In biological nomenclature, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, trivial name, trivial epithet, country name, popular name, or farmer's name) is a name in general use within a community; it is often contrasted with the scientific name for the same organism. A so-called "common name" is not always one that is commonly used.
Sometimes common names are created by authorities on one particular subject, in an attempt to make it possible for members of the general public (including interested parties such as fishermen, farmers etc.) to refer to a species of organism without needing to be able to memorise or pronounce the Latinized scientific name. Creating common names can also be an attempt to standardize the use of common names which can sometimes vary a great deal between one part of a country and another as well as between one country and another, even where the same language is spoken in both places.
Use as part of folk taxonomy 
Some common names form part of a classification of objects. Folk taxonomy, which is a classification of objects using common names, has no formal rules. In contrast, scientific or biological nomenclature is a global system that uniquely denotes particular organisms. Biological nomenclature involves formal rules and periodic international meetings, of the ICBN and the ICZN.
Common names and the binomial system 
The form of scientific names for organisms that we know as binomial nomenclature is derived from the noun-adjective form of vernacular names used by prehistoric cultures. A collective name such as owl, was made more specific by the addition of an adjective such as screech. Linnaeus himself published a Flora of his homeland Sweden, Flora Svecica (1745), and in this he recorded the Swedish common names, region by region, as well as the scientific names—and the Swedish common names were all binomials (e.g. plant no. 84 Råg-losta and plant no. 85 Ren-losta)—the vernacular binomial system thus preceded his scientific binomial system.
Linnaean authority William T. Stearn said:
By the introduction of his binomial system of nomenclature Linnaeus gave plants and animals an essentially Latin nomenclature like vernacular nomenclature in style but linked to published, and hence relatively stable and verifiable, scientific concepts and thus suitable for international use.
There is a correspondence between many common names and systematic taxonomic names. Studies that compared the names applied to various plants by traditional Oriental herbalists with the classification of the same plants by modern botanists, also showed surprisingly close correspondence.
Many laymen who have the experience and interest to name the creatures that they deal with, also have the powers of observation that equip them to recognise relevant differences and group organisms accordingly. The way in which they do this is generally to create a term for a familiar and inclusive set of entities perceived to have shared characteristics. Such a term is likely not to be a binomial at first. Consider the Afrikaans term "bok" which in this context may be taken to mean "antelope". (It has other meanings that are not relevant in context.) When the waterbuck became known, it was recognised as distinct from other known antelope and it was distinguished by qualification, in effect creating a subset of antelope called "waterbok", a perfectly valid application of intuitive set theory. Subsequently the settlers discovered the lechwe and correctly noted its resemblance to the related waterbuck, but at that point the defensibility of the system showed signs of strain; the new animal was called "basterwaterbok", meaning literally "hybrid waterbuck". The set-theoretical principle remained largely defensible and was recognisably analogous to formal taxonomic principles, but the systematic biological knowledge necessary for functional interpretation was lacking.
Commonly problems would arise even sooner; the Afrikaans name for Cannabis is "dagga"; the indigenous plant Leonotis leonurus is effectively unrelated, but, because of a fancied resemblance of the leaves, is called "wildedagga", meaning "wild dagga".
A possibly more typical example illustrating how common names reflect what might be called folk taxonomy, and for lack of technical insight (though not necessarily of good sense) often undermine the merits of biologically systematic nomenclature can be found in the book Moby-Dick or, The Whale, by Herman Melville. In Chapter 32, "Cetology", concerning the question of whether the whale is a fish or mammal, Melville wrote in about 1851:
The uncertain, unsettled condition of this science of Cetology is in the very vestibule attested by the fact, that in some quarters it still remains a moot point whether a whale be a fish... The grounds upon which Linnaeus would fain have banished the whales from the waters, he states as follows: "On account of their warm bilocular heart, their lungs, their movable eyelids, their hollow ears..." I submitted all this to my friends Simeon Macey and Charley Coffin, of Nantucket, both messmates of mine in a certain voyage, and they united in the opinion that the reasons set forth were altogether insufficient. Charley profanely hinted they were humbug... Be it known that, waiving all argument, I take the good old fashioned ground that the whale is a fish, and call upon holy Jonah to back me.
