazan, Saudi Arabia
El-Shabasy A and Kasem W
Wadi Tashar the border regions Near Yemen frontier, it is more favorable for plant growth The present studies concerned with analysis of floristic composition in addition to the vegetation analysis. A total of 89 species belonging to 68 genera and 27 families were recorded from various sample plots and attached areas. Biological spectrum showedthe most highly represented families were Poaceae, Euphorbiaceae and Amaranthaceae. where therophytes constituted 42% 31 species (35%) of the total species. Phanerophytes in this area represented by 11 species (12%), Only 10 species (11%) constituted cryptophytes. The highest species richness values are recorded in the wadi bed. The lowest species richness value are recorded in the wadi plateau. Chronological analysis revealed bi regional elements of Saharo-Arabian together Sudano-Zambezian have the highest share of species, representing 29 species followed by the Saharo-Arabian region elements at 21 taxa (23%), flowed tropical plants only by 9 species (10%), 8 cosmopolitan species (7%) present in the study. Irano-Turanian and Mediterranean are represented by five species representing 4%. Pluriregional elements that belong to the Saharo-Arabian and Mediterranean and Sudano-Zambezian representing 2% has only one species.