Article 38

38.1. In order to be validly published, a name of a new taxon (see Art. 6.9) must (a) be accompanied by a description or diagnosis of the taxon (see also Art. 38.7 and 38.8) or, if none is provided in the protologue, by a reference (see Art. 38.13) to a previously and effectively published description or diagnosis (except as provided in Art. 13.4 and H.9; see also Art. 14.9 and 14.14); and (b) comply with the relevant provisions of Art. 3245and F.4–F.5.

Note 1. An exception to Art. 38.1 is made for the generic names first published by Linnaeus in Species plantarum, ed. 1 (1753) and ed. 2 (1762–1763), which are treated as having been validly published in those works even though the validating descriptions were published later in Genera plantarum, ed. 5 (1754) and ed. 6 (1764), respectively (see Art. 13.4).

38.2. A diagnosis of a taxon is a statement of that which in the opinion of its author distinguishes the taxon from other taxa.

Ex. 1. “Egeria” (Néraud in Gaudichaud, Voy. Uranie, Bot.: 25, 28. 1826) was published without a description or a diagnosis or a reference to a former one (and thus is a nomen nudum); it was not validly published.

Ex. 2. “Loranthus macrosolen” originally appeared without a description or diagnosis on the printed labels issued about the year 1843 with Sect. II, No. 529, 1288, of the herbarium specimens from Schimper’s “Abyssinische Reise”. The name L. macrosolen Steud. ex A. Rich. (Tent. Fl. Abyss. 1: 340. 1848) was validly published when Richard supplied a description.

*Ex. 3. In Don, Sweet’s Hortus britannicus, ed. 3 (1839), for each listed species the flower colour, the duration of the plant, and a translation into English of the specific epithet are given in tabular form. In many genera the flower colour and duration may be identical for all species and clearly their mention is not intended as a validating description or diagnosis. Names of new taxa appearing in that work are not therefore validly published, except in some cases where reference is made to earlier descriptions or diagnoses.

Ex. 4. “Crepis praemorsa subsp. tatrensis” (Dvořák & Dadáková in Biológia (Bratislava) 32: 755. 1977) appeared with “a subsp. praemorsa karyotypo achaeniorumque longitudine praecipue differt”. This statement specifies the features in which the two taxa differ but not how these features differ and so it does not satisfy the requirement of Art. 38.1(a) for a “description or diagnosis”.

Ex. 5. The generic name Epilichen Clem. (Gen. Fungi: 69, 174. 1909) is validly published by means of the key character “parasitic on lichens” (contrasting with “saprophytic” for Karschia) and the Latin diagnosis “Karschia lichenicola”, referring to the ability of the included species formerly included in Karschia to grow on lichens. These statements, in the opinion of Clements, distinguished the genus from others, although provision of such a meagre diagnosis is not good practice.

Ex. 6. The protologue of Iresine borschii Zumaya & Flores Olv. (in Willdenowia 46: 166. 2016) includes both a morphological and a molecular diagnosis. Both are diagnoses because they indicate how the features of the new species, in the opinion of the authors, differ from those of other taxa.

Note 2. Whereas a diagnosis must comprise one or more descriptive statements (Art. 38.2 and 38.3), a validating description (Art. 38.1) need not be diagnostic.

38.3. The requirements of Art. 38.1(a) are not met by statements describing properties such as purely aesthetic features, economic, medicinal or culinary use, cultural significance, cultivation techniques, geographical origin, or geological age.

Ex. 7. “Musa basjoo” (Siebold in Verh. Bat. Genootsch. Kunsten 12: 18. 1830) appeared with “Ex insulis Luikiu introducta, vix asperitati hiemis resistens. Ex foliis linteum, praesertim in insulis Luikiu ac quibusdam insulis provinciae Satzuma conficitur. Est haud dubie linteum, quod Philippinis incolis audit Nippis.” This statement gives information about the economic use (linen is made from the leaves), hardiness in cultivation (scarcely survives the winter), and geographical origin (introduced from the Ryukyu Islands), but because there is no descriptive information on the “leaves”, the only character mentioned, it does not satisfy the requirement of Art. 38.1(a) for a “description or diagnosis”. Musa basjoo Siebold & Zucc. ex Iinuma was later validly published by Iinuma (Sintei Somoku Dzusetsu [Illustrated Flora of Japan], ed. 2, 3: ad t. 1. 1874) with floral details and a description in Japanese.

38.4. When it is doubtful whether a descriptive statement satisfies the requirement of Art. 38.1(a) for a “description or diagnosis”, a request for a decision may be submitted to the General Committee, which will refer it for examination to the specialist committee for the appropriate taxonomic group (see Div. III Prov. 2.2, 7.9, and 7.10). A Committee recommendation as to whether or not the name concerned is validly published may then be put forward to an International Botanical Congress and, if ratified, will become a binding decision with retroactive effect. These binding decisions are listed in App. VI.

