The African forest, which was and still is the heart of biodiversity, is fast losing its bio-components due to natural disasters and human encroachment. A catalogue of the bio-components of the African forest is imminent so that conservation programs can be established to safeguard rare germplasm(s) from extinction. The population density of wild Auricularia (Mushroom) of Southwestern Nigeria was the focus of this research. DNA primers were obtained from Operon Technology, Alameda, California, USA. Characterization was done using phenotype, PCR and electrophoresis gel (RAPD). OPB-11 to OPB-21, OPH-3 to OPH-15, and OPT-1 to OPT-19 primers formed polymorphic bands with DNA samples of the specimens. Three (3) distinct species of Auricularia were identified in the forest of Southwest Nigeria based on PCR and RAPD analyses. Geospatial analysis showed that Auricularia auricula was present in the forests of Ekiti, Osun, Ogun, Oyo and Lagos states, but none was identified in Ondo State. On the contrary, Auricularia polytricha was only identified in the tropical rainforest and grassland vegetation of Ondo, Lagos and Oyo states. Key words: Auricularia, mushrooms, population density, Southwestern Nigeria, phenotypic description, genome similarity index.