DIVISION II. RULES AND RECOMMENDATIONS
CHAPTER V. REJECTION OF NAMES
58.1. The epithet in an illegitimate name if available may be used in a different combination, at the same or a different rank, if no other epithet is available from a name that has priority at that rank. The resulting name is then treated as new, either as a nomen novum with the same type as the illegitimate name (see also
Art. 7.5 and Art. 33 Note
2) 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.
Ex. 1. The name Talinum polyandrum Hook. (1855) is illegitimate, 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."
Ex. 2. Hibiscus ricinifolius E. Mey. ex Harv. (1860) is illegitimate 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. Genčve 4: 170. 1900) his name was legitimate and is treated as a nomen novum,
typified by the type of H. ricinoides, that is to be cited as H. vitifolius var. ricinifolius Hochr.,
not “(E. Mey. ex Harv.) Hochr.”
Ex. 3. When publishing Collema tremelloides var. cyanescens, Acharius (Syn. Meth. Lich.: 326. 1814) cited in synonymy
C. tremelloides var. caesium Ach. (Lichenogr. Universalis: 656. 1810), a legitimate name at the same rank, thus rendering his new name superfluous and illegitimate. However, the epithet
cyanescens was available for use in Collema at the rank of species, and the name C. cyanescens Rabenh. (1845), based on the same type, is legitimate. The correct author citation for
Leptogium cyanescens, published by Körber (1855) by reference to C. cyanescens "Schaer.", is therefore (Rabenh.) Körb., not (Ach.) Körb. or (Schaer.) Körb.
Körber ascribed the epithet cyanescens to Schaerer because this author was the first to use the epithet at specific rank in the name Parmelia cyanescens Schaerer (1842), which is however illegitimate being a later homonym of P. cyanescens (Pers.) Ach. (1803).
In the case of re-use at the same rank of epithets of illegitimate superfluous names, the type of the name
causing the original superfluity must be explicitly excluded.
Ex. 4. Menispermum villosum Lam. (1797) is an illegitimate superfluous name 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 there was no obstacle to the use of the epithet hirsutus
Ex. 5. Cenomyce ecmocyna Ach. (1810) is an illegitimate superfluous name for Lichen gracilis L. (1753), as
is Scyphophora ecmocyna Gray (1821), based on C. ecmocyna, since the type of L. gracilis was not excluded
and there was no obstacle to the use of the epithet gracilis in Scyphophora. However, when proposing the combination
Cladonia ecmocyna, Leighton (1866) explicitly excluded that type and thereby published a new, legitimate name, Cladonia
Ex. 6. Diospyros discolor Willd. (1806) was illegitimate when published, because Cavanillea philippensis
Desr. (1792) was cited as a synonym. Embryopteris discolor, based on D. discolor
Willd., was published in 1837
by G. Don (Gen. Syst. 4: 41.), who clearly excluded C. philippensis. The name would, therefore, have been attributable
to “G. Don” with priority from 1837. However, D. discolor is now a conserved name and no longer illegitimate, hence this
provision no longer applies and the correct author citation is Embryopteris discolor (Willd.) G. Don, with priority
2006, by International Association for Plant Taxonomy. This page last updated