The objective of the present study was to determine the differences and similarities between the dense forest of Kigwena and the open forest of Rumonge in terms of physiognomics, floristic composition, biological types as well as their origin and chorological affinity. Data were collected by means of systematic surveys for undergrowth species and by measuring the diameter at chest height for tree species in plots of varying size. The equity index was calculated on the basis of biological types and phytogeographical elements. The most dominant tree species in the two forests were also identified. The similarity between the Kigwena and Rumonge forests was analyzed based on the values of the Margalef Index, the Sørensen Similarity Index, and the χ 2 test.