Merismopedia angularis is a species of cyanobacteria characterized by small, spherical or slightly oval cells ranging from 1 to 3 micrometers in diameter. These cells form flat, grid-like colonies that are typically rectangular or square-shaped, containing from a few to hundreds of cells arranged in a regular pattern. The cells exhibit a blue-green color due to the presence of phycocyanin and chlorophyll a, which are crucial for photosynthesis.