Is Coprosma grandifolia the scientific name for kanono, the largest-leaved Coprosma in New Zealand?

Is Coprosma grandifolia the scientific name for kanono, the largest-leaved Coprosma in New Zealand?

Curator of Botany Leon Perrie discusses some of the rules governing scientific names, and explains why we can continue using the name Coprosma grandifolia – at least for now.

A fundamental aspect of scientific names for biological species is that they have two principal parts. The first or generic part names the Genus to which a species belongs.

The second or specific part denotes the particular species. Examples include Homo sapiens (humans), Coprosma robusta (karamū), Coprosma repens (taupata), and Coprosma propinqua (mingimingi).

Three photos of green shrubs, the one on the left also has orange berries
Despite their different superficial appearances, these three species are all fairly closely related. This is indicated by details like their flowers, fruits, and branching, as well as DNA analyses of their relationship. All are placed in the genus Coprosma, of which there are 57 species in New Zealand.
(Left) karamū (Coprosma robusta), (middle) taupata (C. repens). CC0 1.0. Photos by John Barkla via iNaturalist. (Right) mingimingi (C. propinqua). CC BY 4.0. Photo by Leon Perrie via iNaturalist

The rules

Scientific names are governed by a strict set of rules. For plants, it is the International Code of Nomenclature for algae, fungi, and plants. One of the most important rules for scientific names is that a species can have only one accepted scientific name.

While there might be taxonomic debates about the genus in which to classify a species, the second part of the name is dictated by the principle of priority.

That is, when multiple specific names (i.e. the second part of a scientific name combination) have been applied to a particular species, whichever was first legitimately published is the one to be used.

This idea of priority is unambiguous – whatever name is first is the ‘winner’. But it can be a pain. For instance, trawling through ancient texts or changes in the circumscription of a species may result in a little or never used name being found to have precedence over a well-established name.

Not only does that mean learning a new name, but identification books, garden labels, and other resources become out-of-date. To deal with such disruptive cases, the International Code of Nomenclature for algae, fungi, and plants contains a mechanism – called conservation – to override priority.

Bending the rules

Three leading custodians for the rules for naming recently wrote:

“Successive Nomenclature Sections have made it quite clear that indulging in name changes for purely nomenclatural reasons is now reprehensible unless new conservation/rejection avenues have been explored.” (reference 1)

This statement really struck me. From my interactions with botanical societies and online plant groups, I know that many users of scientific names dislike changes!

My reading of the above statement is that taxonomists should be delving into the nomenclatural tool-box to stabilise scientific names whenever possible. After all, who wants to be reprehensible?!

What of Coprosma grandifolia?

The largest-leaved Coprosma in New Zealand is one of our most commonly-encountered indigenous plants (among the top 1% as judged by iNaturalist observations). Among many te reo Māori names, perhaps kanono and manono are the most commonly used.

A close up photo of green leaves with orange berries
Coprosma grandifolia, or should it be Coprosma autumnalis? It is the largest-leaved Coprosma in New Zealand, and often known as kanono. It is endemic to Aotearoa, being indigenous to the North Island and northern South Island, where it can be common in warmer forests. Human-mediated spread has seen it establish in the southern South Island, where it is regarded as a weed in places. 
Coprosma grandifolia. CC0 1.0. Photo by John Barkla via iNaturalist

In recent times, the especially-apt scientific name Coprosma grandifolia has been applied to this species. That was published by Joseph Hooker in 1852, and was in widespread use by New Zealand botanists during the early part of the 20th century.

The middle of the 20th century saw a mistaken switch to Coprosma australis (which actually applies to a different species), before reversion in 1987 to Coprosma grandifolia. The latter name again became pretty much universally adopted.

Brown leaves on a twig branch pressed on cream card with official notes and stamps
Joseph Hooker based his name Coprosma grandifolia on specimens like these, collected by Joseph Banks and Daniel Solander in 1769-1770 during James Cook’s Endeavour expedition. 
Kanono, Coprosma grandifolia Hook.f., collected 15 January 1770, “prope Totaranui” [Marlborough Sounds, Queen Charlotte Sound], New Zealand. CC BY 4.0. Te Papa (SP063859/A)
However, others (reference 2) recently noted that Joseph Hooker made a technical error (at least as judged by today’s scientific naming rules).

Consequently, his name Coprosma grandifolia was not legitimately published. In that case, the earliest legitimately published name is Coprosma autumnalis, by William Colenso in 1887.

A potential fix

On learning of this, I thought it could be a good case for using the nomenclatural tool-box to conserve the name Coprosma grandifolia as the correct scientific name for this species. This would maintain prevailing usage, and avoid the disruption of a name change for one of New Zealand’s most common native plants.

After all, Joseph Hooker’s error hadn’t been noticed for over 160 years, and William Colenso’s Coprosma autumnalis had never been previously used in modern times.

