Nostoc

{{Short description|Genus of cyanobacteria}} {{Automatic taxobox | fossil_range = {{Geological range|423|0| earliest=590}}<ref>{{Cite journal |last=Pardo-De la Hoz |first=Carlos J |last2=Haughland |first2=Diane L |last3=Thauvette |first3=Darcie |last4=Toni |first4=Sydney |last5=Goyette |first5=Spencer |last6=White |first6=William |last7=Medeiros |first7=Ian D |last8=Cornet |first8=Luc |last9=Dvořák |first9=Petr |last10=Garfias-Gallegos |first10=Diego |last11=Miadlikowska |first11=Jolanta |last12=Magain |first12=Nicolas |last13=Lutzoni |first13=François |date=2025-10-01 |editor-last=Falush |editor-first=Daniel |title=Rapid Radiations Outweigh Reticulations During the Evolution of a 750-Million-Year-Old Lineage of Cyanobacteria |url=https://academic.oup.com/mbe/article/doi/10.1093/molbev/msaf244/8271035 |journal=Molecular Biology and Evolution |language=en |volume=42 |issue=10 |doi=10.1093/molbev/msaf244 |issn=0737-4038 |pmc=12559999 |pmid=41037509}}</ref> | image = Nostoc commune.jpg | image_alt = Nostoc commune | image_caption = ''Nostoc commune'' | taxon = Nostoc | authority = Vaucher, 1888, ex Bornet and Flahaul | synonyms = | synonyms_ref = | subdivision_ranks = Species | subdivision = {{collapsible list |''Nostoc agglutinans'' Meneghini ex Kützing, 1849 |''Nostoc alatosporum'' Sant'Anna et al., 2007 |''Nostoc album'' N.L.Gardner, 1927 |''Nostoc alpinum'' Kützing, 1843 |''Nostoc ambiceps'' C.-C.Jao, 1940 |''Nostoc amplissimum'' Setchell, 1899 |''Nostoc anisococcum'' Sprengel, 1827 |''Nostoc antarcticum'' West & G.S.West, 1911 |''Nostoc apuanum'' De Notaris, 1869 |''Nostoc arctum'' Kützing, 1847 |''Nostoc arenarium'' Desmazières, 1865 |''Nostoc austinii'' H.C.Wood, 1873 |''Nostoc belmonticum'' C.G.M.Archibald, 1967 |''Nostoc bicalyptratum'' Skuja, 1937 |''Nostoc bornetii'' Gain, 1911 |''Nostoc borzioides'' S.Skinner & T.J.Entwisle, 2002 |''Nostoc brittoni'' N.L.Gardner, 1927 |''Nostoc caeruleum'' Lyngbye ex Bornet & Flahault, 1886 |''Nostoc caladarium'' H.C.Wood, 1868 |''Nostoc calcicola'' Brébisson ex Bornet & Flahault, 1886 |''Nostoc carneum'' C.Agardh ex Bornet & Flahault, 1886 |''Nostoc catenatum'' P.J.L.Dangeard, 1949 |''Nostoc cesatii'' Balsamo, 1863 |''Nostoc ciniflonum'' Tournefort ex Bornet, 1880 |''Nostoc citrisporum'' Prasad & Mehrotra, 1976 |''Nostoc coimbatorense'' Laloraya & Mitra, 1974 |''Nostoc comminutum'' Kützing, 1850 |''Nostoc commune'' Vaucher ex Bornet & Flahault, 1888 |''Nostoc conglomeratum'' Hirose, 1962 |''Nostoc copiosum'' Kogan & Jazkulieva, 1972 |''Nostoc cordubense'' C.H.Prosperi, 1985 |''Nostoc crassisporum'' Meneghini, 1837 |''Nostoc crassisporum'' Geitler, 1933 |''Nostoc cristatum'' Bailey, 1847 |''Nostoc cycadae'' Maruyama & Fukushima, 1963 |''Nostoc delpinoi'' Borzì, 1878 |''Nostoc depressum'' H.C.Wood, 