A name, unless conserved (Art. 14) or sanctioned (Art. 15), is illegitimate and is to be rejected if it was nomenclaturally superfluous when published, i.e. if the taxon to which it was applied, as circumscribed by its author, definitely included the type (as qualified in Art. 52.2) of a name that ought to have been adopted, or of which the epithet ought to have been adopted, under the rules (but see Art. 52.3 and Art. 59.1).
For the purpose of Art. 52.1, definite inclusion of the type of a name is effected by citation (a) of the holotype under Art. 9.1 or the original type under Art. 10 or all syntypes under Art. 9.5 or all elements eligible as types under Art. 10.2; or (b) of the previously designated type under Art. 9.11–13 or 10.2; or (c) of the previously conserved type under Art. 14.9; or (d) of the illustrations of these. It is also effected (e) by citation of the name itself or any name homotypic at that time, unless the type is at the same time excluded either explicitly or by implication.
The generic name Cainito Adans. (1763) is illegitimate because it was a superfluous name for Chrysophyllum L. (1753), which Adanson cited as a synonym.
Chrysophyllum sericeum Salisb. (1796) is illegitimate, being a superfluous name for C. cainito L. (1753), which Salisbury cited as a synonym.
On the other hand, Salix myrsinifolia Salisb. (1796) is legitimate, being explicitly based on “S. myrsinites” of Hoffmann (Hist. Salic. Ill.: 71. 1787), a misapplication of S. myrsinites L. (1753), a name that Salisbury excluded by implication by not citing Linnaeus as he did under each of the other 14 species of Salix.
Picea excelsa Link (1841) is illegitimate because it is based on Pinus excelsa Lam. (1779), a superfluous name for Pinus abies L. (1753). Under Picea the correct name is Picea abies (L.) H. Karst. (1881).
On the other hand, Cucubalus latifolius Mill. and C. angustifolius Mill. are not illegitimate names, although Miller’s species are now united with the species previously named C. behen L. (1753): C. latifolius and C. angustifolius as circumscribed by Miller (1768) did not include the type of C. behen L., a name that he adopted for another species.
Explicit exclusion of type. When publishing the name Galium tricornutum, Dandy (in Watsonia 4: 47. 1957) cited G. tricorne Stokes (1787) pro parte as a synonym while explicitly excluding its type.
Exclusion of type by implication. Tmesipteris elongata P. A. Dang. (in Botaniste 2: 213. 1891) was published as a new species but Psilotum truncatum R. Br. was cited as a synonym. However, on the following page, T. truncata (R. Br.) Desv. is recognized as a different species and two pages later both are distinguished in a key, thus showing that the meaning of the cited synonym was either “P. truncatum R. Br. pro parte” or “P. truncatum auct. non R. Br.”
Under Persicaria maculosa Gray (1821), the name Polygonum persicaria L. (1753) was cited as the replaced synonym, and hence the type of Polygonum persicaria was definitely included. However, Persicaria mitis Delarbre (1806), as the earlier legitimate replacement name for Polygonum persicaria, is necessarily homotypic; hence, Persicaria maculosa when published was an illegitimate superfluous name for Persicaria mitis. Its continued use has been made possible by conservation.
Under Bauhinia semla Wunderlin (1976), the name B. retusa Roxb. (1832) non Poir. (1811), was cited as the replaced synonym while B. emarginata Roxb. ex G. Don (1832) non Mill. (1768), was also cited in synonymy, and hence the types of the two synonyms were definitely included. However, B. roxburghiana Voigt (1845), which was published as a replacement name for B. emarginata, is necessarily homotypic with it and should have been adopted by Wunderlin. Therefore, B. semla is an illegitimate superfluous name but is typified by the type of its replaced synonym, B. retusa (see Art. 7 Ex. 5).
Both Apios americana Medik. (1787) and A. tuberosa Moench (1794) are replacement names for the legitimate Glycine apios L. (1753), the epithet of which in combination with Apios would form a tautonym and would not therefore be validly published (Art. 23.4). Apios tuberosa was nomenclaturally superfluous when published, and is therefore illegitimate, because Moench cited in synonymy G. apios, which was then, as now, homotypic with A. americana, the name that has priority and that Moench should have adopted.
