Nomenclature Codes

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Nomenclature codes

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Nomenclature codes or codes of nomenclature are the various rulebooks that govern biological taxonomic nomenclature, each in their own broad field of organisms. To an end- user who only deals with names of species, with some awareness that species are assignable to families, it may not be noticeable that there is more than one code, but beyond this basic level these are rather different in the way they work.

The successful introduction of two-part names for species by Linnaeus was the start for an ever-expanding system of nomenclature. With all naturalists worldwide adopting this approach to thinking up names there arose several schools of thought about the details. It became ever more apparent that a detailed body of rules was necessary to govern scientific names. From the mid-nineteenth century onwards there were several initiatives to arrive at worldwide-accepted sets of rules. Presently nomenclature codes govern the naming of:

• Algae, Fungi and Plants – International Code of Nomenclature for algae, fungi, and plants (ICN), which in July 2011 replaced the International Code of Botanical Nomenclature (ICBN) and the earlier International Rules of Botanical Nomenclature. • Animals – International Code of Zoological Nomenclature (ICZN) • Bacteria – International Code of Nomenclature of Bacteria (ICNB) • Cultivated plants – International Code of Nomenclature for Cultivated Plants (ICNCP) • Plant associations – International Code of Phytosociological Nomenclature • Viruses – International Committee on Taxonomy of Viruses (ICTV); see also virus classification Contents

• 1 Differences between codes o 1.1 Starting point o 1.2 Workings o 1.3 Terminology o 1.4 Types • 2 Other codes • 3 Ambiregnal protists • 4 Unregulated taxa • 5 See also • 6 References • 7 External links

Differences between codes

Starting point The starting point, that is the time from which these codes are in effect (usually retroactively), varies from group to group, and sometimes from rank to rank. In botany and mycology the starting point is often 1753, in zoology 1758. On the other hand bacteriology started anew, making a clean sweep in 1980, although maintaining the original authors and dates of publication.

Workings

There are also differences in the way codes work. For example, the ICN (the code for algae, fungi and plants) forbids tautonyms, while the ICZN, (the animal code) allows them.

Terminology

These codes differ in terminology, and there is a long-term project to "harmonize" this. For instance, the ICN uses "valid" in "valid publication of a name" (= the act of publishing a formal name), with "establishing a name" as the ICZN equivalent. The ICZN uses "valid" in "valid name" (= "correct name"), with "correct name" as the ICN equivalent. Harmonization is making very limited progress.

Types

There are differences in respect of what kinds of types are used. The bacteriological code prefers living type cultures, but allows other kinds. There has been ongoing debate regarding which kind of type is more useful in a case like cyanobacteria.[1]

Other codes

A more radical approach was to replace all existing codes with a new BioCode, basically a synthesis of the existing Codes.[2][3] The originally planned implementation date for the BioCode draft was January 1, 2000, but agreement was not reached.

A revised BioCode that, instead of replacing the existing codes, would provide a unified context for them, was proposed in 2011.[4][5][6] The International Botanical Congress of 2011 declined to consider the BioCode proposal.

Another code in development is the PhyloCode, which would regulate phylogenetic nomenclature rather than Linnaean nomenclature (that is, it requires phylogenetic definitions for every name, and does not contain mandatory ranks). The accompanying volume (meant to serve the code as Systema naturae functions relative to the Zoological code) is however still on the draft stage, and it is uncertain when, or even if, the code will see any form of implementation.

Ambiregnal protists

Some protists, sometimes called ambiregnal protists, have been considered to be both protozoa and algae, or protozoa and fungi, and names for these have been published under either or both of the ICZN and the ICN.[7][8] These unnecessary duplications introduced a double language throughout protist classification schemes that resulted in confusion.[9][10] Groups claimed by protozoologists and phycologists include euglenids, dinoflagellates, cryptomonads, haptophytes, glaucophytes, many heterokonts (e.g., chrysophytes, raphidophytes, silicoflagellates, some xanthophytes, proteromonads), some monadoid green algae (volvocaleans and prasinophytes), choanoflagellates, bicosoecids, ebriids and chlorarachniophytes.

Slime molds, plasmodial forms and other "fungus-like" organisms claimed by protozoologists and mycologists include mycetozoans, plasmodiophorids, acrasids, labyrinthulomycetess and chytrids.

Other problematic groups are the Cyanobacteria and Microsporidia.

Unregulated taxa

The zoological code doesn't regulate names of taxa lower than subspecies or higher than superfamily. There are many attempts to introduce some order on the nomenclature of these taxa,[11][12] including the use of typified nomenclature, of the PhyloCode, or also of circumscriptional nomenclature.[13][14]

The botanical code is applied primarily to the ranks of family and below. There are some rules for names above the rank of family, but the principle of priority does not apply to them, and the principle of typification is optional. These names may be either automatically typified names or be descriptive names.[15] In some circumstances, a taxon has two possible names (e.g., Chrysophyceae Pascher, 1914, nom. descrip.; Hibberd, 1976, nom. typificatum). Descriptive names are problematic, once that, if a taxon is split, it is not obvious which new group takes the existing name. Meanwhile, with typified names, the existing name is taken by the new group that still bears the type of this name. However, typified names presents special problems for microrganisms.[16]

Binomial nomenclature

From Wikipedia, the free encyclopedia "Latin name" redirects here. For personal names in the Roman Empire, see Roman naming conventions. For the system used for voting, see Binomial System.

Binomial nomenclature (also called binominal nomenclature or binary nomenclature) is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages. Such a name is called a binomial name (which may be shortened to just "binomial"), a binomen or a scientific name; more informally it is also called a Latin name. The first part of the name identifies the genus to which the species belongs; the second part identifies the species within the genus. For example, humans belong to the genus Homo and within this genus to the species Homo sapiens. The formal introduction of this system of naming species is credited to Swedish natural scientist Carl Linnaeus, effectively beginning with his work Species Plantarum in 1753.[1] The application of binomial nomenclature is now governed by various internationally agreed codes of rules, of which the two most important are the International Code of Zoological Nomenclature (ICZN) for animals and the International Code of Nomenclature for algae, fungi, and plants (ICN) for plants. Although the general principles underlying binomial nomenclature are common to these two codes, there are some differences, both in the terminology they use and in their precise rules.

In modern usage, the first letter of the first part of the name, the genus, is always capitalized in writing, while that of the second part is not, even when derived from a proper noun such as the name of a person or place. Similarly, both parts are italicized when a binomial name occurs in normal text. Thus the binomial name of the annual phlox (named after botanist Thomas Drummond) is now written as Phlox drummondii.

In scientific works, the "authority" for a binomial name is usually given, at least when it is first mentioned, and the date of publication may be specified.

