Combretaceae R. Br. is an angiosperm family of high economic value. However, there is dearth of information on the phylogenetic relationship of the members of this family using ribulose biphosphate carboxylase (rbcL) gene. Previous studies with electrophoretic-based and morphological markers revealed that this family is phylogenetically complex.

   In the present study, 79 sequences of rbcL were used to study the phylogenetic relationship among the members of Combretaceae of African origin with a view to provide more information required for the utilization and management of this family. Multiple Sequence alignment was executed using the MUSCLE component of Molecular Evolutionary Genetics Version X Analysis (MEGA X). Transition/Transversion ratio, Consistency index, Retention Index and Composite Index were also determined. Phylogenetic trees were constructed using Maximum parsimony (MP) and Neighbor joining methods.

   The alignment of rbcL in the family Combretaceae shows 0.59 for both variation and parsimony sites with the overall mean distance of 0.71. Result shows that the genera Combretum, Terminalia are polyphyletic, while Conocarpus, Quisqualis and Meiostemon are monophyletic.

   Findings from this study can be applied to the scientific classification of the African Combretaceae, especially where morphological and electrophoretic-based molecular delimitations have failed. rbcL from this family can also be used as barcodes against drug adulteration of the medicinal species.

Keywords: Phylogeny, rbcL gene, Combretum, Terminalia