DIVISION II. RULES AND RECOMMENDATIONS
CHAPTER III. NOMENCLATURE OF TAXA ACCORDING TO THEIR RANK
SECTION 4. NAMES OF SPECIES
23.1. The name of a species is a
binary combination consisting of the name of the genus followed by a
single specific epithet in the form of an adjective, a noun in the
genitive, or a word in apposition, or several words, but not a phrase
name of one or more descriptive nouns and associated adjectives in the
ablative (see Art. 23.6(a)), nor certain other irregularly formed
designations (see Art. 23.6(c)). If an epithet consists of two or more
words, these are to be united or hyphenated. An epithet not so joined
when originally published is not to be rejected but, when used, is to
be united or hyphenated, as specified in Art. 60.9.
23.2. The epithet in the name of a species may be taken from any source whatever, and may even be composed arbitrarily (but see
Ex. 1. Cornus sanguinea
, Papaver rhoeas
, Uromyces fabae
, Fumaria gussonei
, Embelia sarasiniorum
, Atropa bella-donna
, Adiantum capillus-veneris
, Spondias mombin
(an indeclinable epithet).
23.3. Symbols forming part of specific epithets proposed
by Linnaeus do not prevent valid publication of the relevant names but must be transcribed.
Ex. 2. Scandix pecten C
L. is to be transcribed as Scandix pecten-veneris; Veronica anagallis
L. is to be transcribed as Veronica anagallis-aquatica
23.4. The specific epithet, with
or without the addition of a transcribed symbol, may not exactly repeat
the generic name (such repetition would result in a tautonym).
Ex. 3. "Linaria linaria"
and "Nasturtium nasturtium-aquaticum"
are contrary to this rule and cannot be validly published.
Ex. 4. Linum radiola
L. (1753) when transferred to Radiola
Hill may not be named
as was done by Karsten (1882), since that combination cannot be validly published (see
). The next oldest name,
Lam. (1779), is illegitimate, being a superfluous name for
. Under Radiola,
the species has been given the legitimate name
23.5. The specific epithet, when
adjectival in form and not used as a noun, agrees grammatically with
the generic name; when it is a noun in apposition or a genitive noun,
it retains its own gender and termination irrespective of the gender of
the generic name. Epithets not conforming to this rule are to be
corrected (see Art. 32.7). In particular, the usage of the word element -cola as an adjective is a correctable error.
Adjectival epithets: Helleborus niger
L., Brassica nigra
(L.) W. D. J. Koch,
L.; Rumex cantabricus
Rech. f., Daboecia cantabrica
(Huds.) K. Koch (
≡ Vaccinium cantabricum
Huds.); Vinca major
L., Tropaeolum majus
L., Geranium molle
Peck, derived from the epithet of Abies balsamea
(L.) Mill., treated as an adjective.
Names with a noun for an epithet:
L., Gentiana pneumonanthe
L., Lythrum salicaria
L., Schinus molle
L., all with epithets featuring pre-Linnaean generic names.
Davis, derived from the epithet of Abies balsamea
(L.) Mill., treated as a noun.
Correctable errors: The epithet of Polygonum segetum
Kunth (1817) is a genitive plural noun (of the corn fields); the combination
, proposed by Small, is a correctable error for Persicaria segetum
(Kunth) Small (1903). - In
Rchb. f. (1855), the epithet corresponds to the generic name of an animal; upon transfer to
Schltr., the combination P. "echidnum"
was proposed by Garay, which is a correctable error for
(Rchb. f.) Garay (1953).
Ex. 8. Rubus "amnicolus"
is a correctable error for R. amnicola
23.6. The following designations are not to be regarded as specific names:
- Descriptive designations
consisting of a generic name followed by a phrase name (Linnaean "nomen
specificum legitimum") of one or more descriptive nouns and associated
adjectives in the ablative.
Ex. 9. Smilax "caule inermi"
(Aublet, Hist. Pl. Guiane 2, Tabl.: 27. 1775) is an abbreviated
descriptive reference to an imperfectly known species which is not
given a binomial in the text but referred to merely by a phrase name
cited from Burman.
- Other designations of species consisting of a generic name followed by one or more words not intended as a specific epithet.
Ex. 10. Viola "qualis"
(Krocker, Fl. Siles. 2: 512, 517. 1790);
(Forsskål, Fl. Aegypt.-Arab.: cxxi. 1775), the
word "dubia?" (doubtful) being repeatedly used in Forsskål's work for species
which could not be reliably identified.
Ex. 11. Atriplex "nova"
(Winterl, Index Hort. Bot. Univ. Hung.: fol. A  recto et verso.
1788), the word "nova" (new) being here used in connection with four
different species of
. However, in Artemisia nova
A. Nelson (in Bull. Torrey Bot. Club 27: 274. 1900),
was intended as a specific epithet, the species having been newly distinguished from others.
Ex. 12. Cornus "gharaf"
(Forsskål, Fl. Aegypt.-Arab.: xci, xcvi. 1775) is an interim
designation not intended as a species name. An interim designation in
Forsskål's work is an original designation (for an accepted taxon and
thus not a "provisional name" as defined in
) with an epithet-like vernacular which is not used as an epithet in the "Centuriae" part of the work.
