In biology, a genus (plural: genera) is a taxonomic rank used in the biological classification of living and fossil organisms. In the hierarchy of biological classification, genus comes:
- above species; and
- below family.
In binomial nomenclature (see below), the genus name forms the first part of the binomial species name for each species within the genus.
This is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms (although they can be based on words from other languages).