Hymenoscyphus albidus is a small, white cup fungus in the family Helotiaceae, closely related to the highly invasive ash dieback pathogen H. fraxineus. It forms tiny, stalked apothecia on fallen ash leaf petioles in European forests and is now considered a rare native species displaced by the introduced pathogen. Assessed as Data Deficient, its current population status across Europe is uncertain due to confusion with the pathogenic relative.