Geographic range of use 
The geographic range over which a particular common name is used varies; some common names have a very local application, while others are virtually universal within a particular language. Some such names even apply across ranges of languages; the word for cat, for instance, is easily recognizable in most Germanic and many Romance languages. Vernacular names often are restricted to a single country, and colloquial names to local districts.
Constraints and problems 
Common names are used in the writings of both professionals and laymen. Lay people sometimes object to the use of scientific names over common names, but the use of scientific names can be defended, as it is in these remarks from a book on marine fish:
- Because, as already remarked, common names often have a very local distribution, we find that the same fish in a single area may have several common names.
- Because of ignorance of relevant biological facts among the lay public, a single species of fish might have several extra common names, say because individuals differ according to maturity, gender, or their natural surroundings.
- Formal taxonomic names imply biological relationships between similarly named creatures.
- Because of incidental events, contact with other languages, or simple confusion, common names in a given region change with time.
- In a book that lists over 1200 species of fishes more than half have no widely recognised common name; they either are too nondescript or too rarely seen to have earned any widely accepted common name.
- Conversely, a single common name often applies to multiple species of fishes. The lay public might simply not recognise or care about subtle differences in appearance between effectively unrelated species with very different biologies.
Coining common names 
The Latinized names used in scientific binomial nomenclature can be difficult for laymen to learn, remember, and pronounce, therefore in such books as field guides, biologists have coined and published lists of coined common names. On occasion, the common names are simply an attempt to translate the Latinized name into English. Such translation is sometimes confusingly inaccurate, for example, gratiosus does not mean "gracile" and gracilis does not mean "graceful".
The practice of coining common names has long been discouraged; de Candolle's Laws of Botanical Nomenclature, 1868, the non-binding recommendations that form the basis of the modern (now binding) International Code of Nomenclature for algae, fungi, and plants contains the following:
Art. 68. Every friend of science ought to be opposed to the introduction into a modern language of names of plants that are not already there, unless they are derived from a Latin botanical name that has undergone but a slight alteration. ... ought the fabrication of names termed vulgar names, totally different from Latin ones, to be proscribed. The public to whom they are addressed derive no advantage from them, because they are novelties. Lindley's work, The Vegetable Kingdom, would have been better relished in England had not the author introduced into it so many new English names, that are to be found in no dictionary, and that do not preclude the necessity of learning with what Latin names they are synonymous. A tolerable idea may be given of the danger of too great a multiplicity of vulgar names, by imagining what geography would be, or, for instance, the Post-office administration, supposing every town had a totally different name in every language.
Various bodies, and the authors of many technical and semi-technical books, do not simply adapt existing common names for various organisms; they try to coin (and put into common use) comprehensive, useful, authoritative, and standardised lists of new names. The purpose typically is:
- to create names from scratch where no common names exist
- to impose a particular choice of name where there is more than one common name
- to improve existing common names
- to replace them with names that conform more to the relatedness of the organisms
Other attempts to reconcile differences between widely separated regions, traditions and languages, by arbitrarily imposing nomenclature, sometimes have narrow perspectives and unfortunate outcomes. For example, members of the genus Burhinus occur in Australia, Southern Africa, Eurasia, and South America. A recent trend in field manuals and bird lists is to use the name "thick-knee" for members of the genus. This, in spite of the fact that the majority of the species occur in non-English-speaking regions and have various common names, not always English. For example "Dikkop" is the centuries-old South African vernacular name for their two local species: Burhinus capensis is the (Cape dikkop or “gewone dikkop”, not to mention the presumably much older Zulu name “umBangaqhwa”). Burhinus vermiculatus is the "water dikkop". The thick joints in question are not even in fact the birds’ knees, but the intertarsal joints—in lay terms the ankles. Furthermore, not all species in the genus have “thick knees”, so the thickness of the "knees" of some species is not of clearly descriptive significance. The family Burhinidae has members that have various common names even in English, including “Stone curlews”, so the choice of the name “thick-knees” is not easy to defend.
Lists that include common names 
Lists of general interest 
Collective nouns 
Official lists 
Some organizations have created official lists of common names, or guidelines for creating common names, hoping to standardize the use of common names.
