Tautonymy in nomenclature refers to the genus name and species epithet having exactly the same spelling. Nomenclature is a system of naming and categorizing objects in a given category. ... See genus (mathematics) for the use of the term in mathematics. ... In biology, a species is, loosely speaking, a group of related organisms that share a more or less distinctive form and are capable of interbreeding. ...

Examples

• Natrix natrix (Linnaeus, 1758)
• Larix larix (L.) H. Karsten

The first, a snake, is ruled by the International Code of Zoological Nomenclature for animals, where this is allowed. Superfamilies and Families Henophidia Aniliidae Anomochilidae Boidae Bolyeriidae Cylindrophiidae Loxocemidae Pythonidae Tropidophiidae Uropeltidae Xenopeltidae Typhlopoidea Anomalepididae Leptotyphlopidae Typhlopidae Xenophidia Acrochordidae Atractaspididae Colubridae Elapidae Hydrophiidae Viperidae Snakes are cold blooded legless reptiles closely related to lizards, which share the order Squamata. ... The International Code of Zoological Nomenclature (ICZN) is a set of rules in zoology that have one fundamental aim: to provide the maximum universality and continuity in classifying all animals according to taxonomic judgment. ... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria Placozoa Subregnum Bilateria  Acoelomorpha  Orthonectida  Rhombozoa  Myxozoa  Superphylum Deuterostomia     Chordata (vertebrates, etc. ...

The second, a published name for the European Larch, is ruled by the International Code of Botanical Nomenclature for plants, where tautonymy is not allowed. If a species (in this example, originally Pinus larix L.) is transferred to another genus (here, to the new genus Larix), and this move creates a tautonym, one must find the next earliest validly published name, or propose a new name (in this case Larix decidua Miller). Binomial name Larix decidua Mill. ... The International Code of Botanical Nomenclature is the set of rules according to which plants are given their formal botanical names (scientific names). ... Divisions Land plants (embryophytes) Non-vascular plants (bryophytes) Hepatophyta - liverworts Anthocerophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta - flowering plants Adiantum pedatum (a fern...

It is allowed for the genus and species of a plant to mean the same, without being identical in spelling. For instance, Arctostaphylos uva-ursi means bearberry, in Greek and Latin respectively. There are also a few instances of modification of the genus name in the species, such as the fern Polypodium polypodioides, which means "a polypodium that is like a polypodium". Differences as small as a single letter are permissible, as in the Jujube shrub, Ziziphus zizyphus. Species Arctostaphylos alpina - Alpine Bearberry Arctostaphylos uva-ursi - Common Bearberry Bearberries are three species of dwarf shrubs in the genus Arctostaphylos. ... Classes Marattiopsida Osmundopsida Gleicheniopsida Pteridopsida A fern, or pteridophyte, is any one of a group of some twenty thousand species of plants classified in the Division Pteridophyta, formerly known as Filicophyta. ... Species Polypodium polypodioides The Resurrection fern (Polypodium polypodioides) is a species of creeping, course-textured fern very common in the Southeastern United States, being found as far east as Florida north to New York and west to Texas. ... Binomial name Ziziphus zizyphus (L.) H. Karst. ...

See also

• binomial nomenclature