Recent phylogenetic analyses of members of the Tolypothrichaceae (Nostocales, Cyanobacteria) based on 16S rRNA gene sequence data have demonstrated that the soil-inhabiting members of the family belong to a clade separate from the aquatic and subaerial members of the family. The soil-inhabiting species clade includes Spirirestis, a monophyletic taxon originally defined by its tight spiral coiling. Most of the soil-inhabiting species have been identified in the past as belonging either to Hassallia or Tolypothrix, which are subaerial and aquatic taxa, respectively. A comprehensive study of the terrestrial Tolypothrichaceae led us to conclude that all terrestrial Tolypothrichaceae should be included in the genus Spirirestis, even though most of those isolates lack the spiral coiling diagnostic of the genus. Using a polyphasic approach, we recognize seven distinct clades in Spirirestis, which we split into seven species: S. rafaelensis (the generitype), S. californica comb. nov., S. pseudoramosissima comb. nov., S. lignicolor sp. nov., S. williamsae sp. nov., S. hydroterrestris sp. nov., and S. atacamensis sp. nov. Spirirestis rafaelensis and S. californica are represented by multiple isolates, and we postulate that with time and further taxon sampling, some of the strains we included in these two species may be recognized as additional species. As the study of soil cyanobacteria continues, additional species of Spirirestis will likely be discovered and described.

Botany and Microbiology Department College of Science King Saud University Riyadh Saudi Arabia

Department of Biology John Carroll University University Heights Ohio USA

Department of Botany Faculty of Science University of South Bohemia České Budějovice Czech Republic

Department of Botany Institute of Science Banaras Hindu University Varanasi India

Department of Conservation and Research Santa Barbara Botanical Garden Santa Barbara California USA

Geography Science College Shanxi Normal University Taiyuan Shanxi China

Institute of Hydrobiology Biology Centre of AS CR České Budějovice Czech Republic

National Autonomous University of Mexico Facultad de Ciencias Mexico City Mexico

Naval Base Ventura County NAS Point Mugu California USA

School of Life Sciences University of Nevada Las Vegas Nevada USA

Zobrazit více v PubMed

Alvarenga, D. O. , Andreote, A. P. D. , Branco, L. H. Z. , & Fiori, M. F. (2017). PubMed

Baas‐Becking, L. G. M. (1934). Geobiologie of inleiding tot de milieukunde. W.P. Van Stockum & Zoon.

Baldarelli, L. M. , Pietrasiak, N. , Osorio‐Santos, K. , & Johansen, J. R. (2022). PubMed

Becerra‐Absalón, I. , Muñoz‐Martin, M. A. , Montejano, G. , & Mateo, P. (2019). Differences in the cyanobacterial community composition of biocrusts from the drylands of central Mexico. Are there endemic species? Frontiers in Microbiology, 10, 937. PubMed PMC

Bohunická, M. , Johansen, J. R. , Villanueva, C. D. , Mareš, J. , Štenclová, L. , Becerra‐Absalón, I. , Hauer, T. , & Kaštovský, J. (2024). Revision of the pantropical genus

Bohunická, M. , Pietrasiak, N. , Johansen, J. R. , Gómez, E. B. , Hauer, T. , Gaysina, L. A. , & Lukešová, A. (2015).

Burger‐Wiersma, T. , Stal, L. J. , & Mur, L. R. (1989).

Casamatta, D. A. , Gomez, S. R. , & Johansen, J. R. (2006).

Chisholm, S. W. , Frankel, S. L. , Goericke, R. , Olson, R. J. , Palenik, B. , Waterbury, J. B. , Westjohnsrud, L. , & Zettler, E. R. (1992).

Chisholm, S. W. , Olsen, R. J. , Zettler, E. R. , Goericke, R. , Waterbury, J. B. , & Welschmeyer, N. A. (1988). A novel free‐living prochlorophyte abundant in the oceanic euphotic zone. Nature, 334, 340–343.