• In zoology o "Patella vulgata Linnaeus, 1758". The name "Linnaeus" tells the reader who it was that first published a description and name for this species of sea snail; 1758 is the date of the publication in which the original description can be found (in this case the 10th edition of the book Systema Naturae). o "Passer domesticus (Linnaeus, 1758)". The original name given by Linnaeus was Fringilla domestica; the parentheses indicate that the species is now considered to belong in a different genus. The ICZN does not require that the name of the person who changed the genus be given, nor the date on which the change was made, although nomenclatorial catalogs usually include such information. • In botany o "Amaranthus retroflexus L." – "L." is the standard abbreviation used in botany for "Linnaeus". o "Hyacinthoides italica (L.) Rothm. – Linnaeus first named this bluebell species Scilla italica; Rothmaler transferred it to the genus Hyacinthoides; the ICN does not require that the dates of either publication be specified. Contents

• 1 History • 2 Value • 3 Problems • 4 Relationship to classification and taxonomy • 5 Derivation of binomial names • 6 Codes • 7 Writing binomial names o 7.1 Authority • 8 Other ranks • 9 See also • 10 Notes • 11 References • 12 External links History

Carolus Linnaeus (1707–1778), a Swedish botanist, invented the modern system of binomial nomenclature. See also: Biological classification: Early systems

Prior to the adoption of the modern binomial system of naming species, a scientific name consisted of a generic name combined with a specific name that was from one to several words long. Together they formed a system of polynomial nomenclature.[2] These names had two separate functions. First, to designate or label the species, and second, to be a diagnosis or description; however these two goals were eventually found to be incompatible.[3] In a simple genus, containing only two species, it was easy to tell them apart with a one-word genus and a one-word specific name; but as more species were discovered the names necessarily became longer and unwieldy, for instance Plantago foliis ovato-lanceolatus pubescentibus, spica cylindrica, scapo tereti (Plantain with pubescent ovate-lanceolate leaves, a cylindric spike and a terete scape), which we know today as Plantago media.

Such "polynomial names" may sometimes look like binomials, but are significantly different. For example, Gerard's herbal (as amended by Johnson) describes various kinds of spiderwort: "The first is called Phalangium ramosum, Branched Spiderwort; the second, Phalangium non ramosum, Unbranched Spiderwort. The other ... is aptly termed Phalangium Ephemerum Virginianum, Soon-Fading Spiderwort of Virginia".[4] The Latin phrases are short descriptions, rather than identifying labels.

The Bauhins, in particular Caspar Bauhin (1560–1624), took some important steps towards the binomial system, by pruning the Latin descriptions, in many cases to two words.[5] The adoption by biologists of a system of strictly binomial nomenclature is due to Swedish botanist and physician Carl von Linné, more commonly known by his Latinized name Carolus Linnaeus (1707–1778). It was in his 1753 Species Plantarum that he first began consistently using a one-word "trivial name" together with a generic name in a system of binomial nomenclature.[6] This trivial name is what is now known as a specific epithet (ICN) or specific name (ICZN).[6] The Bauhins' genus names were retained in many of these, but the descriptive part was reduced to a single word.

Linnaeus's trivial names introduced an important new idea, namely that the function of a name could simply be to give a species a unique label. This meant that the name no longer need be descriptive; for example both parts could be derived from the names of people. Thus Gerard's phalangium ephemerum virginianum became Tradescantia virginiana, where the genus name honoured John Tradescant the younger,[7] an English botanist and gardener.[8] A bird in the parrot family was named Psittacus alexandri, meaning "Alexander's parrot", after Alexander the Great whose armies introduced eastern parakeets to Greece.[9] Linnaeus' trivial names were much easier to remember and use than the parallel polynomial names and eventually replaced them.[1]

Value

The value of the binomial nomenclature system derives primarily from its economy, its widespread use, and the uniqueness and stability of names it generally favors:

• Economy. Compared to the polynomial system which it replaced, a binomial name is shorter and easier to remember.[1] It corresponds to the widespread system of family name plus given name(s) used to name people in many cultures.[5] • Widespread use. The binomial system of nomenclature is governed by international codes and is used by biologists worldwide.[10] A few binomials have also entered common speech, such as Homo sapiens, E. coli, and Tyrannosaurus rex. • Clarity. Binomial names avoid the confusion that can be created when attempting to use common names to refer to a species.[11] Common names often differ from one country to another, or even from one part of a country to another. In English-speaking parts of Europe, the bird called a "robin" is Erithacus rubecula. In English-speaking North America, a "robin" is Turdus migratorius. In contrast, the scientific name can be used all over the world, in all languages, avoiding confusion and difficulties of translation.[12][13] • Uniqueness. Provided that taxonomists agree as to the limits of a species, it can have only one name that is correct under the appropriate nomenclature code, generally the earliest published if two or more names are accidentally assigned to a species.[13] However, establishing that two names actually refer to the same species and then determining which has priority can be difficult, particularly if the species was named by biologists from different countries. Therefore, a species may have more than one regularly used name; these names are "synonyms".[14] • Stability. Although stability is far from absolute, the procedures associated with establishing binomial names, such as the principle of priority, tend to favor stability.[11] For example, when species are transferred between genera (as not uncommonly happens as a result of new knowledge), if possible the second part of the binomial is kept the same. Thus there is disagreement among botanists as to whether the genera Chionodoxa and Scilla are sufficiently different for them to be kept separate. Those who keep them separate give the plant commonly grown in gardens in Europe the name Chionodoxa siehei; those who do not give it the name Scilla siehei.[15] The siehei element is constant. Similarly if what were previously thought to be two distinct species are demoted to a lower rank, such as subspecies, where possible the second part of the binomial name is retained as the third part of the new name. Thus the Tenerife robin may be treated as a different species from the European robin, in which case its name is Erithacus superbus, or as only a subspecies, in which case its name is Erithacus rubecula superbus.[16] The superbus element of the name is constant. Since taxonomists can legitimately disagree as to whether two genera or two species are distinct or not, more than one name can be in use.[17] The only reason a specific epithet may need to be changed is if that by transferring it to a new genus it becomes a junior homonym of an older specific epithet for a different species in the same genus.

Problems Binomial nomenclature for species has the effect that when a species is moved from one genus to another, not only is its genus name changed but sometimes its species name must be changed as well (e.g. because the name is already used in the new genus, or to agree in gender with the new genus). Some biologists have argued for the combination of the genus name and specific epithet into a single unambiguous name, or for the use of uninomials (as used in nomenclature of ranks above species).[18]

Relationship to classification and taxonomy

Nomenclature (including binomial nomenclature) is not the same as classification, although the two are related. Classification is the ordering of items into groups based on similarities and/or differences; in biological classification, species are one of the kinds of item to be classified.[19] In principle, the names given to species could be completely independent of their classification. This is not the case for binomial names, since the first part of a binomial is the name of the genus into which the species is placed. Above the rank of genus, binomial nomenclature and classification are partly independent; for example, a species retains its binomial name if it is moved from one family to another or from one order to another, unless it better fits a different genus in the same or different family, or it is split from its old genus and placed in a newly created genus. The independence is only partial since the names of families and other higher taxa are usually based on genera.[citation needed]

Taxonomy includes both nomenclature and classification. Its first stages (sometimes called "alpha taxonomy") are concerned with finding, describing and naming species of living or fossil organisms.[20] Binomial nomenclature is thus an important part of taxonomy as it is the system by which species are named. Taxonomists are also concerned with classification, including its principles, procedures and rules.[21]

Derivation of binomial names

See also: List of Latin and Greek words commonly used in systematic names

A complete binomial name is always treated grammatically as if it were a phrase in the Latin language (hence the common use of the term "Latin name" for a binomial name). However, the two parts of a binomial name can each be derived from a number of sources, of which Latin is only one. These include:

• Latin, either classical or medieval. Thus both parts of the binomial name Homo sapiens are Latin words, meaning "wise" (sapiens) "human/man" (Homo). • Classical Greek. The genus Rhododendron was named by Linnaeus from the Greek word ῥοδόδενδρον, itself derived from rhodos, rose, and dendron, tree.[22] Greek words are often converted to a Latinized form. Thus coca (the plant from which cocaine is obtained) has the name Erythroxylum coca. Erythroxylum is derived from the Greek words erythros, red, and xylon, wood.[23] The Greek neuter ending -ον (-on) is often converted to the Latin neuter ending -um.[a]

• Other languages. The second part of the name Erythroxylum coca is derived from kuka, the name of the plant in Aymara and Quechua.[24][25] Since many dinosaur fossils were found in Mongolia, their names often use Mongolian words, e.g. Tarchia from tarkhi, meaning "brain", or Saichania meaning "beautiful one". • Names of people (often naturalists or biologists). The name Magnolia campbellii commemorates two people: Pierre Magnol, a French botanist, and Archibald Campbell, a doctor in British India.[26] • Names of places. The lone star tick, Amblyomma americanum, is widespread in the United States.[27] • Other sources. Some binominal names have been constructed from anagrams or other re-orderings of existing names. Thus the name of the genus Muilla is derived by reversing the name Allium.[28] Names may also be derived from jokes or puns. For example, Ratcliffe described a number of species of Rhinoceros beetle, including Cyclocephala nodanotherwon.[29]

The first part of the name, which identifies the genus, must be a word which can be treated as a Latin singular noun in the nominative case. It must be unique within each kingdom, but can be repeated between kingdoms. Thus Huia recurvata is an extinct species of plant, found as fossils in Yunnan, China,[30] whereas Huia masonii is a species of frog found in Java, Indonesia.[31]

The second part of the name, which identifies the species within the genus, is also treated grammatically as a Latin word. It can have one of a number of forms.

