Thursday, February 5, 2015

What's In A Name?

Written by Mr John Carter
Iris pseudacorus pallidoflora "Rowden Brimstone" Iris pseudacorus pallidoflora "Rowden Brimstone"

A little over a year ago a charming horticultural journalist called Ambra Edwards asked to write an article about our National Collection of Water Irises. It was to appear in the prestigious magazine Gardens Illustrated in the July of 2014.

We awaited the article's appearance with bated breath and after a bit of a wobble with ordering a copy - the July copies of magazines coming out in the previous month, consequently having ordered in July we initially got the August edition. Having finally got the right magazine, we opened it with much excitement. You will understand our consternation to find that out of the blue, the name of one of our own cultivars which we have called and registered as Iris pseudacorus "Rowden Brimstone" had been labelled Iris pseudacorus pallidoflora "Rowden Brimstone".

Naturally when one of one's children has their name wrongly used, we wrathfully prepare to expostulate to the editor. In the meantime I had discovered that Dr James Compton, an old friend and son of our first National President, was on the Board of the magazine. Rather furiously I pointed out to the editor that they had a top notch taxonomic authority at their fingertips and so there was no reason for them to have got the name wrong. Patiently the editor replied that it was James who had changed the name! Next stop James.

It transpired that not only our "Brimstone" was affected but the epithet "pallidoflora" was to apply to ALL pale yellow pseudacorus plants and so var bastardii would have to disappear as a name as well. James has generously sent me a full explanation which I paraphrase below.

First of all in the Linnaean system for naming variation within a species, there are three main categories. The first of these is a "sub-species" which refers to a consistent variation almost entirely based on geographical distribution. The second is a "variety". This is usually identified as having a smaller variation from the type and is found within populations of the type species. Thirdly there is a "form" which is usually a single character of variation and is often no more than an alternative for "variety".

You will be thrilled to know that whilst there are many rules as to how these things are to be applied there are really only two that affect the matter in hand. These are that to start with the Latin name applied to any of the three categories above is only valid at that rank and secondly the earliest given name is the right one.

As far as Iris pseudacorus is concerned, the first person to see that there are pale yellow flowered "variations" was one John Sims, who was editor of Curtis's Botanical Magazine in 1820! He chose to recognise this in the rank of variety under the name of pallidoflora.

It was not until 1857 that a Frenchman, Alexandre Boreau, elected to recognise a pale flowered Iris as a separate species which he named after a friend Toussaint Bastard. Though this name was validly published under the rules it is illegitimate as it refers to Iris pseudacorus itself which had been previously described by Linnaeas himself! ( I note with some amusement that the epithet "bastardii" is to be considered illegitimate). However it may be possible to retain the widely used name of bastardii in the rank of a "form" which James is going to do. This will save a lot of confusion, particularly for gardeners using the Plant Finder and nurserymen too.

I myself remain a trifle confused as the present International rules appear to be unable to differentiate between the genetic make up of a plant (genotype) and what it looks like (phenotype) though in the case of these variations in Iris pseudacorus this is nicely slid around by using "pallidoflora" as a catchall.

I do hope this will give you all something to worry about in 2015. In the meanwhile the Persicaria virginiana "Compton's Form" which James thoughtfully brought to us from China, continues to flourish here at Rowden.


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