For example, the Australian Fish Names List or AFNS was compiled through a process involving work by taxonomic and seafood industry experts, drafted using the CAAB (Codes for Australian Aquatic Biota) taxon management system of the CSIRO, and including input through public and industry consultations by the Australian Fish Names Committee (AFNC). The AFNS has been an official Australian Standard since July 2007 and has existed in draft form (The Australian Fish Names List) since 2001. Seafood Services Australia (SSA) serve as the Secretariat for the AFNC. SSA is an accredited Standards Australia (Australia’s peak non-government standards development organisation) Standards Development
See also 
- Kruckeberg, Arthur (1991). The Natural History of Puget Sound Country – Appendix I: The naming of plants and animals. Seattle: University of Washington Press. ISBN 978-0-295-97477-4.
- List of standardised Australian fish names – November 2004 Draft. CSIRO
- Conklin, Harold C. 1980. Folk Classification: A Topically Arranged Bibliography of Contemporary and Background References through 1971. New Haven, CT: Yale University Department of Anthropology. ISBN 0-913516-02-3.
- Stearn 1959, p. 6, 9.
- Stearn 1959, pp. 9–10.
- Stearn 1959, p.10.
- Mills, Gus and Hes, Lex (1997). The Complete Book of Southern African Mammals. Cape Town: Struik Publishers. ISBN 0947430555.
- Watt, John Mitchell; Breyer-Brandwijk, Maria Gerdina: The Medicinal and Poisonous Plants of Southern and Eastern Africa 2nd ed Pub. E & S Livingstone 1962
- Melville, Herman (2009). Moby-Dick: or, the Whale. City: Penguin Classics. ISBN 978-0-14-310595-4.
- Brickell, C.D., Baum, B.R., Hetterscheid, W.J.A., Leslie, A.C., McNeill. J., Trehane, P., Vrugtman, F., Wiersema, J.H. (eds.) 2004. International Code of Nomenclature for Cultivated Plants. ed. 7. Acta Horticulturae 647 (Regnum Veg. 144)
- Heemstra, Phillip C.; Smith, Margaret (1999). Smith's Sea Fishes. Southern Book Publishers. ISBN 1-86812-032-5.
- Deeann Reeder; Wilson, Don W. (2005). Mammal species of the world: a taxonomic and geographic reference. Baltimore: Johns Hopkins University Press. ISBN 0-8018-8221-4.
- Marchant, J.R.V. ; Charles Joseph F. (1952). Cassell's Latin dictionary. London: Cassell.
- Tucker, T. G. (1931). A Concise Etymological Dictionary of Latin. Halle (Saale): Max Niemeyer Verlag.
- de Candolle, A. (1868). Laws of Botanical Nomenclature adopted by the International Botanical Congress held at Paris in August 1867; together with an Historical Introduction and Commentary by Alphonse de Candolle, Translated from the French. translated by Hugh Algernon Weddell. London: L. Reeve and Co. p. 36, 72
- Bosman, D. B.; Van der Merwe, I. W.; Hiemstra, L. W. (1984). Tweetalige Woordeboek Afrikaans-Engels. Tafelberg-uitgewers. ISBN 0-624-00533-X.
- Lockwood, Geoffrey; Roberts, Austin; Maclean, Gordon L.; Newman, Kenneth B. (1985). Robertsڃ birds of southern Africa. Cape Town: Trustees of the J. Voelcker Bird Book Fund. ISBN 0-620-07681-X.
- Roberts, Austin (2005). Roberts' Birds of Southern Africa. Trustees of J. Voelcker Bird Book Fund. ISBN 0-620-34053-3.
- Scott, Thomas (1996). Concise Encyclopedia Biology. Berlin: Walter de Gruyter. ISBN 3-11-010661-2.
- Overview: Australian Fish Names Standard. Seafood Services Australia
- Parkes K.C. (1978). "A guide to forming and capitalizing compound names of birds in English". The Auk 95 (2): 324–326.
- Stearn, William T. (1959). "The Background of Linnaeus's Contributions to the Nomenclature and Methods of Systematic Biology". Systematic Zoology 8: 4–22.