• The second part of a binomial may be an adjective. The adjective must agree with the genus name in gender. Latin has three genders, masculine, feminine and neuter, shown by varying endings to nouns and adjectives. The house sparrow has the binomial name Passer domesticus. Here domesticus ("domestic") simply means "associated with the house". The sacred bamboo is Nandina domestica[32] rather than Nandina domesticus, since Nandina is feminine whereas Passer is masculine. The tropical fruit langsat is a product of the plant Lansium parasiticum, since Lansium is neuter. Some common endings for Latin adjectives in the three genders (masculine, feminine, neuter) are -us, -a, -um (as in the previous example of domesticus); -is, -is, -e (e.g. tristis, meaning "sad"); and -or, -or, -us (e.g. minor, meaning "smaller"). For further information, see Latin declension: Adjectives. • The second part of a binomial may be a noun in the nominative case. An example is the binomial name of the lion, which is Panthera leo. Grammatically the noun is said to be in apposition to the genus name and the two nouns do not have to agree in gender; in this case, Panthera is feminine and leo is masculine. • The second part of a binomial may be a noun in the genitive (possessive) case. The genitive case is constructed in a number of ways in Latin, depending on the declension of the noun. Common endings for masculine and neuter nouns are -ii or -i in the singular and -orum in the plural, and for feminine nouns -ae in the singular and -arum in the plural. The noun may be part of a person's name, often the surname, as in the Tibetan antelope Pantholops hodgsonii, the shrub Magnolia hodgsonii, or the olive- backed pipit Anthus hodgsoni. The meaning is "of the person named", so that Magnolia hodgsonii means "Hodgson's magnolia". The -ii or -i endings show that in each case Hodgson was a man (not the same one); had Hodgson been a woman, hodgsonae would have been used. The person commemorated in the binomial name is not usually (if ever) the person who created the name; for example Anthus hodgsoni was named by Charles Wallace Richmond, in honour of Hodgson. Rather than a person, the noun may be related to a place, as with Latimeria chalumnae, meaning "of the Chalumna River". Another use of genitive nouns is in, for example, the name of the bacterium Escherichia coli, where coli means "of the colon". This formation is common in parasites, as in Xenos vesparum, where vesparum means "of the wasps", since Xenos vesparum is a parasite of wasps.

Whereas the first part of a binomial name must be unique within a kingdom, the second part is quite commonly used in two or more genera (as is shown by examples of hodgsonii above). The full binomial name must be unique within a kingdom. Codes

From the early 19th century onwards it became ever more apparent that a body of rules was necessary to govern scientific names. In the course of time these became nomenclature codes. The International Code of Zoological Nomenclature (ICZN) governs the naming of animals,[33] the International Code of Nomenclature for algae, fungi, and plants (ICN) that of plants (including cyanobacteria), and the International Code of Nomenclature of Bacteria (ICNB) that of bacteria (including Archaea). Virus names are governed by the International Committee on Taxonomy of Viruses (ICTV), a taxonomic code, which determines taxa as well as names. These codes differ in certain ways, e.g.:

[34] • "Binomial nomenclature" is the correct term for botany, although it is also used by zoologists.[35] Since 1953, "binominal nomenclature" is the technically correct term in zoology. A binominal name is also called a binomen (plural binomina).[36] • Both codes consider the first part of the two-part name for a species to be the "genus name". In zoological code (ICZN), the second part of the name is a "specific name", or in the botanical code (ICN) a "specific epithet". Together, these two parts are referred to as a "species name" or "binomen" in the zoological code; or "species name", "binomial", or "binary combination" in the botanical code. • The ICN, the plant Code, does not allow the two parts of a binomial name to be the same (such a name is called a tautonym), whereas the ICZN, the animal Code, does. Thus the American bison has the binomial Bison bison; a name of this kind would not be allowed for a plant. • The starting points, the time from which these codes are in effect (retroactively), vary from group to group. In botany the starting point will often be in 1753 (the year Carl Linnaeus first published Species Plantarum). In zoology the starting point is 1758 (1 January 1758 is considered the date of the publication of Linnaeus's Systema Naturae, 10th Edition, and also Clerck's Aranei Svecici). Bacteriology started anew, with a starting point on 1 January 1980.[37]

Unifying the different codes into a single code, the "BioCode", has been suggested, although implementation is not in sight. (There is also a code in development for a different system of classification which does not use ranks, but instead names clades. This is called the PhyloCode.)

Writing binomial names

By tradition, the binomial names of species are usually typeset in italics; for example, Homo sapiens.[38] Generally, the binomial should be printed in a font style different from that used in the normal text; for example, "Several more Homo sapiens fossils were discovered." When handwritten, each part of a binomial name should be underlined; for example, Homo sapiens.[39] The first part of the binomial, the genus name, is always written with an initial capital letter. In current usage, the second part is never written with an initial capital.[40][41] Older sources, particularly botanical works published before the 1950s, use a different convention. If the second part of the name is derived from a proper noun, e.g. the name of a person or place, a capital letter was used. Thus the modern form Berberis darwinii was written as Berberis Darwinii. A capital was also used when the name is formed by two nouns in apposition, e.g. Panthera Leo or Centaurea Cyanus.[42][43]

When used with a common name, the scientific name often follows in parentheses, although this varies with publication.[44] For example, "The house sparrow (Passer domesticus) is decreasing in Europe."

The binomial name should generally be written in full. The exception to this is when several species from the same genus are being listed or discussed in the same paper or report, or the same species is mentioned repeatedly; in which case the genus is written in full when it is first used, but may then be abbreviated to an initial (and a period/full stop).[45] For example, a list of members of the genus Canis might be written as "Canis lupus, C. aureus, C. simensis". In rare cases, this abbreviated form has spread to more general use; for example, the bacterium Escherichia coli is often referred to as just E. coli, and Tyrannosaurus rex is perhaps even better known simply as T. rex, these two both often appearing in this form in popular writing even where the full genus name has not already been given.

The abbreviation "sp." is used when the actual specific name cannot or need not be specified. The abbreviation "spp." (plural) indicates "several species". These abbreviations are not italicised (or underlined).[46] For example: "Canis sp." means "an unspecified species of the genus Canis", while "Canis spp." means "two or more species of the genus Canis". (The abbreviations "sp." and "spp." can easily be confused with the abbreviations "ssp." (zoology) or "subsp." (botany), plurals "sspp." or "subspp.", referring to one or more subspecies. See trinomen (zoology) and infraspecific name.)

