Chaetosphaeridium globosum is a one-celled alga which is thought to represent an ancient lineage of the green plants. This organism exists in a filamentous form with one flagella per cell. It is a freshwater species. The flagellum is covered in scales in a 3-prong irregular shape called ‘maple leafs’. The cells are usually 11–18 micrometres (0.00043–0.00071 in) in diameter and with one pyrenoid. Each cell bears long bristle.