1873 |''Nostoc desertorum'' Reháková & Johansen, 2007 |''Nostoc diamorphoticum'' Itzigsohn, 1857 |''Nostoc diplonema'' Montagne, 1857 |''Nostoc disciforme'' F.E.Fritsch, 1912 |''Nostoc edaphicum'' Kondrateva, 1962 |''Nostoc edule'' Montagne & Berkeley ex Bornet & Flahault, 1886 |''Nostoc elgonense'' Naumann, 1925 |''Nostoc ellipsoideum'' N.L.Gardner, 1927 |''Nostoc ellipsosporum'' Rabenhorst ex Bornet & Flahault, 1886 |''Nostoc endophytum'' Bornet & Flahault, 1886 |''Nostoc epilithicum'' Ercegovic, 1925 |''Nostoc expansum'' Harvey & Bailey, 1851 |''Nostoc filarzskyi'' G.De Toni, 1936 |''Nostoc flagelliforme'' Harvey ex Molinari-Novoa, Calvo-Pérez & Guiry, 2016 |''Nostoc flavicans'' Bory de Saint-Vincent, 1827 |''Nostoc fluviatile'' Liljeblad, 1816 |''Nostoc foliaceum'' Mougeot ex Bornet & Flahault, 1886 |''Nostoc fonticola'' Brabez, 1941 |''Nostoc fragiforme'' (Roth) Brébisson, 1870 |''Nostoc fuscescens'' F.E.Fritsch, 1912 |''Nostoc fuscum'' Kützing, 1863 |''Nostoc gelatinosum'' Schousboe ex Bornet & Flahault, 1886 |''Nostoc ghotgewadense'' G.R.Hegde & K.Somanna, 1992 |''Nostoc glomeratum'' Kützing, 1850 |''Nostoc granulare'' (Kützing) Rabenhorst, 1865 |''Nostoc gregarium'' Thuret ex Kützing, 1849 |''Nostoc gymnosphaericum'' Kützing, 1843 |''Nostoc hatei'' S.C.Dixit, 1936 |''Nostoc heterothrix'' Zeller, 1873 |''Nostoc humifusum'' Carmichael ex Bornet & Flahault, 1886 |''Nostoc hyalinum'' Roemer, 1845 |''Nostoc hyalinum'' A.W.Bennett, 1886 |''Nostoc hydrocoleoides'' Reinsch, 1876 |''Nostoc imperfectum'' Schwabe & El Ayouty, 1966 |''Nostoc indistinguendum'' Reháková & J.R.Johansen, 2007 |''Nostoc insulare'' Borzì, 1907 |''Nostoc interbryum'' Sant'Anna et al., 2007 |''Nostoc intestinale'' G.S.An, 1992 |''Nostoc inundatum'' Kützing, 1843 |''Nostoc kihlmanii'' Lemmermann, 1900 |''Nostoc koraiense'' G.S.An, 1990 |''Nostoc krishnamurthyi'' S.Chandra, 2005 |''Nostoc lacerum'' Kützing, 1843 |''Nostoc lacunosum'' Montagne, 1850 |''Nostoc lacustre'' Kützing, 1843 |''Nostoc leptonema'' Reinsch, 1876 |''Nostoc letestui'' Frémy, 1930 |''Nostoc lichenoides'' Vaucher ex Reháková & J.R.Johansen, 2007 |''Nostoc limosum'' Zeller, 1873 |''Nostoc linckia'' Bornet ex Bornet & Flahault, 1886 |''Nostoc littorale'' Kützing, 1842 |''Nostoc locularis'' G.S.An, 1992 |''Nostoc longstaffi'' F.E.Fritsch, 1912 |''Nostoc lophotelos'' G.S.An, 1992 |''Nostoc maculiforme'' Bornet & Flahault, 1888 |''Nostoc mamillosum'' C.