Nomenclatural FAQs for Phycologists

This brief FAQ document is designed to help phycological authors avoid common mistakes in frequently used nomenclatural procedures. For more information and questions not covered here, please consult a nomenclatural expert or the current on-line version of The International Code of Nomenclature for algae, fungi and plants. This FAQ guide is provided with the caveat that the Code is the definitive source of the rules and that, like all regulatory instruments, it is open to interpretation.

Please note a major change in the Code (see McNeill & Turland, 2011):

"The second change to the Code approved in Melbourne to take effect from 1 January 2012 is that the description or diagnosis required for valid publication of the name of a new taxon of all organisms falling under the Code may be in either English or Latin. This is the current provision for names of plant fossils, but all new non-fossil taxa have required a Latin description or diagnosis (fungi and plants from 1 January 1935; algae (including cyanobacteria, if treated under the Code) from 1 January 1958). This has no bearing on the form of scientific names, which continue to be Latin or treated as Latin. Individual journal requirements for Latin and/or English will, of course, be determined by the editors of those journals."

1. How do I describe new taxa at the rank of species?

a. Validation (valid publication)

Ensure that the new name is in Latin (or is acceptably Latinized); however, there are an extraordinary range of options open to the nomenclaturalist.

Construct the name according to ICBN Arts. 23 and 60. Make sure that the epithet conforms to recommendations and conventions if dedicating the name to a person, a place, or referring to growth on a substrate or host. Pay special attention to gender of generic names and the corresponding adjectival species epithets. However, this does not apply to epithets that are nouns — they retain their own gender and never change their endings, e.g., epithets ending in "-cola". A common error in naming a species after a female person is to use "-ii", wherease persononification for a female should be "-iae". For people whose names end in "a" (e.g., Okamura) an "e" is added ("okamurae").

Paul Silva has provided an excellent guide to the formation of commerative specific epithets, a complex minefield for the unwary.

Provide a description or diagnosis for your taxon or give a full and direct reference to a previously published description or diagnosis uniquely applicable to your alga. From January 1, 2012, for valid publication an English or Latin diagnosis or description must be provided.

You may use a single combined description or diagnosis (i.e. a descriptio generico-specifica) for both a new genus and a new species if there is a single species in the new genus and both are new.

Designate a holotype (authors must use the word "holotypus" or "holotype," or "typus" or "type", and cite the single herbarium or place the specimen is housed). See Index Herbariorum for proper insitutional acronyms. The phrase "hic designatus" (designated here) is not required.

Designate a single collection made at one place and time represented as a single specimen in a single institute (list the collector, date, and collection number);

Or designate a permanently metabolically inactive culture or tissue (e.g. frozen, dried, or pickled] designated by a unique reference and in a single institute (write 'preserved in a permanently inactive state' to ensure that readers know the type is not a living culture or one that is in a temporarily inactive state);

Or designate an effectively published illustration (concurrently or previously published) if and only if there are technical difficulties preserving a collection of a microalga. If previously published, a full and direct reference to the place of prior publication is required.

Do not indicate that the 'holotype' is in more than one physical location. Duplicates of the holotype collection are isotypes when deposited elsewhere or are otherwise separate from the holotype. Cultures derived from the holotype, or used to generate the holotype are not themselves types. Because preserved cultures can serve as 'type,' do not indiscriminately cite both a specimen and a culture as type. Ensure one is specifically designated as holotype and specifically state where that single type is located. Otherwise the name will be invalid.

Do not provide alternative Latin names for the same taxon. Otherwise all will be invalid.

Do not suggest that your new scientific name is tentative, provisional, a temporary fix, or express any other doubt about accepting a name for a new taxon. Otherwise it will be invalid.

