The order as a distinct rank of biological classification having its own distinctive name (and not just called a
higher genus ()) was first introduced by the German botanist
Augustus Quirinus Rivinus in his classification of plants that appeared in a series of treatises in the 1690s.
Carl Linnaeus was the first to apply it consistently to the division of all three kingdoms of nature (then
minerals,
plants, and
animals) in his
Systema Naturae (1735, 1st. Ed.).
Botany For plants, Linnaeus' orders in the
Systema Naturae and the
Species Plantarum were strictly artificial, introduced to subdivide the artificial classes into more comprehensible smaller groups. When the word was first consistently used for natural units of plants, in 19th-century works such as the
Prodromus Systematis Naturalis Regni Vegetabilis of
Augustin Pyramus de Candolle and the
Genera Plantarum of Bentham & Hooker, it indicated taxa that are now given the rank of family (see
ordo naturalis,
natural order). In French botanical publications, from
Michel Adanson's (1763) and until the end of the 19th century, the word (plural: ) was used as a French equivalent for this Latin . This equivalence was explicitly stated in the 's (1868), the precursor of the currently used
International Code of Nomenclature for algae, fungi, and plants. In the first international
Rules of
botanical nomenclature from the
International Botanical Congress of 1905, the word
family () was assigned to the rank indicated by the French , while order () was reserved for a higher rank, for what in the 19th century had often been named a 'cohort' (, plural ). Some of the plant families still retain the names of Linnaean "natural orders" or even the names of pre-Linnaean natural groups recognized by Linnaeus as orders in his natural classification (e.g.
Palmae or
Labiatae). Such names are known as
descriptive family names.
Zoology In the field of
zoology, the Linnaean orders were used more consistently. That is, the orders in the zoology part of the
Systema Naturae refer to natural groups. Some of his ordinal names are still in use, e.g.
Lepidoptera (moths and butterflies) and
Diptera (flies, mosquitoes, midges, and gnats).
Virology From 1991 to 2017, order was the highest rank used to
classify viruses in a system that ranged from order to species. In 2018, the
International Committee on Taxonomy of Viruses, which oversees
virus taxonomy, added ranks higher than order up to the highest taxonomic rank of
realm. Virus orders are indicated by the suffix -
virales. ==See also==