(245–248) Proposals regarding rank‐denoting terms (Articles 6, 21, 24 and 32)

Abstract

Presumably, all professional botanists are familiar with the four different categories of names – names of new taxa, new combinations, names at new rank, and replacement names. However, many might be surprised to learn the Shenzhen Code (Turland & al. in Regnum Veg. 159. 2018) added a fifth kind of name. Article 6 Note 5 states “A new combination can at the same time be a name at new rank (comb. & stat. nov.); a nomenclatural novelty with a basionym need not be either of these.” Example 13 illustrates this point: “Centaurea jacea subsp. weldeniana (Rchb.) Greuter, […] based on C. weldeniana Rchb. […], was not a new combination because C. jacea var. weldeniana (Rchb.) Briq. […] had been published previously; nor was it a name at new rank, due to the existence of C. amara subsp. weldeniana (Rchb.) Kušan […]; it was nevertheless a nomenclatural novelty.” Surprisingly, no provision in the Shenzhen Code addresses how to publish these names. One might assume that Art. 41 would apply, but that applies to new combinations, names at new ranks and replacement names; Art. 6 Note 5 makes clear that these names are none of those. Similarly, no provision in Art. 7 tells us the type of a name described in Art. 6 Note 5. Article 49 provides the correct author citation because it covers names with a basionym. It is unclear how a Note, which is described as a clarification of an Article in the Preface of the Shenzhen Code, can create a new fifth kind of name. Finally, and most important, the very notion that a name other than a new combination or name at a new rank has a basionym is inconsistent with Art. 6.10, which in effect defines a basionym as the legitimate earlier name upon which a later new combination or name at a new rank is based. One could solve these problems by converting Note 5 into an Article, and further state that names covered by this new Article are treated as new combinations or names at new ranks for purposes of Art. 7 and 41 (and perhaps other Articles) even though they are not new combinations or names at new ranks. Apart from that statement seeming rather incredible, why are these names not new combinations or names at new ranks? Nothing in Art. 6 provides an explanation. The presumable rationale for Art. 6 Ex. 13 is set forth in Art. 24. Article 24.1 states “The name of an infraspecific taxon is a combination of the name of a species and an infraspecific epithet. A connecting term is used to denote the rank.” In turn, Art. 24 Note 2 (which appears after Art. 24.4, not Art. 24.1) clarifies that “Names of infraspecific taxa within the same species, even if they differ in rank, are homonyms if they have the same final epithet but are based on different types (Art. 53.3), because the rank-denoting term is not part of the name.” [Emphasis added.] Similar language appears in Art. 21 Note 1 pertaining to names of subdivisions of the same genus. However, the emphasized language does not appear in Art. 53.3. It therefore appears that this emphasized language adds a new rule, as opposed to clarifying a rule. This raises a question as to whether the Note should be converted into an Article, or the emphasized language should be deleted. In our view, the statement that the rank-denoting term is not part of the name makes little sense. For example, the rank-denoting term is not ignored for purposes of determining priority – see Art. 11 Ex. 3. If the rank-denoting term is ignored, it would seem appropriate to treat C. jacea subsp. weldeniana (Rchb.) Greuter and C. jacea var. weldeniana (Rchb.) Briq. as isonyms. After all, Art. 53.3 provides they would be homonyms if based on different types. The two names fit the definition of isonym (the same name based on the same type) perfectly if the rank-denoting term is ignored. As isonyms, the latter of the two names has no nomenclatural status under Art. 6 Note 2. The rationale of Art. 53.3 is best explained by Art. 53.2, which provides that two names based on different types are homonyms if they “are so similar that they are likely to be confused”. Similarly, permitting two identical names, except for their infraspecific rank, to be legitimate if they are based on different types would be immensely confusing. In contrast, there is little confusion if two names are spelled the same, except for their infraspecific rank, and are based on the same type. This should make it clear that the rationale behind Art. 53.3 is not that the rank-denoting term is not part of the name, as expressed in Art. 24 Note 2. Based on the comments above, we present the necessary changes as follows. “Note 5. A new combination can at the same time be a name at new rank (comb. & stat. nov.); a nomenclatural novelty with a basionym need not be either of these.” “ Ex. 13. Centaurea jacea subsp. weldeniana (Rchb.) Greuter, “comb. in stat. nov.” (in Willdenowia 33: 55. 2003), based on C. weldeniana Rchb. (Fl. Germ. Excurs.: 213. 1831), was not a new combination because C. jacea var. weldeniana (Rchb.) Briq. (Monogr. Centaurées Alpes Marit.: 69. 1902) had been published previously; nor was it a name at new rank, due to the existence of C. amara subsp. weldeniana (Rchb.) Kušan (in Prir. Istraž. Kral. Jugoslavije 20: 29. 1936); it was nevertheless a nomenclatural novelty.” “Note 1. Names of subdivisions of the same genus, even if they differ in rank, are homonyms if they have the same epithet but are based on different types (Art. 53.3), because the rank-denoting term is not part of the name.” “Note 2. Names of infraspecific taxa within the same species, even if they differ in rank, are homonyms if they have the same final epithet but are based on different types (Art. 53.3), because the rank-denoting term is not part of the name.” Article 32 Note 1 states “The use of typographical signs, numerals, or letters of a non-Latin alphabet in the arrangement of taxa (such as Greek letters α, β, γ, etc. in the arrangement of varieties under a species) does not prevent valid publication because rank-denoting terms and devices are not part of the name.” It is also desirable to delete the statement about rank-denoting terms here. Article 32.1(b) states that a name must “be composed only of letters of the Latin alphabet, except as provided in Art. 23.3, 60.4, 60.7, and 60.11–14”. The statement in Art. 32 Note 1 provides an exception that is more appropriately stated in an Article. “32.1. In order to be validly published, a name of a taxon (autonyms excepted) must: (a) be effectively published (Art. 29–31) on or after the starting-point date of the respective group (Art. 13.1 and F.1.1); (b) be composed only of letters of the Latin alphabet, except as provided in Art. 23.3, 60.4, 60.7, and 60.11–14; and (c) have a form that complies with the provisions of Art. 16–27 (but see Art. 21.4 and 24.4) and Art. H.6 and H.7 (see also Art. 61). The However, the use of typographical signs, numerals, or letters of a non-Latin alphabet in the arrangement of taxa (such as Greek letters α, β, γ, etc. in the arrangement of varieties under a species) does not prevent valid publication because rank-denoting terms and devices are not part of the name.” We thank Nicholas J. Turland and John H. Wiersema for their helpful revisions and comments.