Ternary name
Encyclopedia
In botany
, an infraspecific name is the name for any taxon
below the rank of species, i.e. an infraspecific taxon. (A 'taxon', plural 'taxa', is a group of organisms to be given a particular name; 'infraspecific' means 'any rank below the level of species'.) The scientific names of plants (and some other groups) are regulated by the International Code of Botanical Nomenclature (ICBN). This specifies a 'three part name' for infraspecific taxa, plus a 'connecting term' to indicate the rank of the name. An example of such a name is Astrophytum myriostigma subvar. glabrum, the name of a subvariety of the species Astrophytum myriostigma
(bishop's hat cactus).
It is customary to italicize all three parts of such a name, but not the connecting term. For example:
The ranks below species explicitly allowed in the ICBN are:
Sometimes more than three parts will be given; strictly speaking, this is not a name, but a classification. The ICBN gives the example of Saxifraga aizoon var. aizoon subvar. brevifolia f. multicaulis subf. surculosa; the name of the subform would be Saxifraga aizoon subf. surculosa.
A key concept in botanical names is that of a type. In many cases the type will be a particular preserved specimen stored in a herbarium
, although there are other kinds of type. Like other names, an infraspecific name is attached to a type. Whether a plant should be given a particular infraspecific name can then be decided by comparing it to the type.
There is no requirement for a species to be divided into infraspecific taxa, of whatever rank; in other words, a species does not have to have subspecies, varieties, forms, etc. However, if infraspecific ranks are created, then the name of the type of the species must repeat the specific epithet as its infraspecific epithet. The type acquires this name automatically as soon as any infraspecific rank is created. As an example, consider Poa secunda
J.Presl, whose type specimen is in the Wisconsin State Herbarium.
The same epithet can be used again within a species, at whatever level, only if the names with the re-used epithet are attached to the same type. Thus there can be a form called Poa secunda f. juncifolia as well as the subspecies Poa secunda subsp. juncifolia if, and only if, the type specimen of Poa secunda f. juncifolia is the same as the type specimen of Poa secunda subsp. juncifolia (in other words, if there is a single type specimen whose classification is Poa secunda subsp. juncifolia f. juncifolia).
If two infraspecific taxa which have different types are accidentally given the same epithet, then a homonym has been created. The earliest published name is the legitimate one and the other must be changed.
or 'trinomial name'. No connecting term is required as there is only one rank below species, the subspecies
.
Botany
Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...
, an infraspecific name is the name for any taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
below the rank of species, i.e. an infraspecific taxon. (A 'taxon', plural 'taxa', is a group of organisms to be given a particular name; 'infraspecific' means 'any rank below the level of species'.) The scientific names of plants (and some other groups) are regulated by the International Code of Botanical Nomenclature (ICBN). This specifies a 'three part name' for infraspecific taxa, plus a 'connecting term' to indicate the rank of the name. An example of such a name is Astrophytum myriostigma subvar. glabrum, the name of a subvariety of the species Astrophytum myriostigma
Astrophytum myriostigma
Astrophytum myriostigma is a species of cactus native to the highlands of northeastern and central Mexico....
(bishop's hat cactus).
Construction of infraspecific names
Article 24 of the International Code of Botanical Nomenclature (ICBN) describes how infraspecific names are constructed. The order of the three parts of an infraspecific name is:- genus name, specific epithet, connecting term indicating the rank (not part of the name, but required), infraspecific epithet.
It is customary to italicize all three parts of such a name, but not the connecting term. For example:
- Acanthocalycium klimpelianum var. macranthum
- genus name = Acanthocalycium, specific epithet = klimpelianum, connecting term = var. (short for 'varietas' or variety), infraspecific epithet = macranthum
- Astrophytum myriostigma subvar. glabrum
- genus name = Astrophytum, specific epithet = myriostigma, connecting term = subvar. (short for 'subvarietas' or subvariety), infraspecific epithet = glabrum
The ranks below species explicitly allowed in the ICBN are:
- subspeciesSubspeciesSubspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
- recommended abbreviation: subsp. (but "ssp." is also in use) - varietas (variety) - recommended abbreviation: var.
- subvarietas (subvarietySubvarietyIn botanical nomenclature, a subvariety is a taxonomic rank below that of variety but above that of form : it is an infraspecific taxon. Its name consists of three parts: a genus name, a specific epithet and an infraspecific epithet. To indicate the rank, the abbreviation "subvar." should be put...
) - recommended abbreviation: subvar. - forma (formForm (botany)In botanical nomenclature, a form is one of the "secondary" taxonomic ranks, below that of variety, which in turn is below that of species; it is an infraspecific taxon...
) - recommended abbreviation: f. - subforma (subform) - recommended abbreviation: subf.