The abbreviation "cf." (i.e. confer in Latin) is used to compare individuals/taxa with known/described species. Conventions for use of the "cf." qualifier vary.[47] In paleontology, it is typically used when the identification is not confirmed.[48] For example, "Corvus cf. nasicus" was used to indicate "a fossil bird similar to the Cuban crow but not certainly identified as this species".[49] In molecular systematics papers, "cf." may be used to indicate one or more undescribed species assumed related to a described species. For example, in a paper describing the phylogeny of small benthic freshwater fish called darters, five undescribed putative species (Ozark, Sheltowee, Wildcat, Ihiyo, and Mamequit darters), notable for brightly colored nuptial males with distinctive color patterns,[50] were referred to as "Etheostoma cf. spectabile" because they had been viewed as related to, but distinct from, Etheostoma spectabile (orangethroat darter).[51] This view was supported in varying degrees by DNA analysis. The somewhat informal use of taxa names with qualifying abbreviations is referred to as open nomenclature and it is not subject to strict usage codes.

In some contexts the dagger symbol ("†") may be used before or after the binomial name to indicate that the species is extinct.

Authority

Main articles: Author citation (zoology) and Author citation (botany) In scholarly texts, at least the first or main use of the binomial name is usually followed by the "authority" – a way of designating the scientist(s) who first published the name. The authority is written in slightly different ways in zoology and botany. For names governed by the ICZN the surname is usually written in full together with the date (normally only the year) of publication. The ICZN recommends that the "original author and date of a name should be cited at least once in each work dealing with the taxon denoted by that name."[52] For names governed by the ICN the name is generally reduced to a standard abbreviation and the date omitted. The International Plant Names Index maintains an approved list of botanical author abbreviations. Historically, abbreviations were used in zoology too.

When the original name is changed, e.g. the species is moved to a different genus, both Codes use parentheses around the original authority; the ICN also requires the person who made the change to be given. Some examples:

• (Plant) Amaranthus retroflexus L. – "L." is the standard abbreviation for "Linnaeus"; the absence of parentheses shows that this is his original name. • (Plant) Hyacinthoides italica (L.) Rothm. – Linnaeus first named the Italian bluebell Scilla italica; Rothmaler transferred it to the genus Hyacinthoides. • (Animal) Passer domesticus (Linnaeus, 1758) – the original name given by Linnaeus was Fringilla domestica; unlike the ICN, the ICZN does not require the name of the person who changed the genus to be given.

Other ranks

This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (June 2011) Main articles: Biological nomenclature, Trinomial nomenclature and Infraspecific name (botany)

Binomial nomenclature, as described here, is a system for naming species. Implicitly it includes a system for naming genera, since the first part of the name of the species is a genus name. In a classification system based on ranks there are also ways of naming ranks above the level of genus and below the level of species. Ranks above genus (e.g., family, order, class) receive one-part names, which are conventionally not written in italics. Thus the house sparrow, Passer domesticus, belongs to the family Passeridae. Family names are normally based on genus names, although the endings used differ between zoology and botany.

Ranks below species receive three-part names, conventionally written in italics like the names of species. There are significant differences between the ICZN and the ICN. In zoology, the only rank below species is subspecies and the name is written simply as three parts (a trinomen). Thus one of the subspecies of the olive-backed pipit is Anthus hodgsoni berezowskii. In botany, there are many ranks below species and although the name itself is written in three parts, a "connecting term" (not part of the name) is needed to show the rank. Thus the American black elder is Sambucus nigra subsp. canadensis; the white-flowered form of the ivy-leaved cyclamen is Cyclamen hederifolium f. albiflorum. Hybrid name From Wikipedia, the free encyclopedia The examples and perspective in this article may not include all significant viewpoints. Please improve the article or discuss the issue. (May 2010)

In botanical nomenclature, a hybrid may be given a hybrid name, which is a special kind of botanical name. The International Code of Nomenclature for algae, fungi, and plants provides the following options in dealing with a hybrid:[1]

• A hybrid may get a name; this will usually be the option of choice for naturally occurring hybrids. • A hybrid may also be indicated by a formula listing the parents. Such a formula uses the multiplication sign "×" to link the parents.

A hybrid name can be indicated by:

• a multiplication sign "×" placed before the name of an intergeneric hybrid, or before the epithet of a species hybrid, e.g.: o Sorbaronia or ×Sorbaronia is the name of hybrids between the genera Sorbus and Aronia, o Iris germanica or Iris ×germanica is a species derived by hybrid speciation • or by the prefix notho- attached to the rank, o Crataegus nothosect. Crataeguineae o Iris germanica nothovar. florentina.

The provisions in the ICN that deal with hybrid names are Articles H.1 to H.12.[1]

A hybrid name is treated like other botanical names, for most purposes. The multiplication sign is not part of the actual name and is to be disregarded for nomenclatural purposes such as synonymy, homonymy, etc. This means that a taxonomist could decide to use either form of this name: Drosera ×anglica to emphasize that it is a hybrid, or Drosera anglica to emphasize that it is a species.

A hybrid name does not necessarily refer to a morphologically distinctive group, but applies to all progeny of the parents, no matter how much the variation. So, Magnolia ×soulangeana applies to all progeny from the cross Magnolia denudata × Magnolia liliiflora, and from the crosses of all their progeny, as well as from crosses of any of the progeny back to the parents. This covers quite a range in flower colour.

The names of intergeneric hybrids have a special form called a condensed formula. The provisions in the ICN that deal with condensed formulae are Articles H.6 to H.9.[1] Type (biology)

From Wikipedia, the free encyclopedia

"Type specimen" redirects here. For the mineralogy term, see type specimen (mineralogy).

This article needs additional citations for verification. Please help improve this article by

adding citations to reliable sources. Unsourced material may be challenged and removed. (June 2010)

Type specimen for Marocaster coronatus - Muséum de Toulouse

In biology, a type is one particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralize the defining features of that particular taxon. In older usage (pre-1900 in botany), a type was a taxon rather than a specimen.[1]

A taxon is a scientifically named grouping of organisms with other like organisms, a set that includes some organisms and excludes others, based on a detailed published description (for example a species description) and on the provision of type material, which is usually available to scientists for examination in a major museum research collection, or similar institution. Contents

• 1 Type specimen • 2 Older terminology • 3 In botany • 4 In zoology o 4.1 Definitions o 4.2 Use of type specimens . 4.2.1 Holotype . 4.2.2 Paratype . 4.2.3 Allotype . 4.2.4 Neotype . 4.2.5 Syntype . 4.2.6 Lectotype . 4.2.7 Paralectotype . 4.2.8 Hapantotype . 4.2.9 Ergatotype . 4.2.10 Alternatives to preserved specimens . 4.2.11 Formalisation of the type system o 4.3 Type species o 4.4 Type genus • 5 See also • 6 References • 7 External links Type specimen

According to a precise set of rules laid down in the International Code of Zoological Nomenclature (ICZN) and the International Code of Nomenclature for algae, fungi, and plants (ICN), the scientific name of every taxon is almost always based on one particular specimen, or in some cases specimens. Types are of great significance to biologists, especially to taxonomists. Types are usually physical specimens that are kept in a museum or herbarium research collection, but failing that, an image of an individual of that taxon has sometimes been designated as a type. Describing species and appointing type specimens is part of scientific nomenclature and alpha taxonomy.

When identifying material, a scientist attempts to apply a taxon name to a specimen or group of specimens based on his or her understanding of the relevant taxa, based on (at least) having read the type description(s), preferably based on an examination of all the type material of all of the relevant taxa. If there is more than one named type that all appear to be the same taxon, then the oldest name takes precedence, and is considered to be the correct name of the material in hand. If on the other hand the taxon appears never to have been named at all, then the scientist or another qualified expert picks a type specimen and publishes a new name and an official description.