-C.Jao, 1940 |''Nostoc maramorgellons'' Smith & Gerbaux, 2020 |''Nostoc margaritaceum'' (Kützing) Rabenhorst, 1865 |''Nostoc membranaceum'' N.L.Gardner, 1927 |''Nostoc microscopicum'' Carmichael ex Bornet & Flahault, 1886 |''Nostoc microtis'' Montagne, 1839 |''Nostoc minimum'' Currey, 1858 |''Nostoc minutissimum'' Kützing ex Bornet & Flahault, 1886 |''Nostoc minutum'' Desmazières ex Bornet & Flahault, 1886 |''Nostoc molle'' C.Agardh, 1827 |''Nostoc mougeotii'' Brébisson ex Kützing, 1849 |''Nostoc myriococcum'' Montagne, 1857 |''Nostoc nivale'' Kützing, 1849 |''Nostoc notarisii'' Franzoni, 1865 |''Nostoc nylstromicum'' Claassen, 1961 |''Nostoc opalinum'' A.W.Bennett, 1890 |''Nostoc oryzae'' (F.E.Fritsch) J.Komárek & K.Anagnostidis, 1989 |''Nostoc palmelioides'' Kützing |''Nostoc paludosum'' Kützing ex Bornet & Flahault, 1886 |''Nostoc papillosum'' Kurz, 1870 |''Nostoc paradoxum'' Welwitsch ex West & G.S.West, 1897 |''Nostoc parietinum'' Rabenhorst, 1863 |''Nostoc parmelioides'' Kützing ex Bornet & Flahault, 1886 |''Nostoc parvulum'' C.-C.Jao, 1940 |''Nostoc passerinianum'' Bornet & Thuret ex Bornet & Flahault, 1886 |''Nostoc pellucidum'' Kützing, 1843 |''Nostoc peloponnesiacum'' Kützing, 1849 |''Nostoc peltigerae'' Letellier, 1918 |''Nostoc polysaccum'' Reinsch, 1876 |''Nostoc polysporum'' Reinsch, 1876 |''Nostoc prismaticum'' Cesati, 1865 |''Nostoc pruniforme'' C.Agardh ex Bornet & Flahault, 1886 |''Nostoc pseudogelatinosum'' Claassen, 1961 |''Nostoc punctatum'' H.C.Wood, 1873 |''Nostoc punctiforme'' Hariot, 1891 |''Nostoc purpurascens'' Kützing, 1843 |''Nostoc purpureum'' Dickie, 1874 |''Nostoc ramosum'' Ercegovic, 1925 |''Nostoc repandum'' West & G.S.West, 1897 |''Nostoc reticulatum'' Roussel, 1806 |''Nostoc riabuschinskii'' Elenkin, 1914 |''Nostoc rupestre'' Kützing, 1849 |''Nostoc salsum'' Kützing, 1843 |''Nostoc saxatile'' Zeller, 1873 |''Nostoc segawae'' Okada, 1932 |''Nostoc sergianum'' Borzì, 1892 |''Nostoc shensiense'' C.C.Jao, 1948 |''Nostoc simulans'' N.L.Gardner, 1927 |''Nostoc sinuatum'' G.S.An, 1992 |''Nostoc sphaericum'' Vaucher ex Bornet & Flahault, 1886 |''Nostoc sphaeroides'' Kützing ex Bornet & Flahault, 1886 |''Nostoc sphaerosporum'' N.L.Gardner, 1927 |''Nostoc spinosum'' Tiwari, 1979 |''Nostoc subtilissimum'' Reinsch, 1890 |''Nostoc symbioticum'' F.V.Wettstein, 1915 |''Nostoc tenax'' Thuret, 1874 |''Nostoc tenuissimum'' (Kützing) Rabenhorst, 1865 |''Nostoc thermophilum'' Vouk, 1916 |''Nostoc thermotolerans'' Suradkar, 2017 |''Nostoc tibeticum'' C.-C.Jao & Y.Y.Lee, 1974 |''Nostoc torulosum'' Hirose, 1962 |''Nostoc trentepohlii'' Mohr, 1806 |''Nostoc tuberculosum'' Kützing, 1843 |''Nostoc undulatum'' Archibald, 1967 |''Nostoc vaillantii'' Behre, 1953 |''Nostoc variegatum'' Moore, 1841 |''Nostoc verrucosum'' Vaucher ex Bornet & Flahault, 1886 |''Nostoc vesicarium'' A.B.Frank, 1886 |''Nostoc viride'' Sant'Anna et al., 2007 |''Nostoc vulgare'' Schrank, 1812 |''Nostoc wartisporum'' Prasad et al., 1977 |''Nostoc wichmannii'' Weber-van Bosse, 1913 |''Nostoc willei'' N.L.Gardner, 1927 |''Nostoc wollnyanum'' Richter, 1884 |''Nostoc zetterstedtii'' Areschoug ex Bornet & Flahault, 1886 }} }}

