Certainly many roses have a great fragrance, but like Shakespeare I am not talking about roses specifically in this article, but about plant names and why they change. It can be very frustrating for gardeners, me included, when plant names change, apparently randomly, from those with which we are familiar to a new botanical name that always seems to be longer and more complicated. This also seems to be a trend that has accelerated in the last 10 years or so.  But I think it is worth understanding what is changing and why, and it really isn’t just plant scientists making changes to irritate domestic gardeners. There are two reasons why the names on plant labels may change, and this is linked to the two different parts of plant names: the latinised, botanical name that is followed by the cultivated variety (cultivar) name in English.

Cultivar name changes are less frequent and simpler.  The cultivar name is given to plants which have been bred for a characteristic and do not occur naturally.  It is chosen by the person who developed the variety and frequently this is a description or somebody’s name for example Rosa ‘Graham Thomas’, shown here.  Why might that change? Well, simply because the standard is that the name used, is the name assigned by the first person who identified the plant and historically, before the internet and global databases, labels were lost as plants were moved around and plants were simply renamed. Nowadays, with much greater ability to store and share information, it is much more likely that these duplicates will be detected and the original name restored.

The second change to a plant name comes in the Latin part and this is much more significant. All plants are grouped into a multi-level naming structure based on how closely they are related and the two plant names that we usually see are the genus and the species uniquely identifying the plant.  In the 18th century, Carl Linnaeus started to define these plant groupings using the flower structure to determine related plants: the number of petals, the number of stamens and the form they take for example,  With the understanding of DNA and genome sequencing, we are now seeing plants being analysed genetically and this is why plants may change their name.  What they are really doing is moving into the correct species, genus or family based on the DNA, rather than using the flower structure as an approximation.  And it amazes me how few plants are moved into a different grouping and how accurate Linnaeus and his botanist colleagues were.

Of course, that doesn’t change the effort of learning new names for favourite plants, but at least we understand why. As for the names of plants such as Sedum spectabile, the butterfly or ice plant that has now become Hylotelephium or Stipa tenuissima, the feather grass now called Nasella, the old familiar names will simply become a common name that many people continue to use. Helpfully, previous names are often listed as synonyms so if you are struggling to source plants identical to some you’ve already have, do check before giving up hope.

Clearly Shakespeare had no inkling of binomial plant names and subsequent changes when he wrote that a Rose by any other name would smell as sweet. I suspect that he was just picking a plant that was well known to his audience, but ironically Roses have stood the test of many, many centuries without a change of name!  Take time this July to enjoy all the plants in your garden, scented or not, and whatever they are currently called.

Happy Gardening from Alison