• Closterium Nitzsch ex Ralfs, 1848
• Closterium abruptum West, 1892
• Closterium acerosum Ehrenberg ex Ralfs, 1848
• Closterium aciculare T. West, 1860
• Closterium acuminatum Corda
• Closterium acuminatum Kützing ex Ralfs accepted as Closterium dianae Ehrenberg ex Ralfs, 1848
• Closterium acus (O.F. Müller) Nitzsch, 1816 accepted as Lepocinclis acus (O.F. Müller) Marin & Melkonian, 2003
• Closterium acutum Brébisson, 1848
• Closterium affine F. Gay accepted as Closterium lunula Ehrenberg & Hemprich ex Ralfs, 1848
• Closterium amblyonema Ehrenberg ex J. Ralfs
• Closterium amphiceps C.C. Jao
• Closterium anastomosans
• Closterium anastomosum W. West & G.S. West
• Closterium anguineum D.B. Williamson, 1996
• Closterium angustatum Kützing ex Ralfs, 1848
• Closterium angustum Hantzsch
• Closterium annandalei P.J. Brühl & K.P. Biswas
• Closterium antarcticum Ehrenberg
• Closterium antiacerosum De Notaris
• Closterium archerianum Cleve ex P. Lundell, 1871
• Closterium arcuarium E.O. Hughes
• Closterium arcuatum Brébisson ex Ralfs, 1848 accepted as Closterium dianae Ehrenberg ex Ralfs, 1848
• Closterium arcus A.J. Brook & D.B. Williamson, 1988
• Closterium areolatum H.C. Wood
• Closterium arnoldianum Y.V. Roll
• Closterium atomicum M.I. Claassen
• Closterium attenuatum Ralfs, 1848
• Closterium auerswaldii G.L. Rabenhorst
• Closterium aureum C.G.T. Preuss
• Closterium australe (Raciborski) Lütkemüller accepted as Actinotaenium australe (Raciborski) Croasdale
• Closterium bacillum W. Joshua
• Closterium baculum L.A. Brébisson
• Closterium baileyanum
• Closterium baillyanum (Brébisson ex Ralfs) Brébisson, 1856
• Closterium balatonicum T. Hortobágyi
• Closterium balmacarense W.B. Turner, 1893
• Closterium barbaricum M.I. Claassen, 1961
• Closterium biclavatum Börgesen
• Closterium bicurvatum Delponte accepted as Closterium gracile Brébisson ex Ralfs, 1848
• Closterium bienense G. De Notaris
• Closterium bogoriense C. Bernard
• Closterium borodinianum Y.V. Roll
• Closterium boyanum M.I. Claasen
• Closterium braunianum Reinsch
• Closterium braunii Reinsch, 1867
• Closterium brebissonii Meneghini, 1840 accepted as
• Closterium brunelii P. Bourrelly
• Closterium bucharica I.A. Kisselev
• Closterium caffrorum M.I. Claassen
• Closterium calamus Playfair accepted as
• Closterium calmus Playfair, 1907 accepted as Closterium acerosum Ehrenberg ex Ralfs, 1848
• Closterium calosporum Wittrock, 1869
• Closterium cancer Playfair
• Closterium candianum G.B. Delponte
• Closterium capense G.L. Rabenhorst
• Closterium capillare Delponte
• Closterium capitatum Y.V. Roll
• Closterium carniolicum J. Lütkemüller
• Closterium caudatum Corda
• Closterium ceratium Perty, 1852
• Closterium cingulum Playfair accepted as Closterium dianae Ehrenberg ex Ralfs, 1848
• Closterium clandestinum Kützing
• Closterium closterioides (Ralfs) A. Louis & F. Peeters, 1967 accepted as Closterium closteroides (Ralfs) A. Louis & Peeters, 1967
• Closterium closteroides (Ralfs) A. Louis & Peeters, 1967
• Closterium coloratum (G.A. Klebs) R. Gutwinski
• Closterium columbianum G.S. West
• Closterium compactum Norstedt, 1887
• Closterium complanatum Delponte, 1877
• Closterium concinnum T. Hinode
• Closterium constrictum R. Gutwinski
• Closterium cordanum R. Gutwinski
• Closterium cornu Ehrenberg ex Ralfs, 1848
• Closterium cornutum Playfair accepted as Closterium leibleinii Kützing ex Ralfs, 1848
• Closterium costatosporum Taft
• Closterium costatum Corda ex Ralfs, 1848
• Closterium crameri C. Bernard
• Closterium crassestriatum W. Archer, 1879
• Closterium crassum G.B. Delponte
• Closterium crassum G.L. Rabenhorst
• Closterium crenulatum Ehrenberg, 1843 accepted as Pleurotaenium crenulatum (Ehrenberg ex Ralfs) Rabenhorst, 1868
• Closterium croasdaleae A.K.M.N. Islam
• Closterium cucumis Ehrenberg
• Closterium cucumis Ehrenberg ex J. Ralfs
• Closterium curtum L.A. Brébisson
• Closterium curtum L.A. Brébisson ex Kützing
• Closterium cuspidatum (Bailey) Hirano accepted as Spinoclosterium cuspidatum (Bailey) Hirano
• Closterium cylindrocystis Kützing
• Closterium cylindrus Ehrenberg, 1838 accepted as Penium cylindrus Brébisson ex Ralfs, 1848
• Closterium cymbellaeformis M.I. Claassen
• Closterium cynthia De Notaris, 1867 accepted as Closterium jenneri Ralfs, 1848
• Closterium cynthioides J. Sampaio
• Closterium dacchense A.K.M.N. Islam
• Closterium decorum Brébisson, 1856
• Closterium decussatum Kützing ex Ralfs, 1848
• Closterium decussatum Kützing, 1845 accepted as Closterium decussatum Kützing ex Ralfs, 1848
• Closterium delectum M. Noda & Skvortzov
• Closterium delpontei (Klebs) Wolle, 1885 accepted as Closterium decorum Brébisson, 1856
• Closterium delpontii
• Closterium dianae Ehrenberg ex Ralfs, 1848
• Closterium didymocarpum Schmidle