Department of Biology


The scientific name (species name) of any plant, animal, fungus, alga or bacterium consists of two Latinized words. The first word is the name of the genus to which the organism belongs. The second word is the specific epithet or specific term of the species. Together, the genus plus the specific epithet make up the species name. The species name and scientific name are synonyms.

Acer is the genus of the maples, Homo the genus of humans, and Escherichia a genus of one type of bacterium. This name, the genus, can stand alone and is meaningful to scientists. The specific term or epithet can not stand by itself. It is meaningless without connection to a genus because there are often several genera that have the same species term. Consider Tilia americana, Fraxinus americana and Ulmus americana. All are scientific names, all have the same specific epithet, but all are classified in different genera. By the way, these are the scientific names for the basswood, elm and ash of America.

It is common to hear some refer to the genus and species of an organism. There is a redundancy in this phrase. The species name includes the genus as well as the specific epithet.

Scientific names, or the generic name, are written so readers can recognize these words as scientific names. The genus is capitalized, but the specific epithet is not. Both words are usually written in italics or underlined. However, modern day computer programs have given us even more ways to change fonts. Therefore, you may see a species name written in a number of different fonts, but always that font should differ from the font used for the rest of the words on the paper. You have but one choice when writing longhand; the scientific name is underlined.

Scientific names are the same worldwide. Scientists in all countries use the same species name for a species. Also note that the word "species" is both the singular and plural form of that word.

All other taxa -- Domain, Kingdom, Phylum, Class, Order and Family -- are usually written in the same font as non-species names.

As is common, scientific names are repeated in textbooks, even in the same paragraph. Once a scientist has written the full species name, such as Ulmus americana, the genus may be abbreviated so the species name becomes U. americana. The reader can go back and reread that the U. stands for Ulmus.

Sometimes the name or abbreviation of the biologist (called the authority) who named the organism follows the species name. Ulmus americana L. tells us that Carolus Linnaeus (L.) named the American elm. Other times, the species name is listed, followed by a name(s) in parentheses, followed by another name(s). For example, Laetiporus cincinnatus (Morgan) Burdsall, Banik, & Volk indicates that the species was originally named by Morgan and has been renamed by Burdsall, Banik, and Volk. Under most circumstances, the author's name or abbreviation is not written after the species name.

In those cases where a variety of a species is referred to in a paper or textbook, the variety follows the specific epithet. For example, the peach and nectarine are both the species Prunus persica. The peach is Prunus persica var. persica and the nectarine is Prunus persica var. nucipersica. Note that the species name (both words) and the variety name are written in the same font. The word var. is not written in this font, however.

During your studies, you will have occasion to write scientific names (species names), genera names, species names that have been referred to earlier in the manuscript, scientific names, and species names followed by a variety name. Remember to follow the rules!


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