Erythroxylum suave O. E. Schulz (1907) is illegitimate because Schulz cited “Erythroxylum brevipes DC. var. spinescens (A. Rich.) Griseb.” (1866) in synonymy, thereby including the type of E. spinescens A. Rich. (1841), the name that Schulz should have adopted.
In publishing the name Matricaria suaveolens (1755), Linnaeus adopted the phrase name and included all the synonyms of M. recutita L. (1753) and so Applequist (in Taxon 51: 757. 2002) claimed that “all original elements of M. recutita are found in the protologue of M. suaveolens, making it illegitimate under Art. 52”. However, in 1755 M. recutita had no holotype, no syntypes, no designated lectotype or conserved type, nor was the name itself (i.e. M. recutita) cited by Linnaeus; therefore, none of the criteria of Art. 52.2 is fulfilled and M. suaveolens is a legitimate name.
The inclusion, with an expression of doubt, of an element in a new taxon, e.g. the citation of a name with a question mark, does not make the name of the new taxon nomenclaturally superfluous.
The protologue of Blandfordia grandiflora R. Br. (1810) includes, in synonymy, “Aletris punicea. Labill. nov. holl. 1. p. 85. t. 111 ?”, indicating that the new species might be the same as A. punicea Labill. (1805). Blandfordia grandiflora is nevertheless a legitimate name.
The inclusion, in a new taxon, of an element that was subsequently designated as the type of a name that, so typified, ought to have been adopted, or of which the epithet ought to have been adopted, does not in itself make the name of the new taxon illegitimate.
Leccinum Gray (1821) does not include all potential types (in fact, none) of Boletus L. (1753) and thus is not illegitimate even though it included, as L. edule (Bull. : Fr.) Gray, the subsequently conserved type of Boletus,B. edulis Bull. : Fr.
A name that was nomenclaturally superfluous when published is not illegitimate on account of its superfluity if it has a basionym (which is necessarily legitimate; see Art. 6.10), or if it is based on the stem of a legitimate generic name. When published it is incorrect, but it may become correct later.
Chloris radiata (L.) Sw. (1788) was nomenclaturally superfluous when published, since Swartz cited the legitimate Andropogon fasciculatus L. (1753) as a synonym. However, it is not illegitimate since it has a basionym, Agrostis radiata L. (1759). Chloris radiata is the correct name in the genus Chloris for Agrostis radiata when Andropogon fasciculatus is treated as a different species, as was done by Hackel (in Candolle & Candolle, Monogr. Phan. 6: 177. 1889).
Juglans major (Torr.) A. Heller (1904), based on J. rupestris var. major Torr. (in Rep. Exped. Zuni and Colorado Rivers: 171. 1853), was nomenclaturally superfluous when published because Heller cited the legitimate J. californica S. Watson (1875) as a synonym. Nevertheless, J. major is legitimate because it has a basionym, and it may be correct when considered taxonomically distinct from J. californica.
The generic name Hordelymus (Jess.) Harz (1885) was nomenclaturally superfluous when published because its type, Elymus europaeus L., is also the type of Cuviera Koeler (1802). However, it is not illegitimate since it has a basionym, Hordeum [unranked] Hordelymus Jess. (Deutschl. Gräser: 202. 1863). Cuviera Koeler has since been rejected in favour of its later homonym Cuviera DC., and Hordelymus can now be used as the correct name for a segregate genus containing E. europaeus L.
Carpinaceae Vest (Anleit. Stud. Bot.: 265, 280. 1818) was nomenclaturally superfluous when published because of the inclusion of Salix L., the type of Salicaceae Mirb. (1815). However, it is not illegitimate because it is based on the stem of a legitimate generic name, Carpinus L.
In no case does a statement of parentage accompanying the publication of a name for a hybrid make the name illegitimate (see Art. H.4–5).
The name Polypodium ×shivasiae Rothm. (1962) was proposed for hybrids between P. australe Fée and P. vulgare subsp. prionodes (Asch.) Rothm., while at the same time the author accepted P. ×font-queri Rothm. (1936) for hybrids between P. australe and P. vulgare L. subsp. vulgare. Under Art. H.4.1, P. ×shivasiae is a synonym of P. ×font-queri; nevertheless, it is not an illegitimate name.