Summary
Linnaeus's two-part naming system using genus and species, such as Homo sapiens.
In depth
The genus name is capitalised and the species epithet is lower case, both italicised: Homo sapiens. Names are Latin or Latinised so they are universal. The International Code of Nomenclature sets rules and priority.
Common mistake: the species name is the whole binomial; sapiens alone isn't a species name.
Names are Latinised and unique. Subspecies add a third name; varieties and cultivars are used in plants. Authority names may follow.
Common mistake: writing species names without italics or capitalising the epithet.
Carl Linnaeus popularised the two-part scientific name in Species Plantarum (1753). The first word is the genus (capitalised) and the second the species epithet (lower case); both are written in italics, or underlined when handwritten, as in Homo sapiens or Escherichia coli. After first use the genus can be abbreviated: E. coli.
Scientific names are Latin or Latinised, are universal across languages and avoid confusion from common names (a robin in Britain differs from one in America). Rules are set by international codes (ICZN for animals, ICN for plants); the oldest valid name has priority. Names often describe a trait, place or honour a person.
Example: the big cat Panthera leo shares a genus with the tiger, Panthera tigris.
Key idea: the genus groups close relatives, and the full binomial is unique to one species.
Frequently asked questions
What is Binomial Nomenclature?
Linnaeus's two-part naming system using genus and species, such as Homo sapiens.
Which area of biology covers Binomial Nomenclature, and how advanced is it?
Binomial Nomenclature is one of the 52 topics in Taxonomy & Biodiversity. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Linnaeus, Taxonomic Hierarchy, Taxonomy.
Can you give an example of Binomial Nomenclature?
The domestic dog is Canis lupus familiaris.
What should I learn before Binomial Nomenclature?
Binomial Nomenclature is a Beginner topic, so no earlier topic is required. Other Beginner topics in Taxonomy & Biodiversity that pair well with it include Taxonomy, Taxonomic Hierarchy, Three Domains of Life.
What topics are related to Binomial Nomenclature?
The closest topics to Binomial Nomenclature are Linnaeus, Taxonomic Hierarchy, Taxonomy, PhyloCode. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Binomial Nomenclature?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Binomial Nomenclature. To practise the whole of Taxonomy & Biodiversity, use the Taxonomy & Biodiversity quiz.
How is Binomial Nomenclature different from Linnaeus?
Binomial Nomenclature: Linnaeus's two-part naming system using genus and species, such as Homo sapiens. Linnaeus: Carl Linnaeus, the 18th-century Swedish scientist who established the modern hierarchical classification system. Read both side by side and note what each one explains.
What is a common mistake about Binomial Nomenclature?
The species name is the whole binomial; sapiens alone isn't a species name.
How should I study Binomial Nomenclature step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Linnaeus and explain the difference aloud. Finally, take the Taxonomy & Biodiversity quiz and come back to this page for any question you miss.