Article 6

6.1. Effective publication is publication in accordance with Art. 2931. Except in specified cases (Art. 8.1, 9.4(a), 9.22, Rec. 9A.3, and Art. 40.7), text and illustrations1 must be effectively published to be taken into account for the purposes of this Code.

[footnote]1 Here and elsewhere in this Code, the term “illustration” designates a work of art or a photograph depicting a feature or features of an organism, e.g. a drawing, a picture of a herbarium specimen, or a scanning electron micrograph.

6.2. Valid publication of names is publication in accordance with the relevant provisions of Art. 3245, F.4, F.5.1, F.5.2, and H.9 (see also Art. 61).

Note 1. For nomenclatural purposes, valid publication creates a name, and sometimes also an autonym (Art. 22.1 and 26.1), but does not itself imply any taxonomic circumscription beyond inclusion of the type of the name (Art. 7.1).

6.3. In this Code, unless otherwise indicated, the word “name” means a name that has been validly published, whether it is legitimate or illegitimate (see Art. 12; but see Art. 14.9 and 14.14).

Note 2. When the same name, based on the same type, has been published independently at different times, perhaps by different authors, then only the earliest of these “isonyms” has nomenclatural status. The name is always to be cited from its original place of valid publication, and later isonyms may be disregarded (but see Art. 14.14).

Ex. 1. Baker (Summary New Ferns: 9. 1892) and Christensen (Index Filic.: 44. 1905) independently published the name Alsophila kalbreyeri as a replacement for A. podophylla Baker (in J. Bot. 19: 202. 1881) non Hook. (in Hooker’s J. Bot. Kew Gard. Misc. 9: 334. 1857). As published by Christensen, A. kalbreyeri is a later isonym of A. kalbreyeri Baker without nomenclatural status (see also Art. 41 Ex. 24).

Ex. 2. In publishing “Canarium pimela Leenh. nom. nov.”, Leenhouts (in Blumea 9: 406. 1959) re-used the illegitimate C. pimela K. D. Koenig (in Ann. Bot. (König & Sims) 1: 361. 1805), attributing it to himself and basing it on the same type. He thereby created a later isonym without nomenclatural status.

Ex. 3. The name Dalbergia brownei (Jacq.) Schinz (in Bull. Herb. Boissier 6: 731. 1898) was nomenclaturally superfluous when published because Schinz cited the legitimate name Hedysarum ecastaphyllum L. (Syst. Nat., ed. 10: 1169. 1759) as a synonym. Because D. brownei has a basionym (Amerimnon brownei Jacq.), it is nevertheless legitimate (Art. 52.4). On excluding H. ecastaphyllum, Urban (Symb. Antill. 4: 295. 1905) published “D. Brownei Urb.” as a replacement name. This is a later isonym that has no nomenclatural status.

6.4. An illegitimate name is one that is designated as such in Art. 18.3, 19.6, 5254, F.3.3, or F.6.1 (see also Art. 21 Note 1 and Art. 24 Note 2). A name that according to this Code was illegitimate when published cannot become legitimate later unless Art. 18.3 or 19.6 so provide; unless it is conserved (Art. 14), protected (Art. F.2), or sanctioned (Art. F.3); or unless the name is superfluous under Art. 52 and its intended basionym is conserved or protected.

Ex. 4. Skeletonemopsis P. A. Sims (in Diatom Res. 9: 389. 1995) was illegitimate when published because it included the original type of Skeletonema Grev. (in Trans. Microscop. Soc. London, n.s., 13: 43. 1865). When Skeletonema was conserved with a different type, Skeletonemopsis nevertheless remained illegitimate and had to be conserved in order to be available for use (see App. III).

6.5. A legitimate name is one that is in accordance with the rules, i.e. one that is not illegitimate as defined in Art. 6.4.

6.6. At the rank of family or below, the correct name of a taxon with a particular circumscription, position, and rank is the legitimate name that must be adopted for it under the rules (see Art. 11).

Ex. 5. The generic name Vexillifera Ducke (in Arch. Jard. Bot. Rio de Janeiro 3: 140. 1922), based on the single species V. micranthera Ducke, is legitimate. The same is true of the generic name Dussia Krug & Urb. ex Taub. (in Engler & Prantl, Nat. Pflanzenfam. 3(3): 193. 1892), based on the single species D. martinicensis Krug & Urb. ex Taub. Both generic names are correct when the genera are thought to be separate. Harms (in Repert. Spec. Nov. Regni Veg. 19: 291. 1924), however, united Vexillifera and Dussia in a single genus; the latter is the correct name for the genus with that particular circumscription. The legitimate name Vexillifera may therefore be correct or incorrect according to different taxonomic concepts.

