Understanding Plant Name Changes: The Story Behind Plant Reclassifications
Hey plant friends, buckle up, it’s about to get super plant nerdy!
We're about to delve deep into the fascinating and sometimes infuriating world of plant taxonomy. If you've ever wondered why the names of your favourite plants keep changing, you're not alone. Botanists are on a relentless quest to ensure plant names accurately reflect their evolutionary relationships. This journey is driven by groundbreaking advancements in DNA analysis, which have exposed some surprising truths about plant families.
The Aster Saga
Let's start with a classic example: Aster. Our story begins with Carl Linnaeus, the Swedish botanist who laid the foundation of modern taxonomy. He named the European aster ‘Aster amellus’ and grouped other similar-looking European plants under this genus. All was well until botanists ventured into North America and discovered a treasure trove of asters, including the New York aster (Aster novi-belgii) and the New England aster (Aster novae-angliae). These are the plants we often call Michaelmas daisies, which add that essential autumn charm to our gardens.
Here's where it gets interesting. DNA evidence from the mid-1990s revealed that the North American asters are not related to their European counterparts. In fact, many of them aren’t even closely related to each other. This revelation led to a major reclassification, and most Michaelmas daisies were reassigned to the genus Symphyotrichum. So, our beloved New York and New England asters are now Symphyotrichum novi-belgii and Symphyotrichum novae-angliae. Meanwhile, the European asters, including hybrids like the popular Aster x frikartii ‘Mönch’, kept their original names.
The Rosemary Riddle
Next, let's explore the rosemary conundrum. Historically, rosemary was classified as Rosmarinus. However, DNA studies uncovered that rosemary is closely related to the sage family (Salvia), which includes the common sage (Salvia officinalis) and clary sage (Salvia sclarea). To maintain taxonomic consistency, botanists decided to reclassify rosemary as Salvia rosmarinus. While this change might seem like a nuisance, it accurately reflects the plant's evolutionary lineage.
Salvia rosmarinus (rosemary)
Pineapple Guava's Journey
Now, let's talk about the pineapple guava. This evergreen shrub, originally named Feijoa sellowiana, has had quite a journey. In the 1980s, botanists noticed its similarity to ‘Acca lanuginosa’ and decided to merge the two genera, renaming pineapple guava as ‘Acca sellowiana’. Fast forward to 2019, and new DNA analysis revealed that ‘Acca sellowiana’ isn't closely related to other Acca species. Consequently, the name ‘Feijoa sellowiana’ was reinstated. So, if you have an old label with ‘Feijoa sellowiana’, you can feel quite smug about never updating it! Try pronouncing some of those I dare you!
The Hylotelephium Twist
For those who are really into plant classification, here's another twist: Many plants previously lumped into the genus Sedum have been reclassified into Hylotelephium. This change came about through detailed DNA analysis showing that certain sedums were distinct enough to merit their own genus. So, garden favorites like ‘Autumn Joy sedum’ are now known as ‘Hylotelephium telephium’. Another example is the ‘Sedum spectabile’, often called Showy Stonecrop, which is now Hylotelephium spectabile. These reclassifications bring clarity to the evolutionary relationships within this diverse group of plants, even though it means updating those plant tags once more.
The Ever-Changing Landscape of Plant Taxonomy
Plant taxonomy is an ever-evolving field, constantly updated to reflect new scientific discoveries. Take Gertrude Jekyll’s ‘shrubby veronicas’, for instance. They were first reclassified under the genus Hebe and then later returned to Veronica.
While these changes can be exasperating, they highlight the importance of accuracy in reflecting evolutionary relationships. Staying updated with these changes is crucial for plant enthusiasts who want to stay informed about the latest in botany.
Ultimately, these updates aim to enhance our understanding of plant relationships, ensuring that our beloved garden plants are correctly named. And who knows? The next name change might bring back a familiar name, rewarding those who never got around to updating their plant labels.
After all my research for this blog, I’m in awe of how Guy Barter, Chief Horticulturist at the RHS, keeps track of all these new classifications. The man must have a superhuman memory, or perhaps a secret plant taxonomy cheat sheet! Happy gardening and happy learning!