Plant taxonomy and nomenclature
Nomenclature
Plants are named in a specific and systematic way. It is important to understand the structure of this system to minimise confusion and mix-ups when dealing with nurseries or when working on planting jobs.
Because there are now nearly 400,000 different species known to modern science across the world it is necessary that a clear universal system is used across the world. The use of latin to categorise plant species is used as it is a somewhat neutral language that can be used internationally to avoid confusion.
For example, in the UK our common names such as ‘holly’ will not be used in non-english speaking countries but the genus Ilex will of course exist in these countries. Even within the UK common names differ from region to region but the scientific name will remain the same meaning misunderstandings are eliminated. A nusrsery in Japan would be unable to help if asked for ‘holly’ but if Ilex aquifolium is requested you would recieve the exact plant you are looking for regardless of the language barrier.
Asteraceae flowers, all known as ‘aster’
Taxonomy
Taxonomy is the science of classification and categorisation of organisms. The plant kingdom is divided into 7 distinct categories:
Bryphota (Mosses)
Hepatophyta (Liverworts)
Equisetophyta (Horsetails)
Pteridophyta (Ferns)
Coniferophyta (Conifers)
Ginkgophyta (Ginkgo)
Angiosperms (Flowering plants)
The Linnaeus taxonomy system covers 3 main goals, the identification, classification and description of the plant.
For example, Eryngium yuccafolium of the Appiaceae family.
Appiaceae is the family that Eryngium is part of. This particular family is characterised by and made up of plants bearing umbellifer flowers.
This idenfifies the Eryngium as a member of the appiaceae family.
Eryngium is the genus that Eryngium yuccafolium is part of. This genus contains only plants determined to be Eryngiums based on their growing habit, foliage and flower.
This categorises the Eryngium yuccafolium as genus Eryngium.
yuccafolium is the formal description of the specific plant and is the species. “yuccafolium” literally means foliage similar to that of a yucca.
This describes the Eryngium yuccafolium as a specific unique species within the Eryngium genus.
Nursery stock labelling
In the world of horticulture the lower intermediate classifications are important when being specific. Below species in the taxonomy heirarchy comes subspecies followed by variety and then cultivar.
Plant labels will be structured in the following order (if applicable):
Genus, species, subspecies, variety, Cultivar and hybrids.
i.e- Ilex aquifolium (holly) or Mahonia x media ‘charity’
Every plant will have at least the Genus and species.
Genus- always is capitalised and italicised
Species- is never capitalised but also italicised
Subspecies- will appear in lower case italics appreviated to ‘subsp.wolfenii’ for example.
Variety- Appears lower case italics and appreviated to ‘var. fastigiate’ for example
Cultivar- Short for cultivated variety and refers to plants bred for their characteristics, often named after the breeders who discovered them. These are displayed in single quotation marks and are always capitalised ie. ‘Varigiata’
Interspecific hybrid – Mahonia × media (bred from Mahonia lomariifolia and Mahonia japonica, note the ‘x’ in the middle and new specific epithet.)
Intergeneric hybrid – × Cupressocyparis leylandii (bred from Cupressus macrocarpa and Chamaecyparis nootkatensis, note the ‘x’ at the beginning and the genus which is a combination of the parents’).
Graft hybrid – +Laburnocytisus ‘Adamii’, (a graft hybrid between Laburnum and Cytisus, note the ‘+’ at the start and genus which is a combination of the parents’.) This graft contains flowers of Laburnum and Cytisus (ie both yellow and purple) but also flowers that are a pinky colour, a mix of the two.
Mahonia x media ‘charity’.
Mahonia- species
x media- interspecies hybrid
‘charity’- cultivar