You must, in Accordance with Art. 39 provide an illustration: "In order to be validly published, a name of a new taxon of non-fossil algae of specific or lower rank published on or after 1 January 1958 must be accompanied by an illustration or figure showing the distinctive morphological features, ...or by a reference to a previously and effectively published illustration or figure. Recommendation 39A.1 is that the illustration or figure should be prepared from actual specimens, preferably including the holotype.

b. Legitimization (legitimate publication)

Ensure that you do not publish a later homonym (a name spelled exactly like an earlier valid name (regardless of whether this is legitimate or illegitimate), or confusingly closely spelled. Later homonyms are illegitimate.

Your may not publish a tautonym: the genus and the species name may not be exactly the same (e.g. Solea solea), even though this is permitted in the Zoological Code

Homonyms for Bacteria and Archaea and for animals (including protozoa) are covered by other Codes (Zoological Code and Bacterial Code). You may create such homonyms, but this should be avoided if at all possible.

Example (not intended for valid publication):

Rhodophyllis imbricata J.J. Smith, sp. nov.
Diagnosis: From other species of the genus differing in the imbricate leaves and marginal cystocarps.
Typus (Fig. 23A): USA: Ancorage, 12 m depth, 07.ii.1910, coll. J.J. Smith, J.J. Smith 22 (US).

Remember: an invalid name can be validated, but an illegitimate name cannot be legitimised, except by conservation.

2.How do I describe new taxa at the rank of genus?

Construct the name according to ICBN Arts. 20 and 60. Follow recommendations 20A(h) and 60B when dedicating the name of the genus to a person. Check databases (see above) to make sure the generic name has not been used previously.

A diagnosis or description must be supplied when describing a new genus or any other taxon.

Designate the type of the genus by citing the name of one previously or concurrently, validly published species. Use the word "typus" or "type."

Example (not intended for valid publication):

Neorhodophyllis J.J Smith, gen. nov.
Diagnosis: Similar to the genus Rhodymenia but differing in the delvelopment of tetrasporangia and cystocarps on the understide of peltate surface proliferations.
Type: Rhodymeniopsis antarctica J.J. Smith

3. What is an ex-type?

A living culture obtained from a type may be referred to as an ex-type (See ICBN Art. 8. for more information). It is linked to the type, but it is not the same as the type. Depending on the nature of the type, it may be called an ex-holotype, ex-neotype, ex-epitype, etc. Such cultures, as well as the place where the living culture is preserved, should be indicated in publications, especially for new taxa. This information is often listed next to the type designation.

Example (not intended for valid publication):

Chlorella arboricola P.M. Smith, sp. nov.
Diagnosis: From other species of the genus differening in its thick cells walls with spiny uutgrowths.
Typus: USA: Idaho, Valley Co., near McCall, on the bark of Pinus sp., 07.vii.1912, coll. P.M. Smith, P.M. Smith 22 (F); ex-type UTEX 7493.

4. How and when do I designate a lectotype for a species?

A lectotype is designated when there was no holotype in the original description or if it has been lost or destroyed. Rarely, a lectotype may be designated when the holotype belongs to more than one taxon (see ICBN Art. 9 for more information).

A lectotype is a designated specimen or illustration that is part of the original material (protologue). Simply speaking, original material consists of specimens and published or unpublished illustrations that were definitely used in the original description of a name.

When designating a lectotype, priority must be given to the following types of materials in the order given below:

1. Isotype (see ICBN Art. 9.3)
2. Syntype (also possibly an isosyntype) (see ICBN Art. 9.4)
3. Paratype (see ICBN Art. 9.5)
4. Uncited specimen, uncited illustration, cited illustration

On or after 1 January 1990, the herbarium housing the specimen or unpublished illustration must be cited and the term "lectotypus" or "lectotype" must be given along with the phrase "hic designatus" or "designated here." A full and direct reference to the place of publication of previously published illustrations should be given, and it is ideal if the illustration can be reproduced in the current work. Lectotypification is only achieved through effective publication, not merely by the annotation of specimens in a collection. In the case of accepted names based on a basionym or replaced synonym, the basionym or replaced synonym should be the name that is lectotypified.

Example (fictional, not intended for valid publication):

Pseudophyllophora baltica (Peck) Peck, Phycologia 3: 377. 1965.
Basionym: Phyllophora baltica Peck, Phycologia 1: 100. 1963.

