By Kate and Len Lucas

In England, the well-known cottage garden plant “sweet william” is familiar enough. However, in Scotland, it is sometimes known as “stinking billy”. You couldn’t get two more dissimilar names. Their origins stem from the arrival in England of William of Orange in the middle of the seventeenth century who was loved by the English but was less than popular in Scotland.

In the distant past such differences in common names created lots of confusion. What was needed was a naming system that was the same wherever you were in the world. That system, which is used today, is called the “Binomial System” and was introduced by Swedish botanist, Carl Linnaeus from around 1750.

So now somebody in Argentina can talk to somebody in India about Dianthus barbatus (sweet william) and everybody is onboard.

However why Latin and not Greek or any other language? At the time, the language of scholars was Latin so to him, and the scientific community, it seemed the obvious choice.

Today Latin would be thought of as a dead language. Here’s a thought, if today you heard someone in Rome order a burger in McDonald’s you would hear something not very far from its Latin origins.

The binomial system applies to all living things and not just plants and has to follow strict grammatical rules. Take Dianthus barbatus, the first word is the genus and has to start with a capital letter the second word is the species and has to start with a small letter. For gardeners, the significance is that if you find a plant label that has the Latin name as just two words like Dianthus barbatus then what you have is a true species, or it should be, and the seed should produce offspring just like its parent.

The science behind the classification of plants and animals is called taxonomy and is designed to show how close is the relationship between one group and another. Our flowering garden plants are classified by botanists according to the structure of the flower and you often find what looks like two completely different plants are closely related like Anemones and Clematis or even more unlikely Laburnum and runner beans. That’s because their flower structure is the same. A change of plant name can therefore occur when someone discovers that a plant is in the wrong group because of its flower structure and it is re-named in the right one.

The best example here is bamboo. Bamboos are grasses and yes they do have flowers but only flower once in about a hundred years and do so at the same time wherever they are in the world. So when the Victorian plant collectors brought back bamboos from around the world, they had nothing to go on to classify them so named them according to whether bamboos just looked similar. And lo and behold when they flowered discovered from the flower structure that many were in the wrong group with the wrong name and so re-named them.

Taxonomists are always looking for ways to establish the true biological relationship between groups of organisms, using ever more refined methods such as chromosome and DNA studies which has lead to a change of name.

And to come right up to date, the intense study of Coronavirus (its Latin name) can reveal exactly where in its molecular structure has a mutation taken place and so a new variant is named and announced.

Fortunately for us gardeners, plants don’t change their name very often but somebody somewhere is beavering away in a laboratory with a microscope and a change of name is often the outcome.

The plant of course is still the same no matter what you call it.