Nomenclature and Taxonomy

Refer to the AMA Manual of Style for comprehensive guidelines on the correct format and style of biological and scientific terminology. Below are very general guidelines, from the AMA Manual of Style, 10th edition (Oxford University Press). 

Capitalize the formal name of a genus in the singular, with or without a species name. Do not capitalize traditional plural generic designations (e.g., streptococci) or derived adjectives (streptococcal). Do not capitalize the name of a species, variety, or subspecies. Do capitalize phylum, class, order, or family.  

Initial capitals are used for all taxonomic groups, except for the second portion of the binomial. Use italics for the genus and species components of the binomial. After first mention of the binomial species name, abbreviate the genus portion of the name. (In a departure from AMA style, use a period.)

Homo sapiens; H. sapiens

Staphylococcus aureus; S. aureus

Capitalize formal virus names or virus terms that end in -virales, -viridae, or -virinae. Italicize names of viral taxa of genus and below.