Ex. 8. Ascomycota Caval.-Sm. (in Biol. Rev. 73: 247. 1998, as “Ascomycota Berkeley 1857 stat. nov.”) was published as the name of a phylum with the diagnosis “sporae intracellulares”. Because Cavalier-Smith (l.c.) did not provide a full and direct reference to Berkeley’s publication (Intr. Crypt. Bot.: 270. 1857) of the name Ascomycetes [not Ascomycota], valid publication of Ascomycota is dependent on its meeting the requirements of Art. 38.1(a), and a request was made for a binding decision under Art. 38.4. The Nomenclature Committee for Fungi concluded (in Taxon 59: 292. 2010) that the requirements of Art. 38.1(a) were minimally fulfilled and recommended a binding decision that Ascomycota is validly published. This was endorsed by the General Committee (in Taxon 60: 1212. 2011) and ratified by the XVIII International Botanical Congress in Melbourne in 2011 (see App. VI).

Ex. 9. Brugmansia aurea Harrison (Floric. Cab. & Florist’s Mag. 5: 144. 1837) was described in an account of a garden visit as comprising “plants about two feet high” with flowers “about the size of the B. sanguinea, but of fine rich golden yellow colour”, and was compared with “an inferior kind … the flowers of which are of a dull buff colour”. A binding decision has been made that the name is validly published (see App. VI).

38.5. The names of a genus and a species may be validly published simultaneously by provision of a single description (descriptio generico-specifica) or diagnosis, even though this may have been intended as only generic or specific, if all of the following conditions are satisfied: (a) the genus is at that time monotypic (see Art. 38.6); (b) no other names (at any rank) have previously been validly published based on the same type; and (c) the names of the genus and species otherwise fulfil the requirements for valid publication. A descriptio generico-specifica must accompany the names of the taxa described; reference instead to an earlier description or diagnosis is not acceptable.

38.6. For the purpose of Art. 38.5, a monotypic genus is one for which a single binomial is validly published even though the author may indicate that other species are attributable to the genus.

Ex. 10. Nylander (in Flora 62: 353. 1879) described the new species “Anema nummulariellum” in a new genus “Anema” without providing a generic description or diagnosis. Because in the same publication (l.c.: 354. 1879) he wrote “Affine Anemati nummulario (DR.) Nyl., …”, which was an attempted new combination in “Anema” based on Collema nummularium Dufour ex Durieu & Mont. (Expl. Sci. Algérie 1: 200. 1846–1847), none of his designations was validly published. The names were later validly published by Forssell (Beitr. Gloeolich.: 40, 91, 93. 1885).

Ex. 11. The names Kedarnatha P. K. Mukh. & Constance (in Brittonia 38: 147. 1986) and K. sanctuarii P. K. Mukh. & Constance, the latter designating the single, new species of the new genus, are both validly published although a Latin description was provided only under the generic name.

Ex. 12. Piptolepis phillyreoides Benth. (Pl. Hartw.: 29. 1840) was a new species assigned to the monotypic new genus Piptolepis. Both names were validly published with a combined generic and specific description.

Ex. 13. In publishing “Phaelypea” without a generic description or diagnosis, Browne (Civ. Nat. Hist. Jamaica: 269. 1756) included and described a single species, but he gave the species a phrase name not a validly published binomial. Art. 38.5 does not therefore apply and “Phaelypea” is not a validly published name.

38.7. For the purpose of Art. 38.5, prior to 1 January 1908, an illustration with analysis (see Art. 38.9 and 38.10) is acceptable in place of a written description or diagnosis.

Ex. 14. The generic name Philgamia Baill. (in Grandidier, Hist. Phys. Madagascar 35: t. 265. 1894) was validly published because it appeared on a plate with analysis of the only included species, P. hibbertioides Baill.

38.8. The name of a new species or infraspecific taxon published before 1 January 1908 may be validly published even if only accompanied by an illustration with analysis (see Art. 38.9 and 38.10).

Ex. 15. When “Polypodium subulatum” (Vellozo, Fl. Flumin. Icon. 11: ad t. 67. 1831) was published, only an illustration of part of a frond was presented, without analysis, hence this drawing does not fulfil the provisions of Art. 38.8 and the designation was not validly published there. The name P. subulatum Vell. was validly published when Vellozo’s fern species descriptions appeared (in Arch. Mus. Nac. Rio de Janeiro 5: 447. 1881).

38.9. For the purpose of this Code, an analysis is a figure or group of figures, commonly separate from the main illustration of the organism (though usually on the same page or plate), showing details aiding identification, with or without a separate caption (see also Art. 38.10).

