Genus
In
biology, a
genus (pl.
genera, from the Greek word
γενος) is a taxonomic grouping. That is, in the classification of living organisms, a genus is considered to be distinct from other such genera. A genus has one or more
species: if it has more than one species these are likely to be
morphologically more similar than species belonging to different genera.
In the
binomial nomenclature used worldwide, the name of an organism is composed of two parts: its genus name (always capitalized) and a species modifier. An example is
Homo sapiens, the name for the
human species which belongs to the genus
Homo. See
scientific classification and
nomenclature Codes for more details of this system. Also see
type genus.
A genus in one
kingdom is allowed to bear a name that is in use as a genus name or other taxon name in another kingdom. Although this is discouraged by both the
International Code of Zoological Nomenclature and the
International Code of Botanical Nomenclature there are some five thousand such names that are in use in more than one kingdom. For instance,
Anura is the name of the
order of
frogs but also is the name of a genus of plants (although not current: it is a
synonym); and
Aotus is the genus of
golden peas and
night monkeys;
Oenanthe is the genus of
wheatears and
water dropworts, and
Prunella is the genus of
accentors and
self-heal.
Obviously, within the same kingdom one particular generic name can apply to only one genus. This explains why the
platypus genus is named
Ornithorhynchus â€" it was indeed given the name
Platypus, by
George Shaw in
1799, but by then that name had already been given to the
ambrosia beetle by
Johann Friedrich Wilhelm Herbst in
1793. Names with the same form but applying to different taxa are called
homonyms. Since beetles and platypuses are both members of the kingdom
Animalia, the name
Platypus could not be used for both.
Johann Friedrich Blumenbach published the replacement name
Ornithorhynchus in
1800.
Many genera are divided into
subgenera (singular
subgenus).
*
Linnaean taxonomy*
Cladistics