(Forsskål, Fl. Aegypt.-Arab.: xcv. 1775) is
another example of such an interim designation; in other parts of the
work (p. c, cxvi, 127) this species is not named.
In Agaricus "octogesimus nonus"
and Boletus "vicesimus sextus"
(Schaeffer, Fung. Bavar. Palat. Nasc. 1: t. 100. 1762; 2: t. 137.
1763), the generic names are followed by ordinal adjectives used for
enumeration. The corresponding species were given validly published names,
Schaeff. and B. ungulatus
Schaeff., in the final volume of the same work (1774).
Honckeny (1782; see
Art. 46 Ex.
) used species designations such as, in
Agrostis, "A. Reygeri I.", "A. Reyg. II.", "A. Reyg. III."
(all referring to species described but not named in Reyger, Tent. Fl. Gedan.: 36-37. 1763), and also
"A. alpina. II"
for a newly described species following after A. alpina
Scop. These are informal designations used for enumeration, not validly
published binomials; they may not be expanded into, e.g.,
- Designations of species consisting of a generic name followed by two or more adjectival words in the nominative case.
Ex. 15. Salvia "africana coerulea"
(Linnaeus, Sp. Pl.: 26. 1753) and
Gnaphalium "fruticosum flavum"
(Forsskål, Fl. Aegypt.-Arab.:
cxix. 1775) are generic names followed by two adjectival words in the
nominative case. They are not to be regarded as species names.
However, Rhamnus "vitis idaea"
Burm. f. (Fl. Ind.: 61. 1768) is to be regarded as a species name,
since the generic name is followed by a noun and an adjective, both in
the nominative case; these words are to be hyphenated
under the provisions of Art. 23.1
. In Anthyllis "Barba jovis"
L. (Sp. Pl.: 720. 1753) the generic name is followed by nouns in the
nominative and in the genitive case, respectively, and they are to be
). Likewise, Hyacinthus "non scriptus"
L. (Sp. Pl.: 316. 1753), where the generic name is followed by a
negative particle and a past participle used as an adjective, is
and Impatiens "noli tangere"
L. (Sp. Pl.: 938. 1753), where the generic name is followed by two verbs, is corrected to
Similarly, in Narcissus "Pseudo Narcissus"
L. (Sp. Pl.: 289. 1753) the generic name is followed by an independent
prefix and a noun in the nominative case, and the name is to be
under the provisions of Art. 23.1
- Formulae designating hybrids (see
23.7. Phrase names used by
Linnaeus as specific epithets ("nomina trivialia") are to be corrected
in accordance with later usage by Linnaeus himself.
Ex. 18. Apocynum "fol.
L. is to be cited as
L. (Sp. Pl.: 213. 1753 [corr. L., Syst. Nat., ed. 10, 2: 946. 1759]); and
L., as M. frondosa
L. (Sp. Pl.: 177. 1753 [corr. L., Syst. Nat., ed. 10, 2: 931. 1759]).
23.8. Where the status of a designation of a species is uncertain under
Art. 23.6, established custom is to be followed
* Ex. 19. Polypodium "F. mas", P. "F. femina",
and P. "F. fragile"
(Linnaeus, Sp. Pl.: 1090-1091. 1753) are, in accordance with established custom, to be treated as
L., P. filix-femina
L., and P. fragile
L., respectively. Likewise,
Cambogia "G. gutta"
is to be treated as C. gummi-gutta
L. (Gen. Pl.: . 1754). The intercalations
] and "M."
] in the names of Linnaean species of
respectively, are to be deleted, so that names in the form
Asplenium "Trich. dentatum"
and Trifolium "M. indica",
for example, are treated as
L. and T. indicum
L. (Sp. Pl.: 765, 1080. 1753).
23A.1. Names of persons and also of countries and localities used in specific epithets should take the form of nouns in the genitive
(clusii, porsildiorum, saharae) or of adjectives (clusianus, dahuricus) (see also
Art. 60, Rec. 60C and
23A.2. The use of the genitive and
the adjectival form of the same word to designate two different species
of the same genus should be avoided (e.g.
Lysimachia hemsleyana Oliv. and L. hemsleyi Franch.).
23A.3. In forming specific epithets, authors should comply also with the following suggestions:
- To use Latin terminations insofar as possible.
- To avoid epithets which are very long and difficult to pronounce in Latin.
- Not to make epithets by combining words from different languages.
- To avoid those formed of two or more hyphenated words.
- To avoid those which have the same meaning as the generic name (pleonasm).
- To avoid those which express a character common to all or nearly all the species of a genus.
- To avoid in the same genus
those which are very much alike, especially those which differ only in
their last letters or in the arrangement of two letters.
- To avoid those which have been used before in any closely allied genus.
- Not to adopt epithets from
unpublished names found in correspondence, travellers' notes, herbarium
labels, or similar sources, attributing them to their authors, unless
these authors have approved publication (see
- To avoid using the names of little-known or very restricted localities unless the species is quite local.
2006, by International Association for Plant Taxonomy. This page last updated