Article 58

58.1. If there is no obstacle under the rules, the final epithet in an illegitimate name may be re-used in a different name, at either the same or a different rank; or an illegitimate generic name may be re-used as the epithet in the name of a subdivision of a genus. The resulting name is then treated either as a replacement name with the same type as the illegitimate name (Art. 7.4; see also Art. 7.5 and Art. 41 Note 3) or as the name of a new taxon with a different type. Its priority does not date back to the publication of the illegitimate name (see Art. 11.3 and 11.4).

Ex. 1. The name Talinum polyandrum Hook. (in Bot. Mag.: ad t. 4833. 1855) is illegitimate under Art. 53.1 because it is a later homonym of T. polyandrum Ruiz & Pav. (Fl. Peruv. Prodr.: 65. 1794). When Bentham (Fl. Austral. 1: 172. 1863) transferred T. polyandrum Hook. to Calandrinia Kunth, he called it C. polyandra. This name has priority from 1863, and is cited as C. polyandra Benth., not C. polyandra “(Hook.) Benth.”

Ex. 2. Cymbella subalpina Hust. (in Int. Rev. Gesamten Hydrobiol. Hydrogr. 42: 98. 1942) is illegitimate under Art. 53.1 because it is a later homonym of C. subalpina F. Meister (Kieselalg. Schweiz: 182, 236. 1912). When Mann (in Round & al., Diatoms: 667. 1990) transferred C. subalpina Hust. to Encyonema Kütz., he called it E. subalpinum D. G. Mann. This name is a replacement name with priority from 1990 and as such is illegitimate under Art. 52.1 because C. mendosa VanLand. (Cat. Fossil Recent Gen. Sp. Diatoms Syn. 3: 1211, 1236. 1969) had already been published as a replacement name for C. subalpina Hust.

Ex. 3. Hibiscus ricinifolius E. Mey. ex Harv. (Fl. Cap. 1: 171. 1860) is illegitimate under Art. 52.1 because H. ricinoides Garcke (in Bot. Zeitung (Berlin) 7: 834. 1849) was cited in synonymy. When the epithet ricinifolius was combined at varietal rank under H. vitifolius by Hochreutiner (in Annuaire Conserv. Jard. Bot. Genève 4: 170. 1900) his name was legitimate and is treated as a replacement name, typified (Art. 7.4) by the type of H. ricinoides. The name is cited as H. vitifolius var. ricinifolius Hochr., not H. vitifolius var. ricinifolius “(E. Mey. ex Harv.) Hochr.”

Ex. 4. Geiseleria Klotzsch (in Arch. Naturgesch. 7: 254. 1841) is illegitimate under Art. 52.1 because Klotzsch’s circumscription included Croton glandulosus L., the original type of Decarinium Raf. (Neogenyton: 1. 1825). Later, Gray (Manual, ed. 2: 391. 1856) published Croton subg. Geiseleria, which has priority from that date and is cited as C. subg. Geiseleria A. Gray, not C. subg. Geiseleria “(Klotzsch) A. Gray”. Because the subgeneric name is a replacement name, its type is C. glandulosus, the type (Art. 7.4) of Decarinium and automatic type (Art. 7.5) of Geiseleria.

Note 1. When the epithet of a name illegitimate under Art. 52.1 is re-used at the same rank, the resulting name is illegitimate unless either the type of the name causing illegitimacy is explicitly excluded or its epithet is unavailable for use.

Ex. 5. Menispermum villosum Lam. (Encycl. 4: 97. 1797) is illegitimate under Art. 52.1 because M. hirsutum L. (Sp. Pl.: 341. 1753) was cited in synonymy. The name Cocculus villosus DC. (Syst. Nat. 1: 525. 1817), based on M. villosum, is also illegitimate because the type of M. hirsutum was not excluded and the epithet hirsutus was available for use in Cocculus.

Ex. 6. Cenomyce ecmocyna Ach. (Lichenogr. Universalis: 549. 1810) is an illegitimate renaming of Lichen gracilis L. (Sp. Pl.: 1152. 1753). Scyphophorus ecmocynus Gray (Nat. Arr. Brit. Pl. 1: 421. 1821), based on C. ecmocyna, is also illegitimate because the type of L. gracilis was not excluded and the epithet gracilis was available for use. When proposing the combination Cladonia ecmocyna, Leighton (in Ann. Mag. Nat. Hist., ser. 3, 18: 406. 1866) explicitly excluded L. gracilis and thereby published the legitimate name of a new species, Cladonia ecmocyna Leight.

Ex. 7. Ferreola ellipticifolia Stokes (in Bot. Mat. Med. 4: 556. 1812) is illegitimate under Art. 52.1 because Maba elliptica J. R. Forst. & G. Forst. (Char. Gen. Pl., ed. 2: 122. 1776) was cited in synonymy. Bakhuizen van den Brink published Diospyros ellipticifolia Bakh. (in Gard. Bull. Straits Settlem. 7: 162. 1933) as a replacement name for F. ellipticifolia and did not exclude the type of M. elliptica. Diospyros ellipticifolia is nevertheless a legitimate name because in 1933 the epithet elliptica was not available for use in Diospyros due to the existence of D. elliptica Knowlt. (in Bull. U. S. Geol. Surv. 204: 83. 1902), of which D. elliptica (J. R. Forst. & G. Forst.) P. S. Green (in Kew Bull. 23: 340. 1969) is an illegitimate later homonym (Art. 53.1).