Lectotype of Phyllophora baltica (here designated): Sweden: Gothenburg, coll. Peck, Peck 1239 (BM).

5. How and when do I designate a neotype for a species?

A neotype is designated when no original material (specimens and published or unpublished illustrations that were definitely used in the original description of a name) exists. With rare exceptions, a lectotype designated from original material supersedes a neotype. Thus, it is important to not overlook any original material when considering neotype designation.

A neotype is a specimen or illustration, preferably the former. Special consideration should be given so that the designated neotype matches the material described in the protologue as closely as possible.

On or after 1 January 1990, the herbarium housing the specimen or unpublished illustration must be cited and the term "neotypus" or "neotype" must be given along with the phrase "hic designatus" or "designated here." Neotypification is only achieved through effective publication. In the case of accepted names based on a basionym or replaced synonym, the basionym or replaced synonym should be the name that is neotypified.

Example (fictional):

Schottera nyssae (Peck) Peck, Phycologia 3: 9. 1965.
Basionym: Phyllopora nyssae Peck, Phycologia 2: 39. 1964.

Neotypus of Phyllopora nyssae (here designated): USA: California, near Eureka, in pools, 10.vii.2001, coll. J.D. Smith, Smith 2211 (UC).

6. How and when can I designate an epitype for a species?

An epitype is designated when the existing nomenclatural type (holotype, lectotype, or neotype) or all the original material is insufficient to allow for precise application of a name. An epitype may be a specimen or illustration, but a specimen should nearly always be employed. Only one epitype is allowed per name. So, it must be carefully chosen and authors should ensure that the epitype represents the same taxon as the type it supports.

For an epitypification to be effected, the herbarium housing the specimen or unpublished illustration must be cited or in the case of a published illustration, a full and direct bibliographic reference must be given; and on or after 1 January 1990, the term "epitypus" or "epitype" must be given along with the phrase "hic designatus" or "designated here." Additionally, the nomenclatural type (holotype, lectotype, or neotype) that the epitype supports must be explicitly cited. Epitypification is only achieved through effective publication. In the case of accepted names based on a basionym or replaced synonym, the basionym or replaced synonym should be the name that is epitypified.

Example (fictional):

Neosiphonia nyssae (Peck) Peck, Phycologia 5: 9. 1913.
Polysiphonia nyssae Peck, Phycologia 2: 39. 1910.

Neotypus of Polysiphonia nyssae (designated by M.J.Wynne, Phycotaxon 1: 54. 2012): USA: Maine, near Rockland, on Palmaria palmata, 10.vii.2001, coll. C.W.Schneider, Schneider 2211 (MICH).

Epitypus of Polysiphonia nyssae (here designated) USA: Rockland, Maine, 10.viii.2007, coll. Methven, ASM 55891 (UC).

Notes: The preservation in chemicals of the type prevents PCR amplification. Here, we designate a supporting epitype that is associated with DNA sequence data.

7. How do I publish new combinations validly?

The rules for publishing new combinations are covered in large part and in more detail in ICBN Art. 33. The basionym must be cited with a clear and direct reference to its place of valid publication. For this, authors making new combinations must include journal and volume or book title, the page where protologue begins (be sure not to cite the entire pagination of the whole publication that includes the protologue), and date. Authors should make sure that adjectival species epithets agree grammatically with the genus in making new combinations (e.g. Fucus hibernicus becomes Agarum hibernicum amd not Agarum hibernicus or Agarum hibernica), but such an error would invalidate a name.

Examples (fictional):

Halichrysis imbricata (Peck) E.G.Smith, comb. nov.
Basionym: Rhodymenia imbricata Peck, Phycologia 3: 375. 1965.
Homotypic synonym: Chrysymenia imbricata (Peck) M.J.Wynne, Journal of Phycology, 55: 22. 2008.

