Taxa and names in Cynoglossum sensu lato (Boraginaceae, Cynoglosseae): an annotated, synonymic inventory, with links to the protologues and mention of original material

Abstract Background An inventory is presented of all names so far validly published in Cynoglossum sensu lato and its segregate genera: Adelocaryum, Afrotysonia, Kuschakewiczia, Lindelofia, Mattiastrum, Paracaryum, Rindera, Solenanthus, Trachelanthus, and their synonyms. Names and designations that were not validly published in the cited place, and later isonyms, are accounted for when they have been included in the International Plant Name Index (IPNI). Problems with IPNI entries, including errors and omissions, are discussed, and the hope is expressed that the present inventory may be of use for fixing them. New information The inventory, generated from a list of structured data, is presented in two Supplements, as a searchable HTML document comprising a sequence of entries with internal cross-links and links to external sources, in particular to protologues accessible online or, copyright restrictions permitting, made available as scanned documents via DOIs, and as machine-readible file. With minor exceptions, all names have been verified in their original place of publication, and all were nomenclaturally assessed. Colour coding is used to distinguish between names (in green) pertaining to Cynoglossum sensu lato, for which complete synonymies are provided; and names (in orange) pertaining to other genera but published under Cynoglossum or its segregates. They are listed together with their basionym and the corresponding correct name (if it exists), but without complete synonymy. Acceptable, potentially correct names appear in bold-face type, both under a broadly defined Cynoglossum (for which purpose validation of 81 new combinations and the name of 1 new species was necessary) and under one or more of its segregates. When a name was published for a new taxon, original material is indicated, usually by direct quotation from the protologue. New type designations are exceptional (two cases), whereas former type designations are cited whenever known. Furthermore, types and original specimens, especially when their digital images are available online, are mentioned with their locations and accession numbers. Comments are added whenever appropriate, especially to explain nomenclatural assessments that are not self-evident.


Introduction
The cosmopolitan genus Cynoglossum (Boraginaceae sensu stricto) consists of more or less short-lived, predominantly biennial herbs. Anthers and stigma are usually included in the corolla tube, which at the throat is closed by hollow scales or folds called fornices. The fruit separates at maturity into more or less roundish, mostly glochid-bearing dry mericarpids (eremocarps, "nutlets"; German: Klausen).
Delimitation of the genus Cynoglossum (and thus of the main part of the Cynoglosseae) is controversial. Based on an unresolved relationship of taxa traditionally defined by morphological traits, mainly of the fruit, authors such as Greuter & Burdet (in Greuter 1981) plead for a very wide circumscription (with Cynoglossum sensu lato forming a single, large genus); at the other extreme, authors such as Riedl (1967) and many before and after him, subdivided that same assemblage into up to 10 genera, a position that is still favoured by one of the present authors (HHH). Popov (1953), among others, follows an intermediate path, e.g., concerning the possible merger of Mattiastrum and Paracaryum.
In recent years, DNA sequencing studies (Selvi et al. 2011, Weigend et al. 2013) have tended at least in part to support the position of Greuter & Burdet (in Greuter 1981). In phylogenetic trees resulting from such studies, Cynoglossum sensu stricto, as traditionally defined (mainly by fruit characters), is clearly polyphyletic. Even when some discordant (New-World, African and South Asian) elements currently assigned to Cynoglossum are removed, Cynoglossum sensu stricto remains paraphyletic, as morphologically deviating genera such as Paracaryum, Paracynoglossum, Pardoglossum and Solenanthus are nested within it. This means that the characters traditionally used for delimiting genera are insufficient to define monophyletic groups. Only if and when additional, phylogenetically meaningful features are found will it be possible to define natural units, potentially of generic rank, within Cynoglossum sensu lato. This has not happened as yet but is an important task for the future, combined with DNA sequence analyses of those species (more than one half) that have not so far been investigated.
To facilitate future research, it appeared to be a worth-while task to establish a complete inventory of taxa so far described and validly named, at any rank, within Cynoglossum sensu lato. We decided to include into that inventory any and all combinations published under either Cynoglossum itself or the name of a genus pertaining to Cynoglossum sensu lato, with their respective basionyms, even when -on the basis of current phylogenetic understanding -we do not consider that the corresponding taxon belongs to the latter. In order to assess the nomenclatural status of every name, we had to verify the original publication of each, i.e. its protologue. Therefore,it appeared logical to include into our inventory the protologue information relating to the respective original material. As a corollary, we endeavoured to find and put on record as many subsequent type designations as possible. Needless to say, the tracing and incorporation of this additional information increased our self-set task manifold -but we believe that the added value conferred to the inventory justifies our effort.
Our initial approach was to establish a purely nomenclatural inventory, with cross-links between entries of homotypic names. However, we established two levels with different coverage. For all taxa falling within the unit that we call Cynoglossum sensu lato (and also for the members of Afrotysonia, which, while phylogenetically not close to Cynoglossum, are all but distinguishable from it morphologically) we give a complete synonymy. For other, non-Cynoglossum taxa we only list names published under genera that pertain to Cynoglossum sensu lato, plus their basionym, if any. This distinction forced us to assess the appropriate placement of the named taxa, whether within or outside of Cynoglossum sensu lato, which is a taxonomic decision -and, as it turned out, not always a trivial one. Once we realised that we had lost our taxonomically virgin status we decided that we might just as well abandon our self-imposed restraint and introduce taxonomic assessment throughout, appreciating that users are keen to be given that kind of guidance. Since the present authors disagree as to the appropriate generic classification, we are in many cases, for the same taxon, listing more than one name as being potentially correct, i.e., as expressing possible generic placements.
The International Plant Name Index (IPNI: http://www.ipni.org) provided an ideal starting point and first basis for our inventory. Our task then consisted in a literature search for additional names, verification of the source of each and every entry found in IPNI, and nomenclatural (plus ultimately taxonomic) assessment of all names. Especially with respect to taxonomic assessment we made frequent use of the excellent facilities now provided by the Catalogue of Life dynamic checklist (CoL: http://www.catalogueoflife.org/ col). By the way of feedback, our inventory will hopefully be used to improve the completeness and accuracy of the data in both IPNI and CoL.

