Raphidocelis danubiana, previously known as Pseudopediastrum danubianum, is a green algae species that forms colonies (coenobia) characterized by a plate-like or star-shaped arrangement of cells. Each cell within the colony is polygonal or star-shaped, typically organized in groups of 4, 8, or 16 cells in a single layer. These cells are relatively small, ranging from 10 to 30 micrometers in diameter, with smooth and firm cell walls providing structural integrity. Chloroplasts are present in each cell, often positioned along the cell wall and containing pyrenoids essential for photosynthesis. The nucleus is centrally located within each cell. Raphidocelis danubiana reproduces asexually through cell division within the colony, contributing to colony growth. It thrives in freshwater environments such as ponds, lakes, and slow-moving streams, playing a role in the diverse and productive phytoplankton communities found in these habitats.