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. 11.3–11.4).
The name Talinum polyandrum Hook. (1855) is illegitimate under Art. 53.1, being a later homonym of T. polyandrum Ruiz & Pav. (1798). When Bentham, in 1863, transferred T. polyandrum Hook. to Calandrinia, he called it C. polyandra. This name has priority from 1863, and is cited as C. polyandra Benth., not C. polyandra “(Hook.) Benth.”
Hibiscus ricinifolius E. Mey. ex Harv. (1860) is illegitimate under Art. 52.1 because H. ricinoides Garcke (1849) was cited in synonymy. When the epithet ricinifolius was combined at varietal rank under H. vitifolius by Hochreutiner (in Annuaire Conserv. Jard. Bot. Geneve 4: 170. 1900) his name was legitimate and is treated as a replacement name, automatically typified (Art. 7.5) 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.”
Collema tremelloides var. cyanescens Ach. (Syn. Meth. Lich.: 326. 1814) is illegitimate under Art. 52.1 because Acharius cited in synonymy C. tremelloides var. caesium Ach. (Lichenogr. Universalis: 656. 1810), a legitimate name at the same rank. Schaerer was the first to raise the variety to specific rank, but Parmelia cyanescens Schaerer (1842) is illegitimate under Art. 53.1, being a later homonym of P. cyanescens (Pers.) Ach. (1803). Rabenhorst (1845) transferred the species to Collema, where the epithet cyanescens was available. Collema cyanescens Rabenh. is a legitimate name dating from 1845. The subsequent combination in Leptogium is cited as L. cyanescens (Rabenh.) Körb.
Geiseleria Klotzsch (1841) is illegitimate under Art. 52.1, being a superfluous replacement name for Decarinium Raf. (1825). In 1856, Gray 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”. As it was proposed as a replacement name, its type is C. glandulosus L., the type of Decarinium Raf. and automatic type (Art. 7.5) of Geiseleria Klotzsch.
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.
Menispermum villosum Lam. (1797) is illegitimate under Art. 52.1 because M. hirsutum L. (1753) was cited in synonymy. The name Cocculus villosus DC. (1817), based on M. villosum, is also illegitimate since the type of M. hirsutum was not excluded and the epithet hirsutus was available for use in Cocculus.
Cenomyce ecmocyna Ach. (1810) is an illegitimate renaming of Lichen gracilis L. (1753). Scyphophora ecmocyna Gray (1821), based on C. ecmocyna, is also illegitimate since the type of L. gracilis was not excluded and the epithet gracilis was available for use. When proposing the combination Cladonia ecmocyna, Leighton (1866) explicitly excluded L. gracilis and thereby published the legitimate name of a new species, Cladonia ecmocyna Leight.
Ferreola ellipticifolia Stokes (1812) is illegitimate under Art. 52.1 because Maba elliptica J. R. Forst. & G. Forst. (1776) was cited in synonymy. Bakhuizen van den Brink published Diospyros ellipticifolia Bakh. (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. (1902), of which D. elliptica (J. R. Forst. & G. Forst.) P. S. Green (1969) is an illegitimate later homonym (Art. 53.1).