'''''Nostoc''''', also known as '''star jelly''', '''troll's butter''', '''spit of moon''', '''fallen star''', '''witch's butter''' (not to be confused with the fungi commonly known as witches' butter), and '''witch's jelly,''' is the most common genus of cyanobacteria found in a variety of both aquatic and terrestrial environments that may form colonies composed of filaments of moniliform cells in a gelatinous sheath of polysaccharides.<ref name=":1">{{Cite journal |last1=Fidor |first1=Anna |last2=Konkel |first2=Robert |last3=Mazur-Marzec |first3=Hanna |date=2019-09-29 |title=Bioactive Peptides Produced by Cyanobacteria of the Genus Nostoc: A Review |journal=Marine Drugs |volume=17 |issue=10 |pages=561 |doi=10.3390/md17100561 |pmid=31569531 |pmc=6835634 |issn=1660-3397|doi-access=free }}</ref> It may also grow symbiotically within the tissues of plants, providing nitrogen to its host through the action of terminally differentiated cells known as heterocysts. ''Nostoc'' is a genus that includes many species that are diverse in morphology, habitat distribution, and ecological function.<ref name=":3">{{Cite journal |last=Sand-Jensen |first=Kaj |date=July 2014 |title=Ecophysiology of gelatinous Nostoc colonies: unprecedented slow growth and survival in resource-poor and harsh environments |url=http://dx.doi.org/10.1093/aob/mcu085 |journal=Annals of Botany |volume=114 |issue=1 |pages=17–33 |doi=10.1093/aob/mcu085 |issn=1095-8290 |pmc=4071103 |pmid=24966352}}</ref> ''Nostoc'' can be found in soil, on moist rocks, at the bottom of lakes and springs, and rarely in marine habitats. It may also be found in terrestrial temperate, desert, tropical, or polar environments.<ref name=":2">{{Cite web |title=SS-AGR-431/AG430: Biology and Management of Nostoc (Cyanobacteria) in Nurseries and Greenhouses |url=https://edis.ifas.ufl.edu/publication/AG430 |access-date=2022-04-24 |website=edis.ifas.ufl.edu |language=en}}</ref>