This process is crucial to the science of biological taxonomy. People's ideas of how living things should be grouped change and shift over time. How do we know that what we call "Canis lupus" is the same thing, or approximately the same thing, as what they will be calling "Canis lupus" in 200 years time? It is possible to check this because there is a particular wolf specimen preserved in Sweden[2] and everyone who uses that name – no matter what else they may mean by it – will include that particular specimen.

Depending on the nomenclature code applied to the organism in question, a type can be a specimen, a culture, an illustration, or (under the bacteriological code) a description. Some codes consider a subordinate taxon to be the type, but under the botanical code the type is always a specimen or illustration.

For example, in the research collection of the Natural History Museum in London, there is a bird specimen numbered 1886.6.24.20. This is a specimen of a kind of bird commonly known as the spotted harrier, which currently bears the scientific name Circus assimilis. This particular specimen is the holotype for that species; the name Circus assimilis refers, by definition, to the species of that particular specimen. That species was named and described by Jardine and Selby in 1828, and the holotype was placed in the museum collection so that other scientists might refer to it as necessary.

Note that at least for type specimens there is no requirement for a "typical" individual to be used. Genera and families, particularly those established by early taxonomists, tend to be named after species that are more "typical" for them, but here too this is not always the case and due to changes in systematics cannot be. Hence, the term name-bearing type or onomatophore is sometimes used, to denote the fact that biological types do not define "typical" individuals or taxa, but rather fix a scientific name to a specific operational taxonomic unit. Type specimens are theoretically even allowed to be aberrant or deformed individuals or color variations, though this is rarely chosen to be the case, as it makes it hard to determine to which population the individual belonged. The usage of the term type is somewhat complicated by slightly different uses in botany and zoology. In the PhyloCode, type-based definitions are replaced by phylogenetic definitions.

Older terminology

In some older taxonomic works the word "type" has sometimes been used differently. The meaning was similar in the first Laws of Botanical Nomenclature,[3][4] but has a meaning closer to the term taxon in some other works:[5]

Ce seul caractère permet de distinguer ce type de toutes les autres espèces de la section. … Après avoir étudié ces diverses formes, j'en arrivai à les considérer comme appartenant à un seul et même type spécifique.

Translation: This single character permits [one to] distinguish this type from all other species of the section ... After studying the diverse forms, I came to consider them as belonging to the one and the same specific type.

In botany

In botanical nomenclature, a type (typus, nomenclatural type), "is that element to which the name of a taxon is permanently attached." (article 7.1)[6] In botany a type is either a specimen or an illustration. A specimen is a real plant (or one or more parts of a plant or a lot of small plants), dead and kept safe, "curated", in a herbarium (or the equivalent for fungi). Examples of where an illustration may serve as a type include:

• A detailed drawing, painting, etc., depicting the plant, from the early days of plant taxonomy. A dried plant was difficult to transport and hard to keep safe for the future; many specimens from the early days of botany have since been lost or damaged. Highly skilled botanical artists were sometimes employed by a botanist to make a faithful and detailed illustration. Some such illustrations have become the best record and have been chosen to serve as the type of a taxon. • A detailed picture of something that can be seen only through a microscope. A tiny "plant" on a microscope slide makes for a poor type: the microscope slide may be lost or damaged, or it may be very difficult to find the "plant" in question among whatever else is on the microscope slide. An illustration makes for a much more reliable type (Art 37.5 of the Vienna Code, 2006).

Note that a type does not determine the circumscription of the taxon. For example, the common dandelion is a controversial taxon: some botanists consider it to consist of over a hundred species, and others regard it as a single species. The type of the name Taraxacum officinale is the same whether the circumscription of the species includes all those small species (Taraxacum officinale is a "big" species) or whether the circumscription is limited to only one small species among the other hundred (Taraxacum officinale is a "small" species). The name Taraxacum officinale is the same and the type of the name is the same, but the extent of what the name actually applies to varies greatly. Setting the circumscription of a taxon is done by a taxonomist in a publication.

Miscellaneous notes: 1. Only a species or an infraspecific taxon can have a type of its own. For most new taxa (published on or after 1 January 2007, article 37) at these ranks a type should not be an illustration. 2. A genus has the same type as that of one of its species (article 10). 3. A family has the same type as that of one of its genera (article 10).

The ICN provides a listing of the various kinds of type (article 9),[6] the most important of which is the holotype. These are

• holotype • lectotype • isotype • syntype • paratype • neotype • epitype

Note that the word "type" appears in botanical literature as a part of some older terms that have no status under the ICN: for example a clonotype.

In zoology

Gossamer-winged butterfly Jamides elioti, upper pair is upper and lower surface of the holotype, lower pair is the paratype

In zoological nomenclature, the type of a species (or subspecies) is a specimen (or series of specimens), the type of a genus (or subgenus) is a species, and the type of a suprageneric taxon (e.g., family, etc.) is a genus. Names higher than superfamily rank do not have types. A "name-bearing type" "provides the objective standard of reference whereby the application of the name of a nominal taxon can be determined."

Definitions

• A type specimen is a vernacular term (not a formally defined term) typically used for an individual or fossil that is any of the various name-bearing types for a species. For example, the type specimen for the species Homo neanderthalensis was the specimen "Neanderthal-1" discovered by Johann Karl Fuhlrott in 1856 at Feldhofer in the Neander Valley in Germany, consisting of a skullcap, thigh bones, part of a pelvis, some ribs, and some arm and shoulder bones. There may be more than one type specimen, but there is (at least in modern times) only one holotype. • A type species is the nominal species that is the name-bearing type of a nominal genus or subgenus. • A type genus is the nominal genus that is the name-bearing type of a nominal family-group taxon. • The type series are all those specimens included by the author in a taxon's formal description, unless the author explicitly or implicitly excludes them as part of the series.

Use of type specimens

Type illustration of Mormopterus acetabulosus

Although in reality biologists may examine many specimens (when available) of a new taxon before writing an official published species description, nonetheless, under the formal rules for naming species (the International Code of Zoological Nomenclature), a single type must be designated, as part of the published description.

A type description must include a diagnosis (typically, a discussion of similarities to and differences from closely related species), and an indication of where the type specimen or specimens are deposited for examination. The geographical location where a type specimen was originally found is known as its type locality. In the case of parasites, the term type host (or symbiotype) is used to indicate the host organism from which the type specimen was obtained.[7]

Zoological collections are maintained by universities and museums. Ensuring that types are kept in good condition and made available for examination by taxonomists are two important functions of such collections. And, while there is only one holotype designated, there can be other "type" specimens, the following of which are formally defined:

Holotype Main article: Holotype

When a single specimen is clearly designated in the original description, this specimen is known as the holotype of that species. The holotype is typically placed in a major museum, or similar well-known public collection, so that it is freely available for later examination by other biologists.

Paratype Main article: Paratype When the original description designated a holotype, there may still be additional specimens listed in the type series and those are termed paratypes. These are not name-bearing types.

Allotype

An allotype is a specimen of the opposite sex to the holotype, designated from among paratypes. It was also formerly used for a specimen that shows features not seen in the holotype of a fossil.[8] The term is not regulated by the ICZN.

Neotype

A neotype is a specimen later selected to serve as the single type specimen when an original holotype has been lost or destroyed or where the original author never cited a specimen.

Syntype Main article: Syntype

A syntype is any one of two or more specimens that is listed in a species description where no holotype was designated; historically, syntypes were often explicitly designated as such, and under the present ICZN this is a requirement, but modern attempts to publish species description based on syntypes are generally frowned upon by practicing taxonomists, and most are gradually being replaced by lectotypes. Those that still exist are still considered name-bearing types.

