Synonyms

Tradescantia (Andersoniana Group) ‘Carmine Glow’ or ‘Karminglut’?

Synonyms are a really BIG problem for gardeners in general and National Collection Holders in particular. When a plant becomes popular and sales increase, it usually isn’t long before a commercial plant nursery offers an extremely similar plant for sale under a different name. There might be a tiny difference in flower or leaf colour or no difference at all! They want more sales and if people are buying a particular plant they will also buy ones which are very similar, thinking they are getting something new and different. Collection Holders like myself might hunt down a plant with a name they don’t recognise only to find it is something else they already have but under a different name. This is very frustrating and can be time consuming and sometimes expensive. I would normally advise people only to buy from reputable sources but they are often the biggest culprits!

It seems to me that because Tradescantias are so promiscuous, and produce cross pollinated seedlings at the drop of a hat, this is why there are so many different hybrids, many of which are only subtly different to each other. On any given plant, not all the flowers will be identical, so are the two flowers featured above from the same plant or differently named plants? They are accepted by the RHS as different plants, ‘Pauline’ and ‘Pink Chablis’, but at several points last year both plants looked identical. The flowers seem to have stronger or weaker flower colours depending if they are grown in sunny or partly shaded positions, and colours seem to weaken as the flowering period comes to an end. Of course, there are many other differences and variations which characterise specific plants, not just flower colour, but these are often very subtle indeed!

A former Tradescantia National Collection Holder, Hazel Kaye, recently told me that she purchased a Tradescantia Andersoniana Group plant named ‘Bridesmaid’ at a plant sale in Leicester and believed she may have found something new. It turned out to be a self sown seedling from a local garden which the owner had named herself and which had not been trialled or tested before offering it for sale. It was a poor selection and not worth pursuing.

Tradescantia ozarkana – a species widely distributed in Missouri, Arkansas, and Oklahoma, USA

I am indebted to the Botany Advisory Services of the RHS who kindly allowed me to quote from their leaflet ‘Guide to Plant Names‘.

“Although the ideal is for each species or cultivar to have only one name, anyone dealing with plants soon comes across a situation where one plant has received two or more names, or two plants have received the same name. In each case, only one name and application, for reasons of precision and stability, can be regarded as correct. Additional names are known as synonyms.

In the past, and in the nineteenth century in particular, when a huge amount of botanical exploration was taking place, it was possible for botanists to be beavering away describing and naming plants in different parts of the world, blissfully unaware that they were duplicating someone else’s work. This is perhaps difficult to understand in these days of instant global communication, but it led to many cases of a single species with two or more names, or two or more species with the same name. The simplest way to resolve the problem of duplicated and superfluous names is to invoke a rule of priority – the earliest name correctly published wins and new names are therefore needed for some plants with later, incorrect names.

This is a basically sound idea but has led to changes of some very familiar, yet incorrect names due to the discovery of earlier, correct ones in very obscure texts. This can have a destabilising effect, contrary to the intention of the rule of priority, so there is now a much more pragmatic view being taken, with some of the more destabilising proposed name changes vetted by an international panel and often rejected if the technically wrong name is widely known. For example, the popular heather, Erica carnea, was saved in this way from being changed to Erica herbacea.

Cultivars acquire extra names in similar ways to wild plants and also through the deliberate re-naming when the original name is felt not to promote good sales! The same principle of priority applies for cultivars as for wild plants so there are always cases where correction is needed. However, it is not always appropriate to provide a new, unique name for a cultivar which has been given the same name as an existing plant. Where there are large groups of cultivars, such as in the genera Fuchsia and Pelargonium, repetition of cultivar names has proved difficult to avoid. In these cases, names can be qualified with the name of the breeder, the date of introduction or the plant type to help pinpoint their identity.

In the case of wild plants, correct identification and naming relies on knowing what species exist and how they are related. Add to this the increasingly reliable evidence of evolutionary trends provided by DNA and molecular studies and the fact that, for better or worse, the naming system aims to reflect the classification and therefore relationships, and it can be seen that some changes are inevitable….genera being split, new ones created, others amalgamated.”

This is a major source of irritation for National Plant Collection Holders as I have already said. In the main picture above, Tradescantia (Andersoniana Group) ‘Carmine Glow’ is the same plant as ‘Karminglut’ (which means Carmine Glow in German) and is recorded as such on the RHS database. However, I have discovered sellers who offer both as distinctive plants.

Likewise, Tradescantia (Andersoniana Group) ‘Sweet Kate’ (above) is a popular variety for sale in the UK due to it’s distinctive yellow foliage and mauve flowers. However, in the United States, I have discovered a virtually identical variety for sale on the internet called ‘Charlotte’s Web’. It remains to be seen if this is indeed the same plant but the images I have observed would suggest so.

As my Tradescantia journey progresses, I will no doubt be discovering many more instances of the same cultivar with different names and my collection will require constant scrutiny to weed out the synonyms.

