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Plant Focus

The Compton oak at Colonial Williamsburg
A natural hybrid between Quercus lyrata (overcup oak) and Q. virginiana (Southern live oak)

Remembering Piers Trehane

Last March marked the 10 years since the death of Piers Trehane. It seemed a good opportunity to remember him and his contribution to the IOS, especially the Oak Names Checklist, one of the Society’s most significant achievements. A member of the IOS since its inaugural meeting in 1994, Piers was for many years the International Cultivation Registration Authority (ICRA) registrar of oaks for the Society. As part of this task he created a website that would contain all registered names for oak cultivars. Then the project was expanded to include the names, synonyms, distributions and main horticultural references of all accepted oak taxa (see his 2007 article in Oak News & Notes for further detail.) He carried out this monumental task almost single handedly, creating a resource that contributes greatly to the knowledge of oaks and the recognition of the IOS as oak registration authority in the scientific world. His work was by no means restricted to Quercus. He made significant contributions to both the cultivated code (International Code of Nomenclature for Cultivated Plants) and the botanical code (International Code of Nomenclature for algae, fungi, and plants). And he was actively involved in the naming of conifers, hostas, and water lilies, among other groups of plants.

Allen Coombes and James MacEwen have kindly contributed their remembrances of Piers, which you can read below. Scroll further down for other tributes written at the time and links to publications that serve to paint a picture of this remarkable man and his outstanding legacy.

If my memory serves me correctly I first encountered Piers at the NCCPG conference in Leeds in 1989. We sat together on the train back to London and he gave me a copy of his recently published Index Hortensis that meticulously documented the correct names and synonymy of all the herbaceous perennials he had found in cultivation. He was already talking about moving on to woody plants. A connection was obviously established during that trip as we remained friends from that day.

Our shared interest was cultivated plant nomenclature and taxonomy and we would have many discussions on that subject over the years, both of us serving as members of HORTAX, the Horticultural Taxonomy Group. I particularly remember the animated discussions, both face to face and in print, we had over how the Cultivar Group should be applied.

When I moved on to oaks I persuaded him to become the International Registrar for the genus. This inspired him to develop the database still in use today, oaknames.org, where the International Oak Society documents oak species and cultivars. We had frequent discussions by email and Skype during this time about this database while he was putting it together. He would often visit me at home, where I would cook a meal for him or at work when I was at the Sir Harold Hillier Gardens. For several years we would often meet once or twice a year for long weekends at Chevithorne Barton.

Piers was very much a names man, but it was always a pleasure to take him out to see some plants and after the International Oak Society Conference in Mexico in 2009 we took him to see Quercus sebifera and other oaks in Puebla. When he visited Hillier Gardens he would park his car close to my office close to an interesting oak tree and we would usually end up with a short walk to see a few plants. The oak was grown as Quercus hypoleucoides but was obviously not that and I determined it to be a hybrid with Q. emoryi. Later I suggested this oak be named after him and we now have Quercus ‘Piers Trehane’.

The last message I had from him was about a month before he passed away. We were discussing a book I was working on at the time, The A-Z of Plant Names. I was very happy to dedicate this book to him but sorry that he did not get to see a copy, I like to think he would have enjoyed it.

Allen Coombes

Piers Trehane and Eike Jablonski
Piers Trehane (left) and Eike Jablonski wearing the 1st IOS Conference T-shirt (Luxembourg, August 2008) © Eike Jablonski

I was very lucky to have known Piers Trehane, I was introduced to him by Dr Chris Humphries at The Linnean Society. Chris was one of the founders of the Willi Hennig Society that promoted the study of phylogenetic systematics. Piers and Chris had conversations at which I was simply a bystander, but they seemed  to return to their corners with mutual respect.

Piers became a close friend, but I suspect he was that to everybody he came to know. He gave to his friends and his community at Wimborne in a giant way, sometimes exhausting himself in the process. At his funeral the church was flooded by people from every walk of life.

