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DIVISION II.  RULES AND RECOMMENDATIONS
CHAPTER II. STATUS, TYPIFICATION, AND PRIORITY OF NAMES
SECTION 2. TYPIFICATION

Article 8

8.1.  The type (holotype, lectotype, or neotype) of a name of a species or infraspecific taxon is either a single specimen conserved in one herbarium or other collection or institution, or an illustration (but see also Art. 37.4 and 37.6 for names published on or after 1 January 1958).

8.2.  For the purpose of typification a specimen is a gathering, or part of a gathering, of a single species or infraspecific taxon made at one time, disregarding admixtures (see Art. 9.12). It may consist of a single plant, parts of one or several plants, or of multiple small plants. A specimen is usually mounted on a single herbarium sheet or in an equivalent preparation, such as a box, packet, jar or microscope slide.

Ex. 1.  "Echinocereus sanpedroensis" (Raudonat & Rischer in Echinocereenfreund 8(4): 91-92. 1995) was based on a "holotype" consisting of a complete plant with roots, a detached branch, an entire flower, a flower cut in halves, and two fruits, which according to the label were taken from the same cultivated individual at different times and preserved, in alcohol, in a single jar. This material belongs to more than one gathering and cannot be accepted as a type. Raudonat & Rischer's name is not validly published under Art. 37.2.

8.3.  A specimen may be mounted as more than one preparation, as long as the parts are clearly labelled as being part of that same specimen. Multiple preparations from a single gathering that are not clearly labelled as being part of a single specimen are duplicates, irrespective of whether the source was one plant or more than one (but see Art. 8.5).

Ex. 2.  The holotype specimen of Delissea eleeleensis H. St. John, Christensen 261 (BISH), is mounted as two preparations, a herbarium sheet (BISH No. 519675) bearing the annotation "fl. bottled" and an inflorescence preserved in alcohol in a jar labelled "Cyanea, Christensen 261". The annotation indicates that the inflorescence is part of the holotype specimen and not a duplicate, nor is it part of the isotype specimen (BISH No. 519676), which is not labelled as including additional material preserved in a separate preparation.
Ex. 3.  The holotype specimen of Johannesteijsmannia magnifica J. Dransf., Dransfield 862 (K), consists of a leaf mounted on five herbarium sheets, an inflorescence and infructescence in a box, and liquid-preserved material in a bottle.
Ex. 4.  The holotype of Cephaëlis acanthacea Steyerm., Cuatrecasas 16752 (F), consists of a single specimen mounted on two herbarium sheets, labelled "sheet 1" and "sheet 2". Although the two sheets have separate herbarium accession numbers, F-1153741 and F-1153742, respectively, the cross-labelling indicates that they constitute a single specimen. A third sheet of Cuatrecasas 16572, F-1153740, is not cross-labelled and is therefore a duplicate.
Ex. 5.  The holotype specimen of Eugenia ceibensis Standl., Yuncker & al. 8309, is mounted on a single herbarium sheet at F. A fragment was removed from the specimen subsequent to its designation as holotype and is now conserved in LL. The fragment is mounted on a herbarium sheet along with a photograph of the holotype and is labelled "fragment of type!". The fragment is no longer part of the holotype specimen because it is not permanently conserved in the same herbarium as the holotype. Such fragments have the status of a duplicate, i.e. an isotype.

8.4.  Type specimens of names of taxa must be preserved permanently and may not be living plants or cultures. However, cultures of fungi and algae, if preserved in a metabolically inactive state (e.g. by lyophilization or deep-freezing), are acceptable as types.

Ex. 6.  The strain CBS 7351 is acceptable as the type of the name Candida populi Hagler & al. (in Int. J. Syst. Bacteriol. 39: 98. 1989) because it is permanently preserved in a metabolically inactive state by lyophilization (see also Rec. 8B.2).

8.5.  The type, epitypes (Art. 9.7) excepted, of the name of a taxon of fossil plants of the rank of species or below is always a specimen (see Art. 9.13). One whole specimen is to be considered as the nomenclatural type (see Rec. 8A.3).

Recommendation 8A

8A.1.  When a holotype, a lectotype, or a neotype is an illustration, the specimen or specimens upon which that illustration is based should be used to help determine the application of the name (see also Art. 9.13).

8A.2.  When an illustration is designated as the type of a name under Art. 37.5, the collection data of the illustrated material should be given (see also Rec. 32D.2).

8A.3.  If the type specimen of a name of a fossil plant is cut into pieces (sections of fossil wood, pieces of coalball plants, etc.), all parts originally used in establishing the diagnosis should be clearly marked.

8A.4.  When a single specimen designated as type is mounted as multiple preparations, this should be stated in the protologue, and the preparations appropriately labelled.

Recommendation 8B

8B.1.  Whenever practicable a living culture should be prepared from the holotype material of the name of a newly described taxon of fungi or algae and deposited in at least two institutional culture or genetic resource collections. (Such action does not obviate the requirement for a holotype specimen under Art. 8.4.)

8B.2.  In cases where the type of a name is a culture permanently preserved in a metabolically inactive state (see Art. 8 Ex. 6), any living isolates obtained from that should be referred to as "ex-type" (ex typo), "ex-holotype" (ex holotypo), "ex-isotype" (ex isotypo), etc., in order to make it clear they are derived from the type but are not themselves the nomenclatural type.

 

(c) 2006, by International Association for Plant Taxonomy. This page last updated  11.03.2007 .