De Wit, R. , & Bouvier, T. (2006). “ PubMed DOI

Drummond, A. J. , Ho, S. Y. W. , Phillips, M. J. , & Rambaut, A. (2006). Relaxed phylogenetics and dating with confidence. PLoS Biology, 2006(4), e88. PubMed PMC

Engene, N. , Rottacker, E. C. , Kaštovský, J. , Byrum, T. , Choi, H. , Ellisman, M. H. , Komárek, J. , & Gerwick, W. H. (2012). PubMed PMC

Flechtner, V. R. , Boyer, S. L. , Johansen, J. R. , & DeNoble, M. L. (2002).

Flechtner, V. R. , Johansen, J. R. , & Belnap, J. (2008). The biological soil crusts of the san Nicolas Island: Enigmatic algae from a geographically isolated ecosystem. Western North American Naturalist, 68, 405–436.

Fox, G. E. , Wizotzkey, J. D. , & Jurtshuk, P. (1992). How close is close: 16S rRNA sequence identity may not be sufficient to guarantee species identity. International Journal of Systematic Bacteriology, 42, 166–170. PubMed

Gelman, A. , & Rubin, D. B. (1992). Inference from iterative simulation using multiple sequences. Statistical Science, 7, 157–511.

González‐Resendiz, L. , Johansen, J. R. , Alba‐Lois, L. , Segal‐Kischinevzky, C. , Escobar‐Sánchez, V. , Jiménez‐García, L. F. , Hauer, T. , & León‐Tejera, H. (2018).

Greuter, W. , McNeill, J. , Barrie, F. R. , Burdet, H. M. , Demoulin, V. , Filgueiras, T. S. , Nicolson, D. H. , Silva, P. C. , Skog, J. E. , Trehane, P. , Turland, N. J. , & Hawksworth, D. L. (2000). International code of botanical nomenclature (Saint Louis code). Koeltz Scientific Books.

Hanson, C. A. , Fuhrman, J. A. , Horner‐Devine, M. C. , & Martiny, J. B. H. (2012). Beyond biogeographic patterns: Processes shaping the microbial landscape. Nature Reviews Microbiology, 10, 497–506. PubMed

Hauer, T. , Mareš, J. , Bohunická, M. , Johansen, J. R. , & Berrendero‐Gomez, E. (2014). Heterogeneity of the cyanobacterial genus PubMed

Hentschke, G. S. , Johansen, J. R. , Pietrasiak, N. , Fiore, M. F. , Rigonato, J. , Sant'Anna, C. L. , & Komárek, J. (2016). Phylogenetic placement of

Hoffmann, L. , & Greuter, W. (1993). Validation of

Johansen, J. R. , González‐Resendiz, L. , Escobar‐Sánchez, V. , Segal‐Kischinevzky, C. , Martínez‐Yerena, J. , Hernández‐Sánchez, J. , Hernández‐Pérez, G. , & León‐Tejera, H. (2021). When will taxonomic saturation be achieved? A case study in PubMed

Johansen, J. R. , Jusko, B. M. , Mesfin, M. , Luknis, M. A. , Wain, A. , Hoyer, W. F. , & Hasenstab‐Lehman, K. (2025).

Jusko, B. M. , & Johansen, J. R. (2024). Description of six new cyanobacterial species from soil biocrusts on San Nicolas Island, California, in three genera previously restricted to Brazil. Journal of Phycology, 60, 133–151. PubMed

Jusko, B. M. , Johansen, J. R. , Mehda, S. , Perona, E. , & Muñoz‐Martín, M. Á. (2024). Four novel species of

Komárek, J. , Genuário, D. B. , Fiore, M. F. , & Elster, J. (2015). Heterocytous cyanobacteria of the Ulu Peninsula, James Ross Island, Antarctica. Polar Biology, 38(4), 475–492.