Pots & Supports

Apart from the plants themselves, the biggest expense so far has been the pots and the supports, but I considered this a one-off cost and was happy to indulge myself by purchasing the best I could find and afford. As it turned out, the best pots were found on Ebay sold buy Oakland Gardens in Kings Lynn, Norfolk. I decided that heavy duty 20 litre rigid black plastic pots were the most suitable and found them for £3.50 each with free postage and packing. As it turned out, the packaging didn’t account for the way they would be thrown about and damaged by the courier but, all credit to Oakland Gardens, they agreed to replace the broken ones immediately.

They must have been thrown about quite violently because these Aeroplas pots are very well made and unlikely to be damaged simply by a bit of rough handling. Of course, the idea was always to sink them up to their rim in raised beds so they had to be able to withstand the sideways pressure without buckling and be strong enough not to split, should the Tradescantias become pot bound and apply pressure from the inside as Agapanthus do.

So why 20 litres? Why not 10 litres or 35 litres? Well, it was partly down to cost and space, but as I would be splitting them regularly, at least every other year, it seemed to make sense not to go too big. Tradescantias are clumpers, producing more and more thick fleshy roots every year and gradually spreading sideways. I felt I had to give them plenty of growing room and enough growing media to satisfy their water and nutrient requirements, but also contain them and keep their roots in one place and under control.

As you can see from the picture of ‘Purewell Giant’ at the top of this page, some of the Tradescantias get quite tall, but without the company of other neighbouring plants they also tend to droop and fall over, often snapping their stems in the process. Plant supports are essential for the taller varieties and I have chosen these simple ‘Grow Through’ 6mm untreated mild steel ones from Plant Supports of Tenbury Wells in Worcestershire. They are 37cm diameter which is wide enough to span the 20 litre pots, and 57cm high on four sturdy legs pushed into the ground which can be raised as the plant grows taller. I purchased 10 for £63.77 including VAT & delivery. That may sound expensive but they will last a lifetime. They are also much more purposeful and attractive than sticks and string!

And, in case anyone is wondering about the mulch, it is chopped up mineralised straw called Strulch. It prevents weeds germinating, keeps the soil or compost moist by reducing dehydration, discourages slugs and snails who don’t like slithering on it, and dresses the soil surface attractively. Lasts for about 2 years, gets absorbed by soil and provides organic content, doesn’t blow about (surprisingly!) and is recommended by the RHS and all good gardens.

Welcome!

Welcome to this website all about Tradescantia virginiana and the Tradescantia Andersoniana Group.

I hope you find the information I provide useful, the photographs inspirational, and the journey interesting. As the newly accredited National Plant Collection Holder, I am on a mission to collect all known cultivars of hardy Tradescantia listed in the RHS Plant Finder over the last 20 years or so, many of which are no longer cultivated by plant nurseries and may prove difficult to find. However, they may still be available from small independent nurseries who do not list plants in Plant Finder, or fellow gardeners who bought plants many years ago and may not realise those particular cultivars are now threatened and could be lost forever.

As well as playing my part in helping to preserve the plants for future generations to enjoy, I will also revel in the detective work, the research and the joy of sharing all this with other interested gardeners. I hope you enjoy it too.

David Simpson

How it all began

The Missing Genera campaign began in 2016 and every year since, Plant Heritage has highlighted ten different varieties of plant not currently represented in a National Plant Collection.

Vicki Cooke, Conservation Manager at Plant Heritage explained: “The idea of the Missing Genera campaign is to showcase some of the many types of garden plant we have in the UK that don’t have a National Plant Collection to look after them. Anyone can help by starting their own National Plant Collection of one of the types listed this year, which they can care for, grow and ultimately help to conserve for future generations to enjoy.”

In July 2020, just as the UK was slowly emerging from a national lockdown caused by the Coronavirus pandemic, Plant Heritage published the list for that year: ArisaemaAubrietaBerberisDaphneElaeagnusGauraHoyaPapaver,  Robinia and Tradescantia.

Tradescantia ohiensis

To be honest, I only had a passing interest in Tradescantia. It was not a genus I had developed any passion for, either in the garden or as houseplants. However, I had recently decided to redevelop my fruit and vegetable garden with ornamentals of some kind and the appeal to start a National Collection struck a chord. When I delved a bit further into the genus, it was clear that the species originating in the mid-west of North America, the winter-hardy species, were easy to grow and propagate with little specialist care required for their wellbeing. So easy, in fact, that they are considered to be an invasive weed in many States and difficult to eradicate!

Desk research on the internet revealed a fascinating history and an extensive range of species and cultivars, cultivation notes and warnings about prolific seeding and spreading habits but, on the whole, it was a genera that interested me and sparked my curiosity. Could I really build up a National Collection? Could I seek out all known cultivars in the UK? At 70, was I too old to begin the task and who would take it on if I became ill or worse?

My fears were unfounded. Initial discussions with the wonderful team of plant conservationists at Plant Heritage HQ in Guildford, and my local Gloucestershire Group committee emboldened me and I took the plunge!

What follows is my account of how I went about building the Collection, the process of becoming accredited and the responsibilities that come with it. It will also document detailed descriptions of each plant in the Collection and as much useful information as I can offer anyone thinking of either growing Tradescantias for pleasure or taking on a National Collection of their own.