The name ''Nostoc'' was coined by Paracelsus and is a combination of the English ''nost''ril and German ''Nasenloch'' "nose hole, nostril", likely due to appearance of many species' colonies being similar to nasal mucus.<ref>{{cite journal |author=Potts, M. |year=1997 |title=Etymology of the Genus Name Nostoc (Cyanobacteria) |url=http://ijs.sgmjournals.org/content/47/2/584.full.pdf |url-status=live |journal=International Journal of Systematic Bacteriology |volume=47 |issue=2 |page=584 |doi=10.1099/00207713-47-2-584 |archive-url=https://web.archive.org/web/20130811032024/http://ijs.sgmjournals.org/content/47/2/584.full.pdf |archive-date=2013-08-11 |access-date=2011-11-05 |doi-access=free}}</ref> When it is on the ground, a ''Nostoc'' colony is ordinarily not seen, but after a rain, it swells up into a conspicuous, jellylike mass, which was once thought to have fallen from the sky, hence the popular names, like '''star jelly''', '''troll's butter''', and '''witch's butter''' mentioned above.

== Morphology == left|thumb|''Nostoc'' strains

''Nostoc'' are a genus of Gram-negative photosynthetic cyanobacteria.<ref name=":1" /> Many species of ''Nostoc'' possess an outer layer and extensive inner matrix of polysaccharides, giving them their "jelly-like" or gelatinous appearance, and also help to protect them from their environment and can assist in the absorption of moisture. This allows them to survive stressful conditions such as fluctuating temperatures, drought, salt stress, desiccation, UV radiation, and infection by pathogens.<ref name=":3" /><ref name=":4">{{Cite journal |last1=Aguilar |first1=Pablo |last2=Dorador |first2=Cristina |last3=Vila |first3=Irma |last4=Sommaruga |first4=Ruben |date=2019 |title=Bacterial Communities Associated With Spherical Nostoc Macrocolonies |journal=Frontiers in Microbiology |volume=10 |page=483 |doi=10.3389/fmicb.2019.00483 |issn=1664-302X |pmc=6437075 |pmid=30949138 |doi-access=free}}</ref> Some species within the genus also have nitrogen-fixing heterocyst filaments enclosed in this membrane.<ref name=":3" />

Many members of the ''Nostoc'' genus form colonies. These colonies can reach several centimeters in diameter.<ref name=":4" /> These colonies consist of mats or gelatinous masses created by aggregated trichomes that can appear in a range of colors (depending on the species) such as brown, yellow, or green.<ref name=":2" />

Additionally, some species of ''Nostoc'' are able to enter quiescent stages, further aiding in their survival of adverse conditions, and allowing them to resume metabolism when re-hydrated.<ref name=":3" />

== Ecology == === Habitat and distribution === ''Nostoc'' can be found in a variety of environments, both terrestrial and aquatic, depending on the species. Their polysaccharide outer layer and matrix allow them to survive and thrive in a variety of conditions and habitats including deserts, semideserts, grasslands, polar, and tropical regions depending on the particular species of ''Nostoc''.<ref name=":3" /><ref name=":4" /> In terms of aquatic environments, ''Nostoc'' has been documented to be naturally found in marine water and fresh water, as well as brackish water.<ref name=":1" /> thumb|Terrestrial colony of ''Nostoc''|centerthumb|Aquatic ''Nostoc''|center

=== Interactions with other organisms === Depending on the species, ''Nostoc'' may either be free-living in their environment, or they may form relationships with the other organisms in their environment, such as plants, fungi, or other bacteria.<ref name=":3" /> Because ''Nostoc'' is able to form colonies on the surface of bare minerals, it is able to provide a more stable environment for higher vegetation in its environment.<ref name=":3" /> Some species of ''Nostoc'' also form relationships with plants that lack vascular tissue such as Bryophytes because of their ability to fix nitrogen. ''Nostoc'' has also been found to form symbiotic associations and other relationships with other bacteria in their environment. Some species of ''Nostoc'' that form colonies in freshwater environments provide a habitat to other freshwater bacteria. Additionally, some species like ''N. commune'' and ''N. flageliforme'' form relationships with heterotrophic bacteria and actinobacteria present in their environments, likely due to the fact that they are a potential significant player in nitrogen cycling in aquatic ecosystems.<ref name=":4" />

==Usage==

=== Biotechnological usage === ''Nostoc'' has been documented to produce many compounds of interest, including those that are antiviral, antitumor, antifungal, and antibacterial.<ref>{{Cite journal |last1=Nowruzi |first1=Bahareh |last2=Haghighat |first2=Setareh |last3=Fahimi |first3=Hossein |last4=Mohammadi |first4=Ehsan |date=March 2018 |title=Nostoc cyanobacteria species: a new and rich source of novel bioactive compounds with pharmaceutical potential |journal=Journal of Pharmaceutical Health Services Research |language=en |volume=9 |issue=1 |pages=5–12 |doi=10.1111/jphs.12202|s2cid=80405030 |doi-access=free }}</ref><ref name=":1" />

