Acacia s.l. taxa in the Middle East are treated as a single genus and suffer from confusion in its discrimination because of morphological similarities between closely related taxa. So, the current study aims at revealing distinguishing characters, and assessing the taxonomic relationships between studied taxa using recently proposed genera versus Acacia s.l. genus in conventional classificatory systems. Macro-, micro-morphological characters, and SDS-protein pattern of 13 Acacia s.l. spp. were investigated focusing on seeds using the scanning electron microscope (SEM). The generated UPGMA-cluster based on 106 morphological and biochemical character-states split the studied Acacia s.l. taxa into two groups; (1) comprised genera of Vachellia, Acacia s.s. and Faidherbia, and (II) Senegalia genus. The present results gave accurate discrimination of genus Acacia s.l., confirmed the need of its retypification in the Middle East according to the new system of classification and show the close relation between Vachellia, each of Acacia s.s. and Faidherbia genera.
Key words: macro-micromorphology, SDS-PAGE, SEM, Senegalia, Vachellia