Botanical artists are required to provide the Latin name of their plant subjects.
The following notes set out the rules that scientists have devised for the naming of plants, and comes from advice provided by the Royal Horticultural Society to botanical artists. (The website Botanical Art and Artists by Katherine Tyrrell has an excellent webpage on this subject here.)
All living organisms have a scientific (Latin) name and many also have a vernacular or common name. For example, in England the plant commonly known as the bluebell has the scientific name Hyacinthoides non-scripta. The scientific name is preferable, because the common name can be ambiguous: in Scotland the bluebell is Campanula rotundifolia and in Australia the bluebell is Sollya heterophylla.
The way in which scientific names are written or printed is governed by an International Code. This states that scientific names must be italicised or underlined.
The scientific name of a plant has two parts. For example, in the English bluebell (Hyacinthoides non-scripta), the first word (Hyacinthoides) is the name of the genus. The second word (non-scripta) is the name of the species and follows the generic name.
The genus name always begins with a capital (upper case) letter, but the species name never does - even when the species name commemorates a country or a person, such as Rosa chinensis (the China rose) or Rosa banksiae (named for the wife of Sir Joseph Banks).
But the abbreviations for subspecies, variety and forma (subsp., var., and f.) must be written in Roman, not italic, for example Narcissus romieuxii subsp. albidus, Clematis montana var. rubens.
Family names (such as Fagaceae, Campanulaceae) must be written in italics.
Every scientific name is followed by the (sometimes abbreviated) name of an authority (the person or persons who originally published the name). For example Primula vulgaris Huds., Clematis alpina (L.) Mill., Lilium catesbaei Walter var. asprellum (Wherry) Stearn.
A cross between plants of two different species results in a plant called a hybrid. For example Lilium × parkmanii is the name given to the cross between Lilium speciosum and Lilium auratum. The “×” indicates the hybrid status and should be written as ×, not x, and must not be italicised.
Many species and hybrids have named cultivars (cultivar is derived from the words cultivated variety). A cultivar is defined as an assemblage of plants that has been selected for a particular character or combination of characters. Cultivar names must be written in Roman (not italics), and must be placed within single quotation marks, for example Clematis ‘Huldine’ or Clematis ´ cartmanii ‘Joe’.
All the main words in a cultivar name must begin with a capital (upper case) letter, for example Lilium ‘Big Ben’, Lilium ‘Red Brash Bird’: other (less grammatically important) words do not begin with a capital, for example Lilium ‘Pot of Gold’, Lilium ‘Musik der Nacht’.
The names of cultivars are complicated by trade designations (selling names) which are names that are used to market a plant when the cultivar name is considered to be unsuitable for marketing purposes, for example Clematis ‘Evijohill’ has been given the trade designation JOSEPHINE.
Trade designations are usually written be in SMALL CAPITALS, and not italicized. Trade designations must not be placed between quotes.
When cited together with the cultivar name, the order doesn’t matter, but generally it is best to put the best-known name first, for example:
Clematis BLUE ANGEL ‘Błękitny Anioł’
Clematis INSPIRATION ‘Zoin’
Clematis ROSEMOOR ‘Evipo002’
Clematis ‘Warszawska Nike’ MIDNIGHT SHOWERS
Clematis ‘Helios’ AZTEK