• Nostoc Vaucher ex Bornet & Flahault, 1886
• Nostoc agglutinans Meneghini ex Kützing
• Nostoc alatosporum Sant'Anna et al.
• Nostoc album Gardner, 1927
• Nostoc alpinum Kützing
• Nostoc ambiceps C.C. Jao
• Nostoc amplissimum Setchell, 1899
• Nostoc anisococcum Sprengel
• Nostoc antarctica W. West & G.S. West
• Nostoc antarcticum W. West & G.S. West, 1911
• Nostoc antillarum (P.L. Crouan & H.M. Crouan) P.L. Crouan & H.M. Crouan
• Nostoc apuanum De Notaris
• Nostoc apuanum Savi
• Nostoc arctum Kützing
• Nostoc arenarium Desmazières
• Nostoc atrovirens Chevallier
• Nostoc aureum Kützing ex Bornet & Flahault
• Nostoc austinii H.C. Wood
• Nostoc beilschmiedianum Kützing
• Nostoc belmonticum C.G.M. Archibald
• Nostoc bicalyptratum Skuja
• Nostoc birnbaumii Corda
• Nostoc bohemicum Rabenhorst
• Nostoc borneti Gain, 1911
• Nostoc bornetii Gain
• Nostoc borzioides S. Skinner & T.J. Entwisle
• Nostoc botryoides (Linnaeus) C. Agardh
• Nostoc botryosum Rabenhorst
• Nostoc brittoni Gardner, 1927
• Nostoc brittonii Gardner
• Nostoc bullatum (A.P. de Candolle) Duby
• Nostoc caerulescens Rabenhorst
• Nostoc caeruleum Lyngbye ex Bornet & Flahault, 1888
• Nostoc caeruleum Lyngbye, 1819
• Nostoc caladarium H.C. Wood
• Nostoc caladarium Wood
• Nostoc calcicola (C. Agardh) C. Agardh, 1817 accepted as Schizothrix calcicola (C. Agardh) Gomont ex Gomont, 1892
• Nostoc calcicola Brébisson ex Bornet & Flahault, 1888
• Nostoc calcicola Brébisson, 1843
• Nostoc carneum C. Agardh ex Bornet & Flahault, 1888
• Nostoc carneum C. Agardh, 1824
• Nostoc catenatum P.A. Dangeard
• Nostoc cesatii Balsamo
• Nostoc cesatii Rabenhorst
• Nostoc ciniflonum Tournefort ex Bornet
• Nostoc ciniflorum C. Agardh
• Nostoc citrisporum Prasad & Mehrotra
• Nostoc coccymelon Kützing
• Nostoc coimbatorense Laloraya
• Nostoc coimbatorense Laloraya & Mitra
• Nostoc collinum Kützing
• Nostoc comminutum Kützing
• Nostoc commune Vaucher ex Bornet & Flahault, 1888
• Nostoc commune Vaucher, 1803
• Nostoc confluens Kützing
• Nostoc confusum C. Agardh illeg.
• Nostoc conglomeratum Hirose
• Nostoc conicocellulare Huber-Pestalozzi
• Nostoc copiosum Kogan & Jazkulieva
• Nostoc cordubense C.H. Prosperi
• Nostoc cordubensis Prosperi
• Nostoc coriaceum Vaucher
• Nostoc crassisporum Geitler
• Nostoc crassisporum Meneghini
• Nostoc crispum De Notaris
• Nostoc cristatum Bailey ex Harvey
• Nostoc cristatum J. Bailey
• Nostoc cuticulare (Brébisson) Bornet & Flahault, 1888
• Nostoc cycadae Maruyama & Fukushima
• Nostoc cycadeae A. Watanabe & Kiyohara
• Nostoc cylindrosporum De Notaris
• Nostoc delpinoi Borzì
• Nostoc depressum H.C. Wood
• Nostoc desertorum Reháková & Johansen, 2007
• Nostoc diamorphoticum Itzigsohn
• Nostoc dickiaei Wood
• Nostoc diplonema Montagne
• Nostoc disciforme F.E. Fritsch, 1912
• Nostoc edaphicum Kondrat., 1962
• Nostoc edule Montagne & Berkeley
• Nostoc elgonense Naumann, 1925
• Nostoc ellipsoideum Gardner, 1927
• Nostoc ellipsosporum Rabenhorst ex Bornet & Flahault, 1888
• Nostoc ellipsosporum Rabenhorst, 1865 accepted as Nostoc ellipsosporum Rabenhorst ex Bornet & Flahault, 1888
• Nostoc endophytum Bornet & Flahault, 1888
• Nostoc entophytum Bornet & Flahault, 1888
• Nostoc epilithicum Ercegovic, 1925
• Nostoc expansum Harvey & Bailey
• Nostoc falsum Kützing
• Nostoc filarzskyi De Toni
• Nostoc flagelliforme Berkeley & Curtis accepted as Nostoc commune Vaucher, 1803
• Nostoc flavicans Bory nom. nud.
• Nostoc flosaquae (Linnaeus) Lyngbye
• Nostoc flosaquae (Linnaeus) Lyngbye, 1819 accepted as Aphanizomenon flosaquae Ralfs ex Bornet & Flahault, 1886
• Nostoc fluviatile Liljeblad
• Nostoc foliaceum Mougeot
• Nostoc fonticola Brabez
• Nostoc fragiforme (Roth) Brébisson
• Nostoc fritschii (Mitra) Schwabe & El Ayouty
• Nostoc furfuraceum Kützing