Updated: Jan 23, 2021
Botanical nomenclature is the system by which we name plants, it is combined latin and greek and has many rules formed in tradition. Although a complicated thing to do it certainly serves its purpose.
Most horticulturists know genus, species and cultivars, whilst probably knowing the plants common name too. It’s useful to know the family the plant is in, to be able to guess either it’s place of origin or its usefulness. But most important are the descriptions species names convey; they usually give an idea to an outstanding feature of the plant or habit it grows in.
As I work with plants I get more interested in their names and what they mean, I find recurring patterns of species either describing morphological features, being named after the area the type specimen is found or named after the botanist who ‘found’ it.
There are rules to each of these ways of forming names; depending on the original gender of the genus, as in latin; words are either neutral, male or female.
There are books which will help you learn the meanings of these botanical latin words to better understand the habits and features of plants, ‘Plant Names Simplified’ originally published in 1931 is very useful and so is the RHS ‘Latin for Gardeners’ which includes how to pronounce each word, making it easier to read and therefore easier to remember.
Species and subspecies names can also show the difference in the distinguishing colour of the plant, here I will use the example of the colour white whilst giving examples of how the Neutral, Male and Female plays apart in all botanical latin.
Dictamnus albus var. purpureus (Masculine) - the species is white flowering but this variety is purple flowering.
Rhynchospora alba (Feminine) originally Schoenus albus but once found to be in Rhynchospora instead, the species then changes to follow the genus gender.
Chenopodium album (Neuter)
Here are some examples of specific epithet that contains morphological features;
Notholirion macrophyllum (N)
phyllum (greek phyllon) =leaf
So we can now tell by the name that this species has a distinguishing bigger leaf than other species in the genus.
Acer crataegifolium (N)
This is telling us this Acer has leaves shaped similarly to a crataegus.
Rheum acuminatum (N) =acuminate shaped leaf
which tells you it’s different to
Rheum palmatum (N) =leaf shape with five or more lobes
Plant names that are after the areas they belong are called Toponym
Some examples are;
Rehderodendron indochinensis (M)
Indochina was first used in the early 1800’s to map Mainland Southeast Asia including Cambodia, Laos, Myanmar, Peninsular Malaysia, Thailand and Vietnam. The French colony then used the term to establish their colony as French indochina including Cambodia, Indonesia, Vietnam and Laos.
Thalictrum omeiense (N)
Mount Emei/Omei is a mountain in Sichuan Province, China
Tricyrtis formosana (F)
In 1542 Portuguese sailors chartered Taiwan as Ilha formosa (beautiful island) so now when you see anything with formosa in it you know it originates in Taiwan.
Plant names can be in honour to people; usually after the botanist who ‘discovered’ or introduced the plant to cultivation, these are called patronym. The rules dictate that you cannot name a plant after yourself, so when you see sieboldii or wilsonii you know another botanist has named it after them, it usually works in the way of the botanist who collected the plant works with another botanist classifying the plant then the second botanist names it after the first.
Sometimes genus are named in honour of people and follow regular latin gendering forms but if a species is named after someone then the original gender of the genus does not matter as the species will now be gendered by the actual gender of the namesake; i and ii after a man, orum after a group of men or mixed genders, ae after a woman and arum after a group of women.
Some examples of genus and specific epithet that are named after someone;
Ranzania japonica (F)
Ranzan Ono was a scholar of herbalism opening his school of botanical pharmacognosy in Kyoto Japan in 1754, despite the genus being named after a man it is gendered feminine and so the specific epithet follows that gender whilst telling you the species originates in Japan.
The genus is named after Pierre Magnol a french botanist, again the genus is feminine but as the species is named after someone it is then gendered by Ernest Henry Wilson who introduced around 2000 species from Asia to Europe.
Begonia wynn-jonsiae ‘Pink Lady’
Julian Shaw named this Begonia Bleddyn and Sue Wynn-Jones introduced, after Sue, and so it ends in ae. i is sometimes added before the ending to make the word sound better.
Try to notice plants with this ending to see how many plants have been named in honour of women.
In systematic nomenclature plants names change continually especially due to the use of DNA sequencing but, as the tradition of botanical nomenclature rules, whichever was the original plant name is then to be used. For example in issue three’s Naturalis Historia I said Commerçon named a genus after Jeanne Baret Baretia but it was then found to already belong to Turraea so tradition rules that the latter named genus takes the preceding genus name. Which means we will forever be stuck with old fashioned names like indochinensis.
“Botanical latin is essentially a written language, but the scientific names of plants often occur in speech. How they are pronounced really matters little provided they sound pleasant and are understood by all concerned.” from ‘Botanical Latin’ by William T.Stearn
Botanical latin is a worldwide spoken language but people speak it differently, typically how you first learn to pronounce the word is how you go on to speak it, so depending on your language's pronunciation or who you learnt the word from it will be different to how others say it. For example Pinus in Britain is pronounced pie-nus and on the European continent it is pee-nus which is very funny to us but of course we all understand each other.
I am not multilingual but since learning botanical latin I find myself being able to understand English and the similarities in other languages much better. I can start to see the origins of words and instead of just using words from context I can use them with confidence in their meanings. For example Arbutus unedo made me wonder if un was un-edible or one-edible, I know the fruit is edible so I looked it up and found this;
Arbutus unedo species name is attributed to Pliny the Elder who said ‘Unam tantum edo’ meaning ‘I only eat one’