Trinomen

In zoological nomenclature, a trinomen (plural: trinomina), trinominal name, or ternary name, refers to the name of a subspecies. For example: "Homo sapiens sapiens".

A trinomen is a name with three parts: generic name, specific name and subspecific name. The first two parts alone form the binomen or species name. All three names are typeset in italics, and only the first letter of the generic name is capitalised. No indicator of rank is included: in zoology, subspecies is the only rank below that of species. For example: "Buteo jamaicensis borealis is one of the subspecies of the red-tailed hawk (Buteo jamaicensis)."