Gloeocapsa magma is a photosynthetic cyanobacterium that consists of a small group of algae spores. It is responsible for the black/dark green stains that form on roofs. These black stains are the bacteria themselves, in mass amounts, covering the surface of the roof shingles.
Or, to put it more simply, Gloeocapsa Magma are tiny organisms that travel through the air and land on your roof. Once they're on your roof, they start to reproduce and create unsightly black streaks.
If you've noticed black streaks on your roof, you may wonder what's causing them. The truth is, those black streaks are caused by a type of bacteria known as Gloeocapsa magma.
These bacteria are photosynthetic cyanobacteria, meaning they use sunlight to produce energy. And unfortunately, they love to live on roofs! They form small groups of algae spores that can quickly grow and cover the surface of your roofing shingles.