Introduction: Myrciaria dubia “camu-camu” is an economically important Amazonian fruit shrub known for its exceptionally high vitamin C content. Despite its commercial value, comprehensive phenotypic characterization of available genetic resources remains limited, hindering breeding programs and conservation strategies. This study aimed to characterize the phenotypic diversity of wild accessions maintained in a 36-year-old ex situ germplasm bank, one of the most comprehensive M. dubia collections globally, to provide baseline data for genetic improvement and conservation. Methods: We evaluated 43 wild accessions systematically collected from eight major hydrographic basins in the Loreto region using a stratified sampling approach to capture maximum ecological diversity and maintained in an ex situ germplasm bank established in 1988 at the National Institute of Agrarian Innovation in ...