My plan is to add to this post when I come across a new name for a well known plant, so once the ball is rolling the newest name changes should be at the top.
“Why must all these plant names change?” the gardeners ask. I have no intention of discussing ‘why’ in any meaningful sense in this post, only to focus on specific examples in the hope that they might help more committed gardeners keep up to date.
Sorbus > Sorbus and Aria
This is a new one on me and I’m hoping that I will gain clarity over the next few weeks. When you look across the genus ‘Sorbus’ it’s fairly clear that there is something that doesn’t quite fit. There are lots of the easy to recognise species with pinnate leaves and small fleshy fruits (think Sorbus aucuparia), but then there are trees like ‘Sorbus aria’ which have simple leaves (leaf-shaped leaves!) and quite different fruits. There is it seems sufficient difference for the two groups to be split up; those with pinnate leaves stay in Sorbus while those without (and with different fruits) move into Aria. (Does this mean that ‘Sorbus aria’ is now ‘Aria aria’?!). This is a new change, to me anyway, so this part of this post might well change once I get my head around it!
Azaleas > Rhododendrons
This one makes a lot of sense really, after all they’re clearly plants with a lot in common. Genetic research in recent years has firmly put the azaleas into the larger genus Rhododendron, but also threw up something rather interesting; evergreen and deciduous azaleas aren’t all that closely related to each other! Any plant labelled ‘Azalea X’ is in fact ‘Rhododendron X’. Other minor genera around Rhododendrons have also been put into Rhododendron, namely Ledum and Menziesia.
Dicentra > Lamprocapnos, Dactylicapnos, Dicentra*
This change has caused a lot of irritation in gardeners, partly because the formerly ‘Dicentra spectabilis’ is a popular garden plant and gardeners like to resist change, but also because the names assigned are seen as being ‘too difficult’ for normal gardeners to understand. I suspect the latter is probably part of resisting change too, to be honest.
The genus used to be ‘Dicentra’ based on the flowers being the same shape, but now the genus is split. Dicentras grow from a rosette of leaves and have no foliage on their flower stem (the stem is bare from the ground right up to the flowers), while Lamprocapnos contains one species (L. spectabilis) that has leaves on its flowering stem, and all of the yellow flowered climbing species belong in Dactylicapnos.
*I think I’m right in saying these names were the original names used when the plants were discovered.
Michelia > Magnolia
Nice and easy this one; the main difference between Michelia and Magnolia was that the Michelias bore their flowers along their branches while Magnolias bore theirs at their branch tips. Research places the Michelias into Magnolia. This hasn’t created much friction in horticultural circles, but the ‘Michelias’ aren’t particularly hardy and need a little more care, so tend to be grown by more knowledgeable gardeners.
All of my pictures of what were formerly Michelias were lost when my old external hard drive failed. Must make a point of photographing some more this year!
Schizostylis > Hesperantha
The genus Hesperantha has been around in specialist bulb collections for a while, and is really very similar to what we used to call ‘Schizostylis’. In fact the only major difference between them was that ‘Schizostylis’ grows from a short rhizome while Hesperanthas grow from corms. DNA evidence put them firmly together, so ‘Schizostylis coccinea’ is now an autumn flowering, hardy and more moisture tolerant species of Hesperantha, Hesperantha coccinea.
While we’re on the subject of name changes, let’s look at the common name for H. coccinea, ‘Kaffir Lily’. If you go to South Africa and call someone a ‘Kaffir’ they will likely punch you in the face; ‘Kaffir’ is an offensive term for black South African! Nonetheless the common name ‘Kaffir Lily’ is still widely used in the UK, but in a society where the nursery rhyme ‘Baa baa black sheep’ has been banned in some nursery schools because it’s considered racist (despite little to no historical evidence) we should probably be aware that the word could feasibly cause genuine offence. ‘Cape Lily’ or ‘Scarlet River Lily’ could be better alternatives.