I have written a paper making the formal case for conserving the name Coprosma grandifolia. It is freely available here: ‘Proposal to conserve the name Coprosma grandifolia (Rubiaceae) with a conserved type’. It contains more details of who did what, and when.

What happens now?

A committee of international experts on the rules of naming plants will vote to accept or reject the proposal within the next few years (with a 60% majority required for a binding decision). I’ll be interested to see on what side of the “reprehensible” line they decide this case falls.

If they accept the proposal, the name Coprosma grandifolia will be locked in for kanono.

If they vote to reject, then Coprosma autumnalis will be the correct scientific name for this species.

In the meantime, you can continue using Coprosma grandifolia, knowing that a decision is pending.

If you had a vote, which name would you choose?

References

(1) McNeill J, Redhead SA, Wiersema JH. 2015. Guidelines for proposals to conserve or reject names. Taxon 64: 163-166.

(2) Large MF, Mabberley DJ, Wood E. 2020. Coprosma autumnalis (kanono; Rubiaceae) in New Zealand: nomenclature, iconography and phenology. Kew Bulletin 75: 37. DOI 10.1007/S12225-020-9876-4.

7 Comments

  1. I vote for coprosma grandifolia. There is no problem currently with c.grandifolia, it is not close to another name leading to confusion between species, it is not based on a mistaken description (it has the biggest leaf of the coprosmas). The whole thing has more than a whiff of ego and self indulgence. The fact that Wikipedia and NZ Plant Network have been changed is particularly annoying. Wikipedia is understandable, but the NZ Plant Conservation Network claims to be grounded in science, and it has ignored the correct process for considering formal scientific name changes … to engage in some cheap point scoring.

  2. I see those who have argued for a change have had the New Zealand Plant Conservation Network and Wikipedia make the change already. This seems like really poor manipulation of online sources, to influence the public before the appropriate process through the naming convention body has occurred. Given it is scientists arguing for a change from c.grandifolia to c.autumnalis, the fact they and their supporters are changing websites before the matter has been considered properly, is definitely a case of “bending the rules” and reflects a degree of arrogance. Go through the process and stop trying to manipulate public perception by fiddling with Wikipedia and other sites.

  3. Kia ora Peter,
    It’s not that I’m concerned about the Principle of Priority; rather, it is much more that the recommendation of McNeill et al. resonates with me: “indulging in name changes for purely nomenclatural reasons is now reprehensible unless new conservation/rejection avenues have been explored”.
    Scientific names change for many reasons, importantly including when the scientifically-testable understanding of relationships changes. But McNeill et al. seem to be saying that scientific names do not necessarily need to change merely for nomenclatural reasons. I believe this accords with the best interests of general users of scientific names, who seem to generally prefer lower rates of change in scientific names where possible.
    There is little “creative” in what I’ve done; rather, I’ve simply followed McNeill et al.’s recommendation for best practice taxonomy/nomenclature; i.e., the need to change a scientific name for nomenclatural reasons was identified, so I’ve offered a conservation proposal that would mean that change wasn’t required.
    It may be that the committee votes to reject my proposal. That would then seem to be a repudiation of McNeill et al., but so be it – we’ll learn from it. In any case, at least the possibility of name stability would have been explored on behalf of the general users of New Zealand scientific plant names.
    While I like McNeill et al.’s recommendation, I understand that not everyone does – why, for instance, do you disagree with them?

    The zero-sum-game of the Acacia situation seems fundamentally different to me.

    As for Hall’s tōtara, that was before I felt able/compelled to speak on such matters. But if it had been me doing it, and with my present understanding, I would have sought a different outcome. Three scientific names in such a short time did no reputational favours for botanical taxonomy in New Zealand.

  4. Your fix is an interesting alternative but I wonder why the Principle of Priority seems to be so concerning to you? Here the application of the name Coprosma grandifolia Hook.f. is clearly linked to another type and species. Hooker got it wrong. Colenso’s equally “apt” Coprosma autumnalis Colenso – apt because this is an excellent epithet reflecting that this is New Zealand’s only autumn flowering Coprosma, has an unambiguous type that makes clear what he meant and so the name can be applied with confidence. This seems more logical to me, then to try and argue a way around this in a creative fashion. Just such an idea was attempted by Nicholas Turland when he tried a fictitious story to sort out the problem of the type of Acacia in 2011 and that idea was rightly thrown out by the Botanical Congress of the Nomenclature Sessions – not a subset of that, the specialist group either. It also makes me wonder, why if you regard this Coprosma name change as so damaging you haven’t then for consistencies case proposed a case to conserve Podocarpus hallii Kirk against the earlier names P. cunninghamii Colenso and P. laetus Hooibr. ex Endl.? This name change did annoy people here but a case for conservation has never been made. The rules of the code make sense, conserving a name is one option, and that makes sense to me if the types are correctly applied to the same taxon but not if they are applied to another species altogether. I think Mark Large and David Mabberly made the right decision.

  5. I vote Coprosma grandifolia

  6. Most interesting. Thanks Leon.
    Coprosma kanono perhaps?

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