In addition to the suggested pharmaceutical usage, ''Nostoc'' has also been a suggested biofertilizer, and source of fatty acids for biofuel production.<ref name=":1" /><ref>{{Cite journal |last1=Bhandari |first1=Rupali |last2=Sharma |first2=Prabhat Kumar |date=2006 |title=High-light–induced Changes on Photosynthesis, Pigments, Sugars, Lipids and Antioxidant Enzymes in Freshwater (Nostoc spongiaeforme) and Marine (Phormidium corium) Cyanobacteria |url=http://dx.doi.org/10.1562/2005-09-20-ra-690 |journal=Photochemistry and Photobiology |volume=82 |issue=3 |pages=702–710 |doi=10.1562/2005-09-20-ra-690 |pmid=16464127 |s2cid=24222149 |issn=0031-8655|url-access=subscription }}</ref>

=== Environmental usage === ''Nostoc'' has the unique ability to survive and colonize new and bare mineral surfaces by moss and other higher plants, which then allows for more organic soil and stable vegetation. It has been suggested that ''Nostoc'' be used in environments of retreating glaciers in order to establish new and more stable presences of vegetation on newly exposed mineral surfaces.<ref name=":3" />

=== Historical and culinary usage === {{See also|Fat choy}} ''Nostoc'' has historically been utilized as a healthy food and traditional medicine, most notably in Asia <ref name=":0">{{Cite journal |last1=Li |first1=Zhuoyu |last2=Guo |first2=Min |date=2018 |title=Healthy efficacy of Nostoc commune Vaucher |journal=Oncotarget |volume=9 |issue=18 |pages=14669–14679|doi=10.18632/oncotarget.23620 |pmid=29581873 |pmc=5865699 }}</ref> Historically, the species ''N. flagelliforme'' and ''N. commune'' have been consumed in China, where it was used to survive famines and has been used as an ingredient in Chinese medicine since the Eastern Jin Dynasty.<ref name=":0" /> Additionally, ''Nostoc'' has had documented culinary usage in India, Indonesia, Peru, Bolivia, and Ecuador.<ref name=":1" />

''Nostoc'' is also highly nutritious, containing protein and vitamin C,<ref>{{Cite web|url=http://www.eattheweeds.com/nostoc-nasal-nostalgia-and-edible-too-2/|title=Nostoc Num Nums|last=Deane|first=Green|date=2011-08-31|website=Eat The Weeds and other things, too|language=en-US|access-date=2019-02-20|archive-url=https://web.archive.org/web/20190131013211/http://www.eattheweeds.com/nostoc-nasal-nostalgia-and-edible-too-2/|archive-date=2019-01-31|url-status=live}}</ref> as well as all essential amino acids.<ref name=":1" /> It has been suggested to be anti-inflammatory and an antioxidant as well.<ref name=":0" /> Because of this, ''Nostoc'' has also been considered to be a strong candidate for extraterrestrial agriculture.<ref name=":1" />

== Human impact and management == [[File:Nostoc commune on footbridge - geograph.org.uk - 2708011.jpg|left|thumb|''Nostoc commune'' overtaking a footbridge]]

Because of human foot traffic, and contaminated gardening tools and irrigation systems, ''Nostoc'' is usually found outside of its natural habitat in plant nurseries and greenhouses. A number of different control methods can be effective in removing unwanted ''Nostoc'' from these environments, including implementing increased drainage in these facilities, physical removal of ''Nostoc'', and flame weeders or solarization.<ref name=":2" />

==Taxonomy== [[File:CyanobacteriaColl1.jpg|thumb|left|''Nostoc pruniforme'']]

