3. Referenced status assignations: From name to potential taxon and synonym

Diagram 6: Data structure of the referenced status and taxon circumscription

System status

The entity "Referenced Status Assignation" links names of potential taxa with their reference. The assignation combines two functions: The reference may on the one hand create a potential taxon, i.e. assign an accepted status to a potential taxon name. On the other hand, it may assign a status implying non-acceptance to existing potential taxa and/or link existing potential taxa and their data to another potential taxon.

The main stati are defined strictly according to the structural function they perform. For example, for the system it is structurally insignificant if a potential taxon A is a synonym of B, or if it is a misapplied name, wrongly used in the place of B. Both are treated as cases of simple system synonymy. On the other hand, a sensu-lato synonym, which may have more than one accepted name, presents structural problems which lead to a different treatment of the relationship, resulting in an additional entity and a different set of integrity rules.

The basic structural status assignments are in the following called system stati. The assignation of a system status may be further defined by a relation to the entities "System Status Detail" and/or "Nomenclatural Status Designator", and/or by means of a modifying flag (doubtful or tentative flag).

The following system stati and status details are defined (letter codes as used in model diagrams):

• A = Accepted according to the status reference (circumscription reference for a potential taxon).
  By means of a status detail, provisionally accepted names may be differentiated from fully accepted names.
• S = Simple system synonym. The potential taxon is not accepted, i.e. according to the status reference the provided single accepted name should be used instead of this name. The accepted name is designated via a pointer to a potential taxon name, which in turn must be accepted according to the same reference which declared the synonymy. Two principal cases may be differentiated: The accepted potential taxon name may be different from the accepted name („true" synonyms), or the name may be the same and the potential taxa differ only by their circumscription reference („concept synonyms"). Various special cases may be assigned to both alternatives by means of a status detail:
  True synonyms:
  Unspecified synonym; homotypic synonym; heterotypic synonym; misapplied name; alternatively accepted name.
  Concept synonyms (can in part also be handled by the assignation of a I - type system status):
  Actually identical potential taxa (e.g., for records originating from a database, a common primary source record); presumed identify because no further details are available (e.g. non-taxonomic sources citing only the taxon); presumed identify based on comparison of synonymy and geographic distribution given.
• I = Identical taxa form a subgroup of system synonyms which have been separated as a system status for practical reasons: If the concepts are identical and considered to be of the same value, two circumscription references can be cited with the potential taxon. On the other hand, one of them may also be entirely suppressed, a feature which might come handy to avoid an inflation of potential taxa by non-taxonomic references.
• L = Sensu-lato synonym of an accepted name according to the status reference. The same rules and status details apply as for simple system synonyms, but at least two accepted potential taxon names have to be provided.
• V = Variant. According to the status reference, the potential taxon name is either an orthographic variant of another name or a rejected name for which another name must be used. As for simple synonyms, the correct potential taxon name must be provided, but that name does not have to be a an accepted name.
  Both cases can be accounted for by the respective assignation of a nomenclatural status.
• U = Undefined. According to the status reference, the potential taxon name does not refer to a taxon (unresolved names in taxonomic monographs etc.), or the status reference simply does not make clear which status is to be assigned. The two cases may be differentiated by means of a status detail.

Diagram 7: Data structure of potential taxon stati

Nomenclatural status

The assignation of a nomenclatural status adds information which may or may not be the actual reason for the status assignation, but which does not have a direct structural impact. Nomenclatural stati have been separated as an additional entity type to facilitate the addition of new data and to allow for multiple designations.

Table 4: Nomenclatural stati

Basionomy

A basionym is just another system synonym and could be treated as a special kind of synonym. However, a basionym also bears strong importance on the composition of the name (as defined above). So, should it be treated as part of the name? Again no; authors may use the name of a combination rightly and cite the wrong basionym. There are two possible solutions to this dilemma:

(a) introduction of a new entity Basionym, which relates to the two names and to the source of the basionym declaration

(b) define the basionym as a property of the potential taxon name rather than the name itself. This is here done.

Homonyms

Plant names in which all name elements are identical are considered homonyms. This is different from common taxonomic usage of the term, which is usually only applied to later homonyms.

Homonymy is important in the process of the creation of a new potential taxon or of a new infrageneric name. The user must be warned as to the existence of the homonyms to avoid erroneous links. The homonym warning flag in entity type „Plant Name" serves to draw attention to the existence of homonyms, it has to be re-evaluated whenever changes in plant names are made.

Because of the existence of non-identical homonyms ("confusingly similar names" based on different types, Greuter, 1994), and because homonyms may be cited in various forms ("non", "vic"), the homonym declaration must be explicit (i.e., not handled only by a flag but by a separate entity).

The declaration of a homonym involves taxonomic judgment, so this is a property of a potential taxon rather than a name. The source of the homonym assignment is given by the circumscription reference of the potential taxon name it is assigned to. The homonym assignment type cites the original form of the homonym citation for the potential taxon (e.g. "non", "vix"; "nec" has to be added by the database program in case that several homonyms are assigned).

Diagram 8: Entities involved in homonym declarations

Synonyms

Structurally, a synonym is similar to a potential taxon, i.e. it consists of a plant name, a status assignation and a reference according to which the synonym status was assigned. However, a synonym cannot have non-taxonomic information related to it, and it must always be connected to a taxon (accepted name).

Rather than creating a separate entity for synonyms, the model treats it as a new referenced status assignation to an existing potential taxon, i.e. synonyms are considered to be a property of potential taxa rather than a kind of names.

For sensu lato synonyms, i.e. synonyms which have more than one accepted name, a separate associative entity is included. This entity could be used to handle all kinds of system synonymy relationships. However, since the great majority of system synonyms involves only a simple relationship, a direct relationship between potential taxon and status assignation was considered justified.

Diagram 9: Entity-Relation model of synonyms

Specific integrity rules related to the system status

• Every name must have at least one status. If a name is entered for the first time, and the reference from which it is taken assigns it synonym status without referring to a source where the name was accepted, the name is first assigned an accepted status reference according to the authors of the name itself. The thereby created potential taxon can than be declared a synonym.
• Every status must have one reference.
• One reference title may only assign one status to a potential taxon.
• If the system status is "A", the accepted name pointer must be 0 or point to the same potential taxon name record the status is describing.
• If the system status is "V", the accepted name pointer points to a potential taxon pointing to the correct spelling of the name.
• If the status is "S" the accepted name pointer must point to another potential taxon name, which has to be an accepted name with a status record of the same circumscription reference.
• If the status is "L" the accepted name pointer is a zero pointer. In its place, there have to exist at least 2 records pointing to that name in the "s.l. Status/Accepted Names Intersection" entity, each of which points to a record in the "Potential Taxon Name" entity. The latter records must be accepted names according to the same reference which had assigned the sensu lato status in the first place.
• If the status is "I" the accepted name pointer must point to another name, which has to be an accepted name, but which may carry a different circumscription reference.
• If status detail is misapplied (kind of synonym), misapplication warning flag in Plant Name has to be re-evaluated if status assignation record is deleted or changed.
• If a potential taxon record with misapplied name status is deleted or changed to another status, or if a misapplied name status is assigned, the misapplied warning flag in the plant name entity has to be reevaluated.
• This also applies to the homonym warning flag.

Next chapter; Contents of this article; Complete entity list; References cited; Author information. Last updated: June 23, 1995