Ex. 16. Panax nossibiensis Drake (in Grandidier, Hist. Phys. Madagascar 35: t. 406. 1897) was validly published on a plate with analysis that includes details of flower structure.

38.10. For organisms other than vascular plants, single figures showing details aiding identification are considered as illustrations with analysis (see also Art. 38.9).

Ex. 17. Eunotia gibbosa Grunow (in Van Heurck, Syn. Diatom Belgique: t. 35, fig. 13. 1881), a name of a diatom, was validly published by provision of a figure of a single valve.

38.11. For the purpose of valid publication of a name of a new taxon, reference to a previously and effectively published description or diagnosis is restricted as follows: (a) for a name of a family or subdivision of a family, the earlier description or diagnosis must be that of a family or subdivision of a family; (b) for a name of a genus or subdivision of a genus, the earlier description or diagnosis must be that of a genus or subdivision of a genus; and (c) for a name of a species or infraspecific taxon, the earlier description or diagnosis must be that of a species or infraspecific taxon (but see Art. 38.12).

Ex. 18.Pseudoditrichaceae fam. nov.” (Steere & Iwatsuki in Canad. J. Bot. 52: 701. 1974) was not a validly published name of a family as there was no Latin description or diagnosis nor reference to either, but only mention of the single included genus and species (see Art. 36.2), as “Pseudoditrichum mirabile gen. et sp. nov.”, the names of which were both validly published under Art. 38.5 by a single Latin diagnosis.

Ex. 19. Scirpoides Ség. (Pl. Veron. Suppl.: 73. 1754) was published without a generic description or diagnosis. It was validly published by indirect reference (through the title of the book and a general statement in the preface) to the generic diagnosis and further direct references in Séguier (Pl. Veron. 1: 117. 1745).

Ex. 20. Because Art. 38.11 places no restriction on names at ranks higher than family, Eucommiales Němejc ex Cronquist (Integr. Syst. Class. Fl. Pl.: 182. 1981) was validly published by Cronquist, who provided a full and direct reference to the Latin description associated with the genus Eucommia Oliv. (in Hooker’s Icon. Pl. 20: ad t. 1950. 1890).

38.12. A name of a new species may be validly published by reference (direct or indirect; see Art. 38.13 and 38.14) to a description or diagnosis of a genus, if the following conditions are satisfied: (a) the name of the genus was previously and validly published simultaneously with its description or diagnosis and (b) neither the author of the name of the genus nor the author of the name of the species indicates that more than one species belongs to the genus in question.

Ex. 21. Trilepisium Thouars (Gen. Nov. Madagasc.: 22. 1806) was validated by a generic description but without mention of a name of a species. Trilepisium madagascariense DC. (Prodr. 2: 639. 1825) was subsequently proposed without a description or diagnosis of the species and with the generic name followed by a reference to Thouars. Neither author gave any indication that there was more than one species in the genus. Candolle’s species name is therefore validly published.

38.13. For the purpose of valid publication of a name of a new taxon, reference to a previously and effectively published description or diagnosis may be direct or indirect (Art. 38.14). For names published on or after 1 January 1953 it must, however, be full and direct as specified in Art. 41.5.

38.14. An indirect reference is a clear (if cryptic) indication, by an author citation or in some other way, that a previously and effectively published description or diagnosis applies.

Ex. 22. “Kratzmannia” (Opiz in Berchtold & Opiz, Oekon.-Techn. Fl. Böhm. 1: 398. 1836) was published with a diagnosis but was not definitely accepted by the author and was not therefore validly published under Art. 36.1. Kratzmannia Opiz (Seznam: 56. 1852), lacking description or diagnosis, is however definitely accepted, and its citation as “Kratzmannia O.” constitutes an indirect reference to Opiz’s diagnosis published in 1836.

Recommendation 38A

38A.1. A name of a new taxon should not be validated solely by a reference to a description or diagnosis published before 1753.

Recommendation 38B

38B.1. When a description is provided for valid publication of the name of a new taxon, a separate diagnosis should also be presented.

38B.2. Where no separate diagnosis is provided, the description of any new taxon should mention the points that distinguish the taxon from others.

Recommendation 38C

38C.1. When naming a new taxon, authors should not adopt a name that has been previously but not validly published for a different taxon.

Recommendation 38D

38D.1. In describing or diagnosing new taxa, authors should, when possible, supply figures with details of structure as an aid to identification.

38D.2. In the explanation of figures, authors should indicate the specimen(s) on which they are based (see also Rec. 8A.2).

38D.3. Authors should indicate clearly and precisely the scale of the figures that they publish.

Recommendation 38E

38E.1. Descriptions or diagnoses of new taxa of parasitic organisms, especially fungi, should always be followed by indication of the hosts. The hosts should be designated by their scientific names and not solely by names in modern languages, the application of which is often doubtful.