Lectotype

A lectotype is a specimen later selected to serve as the single type specimen for species originally described from a set of syntypes. In zoology, a lectotype is a kind of name-bearing type. When a species was originally described on the basis of a name-bearing type consisting of multiple specimens, one of those may be designated as the lectotype. Having a single name-bearing type reduces the potential for confusion, especially considering that it is not uncommon for a series of syntypes to contain specimens of more than one species.

A notable example is that Carl Linnaeus is the lectotype for the species Homo sapiens.[9]

Paralectotype

A paralectotype is any additional specimen from among a set of syntypes, after a lectotype has been designated from among them. These are not name-bearing types.[10]

Hapantotype

A special case in Protistans where the type consists of two or more specimens of "directly related individuals representing distinct stages in the life cycle"; these are collectively treated as a single entity, and lectotypes cannot be designated from among them.

Ergatotype

An ergatotype is specimen selected to represent a worker member in hymenopterans which have polymorphic castes.[8] Alternatives to preserved specimens

Type illustrations have also been used by zoologists, as in the case of the Réunion parakeet, which is known only from historical illustrations and descriptions.[11]:24

Recently, some species have been described where the type specimen was released alive back into the wild, such as the Bulo Burti boubou (a bushshrike), described as Laniarius liberatus, in which the species description included DNA sequences from blood and feather samples. Assuming there is no future question as to the status of such a species, the absence of a type specimen does not invalidate the name, but it may be necessary in the future to designate a neotype for such a taxon, should any questions arise. However, in the case of the bushshrike, ornithologists have argued that the specimen was a rare and hitherto unknown color morph of a long-known species, using only the available blood and feather samples. While there is still some debate on the need to deposit actual killed individuals as type specimens, it can be observed that given proper vouchering and storage, tissue samples can be just as valuable even in case disputes about the validity of a species arise.

Formalisation of the type system

The various types listed above are necessary[citation needed] because many species were described one or two centuries ago, when a single type specimen, a holotype, was often not designated. Also, types were not always carefully preserved, and intervening events such as wars and fires have resulted in destruction of original type material. The validity of a species name often rests upon the availability of original type specimens; or, if the type cannot be found, or one has never existed, upon the clarity of the description.

The ICZN has existed only since 1961, when the first edition of the Code was published. The ICZN does not always demand a type specimen for the historical validity of a species, and many "type-less" species do exist. The current edition of the Code, Article 75.3, prohibits the designation of a neotype unless there is "an exceptional need" for "clarifying the taxonomic status" of a species (Article 75.2).

There are many other permutations and variations on terms using the suffix "-type" (e.g., allotype, cotype, topotype, generitype, isotype, isoneotype, isolectotype, etc.) but these are not formally regulated by the Code, and a great many are obsolete and/or idiosyncratic. However, some of these categories can potentially apply to genuine type specimens, such as a neotype; e.g., isotypic/topotypic specimens are preferred to other specimens, when they are available at the time a neotype is chosen (because they are from the same time and/or place as the original type).

The term fixation is used by the Code for the declaration of a name-bearing type, whether by original or subsequent designation.

Type species

Main article: Type species

The common toad, Bufo bufo described by Linnaeus, is the type species for the genus Bufo

Each genus must have a designated type species (the term "genotype" was once used for this but has been abandoned because the word has been co-opted for use in genetics and is much better known in that context). The description of a genus is usually based primarily on its type species, modified and expanded by the features of other included species. The generic name is permanently associated with the name-bearing type of its type species.

Ideally, a type species best exemplifies the essential characteristics of the genus to which it belongs, but this is subjective and, ultimately, technically irrelevant, as it is not a requirement of the Code. If the type species proves, upon closer examination, to belong to a pre-existing genus (a common occurrence), then all of the constituent species must be either moved into the pre-existing genus, or disassociated from the original type species and given a new generic name; the old generic name passes into synonymy and is abandoned unless there is a pressing need to make an exception (decided case-by-case, via petition to the International Commission on Zoological Nomenclature).

Type genus

Main article: Type genus

A type genus is that genus from which the name of a family or subfamily is formed. As with type species, the type genus is not necessarily the most representative, but is usually the earliest described, largest or best known genus. It is not uncommon for the name of a family to be based upon the name of a type genus that has passed into synonymy; the family name does not need to be changed in such a situation.

Genetypes

From Wikipedia, the free encyclopedia Not to be confused with Genotypes. For alternate types of a gene, see allele. This article relies largely or entirely upon a single source. Relevant discussion may be found on the talk page. Please help improve this article by introducing citations to additional sources. (April 2011)

Genetypes is a taxonomic concept proposed in 2010 to describe any genetic sequences from type specimens.[1][2] This nomenclature integrates molecular systematics and terms used in biological taxonomy. This nomenclature is designed to label, or flag, genetic sequences that were sampled from type specimens. The nomenclature of genetypes proposes that genetic sequences from a holotype should be referred to as a “hologenetype” (from: holotype and genetype), sequences from a topotype will be a “topogenetype,” and so forth. In addition, the genetic marker(s) used should also be incorporated into the nomenclature (e.g., paragenetype ND2).

The genetypes nomenclatural system could be used to flag “gold standard” sequences that due to their direct link to type specimens will be more credible than standard sequences whose species identification may be problematic. Misidentifications plague many sequences on GenBank[citation needed] and having some sequences that are linked to type specimens will help locate and manage misidentifications and to create positively identified "gold standard" sequences available for comparison. It is suggested that this nomenclature be used in publications and databases that display or discuss sequences from type specimens.[3][2]

Examples of genetypes include:

[4] • Leptoderma macrophthalmum hologenetype mitogenome - AP011500 [5] • Milyeringa brooksi paragenetype COI - HM590595 [5] • Milyeringa brooksi paragenetype NDI - HM590607

The genetypes concept was superseded by the GenSeq concept, proposed in 2013 due to some confusion among researchers that genetypes were equivalent to name-bearing types.[6][clarification needed]

From Wikipedia, the free encyclopedia

In biological nomenclature, the Principle of Typification is one of the guiding principles.[1]

The International Code of Zoological Nomenclature provides that any named taxon in the family group, genus group, or species group have a name-bearing type which allows the name of the taxon to be objectively applied. The type does not define the taxon: that is done by a taxonomist; and an indefinite number of competing definitions can exist side by side. Rather, a type is a point of reference. A name has a type, and a taxonomist (having defined the taxon) can determine which existing types fall within the scope of the taxon. He or she can then use the rules in the Code to determine the valid name for the taxon. Type species

From Wikipedia, the free encyclopedia This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (March 2011)

In zoological nomenclature, a type species (Species typica) is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen(s).[1] A similar concept is used for suprageneric groups called a type genus. In botanical nomenclature, these terms have no formal standing under the code of nomenclature, but are sometimes borrowed from zoological nomenclature. In botany, the type of a genus is a specimen (or, rarely, an illustration).[2] Every named genus or subgenus in zoology, whether or not currently recognized as valid, is theoretically associated with a type species. In practice, however, there is a backlog of untypified names (i.e., names which identify certain animals as belonging to separate species when in fact they belong to the same one).

In use

See also: Types in zoology

A type species is both a concept and a practical system that is used in the classification and nomenclature (naming) of animals. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. This is an important concept whenever a taxon containing multiple species must be divided into more than one genus; the type species automatically assigns the name of the original taxon to one of the resulting new taxa, thus reducing the potential for confusion.

