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A brief explanation of botanical nomenclature
For those unfamiliar with the technical standards used in naming plants, this section offers a very brief explanation
of the methodologies used to name plants. The botanical or scientific name is the accepted standard name for a
plant. Each plant has a unique botanical name that is described and named by its author in Latin. This is the most
accurate way of referring to a plant as many plants have similar or the same common names and regional variations
and differences can cause no end of confusion. Latin is used because it is a dead language and therefore not prone
to change.
Family – The family is the botanical category above genus. Each family contains many genera (the plural of
genus) that share characteristics. For example Rosa canina is in the family Rosaceae whose members share a
number of features. There are several more groupings of plant types above family leading ultimately to the Plant
Kingdom.
The botanical name of a particular plant is made up of two parts; the first is the genus, the second is the species
epithet. The botanical name is always written in italics with the genus name capitalised and the species and any
other names all in lower case. For instance, the plant commonly referred to by many as the ‘dog rose’ is known by
the botanical name, Rosa canina L. In this example, the species epithet is canina. So, while there are many plants in
the genus Rosa, there is only one known as Rosa canina. Taken together, Rosa canina L. is referred to as a species.
Genus – The genus is the lowest level of plant relatives before individual species are described. A genus can contain
from one to many hundreds of species names. A genus with only one species is called monotypic (one type).
Species (spp.) – The species name is not the end of the taxonomic trail, however, with several lower levels of
taxonomic distinction being applied by taxonomists. A highly variable species may have many subspecies, varieties,
subvarieties, forma etc named by taxonomists. For our purposes identification to species level is sufficient but it pays
to understand that subspecific levels of nomenclature do exist. A brief explanation of the most commonly used
subspecific nomenclature follows.
Subspecies (subsp. or ssp.) and Varieties (var.) – These are taxonomic groups that are a distinctive
subdivision of a species whose members have certain hereditary characteristics distinct from other populations
of that species.
Cultivar (cv.) – A cultivar is a plant created by careful selective breeding often using inter or infra generic
hybridisation (within or between related genera). Most cultivars are registered by their breeders and given names.
Often people will quote a cultivar name in the mistaken belief it is a species name. As one species name can
contain many dozens if not hundreds of cultivars it pays to appreciate the difference. Cultivars are not considered
part of the ‘natural’ chain of botanic taxonomy due to their artificial origin but are acknowledged after the author
name in most descriptions when mentioned in publications (example below).
Examples of correctly cited cultivar and hybrid names:
Cultivar examples
Acer negundo L. ‘Flamingo’
Malus baccata (L.) Borkh. ‘Lady Northcliffe’
Hybrid examples
Alocasia X amazonica André (a hybrid of Alocasia lowii Hook. f. and Alocasia sanderiana W.Bull)
Primula X bulleesiana Janson (a hybrid of Primula bulleyana Forrest and Primula beesiana Forrest)
Synonyms – Sometimes a plant that has received a botanical name from one author is given a new name by
another author. These old names become synonyms of the currently accepted names and while no longer in use still
exist in old publications, and often in popular use in trade. It’s important to keep track of these names to maintain
the connections between the old and the new names, eg Vesalea floribunda M.Martens & Galeotti is a synonym of
Abelia floribunda (M.Martens & Galeotti) Decne.
CRC for Australian Weed Management The introduced flora of Australia and its weed status
A brief explanation of botanical nomenclature 9