Binomial Nomenclature: Rules of Scientific Naming

A single organism is very often known by several different common or vernacular names — the same plant may be called by one name in Bengali, another in Hindi, and yet another in English, and even within a single language, folk names can vary from region to region and can be genuinely ambiguous. Science needs a naming system that is universal, unambiguous and stable across every language and every country, so that a researcher in Kolkata and a researcher in Tokyo can be certain they are discussing exactly the same organism.

This need is met by binomial nomenclature, the system in which every organism is given a scientific name made up of exactly two parts — hence "bi-nomial", two names. The system was formalised and popularised by the Swedish naturalist Carolus Linnaeus in the eighteenth century and remains the internationally accepted standard today, governed by formal codes of nomenclature (separate codes exist for botany, zoology and bacteria) that lay down precise rules.

The key conventions that govern every valid scientific (binomial) name are:

• The name has exactly two parts: the first is the generic name (the genus to which the organism belongs), and the second is the specific epithet (which, combined with the genus, identifies the species).
• The generic name always begins with a capital letter; the specific epithet is always written entirely in lower case, even if it honours a person or place.
• Both parts of the name are written in italics when printed (or underlined separately, if handwritten), to signal that they are formal Latin or Latinised scientific terms rather than ordinary words.
• The names are usually derived from Latin, or are Latinised forms of other words, regardless of the language of the country where the organism was first described or named.
• When a name is first used in a piece of writing it is generally written in full; thereafter the genus name may be abbreviated to its initial (for example, Mangifera indica may subsequently be written as M. indica). …