The term "type species" is regulated in zoological nomenclature by article 42.3 of the International Code of Zoological Nomenclature, which defines a type species as the name- bearing type of the name of a genus or subgenus (a "genus-group name") is the "type species". In the Glossary, type species is defined as

"The nominal species that is the name-bearing type of a nominal genus or subgenus".[citation needed]

The type species permanently attaches a genus to its formal name (its generic name) by providing just one species within that genus to which the genus is permanently linked (i.e. the genus must include that species if it is to bear the name). The species name in turn is fixed, in theory, to a type specimen.

For example, the type species for the land snail genus Monacha is Monacha cartusiana. That genus is currently placed within the family Hygromiidae. The type genus for that family is the genus Hygromia.

The concept of the type species in zoology was introduced by Pierre André Latreille.[3] Type genus

From Wikipedia, the free encyclopedia

In biological classification, especially zoology, the type genus is the genus which defines a biological family and the root of the family name.

Contents

• 1 Zoological nomenclature • 2 Botanical nomenclature • 3 See also • 4 References Zoological nomenclature

According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal family-group taxon is a nominal genus called the 'type genus'; the family-group name is based upon that of the type genus."[1]

Any family-group name must have a type genus (and any genus-group name must have a type species, but any species-group name may, but need not, have one or more type specimens). The type genus for a family-group name is also the genus that provided the stem to which was added the ending -idae (for families).

Example: The family name Spheniscidae has as its type genus the genus Spheniscus Brisson, 1760. Botanical nomenclature

In botanical nomenclature, the phrase "type genus" is used, unofficially, as a term of convenience. In the ICN this phrase has no status. The code uses type specimens for ranks up to family, and types are optional for higher ranks.[2] The Code does not refer to the genus containing that type as a "type genus".

Example: "Poa is the type genus of the family Poaceae and of the order Poales" is another way of saying that the names Poaceae and Poales are based on the generic name Poa.

Glossary of scientific naming

From Wikipedia, the free encyclopedia

This is a list of terms and symbols used in scientific names for organisms, and in describing the names. For proper parts of the names themselves, see glossary of scientific names. Note that many of the abbreviations are used with or without a stop.

Contents

• 1 Naming standards and taxonomic organizations and their codes and taxonomies • 2 General terms • 3 Types • 4 Rank names • 5 Latin descriptions of names or taxa • 6 Abbreviations and symbols • 7 See also

Naming standards and taxonomic organizations and their codes and taxonomies • ICTV - International Committee on Taxonomy of Viruses • ICSP - International Committee on Systematics of Prokaryotes o formerly the ICSB - International Committee on Systematic Bacteriology o publishes the ICNB - International Code of Nomenclature of Bacteria or the "Bacteriological Code" • ICZN - International Commission on Zoological Nomenclature o publishes ICZN the International Code of Zoological Nomenclature or "ICZN Code" • IBC - International Botanical Congress o publishes ICN the International Code of Nomenclature for algae, fungi, and plants . formerly ICBN or the International Code of Botanical Nomenclature (current version the Melbourne Code) o also publishes ICNCP or the International Code of Nomenclature for Cultivated Plants

General terms

• synonym a name for a taxon different from the currently accepted name. o senior synonym, (zoology) the earliest (correctly published) name o junior synonym, (zoology) any later name o homotypic synonym (botany) o heterotypic synonym (botany) o objective synonym (zoology) o subjective synonym (zoology) o pro parte or p. p. - for part, • homonym • Principle of the First Reviser • Principle of Priority • taxonomic authority • binomial authority

• binomial nomenclature (also "binominal") • trinomial nomenclature (also "trinominal")

• taxon (pl taxa) o wastebasket taxon (also "wastebin taxon", "dustbin taxon" or "catch-all taxon") o form taxon o Lazarus taxon o Elvis taxon

• polyphyletic taxon • monophyletic taxon • parphyletic taxon

• ichnotaxon (ichnogenus, ichnospecies, etc.) A taxon (genus, species, etc.) only known by its work, e.g. footprints, nests, bite marks. • ootaxon (oospecies, etc.) A taxon (species, etc.) known from fossil eggs.

• conspecific of the same species, for example of two taxa previously thought to be different species • congeners items of the same genus • circumscription the limits of a taxon as laid down by its description

• sensu (Latin "sense") as in sensu stricto (in the strict sense), sensu lato (in a broad sense), etc. See sensu for more variants and details. • secundum - following, as in "Secundum Smith". Types

• type species • type genus • type specimen o Holotype o Paratype o Allotype o Neotype o Syntype o Lectotype o Paralectotype o Hapantotype o Ergatotype Rank names

Main article: Taxonomic rank

The main ranks are kingdom (regnum), phylum or division (divisio), class, order, family, genus and species. The ranks of section and series are also used in botany for groups within genera, while section is used in zoology for a division of an order. Further levels in the hierarchy can be made by the addition of prefixes such as sub-, super-, infra-, and so on.

Divisions such as "form", "variety", "strain", "breed", "cultivar" and "landrace" are used to describe various sub-specific groups in different fields.

It is possible for a clade to be unranked, for example Psoroptidia (Yunker, 1955).

Latin descriptions of names or taxa

Note that in zoology the phrase "conserved name", for example is acceptable.

• nomen nudum (nom. nud.; plural: nomina nuda) – a name published without an accompanying description • nomen dubium (nom. dub.; plural: nomina dubia) – a name of questionable application • nomen illegitimum (nom. illeg.; plural: nomina illegitima) – an illegitimate name • nomen conservandum (nom. cons.; plural: nomina conservanda) – a conserved name • nomen protectum (nom. prot.; plural: nomina protecta) – a name granted protection • nomen suppressum (nom. supp.; plural: nomina suppressa) – a name that has been suppressed and cannot be used • nomen rejiciendum (nom. rej.; plural: nomina rejicienda) – a name that has been rejected and cannot be used • nomen oblitum (nom. obl.; plural: nomina oblita) – a name which has been overlooked and is no longer valid • nomen novum (nom. nov.; plural: nomina nova) – a replacement name • nomen vanum (plural: nomina vana) - a failed emendation • incertae sedis – of uncertain placement • ex errore – made in error

Abbreviations and symbols

• var. – variety • subvar. - subvariety • sp. (plural spp.) – species • subsp. (plural subspp.) – subspecies • f. - forma or form. • subf. - subforma • cf. (confer) – indicates approximate placement • s.s. - sensu stricto • s.l. - sensu lato

• † – extinct • × – cross – indicates a hybrid • + - indicates a graft hybrid Graft-chimaera

From Wikipedia, the free encyclopedia (Redirected from Graft hybrid) This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (February 2013)

The small tree +Laburnocytisus 'Adamii' is a spectacular example of a graft-chimaera

In horticulture, a graft-chimaera may arise in grafting at the point of contact between rootstock and scion and will have properties intermediate between those of its "parents". A graft-chimaera is not a true hybrid but a mixture of cells, each with the genotype of one of its "parents": it is a chimaera. Hence, the once widely used term "graft-hybrid" is not descriptive; it is now frowned upon. Propagation is by cloning only. In practice graft-chimaeras are not noted for their stability and may easily revert to one of the "parents".

Contents

• 1 Nomenclature • 2 In Darwin's works • 3 See also • 4 References Nomenclature

Article 21 of the ICNCP stipulates that a graft-chimaera can be indicated either by

• a formula: the names of both "parents", in alphabetical order, joined by the plus sign "+":

Crataegus + Mespilus

• a name: o if the "parents" belong to different genera a name may be formed by joining part of one generic name to the whole of the other generic name. This name must not be identical to a generic name published under the ICBN. For example +Crataegomespilus is the name for the graft-chimaera which may also be indicated by the formula Crataegus + Mespilus. This name is clearly different from ×Crataemespilus, the name under the ICBN for the true hybrid between Crataegus and Mespilus, which can also be designated by the formula Crataegus × Mespilus. o if both "parents" belong to the same genus the graft-chimaera may be given a cultivar name. For example Syringa 'Correlata' is a graft-chimaera involving Syringa vulgaris (common lilac) and Syringa ×chinensis (Rouen lilac, which is itself a hybrid between S. vulgaris and S. laciniata). No plus sign is used, because both "parents" belong to the genus Syringa.

