Monotypic taxon

In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon.^[1] A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described.^[2] In contrast, an oligotypic taxon contains more than one but only a very few subordinate taxa.

The German lichenologist Robert Lücking suggests that the common application of the term monotypic is frequently misleading, "since each taxon by definition contains exactly one type and is hence "monotypic", regardless of the total number of units", and suggests using "monospecific" for a genus with a single species, and "monotaxonomic" for a taxon containing only one unit.^[3]

^ Mayr E, Ashlock PD. (1991). Principles of Systematic Zoology (2nd ed.). McGraw-Hill. ISBN 0-07-041144-1
^ McNeill, J.; Barrie, F.R.; Buck, W.R.; Demoulin, V.; Greuter, W.; Hawksworth, D.L.; Herendeen, P.S.; Knapp, S.; Marhold, K.; Prado, J.; Reine, W.F.P.h.V.; Smith, G.F.; Wiersema, J.H.; Turland, N.J. (2012). "Article 38". International Code of Nomenclature for algae, fungi, and plants (Melbourne Code) adopted by the Eighteenth International Botanical Congress Melbourne, Australia, July 2011. Vol. Regnum Vegetabile 154. A.R.G. Gantner Verlag KG. ISBN 978-3-87429-425-6.
^ Lücking, Robert (2019). "Stop the abuse of time! Strict temporal banding is not the future of rank-based classifications in Fungi (including lichens) and other organisms". Critical Reviews in Plant Sciences. 38 (3): 199–253 [216]. doi:10.1080/07352689.2019.1650517.

[1] Mayr E, Ashlock PD. (1991). Principles of Systematic Zoology (2nd ed.). McGraw-Hill. ISBN 0-07-041144-1

[2] McNeill, J.; Barrie, F.R.; Buck, W.R.; Demoulin, V.; Greuter, W.; Hawksworth, D.L.; Herendeen, P.S.; Knapp, S.; Marhold, K.; Prado, J.; Reine, W.F.P.h.V.; Smith, G.F.; Wiersema, J.H.; Turland, N.J. (2012). "Article 38". International Code of Nomenclature for algae, fungi, and plants (Melbourne Code) adopted by the Eighteenth International Botanical Congress Melbourne, Australia, July 2011. Vol. Regnum Vegetabile 154. A.R.G. Gantner Verlag KG. ISBN 978-3-87429-425-6.

[3] Lücking, Robert (2019). "Stop the abuse of time! Strict temporal banding is not the future of rank-based classifications in Fungi (including lichens) and other organisms". Critical Reviews in Plant Sciences. 38 (3): 199–253 [216]. doi:10.1080/07352689.2019.1650517.

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