''Nostoc'' is a member of the family Nostocaceae of the order Nostocales. Species include (see collapsed list on the right for full listing) :

{{div col|colwidth=17em}} *''Nostoc azollae'' *''Nostoc caeruleum'' Lyngbye ex Bornet et Flahault<ref name="Mollenhauer-et-al-1999">{{cite journal |last1=Mollenhauer |first1=Dieter |last2=Bengtsson |first2=Roland |last3=Lindstrøm |first3=Eli-Anne |title=Macroscopic cyanobacteria of the genus Nostoc: a neglected and endangered constituent of European inland aquatic biodiversity |journal=European Journal of Phycology |date=1999 |volume=34 |issue=4 |pages=349–360 |doi=10.1080/09670269910001736412 }}</ref> *''Nostoc carneum'' *''Nostoc comminutum'' *''Nostoc commune'' (Linnaeus) Vaucher ex Bornet et Flahault<ref name="Mollenhauer-et-al-1999" /> (Chinese: ''Koxianmi'')<ref name=Abbott>{{cite book | last = Abbott | first = I. A. | author-link = Isabella Abbott | chapter = Food and food products from seaweeds | editor1-last = Lembi | editor1-first = C. A. | editor2-last = Waaland | editor2-first = J. R. | title = Algae and human affairs | year = 1989 | page = 141 | publisher = Cambridge University Press, Phycological Society of America | isbn = 978-0-521-32115-0 }}</ref> *''Nostoc ellipsosporum'' *''Nostoc flagelliforme'' *''Nostoc linckia'' *''Nostoc longstaffi'' *''Nostoc microscopicum'' (Carmichael ex Harvey) Bornet et Flahault<ref name="Mollenhauer-et-al-1999" /> *''Nostoc muscorum'' *''Nostoc paludosum'' *''Nostoc pruniforme'' (Linnaeus) C. A. Agardh ex Bornet et Flahault<ref name="Mollenhauer-et-al-1999" /> *''Nostoc punctiforme'' *''Nostoc sphaericum'' *''Nostoc sphaeroides'' *''Nostoc spongiaeforme'' *''Nostoc thermotolerans'' *''Nostoc verrucosum'' Vaucher ex Bornet et Flahault<ref name="Mollenhauer-et-al-1999" />{{div col end}}

==References== ===Citations=== {{Reflist}}

===General sources=== *{{cite web|url=http://www.microscopyu.com/galleries/confocal/nostoc.html|title=Nikon MicroscopyU: Confocal Image Gallery - Nostoc (Cyanobacteria)|date=9 March 2005|archive-url=https://web.archive.org/web/20050309012631/http://www.microscopyu.com/galleries/confocal/nostoc.html|access-date=15 January 2019|archive-date=2005-03-09}} *{{Cite web|url=https://www.glerl.noaa.gov//seagrant/GLWL/Algae/Cyanophyta/Cyanophyta.html|title=GLERL/Sea Grant: Great Lakes Water Life Photo Gallery - Blue-green Algae - Cyanophtya|last=Office|first=NOAA Sea Grant Extension|website=www.glerl.noaa.gov|access-date=2019-02-20|archive-date=2019-02-20|archive-url=https://web.archive.org/web/20190220063030/https://www.glerl.noaa.gov//seagrant/GLWL/Algae/Cyanophyta/Cyanophyta.html|url-status=dead}} *Davidson, Alan. Oxford Companion to Food (1999), "Nostoc". {{ISBN|0-19-211579-0}}

== External links == * {{cite web|url=https://www.arcor.de/|title=Aktuelle News, Schlagzeilen und Berichte aus aller Welt - Arcor.de|website=www.arcor.de|access-date=15 January 2019}} ''Nostoc'' spec. in lichens * {{AlgaeBase genus|name=Nostoc|id=42976}}

Category:Nostocaceae Category:Cyanobacteria genera Category:Lichen photobionts Category:Terrestrial algae Category:Freshwater algae