 The order contains approximately 780 species.Conventionally, many groups of coccoid green algae were lumped in the order Chlorococcales sensu lato by Komárek & Fott (1983), based on Pascher's (1918) idea of establishing orders according to life forms.However, coccoid green algae are currently placed in several orders of Chlorophyceae, Trebouxiophyceae, Ulvophyceae (e.g., "Chlorocystis") and Prasinophyceae within the division Chlorophyta, or in the division Charophyta (e.g., Chlorokybales, Desmidiales).