Merismopedia warmingiana is a species of cyanobacteria that forms colonies consisting of flat, disc-shaped cells arranged in a single layer, resembling sheets or plates. Each cell is small, varying in diameter from approximately 5 to 10 micrometers. These colonies can appear as circular or irregular patches on surfaces such as rocks or aquatic plants in freshwater habitats like lakes, ponds, and slow-moving streams. They play essential roles in aquatic ecosystems through processes such as photosynthesis and nutrient cycling.