''Septoria selenophomoides'' is a
fungal
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...
plant pathogen infecting orchids. It causes leaf spots, starting with small yellowish lesions on the plant's leaves and darkening to brown or black.
If the infection develops further, the leaves and fruit fall from the orchid and spread the infection.
References
selenophomoides
Fungal plant pathogens and diseases
Orchid diseases
Fungi described in 1955
{{fungus-plant-disease-stub