Trinomial nomenclature

In biology,trinomial nomenclatureis the system of names fortaxabelow therankofspecies.These names have three parts. The usage is different inzoologyandbotany.

In zoology

Drying great cormorant subspecies known as "Phalacrocorax carbo novaehollandiae "

Pictured is thecritically endangeredwestern lowland gorilla. Its trinomen isGorilla gorilla gorilla.

Inzoological nomenclature,atrinomen(pl.trinomina), trinominal name, or ternary name is the name of asubspecies.Examples areGorilla gorilla gorilla(Savage,1847) for thewestern lowland gorilla(genusGorilla,specieswestern gorilla),Gorilla gorilla diehlifor theCross River gorilla,Bison bison bison(Linnaeus,1758) for theplains bison(genusBison,speciesAmerican bison), andBison bison athabascaefor thewood bison.

A trinomen is a name with three parts:generic name,specific nameandsubspecific name.The first two parts alone form thebinomenorspeciesname. All three names are typeset in italics, and only the first letter of the generic name is capitalised. No indicator of rank is included: inzoology,subspecies is the only rank below that of species. For example: "Buteo jamaicensis borealisis one of the subspecies of thered-tailed hawk(Buteo jamaicensis). "

In ataxonomicpublication, a name is incomplete without an author citation and publication details. This indicates who published the name, in what publication, and the date of the publication. For example: "Phalacrocorax carbo novaehollandiae(Stephens, 1826) "denotes a subspecies of thegreat cormorant(Phalacrocorax carbo) introduced byJames Francis Stephensin 1826under the subspecies namenovaehollandiae( "of New Holland" ).

If the generic and specific name have already been mentioned in the same paragraph, they are often abbreviated to initial letters. For example, one might write: "The great cormorantPhalacrocorax carbohas a distinct subspecies inAustralasia,the black shagP. c. novaehollandiae".

While binomial nomenclature came into being and immediately gained widespread acceptance in the mid-18th century, it was not until the early 20th century that the current unified standard of trinominal nomenclature was agreed upon. This became the standard mainly because of tireless promotion byElliott Coues– even though trinomina in the modern usage were pioneered in 1828 byCarl Friedrich Bruchand around 1850 were widely used especially byHermann SchlegelandJohn Cassin.As late as the 1930s, the use of trinomina was not fully established in all fields of zoology. Thus, when referring especially European works of the preceding era, the nomenclature used is usually not in accord with contemporary standards.

In botany

Main article:Infraspecific name

For algae, fungi, plants, and their fossils, there is an indeterminate number of infraspecific ranks allowed below the level of species. The secondary ranks below the species rank arevarietyandforma,and more ranks can be made by using the prefix "sub" to make subspecies, subvariety, subforma. Very rarely even more forms are created, such as supersubspecies. Not all of these ranks need to be specified, for example, some authors prefer to divide plant species into subspecies, while others prefer to use varieties.

These ranks are components of abiological classification,for exampleCorylopsissinensisvar.calvescensf.veitchianais an ornamental garden plant.However, anameis not the same as a classification, and the name of this plant is a trinomial with only three parts,the two parts of the species nameCorylopsis sinensis,plus the forma epithetveitchiana,to giveCorylopsis sinensisf.veitchiana.

See also

• Binomial nomenclature
• Nomenclature