Komárek, J. , Johansen, J. R. , Šmarda, J. , & Strunecký, O. (2020). Phylogeny and taxonomy of

Lapage, S. P. , Sneath, P. H. A. , Lessel, E. F. , Skerman, V. B. D. , Seeliger, H. P. R. , & Clark, W. A. (1975). International code of nomenclature of bacteria (Rev. 1975). American Society of Microbiology. PubMed

Larkin, M. A. , Blackshields, G. , Brown, N. P. , Chenna, R. , McGettigan, P. A. , McWilliam, H. , Valentin, F. , Wallace, I. M. , Wilm, A. , Lopez, R. , Thompson, J. D. , Gibson, T. J. , & Higgins, D. G. (2007). Clustal W and Clustal X version 2.0. Bioinformatics, 23(21), 2947–2948. PubMed

León‐Tejera, H. , González‐Resendiz, L. , Johansen, J. R. , Segal‐Kischinevsky, C. , Escobar‐Sánchez, V. , & Alba‐Lois, L. (2016). Phylogenetic position reevaluation of

Lewin, R. A. (1975). A marine

Lewin, R. A. (1977).

Mareš, J. , Johansen, J. R. , Hauer, T. , Zima, J., Jr. , Ventura, S. , Cuzman, O. , Tiribilli, B. , & Kaštovský, J. (2019). Taxonomic resolution of the genus PubMed

Mareš, J. , Komárek, J. , Compère, P. , & Oren, A. (2013). Validation of the generic name

Martiny, J. B. H. , Bohannon, B. J. M. , Brown, J. H. , Colwell, R. K. , Fuhrman, J. A. , Green, J. L. , Horner‐Devine, M. C. , Kane, M. , Krumins, J. A. , Kuske, C. R. , Morin, P. J. , Naeem, S. , Øvreås, L. , Reysenbach, A. , Smith, V. H. , & Staley, J. T. (2006). Microbial biogeography: Putting microorganisms on the map. Nature Reviews Microbiology, 4, 102–112. PubMed

Mikhailyuk, T. I. , Vinogradova, O. M. , Glaser, K. , Demchenko, E. M. , & Karsten, U. (2018). Diversity of terrestrial algae of Cape Kazantip (the Sea of Azov, Ukraine) and some remarks on their phylogeny and ecology. International Journal on Algae, 20, 313–338.

Miller, M. A. , Pfeiffer, W. , & Schwartz, T. (2010). Creating the CIPRES Science Gateway for inference of large phylogenetic trees. DOI

Mühlsteinová, R. , Johansen, J. R. , Pietrasiak, N. , & Martin, M. P. (2014). Polyphasic characterization of

Nübel, U. , Garcia‐Pichel, F. , & Muyzer, G. (1997). PCR primers to amplify 16S rRNA genes from cyanobacteria. Applied and Environmental Microbiology, 63, 3327–3332. PubMed PMC

Oren, A. , Mareš, J. , & Rippka, R. (2022). Validation of the names PubMed

Pietrasiak, N. , Mühlsteinová, R. , Siegesmund, M. A. , & Johansen, J. R. (2014). Phylogenetic placement of

Pietrasiak, N. , Osorio‐Santos, K. , Lipson, D. L. , & Johansen, J. R. (2021). PubMed

Pietrasiak, N. , Osorio‐Santos, K. , Shalygin, S. , Martin, M. P. , & Johansen, J. R. (2019). When is a lineage a species? A case study in PubMed

Řeháková, K. , Johansen, J. R. , Casamatta, D. A. , Xuesong, L. , & Vincent, J. (2007). Morphological and molecular characterization of selected desert soil cyanobacteria: Three species new to science including

Rippka, R. , & Cohen‐Bazire, G. (1983). The Cyanobacteriales: A legitimate order based on the type strain PubMed

Rippka, R. , Waterbury, J. B. , & Cohen‐Bazire, G. (1974). A cyanobacterium which lacks thylakoids. Archives of Microbiology, 100, 419–436.