Taxonomic coverage
Description: Cynoglossum sensu lato, as defined for the purpose of the present inventory, relies heavily on the results of DNA sequencing studies, both published Selvi et al. 2011, Weigend et al. 2013, Selvi et al. 2011) and ongoing (Weigend, pers. comm.). In addition to Cynoglossum sensu lato as it appears in Weigend et al. 2013 (fig. 4), their PAR I ( Paracaryum I) clade is here included.
Conversely, the genera Microparacaryum and Bothriospermum, even though close to Cynoglossum sensu lato according to DNA-based phylogeny, are considered sufficiently distinct to be left outside. The same applies to the not yet sequenced Brandella, a likely synonym of Microparacaryum.
Finally, there are two groups of species, or clades, that have not so far been challenged as members of Cynoglossum but, according not only to sequence data, but at least to some extent morphology, do not belong here. One comprises the indigenous New-World "Cynoglossum" species, the second a group of mainly African species, some of which had been erroneously placed in Paracynoglossum. These groups are here considered as non-Cynoglossum and must await their description as separate genera to be correctly placed. A similar case is that of Afrotysonia, a small African genus morphologically very close to Cynoglossum, but which on account of recent, unpublished sequence data (Weigend, pers. comm.) is akin to the afore-mentioned African group.
To make the above taxonomic distinction immediately clear for the reader, in the inventory the headline with a name of a taxon belonging to Cynoglossum sensu lato appears in green type, and that for a non-Cynoglossum taxon, in orange type. Furthermore a taxonomic distinction is made: for names that are potentially acceptable under either Cynoglossum in the wide sense or one of its constituent segregate genera the headline is set in bold-face type; for those of non-Cynoglossum taxa that are currently accepted it also appears in bold-face print; for all other names (whether legitimate or illegitimate) that we consider as synonyms under any currently acceptable option the headline is left in normal type.
The list of names of genera belonging in Cynoglossum sensu lato, at least with respect to their nomenclatural type (mentioned in parenthesis) is as follows (potentially correct generic names appear in bold-face italics, currently accepted names, when heterotypic, are placed in square brackets): None of the following genera, with respect to their nomenclatural type (mentioned in parenthesis), is assigned by us to Cynoglossum sensu lato. However, each of them (except Afrotysonia) once included taxa that are currently placed, or still includes taxa that were at one time placed, in a genus belonging to Cynoglossum sensu lato (potentially correct generic names appear in bold-face italics, currently accepted names, when heterotypic, are placed in square brackets):

Traits coverage
Designations resembling names but that have not been validly published, being no names in the sense of the ICN (McNeill et al. 2012), have no type and no taxonomic identity (even though they may have been applied to a given taxon): therefore they appear in the database in grey type. No attempt at a complete coverage of such designations has been made. By and large, only those have been retained that have been registered in IPNI, the purpose being to document their actual status of non-names. Most often, they are junior isonyms without nomenclatural status of their own; or in some cases, phantom entries of names not appearing at all in their alleged place of publication. Several were deliberately proposed as new but failed to meet the requirements for valid publication; they were sometimes validly published subsequently -perhaps unnoticed by others, including ourselves, in which case they will have to be added in the future, with their proper source.

