Rank (botany)
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In botanical nomenclature, a taxon is usually assigned to a rank in a hierarchy. The basic rank is that of species, and if an organism is named it most often will receive a species name. The next most important rank is that of genus: if an organism is given a species name it will at the same time be assigned to a genus, as the genus name is part of the species name. Of the botanical names used by Linnaeus only names of genera, species and varieties are still used. The third-most important rank, although it was not used by Linnaeus, is that of family.
According to Art 3.1 of the ICBN the most important ranks of taxa are: kingdom, division or phylum, class, order, family, genus, and species. According to Art 4.1 the secondary ranks of taxa are tribe, section, series, variety and form. There is an indeterminate number of ranks. The ICBN explicitly mentions:
primary ranks
- - - secondary ranks
- - - - - - - further ranks
kingdom (regnum)
- - - - - - - subregnum
division or phylum (divisio, phylum)
- - - - - - - subdivisio or subphylum
class (classis)
- - - - - - - subclassis
order (ordo)
- - - - - - - subordo
family (familia)
- - - - - - - subfamilia
- - - tribe (tribus)
- - - - - - - subtribus
genus (genus)
- - - section (sectio)
- - - - - - - subsectio
- - - series (series)
- - - - - - - subseries
species (species)
- - - - - - - subspecies
- - - variety (varietas)
- - - - - - - subvarietas
- - - form (forma)
- - - - - - - subforma
The rules in the ICBN apply primarily to the ranks of family and below, and only to some extent to those above the rank of family. Also see descriptive botanical names.
Taxa at the rank of genus and above get a botanical name in one part (unitary name); those at the rank of species and above (but below genus) get a botanical name in two parts (binary name); all taxa below the rank of species get a botanical name in three parts (ternary name).
For hybrids, getting a hybrid name, the same ranks apply, preceded by "notho", with nothogenus as the highest permitted rank.