A graft-chimaera cannot have a species name, because it is simultaneously two species. Although +Laburnocytisus 'Adamii', for example, is sometimes seen written as if it were a species (+Laburnocytisus adamii), this is incorrect.

In Darwin's works

Charles Darwin «The Variation of Animals and Plants Under Domestication», 1868 г.:

I will therefore give all the facts which I have been able to collect on the formation of hybrids between distinct species or varieties, without the intervention of the sexual organs. For if, as I am now convinced, this is possible, it is a most important fact, which will sooner or later change the views held by physiologists with respect to sexual reproduction. A sufficient body of facts will afterwards be adduced, showing that the segregation or separation of the characters of the two parent-forms by bud-variation, as in the case of Cytisus adami, is not an unusual though a striking phenomenon. We shall further see that a whole bud may thus revert, or only half, or some smaller segment.

Nomen dubium

From Wikipedia, the free encyclopedia

In zoological nomenclature, a nomen dubium (Latin for "doubtful name", plural nomina dubia) is a scientific name that is of unknown or doubtful application.

In bacteriological nomenclature, nomina dubia may be placed on the list of rejected names by the Judicial Commission. The meaning of these names is uncertain. Other categories of names that may be treated in this way (rule 56a) are:[1]

• ambiguous names, nomina ambigua, have been used with more than one meaning • names causing confusion, nomina confusa, are based on a mixed culture • perplexing names, nomina perplexa, confusingly similar names • perilous names, nomina periculosa, names that may lead to accidents endangering life or health or with potential serious economic consequences

In botanical nomenclature the phrase nomen dubium has no status, although it is informally used for names whose application has become confusing. In this regard however, its synonym nomen ambiguum is of more frequent use. In botany, such names may be proposed for rejection.

In zoology

In case of a nomen dubium it may be impossible to determine whether a specimen belongs to that group or not. This may happen if the original type series (i. e. holotype, isotypes, syntypes, and paratypes) is lost or destroyed. The zoological and botanical codes allow for a new type specimen, or neotype, to be chosen in this case.

A name may also be considered a nomen dubium if its name-bearing type is fragmentary or lacking important diagnostic features (this is often the case for species known only as fossils). To preserve stability of names, the International Code of Zoological Nomenclature allows a new type specimen, or neotype, to be chosen for a nomen dubium in this case.

75.5. Replacement of unidentifiable name-bearing type by a neotype. When an author considers that the taxonomic identity of a nominal species-group taxon cannot be determined from its existing name-bearing type (i.e. its name is a nomen dubium), and stability or universality are threatened thereby, the author may request the Commission to set aside under its plenary power [Art. 81] the existing name-bearing type and designate a neotype.[2] For example, the crocodile-like archosaurian reptile Parasuchus hislopi Lydekker, 1885 was described based on a premaxillary rostrum (part of the snout), but this is no longer sufficient to distinguish Parasuchus from its close relatives. This made the name Parasuchus hislopi a nomen dubium. Texan paleontologist Sankar Chatterjee proposed that a new type specimen, a complete skeleton, be designated.[3] The International Commission on Zoological Nomenclature considered the case and agreed in 2003 to replace the original type specimen with the proposed neotype.[4]

A current example is the Omani owl (Strix omanensis). It was formally described in the journal Dutch Birding in 2013. But because no type specimen was collected, it has been suggested that Strix omanensis should be considered a nomen dubium until a neotype is designated.[5] However, this view has not yet been considered by the ICZN. Nomen nudum

From Wikipedia, the free encyclopedia

The phrase nomen nudum (plural nomina nuda) is a Latin term, meaning "naked name", used in taxonomy (especially in zoological and botanical nomenclature). It may or may not be written in italics, depending on style.

The term is used to indicate a designation[1] which looks exactly like a scientific name of an organism, and may have originally been intended to be a scientific name, but fails to be one because it has not (or has not yet) been published with an adequate description (or a reference to such a description), and thus is a "bare" or "naked" name, one which cannot be accepted as it currently stands.[2]

Because a nomen nudum fails to qualify as a formal scientific name, a later author can publish a real scientific name that is identical in spelling. If one and the same author puts a name in print, first as a nomen nudum and later publishes it for real, accompanied by a description that meets the formal requirements, then the date of publication of the latter, formally correct, publication becomes the name's date of establishment.

Contents

• 1 In zoology • 2 In botany • 3 See also • 4 References

In zoology

According to the rules of zoological nomenclature a nomen nudum is unavailable; the glossary of the International Code of Zoological Nomenclature gives this definition:[3] nomen nudum (pl. nomina nuda), n. A Latin term referring to a name that, if published before 1931, fails to conform to Article 12; or, if published after 1930, fails to conform to Article 13. […] And among the rules of that same Zoological Code:

12.1. To be available, every new name published before 1931 must … be accompanied by a description or a definition of the taxon that it denotes, or by an indication [that is, a reference to such a description or definition]. …

13.1. To be available, every new name published after 1930 must … be accompanied by a description or definition that states in words characters that are purported to differentiate the taxon, or be accompanied by a bibliographic reference to such a published statement.

In botany

According to the rules of botanical nomenclature a nomen nudum is not validly published. The glossary of the International Code of Nomenclature for algae, fungi, and plants gives this definition:[4]

A designation of a new taxon published without a description or diagnosis or reference to a description or diagnosis.

The requirements for the diagnosis or description are covered by articles 32, 36, 41, 42, and 44.[4] Nomen illegitimum

From Wikipedia, the free encyclopedia

Nomen illegitimum (Latin for illegitimate name) is a technical term, used mainly in botany. It is usually abbreviated as nom. illeg. Although the International Code of Nomenclature for algae, fungi, and plants uses Latin terms for other kinds of name (e.g. nomen conservandum for "conserved name"), the glossary defines the English phrase "illegitimate name" rather than the Latin equivalent.[1] However, the Latin abbreviation is widely used by botanists.

A superfluous name is one kind of illegitimate name. Again, although the glossary defines the English phrase,[1] the Latin equivalent nomen superfluum, abbreviated nom. superfl. is widely used by botanists. Contents

• 1 Definition • 2 Examples • 3 See also • 4 References Definition

A nomen illegitimum is a validly published name, but one that contravenes some of the articles laid down by the International Botanical Congress.[2] The name could be illegitimate because: • (article 52) it was superfluous at its time of publication, i.e., the taxon (as represented by the type) already has a name, or • (articles 53 and 54) the name has already been applied to another plant (a homonym).

For the procedure of rejecting otherwise legitimate names, see conserved name.

Examples

• "The generic name Cainito Adans. (1763) is illegitimate because it was a superfluous name for Chrysophyllum L. (1753), which Adanson cited as a synonym."[2] • "The name Amblyanthera Müll. Arg. (1860) is a later homonym of the validly published Amblyanthera Blume (1849) and is therefore unavailable for use, although Amblyanthera Blume is now considered to be a synonym of Osbeckia L. (1753)."[2] • "The name Torreya Arn. (1838) is a nomen conservandum and is therefore available for use in spite of the existence of the earlier homonym Torreya Raf. (1818)."[2]