6.7. The name of a taxon below the rank of genus, consisting of the name of a genus combined with one or two epithets, is termed a combination (see Art. 21, 23, and 24).

Ex. 6. Combinations: Mouriri subg. Pericrene Morley (in Univ. Calif. Publ. Bot. 26: 280. 1953), Arytera sect. Mischarytera Radlk. (in Engler, Pflanzenr. IV. 165 (Heft 98f): 1271. 1933), Gentiana lutea L. (Sp. Pl.: 227. 1753), Gentiana tenella var. occidentalis J. Rousseau & Raymond (in Naturaliste Canad. 79(2): 77. 1952), Equisetum palustre var. americanum Vict. (in Contr. Lab. Bot. Univ. Montréal 9: 51. 1927), Equisetum palustre f. fluitans Vict. (l.c.: 60. 1927).

6.8. Autonyms are names that are established automatically under Art. 22.3 and 26.3, whether or not they actually appear in the publication in which they are created (see Art. 32.3, Rec. 22B.1 and 26B.1).

6.9. The name of a new taxon (e.g. genus novum, gen. nov., species nova, sp. nov.) is a name validly published in its own right, i.e. one not based on a previously validly published name; it is not a new combination, a name at new rank, or a replacement name.

Ex. 7. Cannaceae Juss. (Gen. Pl.: 62. 1789), Canna L. (Sp. Pl.: 1. 1753), Canna indica L. (l.c. 1753), Heterotrichum pulchellum Fisch. (in Mém. Soc. Imp. Naturalistes Moscou 3: 71. 1812), Poa sibirica Roshev. (in Izv. Imp. S.-Peterburgsk. Bot. Sada 12: 121. 1912), Solanum umtuma Voronts. & S. Knapp (in PhytoKeys 8: 4. 2012).

6.10. A new combination (combinatio nova, comb. nov.) or name at new rank (status novus, stat. nov.) is a new name based on a legitimate, previously published name, which is its basionym. The basionym does not itself have a basionym; it provides the final epithet1, name, or stem of the new combination or name at new rank. (See also Art. 41.2).

[footnote]1 Here and elsewhere in this Code, the phrase “final epithet” refers to the last epithet in sequence in any particular name, whether of a subdivision of a genus, a species, or an infraspecific taxon.

Ex. 8. The basionym of Centaurea benedicta (L.) L. (Sp. Pl., ed. 2: 1296. 1763) is Cnicus benedictus L. (Sp. Pl.: 826. 1753), the name that provides the epithet.

Ex. 9. The basionym of Crupina (Pers.) DC. (in Ann. Mus. Natl. Hist. Nat. 16: 157. 1810) is Centaurea subg. Crupina Pers. (Syn. Pl. 2: 488. 1807), the epithet of which name provides the generic name; it is not Centaurea crupina L. (Sp. Pl.: 909. 1753) (see Art. 41.2(b)).

Ex. 10. The basionym of Anthemis subg. Ammanthus (Boiss. & Heldr.) R. Fern. (in Bot. J. Linn. Soc. 70: 16. 1975) is Ammanthus Boiss. & Heldr. (in Boissier, Diagn. Pl. Orient., ser. 1, 11: 18. 1849), the name that provides the epithet.

Ex. 11. The basionym of Ricinocarpaceae Hurus. (in J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 6: 224. 1954) is Ricinocarpeae Müll. Arg. (in Bot. Zeitung (Berlin) 22: 324. 1864), but not Ricinocarpos Desf. (in Mém. Mus. Hist. Nat. 3: 459. 1817) (see Art. 41.2(a); see also Art. 49.2), from which the names of both family and tribe are formed.

Note 3. A descriptive name (Art. 16.1(b)) used at a rank different from that at which it was first validly published is not a name at new rank because descriptive names may be used unchanged at different ranks.

Note 4. The phrase “nomenclatural novelty”, as used in this Code, refers to any or all of the categories: name of a new taxon, new combination, name at new rank, and replacement name.

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. 12. Aloe vera (L.) Burm. f. (Fl. Indica: 83. 1768), based on A. perfoliata var. vera L. (Sp. Pl.: 320. 1753), is both a new combination and a name at new rank.