Abbreviation of infraspecific names
Like specific epithets, infraspecific epithets cannot be used in isolation as names. Thus the name of a particular species of Acanthocalycium is Acanthocalycium klimpelianum, which can be abbreviated to A. klimpelianum where the context makes the genus clear. The species cannot be referred to as just klimpelianum. In the same way, the name of a particular variety of Acanthocalycium klimpelianum is Acanthocalycium klimpelianum var. macranthum, which can be abbreviated to A. k. var. macranthum where the context makes the species clear. The variety cannot be referred to as just macranthum.Sometimes more than three parts will be given; strictly speaking, this is not a name, but a classification. The ICBN gives the example of Saxifraga aizoon var. aizoon subvar. brevifolia f. multicaulis subf. surculosa; the name of the subform would be Saxifraga aizoon subf. surculosa.
Legitimate infraspecific names
For a proposed infraspecific name to be legitimate it must be in accordance with all the rules of the ICBN. Only some of the main points are described here.A key concept in botanical names is that of a type. In many cases the type will be a particular preserved specimen stored in a herbarium
Herbarium
In botany, a herbarium – sometimes known by the Anglicized term herbar – is a collection of preserved plant specimens. These specimens may be whole plants or plant parts: these will usually be in a dried form, mounted on a sheet, but depending upon the material may also be kept in...
, although there are other kinds of type. Like other names, an infraspecific name is attached to a type. Whether a plant should be given a particular infraspecific name can then be decided by comparing it to the type.
There is no requirement for a species to be divided into infraspecific taxa, of whatever rank; in other words, a species does not have to have subspecies, varieties, forms, etc. However, if infraspecific ranks are created, then the name of the type of the species must repeat the specific epithet as its infraspecific epithet. The type acquires this name automatically as soon as any infraspecific rank is created. As an example, consider Poa secunda
Poa secunda
Poa secunda is a widespread species of grass native to North America. It is highly resistant to drought conditions, and provides excellent fodder.-External links:**...
J.Presl, whose type specimen is in the Wisconsin State Herbarium.
- As soon as a subspecies of Poa secunda was created, then the type specimen of P. secunda immediately became the type specimen of Poa secunda subsp. secunda. The name
' Poa secunda subsp. secunda' was automatically created (it is an 'autonym'). Soreng created the subspecies Poa secunda subsp. juncifolia (whose type specimen is also in the Wisconsin State Herbarium), thereby making the type specimen of P. secunda also the type specimen of Poa secunda subsp. secunda. - If in addition to the subspecies any variety of Poa secunda were to be created, then the type specimen of P. secunda would automatically become the type specimen of Poa secunda var. secunda. The type specimen would then have the classification Poa secunda subsp. secunda var. secunda.
The same epithet can be used again within a species, at whatever level, only if the names with the re-used epithet are attached to the same type. Thus there can be a form called Poa secunda f. juncifolia as well as the subspecies Poa secunda subsp. juncifolia if, and only if, the type specimen of Poa secunda f. juncifolia is the same as the type specimen of Poa secunda subsp. juncifolia (in other words, if there is a single type specimen whose classification is Poa secunda subsp. juncifolia f. juncifolia).
If two infraspecific taxa which have different types are accidentally given the same epithet, then a homonym has been created. The earliest published name is the legitimate one and the other must be changed.
Specifying authors
When indicating authors for infraspecific names, it is possible to show either just the author(s) of the final, infraspecific epithet, or the authors of both the specific and the infraspecific epithets. Examples:- Adenia aculeata subsp. inermis de Wilde
- This identifies de Wilde as the author who published this name for the subspecies (i.e. who created the epithet inermis). Note that here it was decided not to indicate authority for the species.
- Pinus nigra J.F.Arnold subsp. salzmannii (Dunal) Franco
- Here, J.F.Arnold is the author who gave the species, European black pineEuropean Black PinePinus nigra, the European Black Pine, is a moderately variable species of pine, occurring across southern Mediterranean Europe from Spain to the Crimea, in Asia Minor and on Cyprus, and in the high mountains of the Maghreb in North Africa....
, its botanical name Pinus nigra; Dunal is the author who was the first to publish the epithet salzmanii for this taxon (as the species Pinus salzmanii); Franco is the author who reduced the taxon to a subspecies of Pinus nigra.
Difference from zoology
In zoology, names of taxa below species rank are formed somewhat differently, using a trinomenTrinomen
In zoological nomenclature, a trinomen , or trinominal name, refers to the name of a subspecies.A trinomen is a name consisting of three names: generic name, specific name and subspecific name. The first two parts alone form the binomen or species name. All three names are typeset in italics, and...
or 'trinomial name'. No connecting term is required as there is only one rank below species, the subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
.