Roncero‐Ramos, B. , Muñoz‐Martin, M. A. , Chamizo, S. , Fernández‐Valbuena, L. , Mendoza, D. , Perona, E. , Cantón, Y. , & Mateo, P. (2019). Polyphasic evaluation of key cyanobacteria in biocrusts from the most arid region in Europe. PeerJ, 7, e6169. PubMed PMC

Sant'Anna, C. L. , Azevedo, T. M. P. , Kaštovský, J. , & Komárek, J. (2010). Two form‐genera of aerophytic heterocytous cyanobacteria from Brasilian rainy forest “Mata Atlântica”. Fottea, 10(2), 217–228.

Saraf, A. , Singh, P. , Kumar, N. , Pal, S. , & Johansen, J. R. (2024). Two new species of PubMed

Stanier, R. Y. , Sistrom, W. R. , Hansen, T. A. , Whitton, B. A. , Castenholz, R. W. , Pfennig, N. , Gorlenko, V. N. , Kondratieva, E. N. , Eimhjellen, K. E. , Whittenbury, R. , Gherna, R. L. , & Truper, H. G. (1978). Proposal to place the nomenclature of the cyanobacteria (blue‐green algae) under the rules of the international code of nomenclature of bacteria. International Journal of Systematic Bacteriology, 28, 335–336.

Swofford, D. L. (1998). PAUP*. Phylogenetic analysis using parsimony (*and other methods). Version 4.02b. Sinauer Associates.

Thiers, B. (2025). Index Herbariorum . https://sweetgum.nybg.org/science/ih/

Tronholm, A. , & Engene, N. (2019).

Turland, N. J. , Wiersema, J. H. , Barrie, F. R. , Greuter, W. , Hawksworth, D. L. , Herendeen, P. S. , Knapp, S. , Kusber, W.‐H. , Li, D.‐Z. , Marhold, K. , May, T. W. , McNeill, J. , Monro, A. M. , Prado, J. , Price, M. J. , & Smith, G. F. (Eds.). (2018). International code of nomenclature for algae, fungi, and plants (Shenzhen code). Koeltz Botanical Books.

Villanueva, C. D. , Bohunická, M. , & Johansen, J. R. (2024). We're doing it wrong: Putting homology before phylogeny in cyanobacterial taxonomy. Journal of Phycology, 60, 1071–1089. PubMed

Wilmotte, A. , Van der Auwera, G. , & De Wachter, R. (1993). Structure of the 16S ribosomal RNA of the thermophilic cyanobacterium PubMed

Yaeger, C. M. , Kornosky, J. L. , Morgan, R. E. , Cain, E. C. , Garcia‐Pichel, F. , Housman, D. C. , Belnap, J. , & Kuske, C. R. (2007). Three distinct clades of cultured heterocystous cyanobacteria constitute the dominant N2‐fixing members of biological soil crusts of the Colorado plateau, USA. FEMS Microbiology Ecology, 60, 85–97. PubMed

Yaeger, C. M. , Kuske, C. R. , Carney, T. D. , Johnson, S. L. , Ticknor, L. O. , & Belnap, J. (2012). Response of biological soil crust diazotrophs to season, altered summer precipitation, and year‐round increased temperature in an arid grassland of the Colorado plateau, USA. Frontiers in Microbiology, 3, 358. PubMed PMC

Yarza, P. , Yilmaz, P. , Pruesse, E. , Glöckner, F. O. , Ludwig, W. , Schleifer, K. H. , Whitman, W. B. , Euzéby, J. , Amann, R. , & Rosselló‐Móra, R. (2014). Uniting the classification of cultured and uncultured bacteria and archaea using 16S rRNA gene sequences. Nature Reviews Microbiology, 12, 635–645. PubMed

Zuker, M. (2003). Mfold web server for nucleic acid folding and hybridization prediction. Nucleic Acids Research, 31, 3406–3415. PubMed PMC