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.

6.11. A replacement name (nomen novum, nom. nov.) is a new name published as an explicit substitute (avowed substitute) for a legitimate or illegitimate, previously published name, which is its replaced synonym. The replaced synonym, when legitimate, does not provide the final epithet, name, or stem of the replacement name (see also Art. 41.2 and 58.1).

Ex. 14. Gussone (Fl. Sicul. Syn. 2: 468. 1844) described plants from the Eolie Islands near Sicily under the name Helichrysum litoreum Guss., citing in synonymy Gnaphalium angustifolium Lam. (Encycl. 2: 746. 1788), but without indication that the existing H. angustifolium (Lam.) DC. (in Candolle & Lamarck, Fl. Franç., ed. 3, 6: 467. 1815) was an illegitimate later homonym of H. angustifolium Pers. (in Syn. Pl. 2: 415. 1807) that needed replacement. At the end of the protologue, Gussone wrote: “nomen mutavi confusionis vitendi gratia [I changed the name to avoid confusion]”. This makes explicit Gussone’s intent to propose H. litoreum as a replacement name based on the type of G. angustifolium (from Posillipo near Naples), not on the material he described and cited in the protologue.

Ex. 15. Mycena coccineoides Grgur. (in Fungal Diversity Res. Ser. 9: 287. 2003) was published as an explicit substitute (“nom. nov.”) for Omphalina coccinea Murrill (in Britton, N. Amer. Fl. 9: 350. 1916) because M. coccinea (Murrill) Singer (in Sydowia 15: 65. 1962) is an illegitimate later homonym of M. coccinea (Sowerby) Quél. (in Bull. Soc. Amis Sci. Nat. Rouen, ser. 2, 15: 155. 1880).

Ex. 16. Centaurea chartolepis Greuter (in Willdenowia 33: 54. 2003) was published as an explicit substitute (“nom. nov.”) for the legitimate name Chartolepis intermedia Boiss. (Diagn. Pl. Orient., ser. 2, 3: 64. 1856) because the epithet intermedia was unavailable in Centaurea due to Centaurea intermedia Mutel (in Rev. Bot. Recueil Mens. 1: 400. 1846).

6.12. A name not explicitly proposed as a substitute for an earlier name is nevertheless a replacement name either (a) if it is validated solely by reference to that earlier name or (b) under the provisions of Art. 7.5.

6.13. A name not explicitly proposed as a substitute for an earlier name and not covered by Art. 6.12 may be treated either as a replacement name or as the name of a new taxon if in the protologue1 both (a) a potential replaced synonym is cited and (b) all requirements for valid publication of the name of a new taxon are independently met. Decision on the status of such a name is to be based on predominant usage and is to be effected by means of appropriate type designation (Art. 9 and 10).

[footnote]1 Protologue (from Greek πρώτος, protos, first; λόγος, logos, discourse): everything associated with a name at its valid publication, e.g. description, diagnosis, illustrations, references, synonymy, geographical data, citation of specimens, discussion, and comments.

Ex. 17. When describing Astragalus penduliflorus Lam. (Fl. Franç. 2: 636. 1779) using material from the French Alps, Lamarck also cited in synonymy Phaca alpina L. (Sp. Pl.: 755. 1753) [non Astragalus alpinus L., Sp. Pl.: 760. 1753], described from Siberia. It is questionable whether Linnaeus’s and Lamarck’s plants belong to the same species. Greuter (in Candollea 23: 265. 1969) designated different types for the two names, so that, in conformity with predominant usage, A. penduliflorus is treated as the name of a new, European species.

6.14. A factually incorrect statement of a name’s status, as defined in Art. 6.96.11, does not preclude valid publication of that name with a different status; it is treated as a correctable error (see also Art. 41.4 and 41.8).

Ex. 18. Racosperma nelsonii was published by Pedley (in Bot. J. Linn. Soc. 92: 249. 1986) as a new combination (“comb. nova”) citing Acacia nelsonii Maslin (in J. Adelaide Bot. Gard. 2: 314. 1980) as “basionym”. However, A. nelsonii Maslin is illegitimate under Art. 53.1 because it is a later homonym of A. nelsonii Saff. (in J. Wash. Acad. Sci. 4: 363. 1914). Racosperma nelsonii Pedley is therefore validly published as a replacement name (Art. 6.11), with A. nelsonii Maslin its replaced synonym, and Pedley’s statement is treated as a correctable error.