Ulva cylindrica (Ellis) A.H.Smith, comb. & stat. nov.
Enteromorpha erecta var. cylindrica Ellis, Phycologia 3: 376. 1965 (basionym).

In the latter example, the new combination also changes the rank from variety to species.

Please note: not citing the exact page invalidates a new combination, which would require subsequent validation.

8. How do I validly publish a replacement name (a nomen novum or new name)?

Replacement names are similar to new combinations, but they are made in cases where there is an illegitimate later homonym or when the epithet of the basionym is already occupied in the genus where a new combination is required. The replaced synonym (not a basionym since the epithet is not being used in the new name) must be cited with a clear and direct reference to its place of valid publication. For this, authors making replacement names must include journal and volume or book title, page where protologue begins (be sure not to cite the entire pagination of the whole publication that includes the protologue), and date. Authors should make sure that species epithets agree grammatically with the genus of their new name. It is also suggested that authors include a citation including a full and direct reference for the earlier homonym or species name already occupying a genus that necessitates the replacement name.

9. How do I correctly give author citations for taxa?

Complete details about author (authority) citations for taxa are found in ICBN Arts. 46-50. For existing algal names, correct author citations may generally be found in Index Nominum Algarum and AlgaeBase. For detailed taxonomic studies, authors should endeavour to verify that these databases are correct since they are not complete and are works in progress. Author abbreviations for plants (including algae and fungi) should follow the standards established by the International Plant Names Index (IPNI).

For new names including new combinations, authors should include author citations for such taxa. These author citations are not necessarily the same as the authorship for the whole publication. Abbreviations should follow IPNI standards and in cases where a standardized abbreviation does not yet exist, authors should still attempt to conform to IPNI practices. Authors should be linked by the use of an "&" (ampersand, the equivalent of "et"), and the serial comma is not employed.

Example:

Rhodymenia erythrophylla T.C.Saunders., H.Y.Hu & Spatafora, sp. nov.

10. What is a basionym?

According to the ICBN a basionym is "a previously published legitimate name-bringing or epithet-bringing synonym from which a new name is formed for a taxon of different rank or position" (Art. 33.4, 49.1 and 52.3). You will note that a basionym does not really exist until it is used as the basis for a new name.

So, for example, the basionym for the name Rhodymenia pseudopalmata (J.V.Lamouroux) P.C.Silva is Fucus pseudopalmatus J.V.Lamouroux.

However, the name Guiryella repense Huisman & Kraft, which has never been combined into another genus, is not a basionym becasue it has never been recombined. It would become a basionym if it were combined into another genus.

In making new combinations there is a very precise way in which the place and publication of the basionym must be cited (see section 7 above).

11. What is a Later Starting Date?

The starting date for the nomenclature of Algae is set by the Code as 1 May 1753 (Linnaeus, Species plantarum, ed. 1).

However, there are a number of exceptions:
NOSTOCACEAE HOMOCYSTEAE, 1 January 1892 (Gomont, "Monographie des Oscillariées", in Ann. Sci. Nat., Bot., ser. 7, 15: 263-368; 16: 91-264). The two parts of Gomont's "Monographie", which appeared in 1892 and 1893, respectively, are treated as having been published simultaneously on 1 January 1892.
NOSTOCACEAE HETEROCYSTEAE, 1 January 1886 (Bornet & Flahault, "Révision des Nostocacées hétérocystées", in Ann. Sci. Nat., Bot., ser. 7, 3: 323-381; 4: 10%3-373; 5: 51-129; 7: 177-262). The four parts of the "Révision", which appeared in 1886, 1886, 1887, and 1888, respectively, are treated as having been published simultaneously on 1 January 1886.
DESMIDIACEAE (s. l.), 1 January 1848 (Ralfs, British Desmidieae).
OEDOGONIACEAE, 1 January 1900 (Hirn, "Monographie und Iconographie der Oedogoniaceen", in Acta Soc. Sci. Fenn. 27(1)).

This page is partly modified from a document prepared by A.M. Minnis, S.A. Redhead & R.E. Halling for the journal Mycologia.