He came to Chevithorne Barton for oak weekends and was a very special guest. He then became involved in our attempt to create the book Oaks of Chevithorne Barton. This had originated as an intended pamphlet and then was extended to be a book. Piers made an enormous contribution towards it not only as the taxonomic editor but also in correcting the English editor's English, Michael Heathcoat Amory's English, mine—and even Allen Coombes's English!

Piers was involved with so many elements of his local community that sometimes he would need a time out and would not be contactable for months at a time. Suddenly I would receive a call at three in the morning from Piers wanting to discuss a photograph or nomenclature of a particular species. We only had limited space in the design of the book to put all the names of the people who had described the species, on the odd occasion only two names could be included Piers would accept this, but after an hour or so on the telephone might think it was worthy of another conversation at three the following night.

I have the privilege of curating the National Oak Collection at Chevithorne Barton and every time I walk in the garden past Quercus 'Piers Trehane' it reminds me of a person I will always think of with love and affection.

Quercus Piers Trehane
Quercus 'Piers Trehane' in winter plumage at Chevithorne Barton (March 2021). It is much denser in summer clothes.

James MacEwen


You can read an account of Piers's life and work in Alan Leslie’s obituary published in Hanburyana, available here. A note in Horticulture Week (June 2011) included these other tributes from colleagues:

The Plant Review (formerly The Plantsman) editor Mike Grant wrote: "I didn’t know him for very long (since 1995, when I started working for the RHS; I was based at Wisley as a Botanist for nine years), and I only used to see him occasionally (about once a year on average). But I always enjoyed his company as he was always so good-humoured and jolly. He seemed to have a formidable intellect which only seemed to be running in second gear for most of the time. And he was always very encouraging to younger persons like me in the field of horticultural taxonomy.

"He made great progress in trying to get an International Society for Horticultural Taxonomy off the ground. I remember how excited we all were at the Third International Symposium on the Taxonomy of Cultivated Plants (Edinburgh, 1998) when he first tried to launch the society, although it fizzled out, and others tried to revive it in later years. And while it lasted, Hortax News (which he edited) was a unique publication that filled a gap for workers in the field. People are still trying to get such a society off the ground and he did a lot of the consciousness raising, without which we wouldn’t be where we are now. And he was also a lynchpin for the various codes of nomenclature (botanical and cultivated) that he was co-author of, but I know less about that side of his work. But I remember being impressed when he said he had studied the naming of thoroughbred racehorses to inform his opinions on plant naming! And I believe he was involved in a cattle breeding network, but I never got to hear much about that.

"And his Index Hortensis book was an amazing achievement of cultivar name aggregation that was probably the main source for horticultural taxonomists for many years. And I know it was used heavily by Tony Lord in the early days of the Plant Finder, so you could say it formed the backbone of the PF.

"I know Piers had his frustrating sides, basically for anyone trying to get stuff out of him for deadlines, but he was one of those people who was never going to fit into the organised ‘corporate’ way of working that most of us are slaves to, and I always admire people like that. And he seemed to have an amazing ability to lose vast quantities of work in ongoing sequences of computer disasters!

"My last contact with him was when I asked him to review a book (Cotoneasters by Jeanette Fryer) for The Plantsman. I eventually published it in the Dec 2009 issue, but it took months to get the 300 words out of him, mainly due to some problem with his email (he told me!).

"It’s a great pity that such an engaging and free spirit has been lost to us." 

Jozef Van Assche, executive director of the International Society for Horticultural Science: "Piers was a good friend of the International Society for Horticultural Science. In his capacity as Chair of the ISHS Commission Nomenclature and Cultivar Registration he served the ISHS for the period 2001–2003 extremely well.

"As rapporteur of the Commission for the International Code of Nomenclature for Cultivated Plants, and the consequent publication of this master piece, Piers assisted in the creation of a work of reference for many generations of taxonomists to come.

"We will remember Piers as a great scientist and excellent botanist, inspiring many of us with his love for plants and nature."

An illuminating account of his work assisting in the nomenclature of Nymphaea is available here.