The data entries
The contents of the nomenclatural database for Cynoglossum sensu lato are shown in the electronic appendices Suppl. materials 1, 2) to this paper as a structured, fully searchable Hypertext Markup Language (HTML) file and a text file for import into as a spreadsheet or database. The entries in both files consist of eight elements, in which the data are connected by internal links and, where appropriate, linked to external sources. The main data fields, in the order in which they appear in each entry, are: 1. Headline (mandatory), showing the name with author citation and reference to the place and year of valid publication. Colour (green, orange, grey) and type (bold-face or normal) used in the headline are those explained above and show taxonomic placement, acceptability, and nomenclatural status (or absence thereof). With minor exceptions, all places of publication cited here have been verified by us. Abbreviation of name authors and publication titles follows the standards of IPNI. Correctable orthographical errors, when they appear in the original publication, are cited parenthetically between single quotes. 2. Field "IPNI" (mandatory except for new names and combinations validated in this paper): a direct copy of the current (November 2014) entry in the International Plant Name Index, underlain by a link to the entry itself (which may and hopefully in many cases will have been modified since that date). When IPNI shows more than one entry, a choice has been made as follows: When a recent entry without stated source exists, it is preferred; otherwise, when the type or original material of the name is from the Americas the Gray Card Index (GCI) entry has been selected; when it is from Australia, the Australian Plant Name Index (APNI) entry shows up; when it is from elsewhere, the Index Kewensis (IK) entry has been chosen; in case of more than one entry from the same source, the more recent, more accurate or more complete was given preference. Names not listed in IPNI at all are marked "absent".
3. Field ASSESSMENT (mandatory for validly published names): In this field, each name is taxonomically referred to the name considered as correct under the option of Cynoglossum sensu lato being treated as a single genus. (A reliable assessment under a different option cannot presently be given because the definition and naming of natural segregate genera, even though it remains an option for the future, currently is not possible.) The name in the headline is either declared "accepted" or referred to the name considered as correct, if it exists; if none exists (in particular, when a taxon hitherto placed in Cynoglossum has been found not to belong to Cynoglossum sensu lato), the existing combination is used but with "Cynoglossum" placed between quotation marks. Names in the rank of variety or below are not normally accepted but assigned to a species or subspecies. In case of heterotypic synonymy, i.e., when the accepted name has a type different from that of the name in the headline, the former is placed between square brackets. Names appearing in the ASSESSMENT field are cross-linked to their own entry. Names that are not validly published remain unassessed, as they have no type hence no taxonomic identity.

Field STATUS (mandatory):
The nomenclatural status of each name is indicated as follows. A legitimate name published as a name of a new taxon is defined by its rank, if any (e.g., sect. nov., spec. nov., var. nov. -or taxon nov.). A legitimate name with a basionym, which results from transfer of a former name to a new rank (both ranks being mentioned) and/or from its use in a new combination, is termed comb. nov., stat. nov., comb. & stat. nov., comb. in stat. nov., as the case may be. A replacement name, based on a replaced synonym, is designated as nom. nov. An illegitimate name (nom. illeg.) is qualified as nomenclaturally superfluous [superfl.] and/or as a junior homonym [homonym] to show the cause of illegitimacy. A name or designation that had been validly published earlier than in the place cited in the headline is termed isonym; when it was not validly published in that place, as inval. [with mention of the requirements it failed to comply with]; and when it does not appear there at all, as no name 5. Field REFERENCE (optional): In this field a link to the protologue is included whenever that text is freely available online. Open-access sources are preferred whenever they exist. Links to journals available through JSTOR (http://www.jstor.org/), to which limited free access is granted to individual scientists, or to items offered by journal or book publishers only upon subscription or against payment of a fee, are also provided -but only to the generally accessible level (e.g., the title and abstract of the corresponding paper).For protologues in publications not (not yet) available online, ad-hoc scans ("clippings" in pdf format) were uploaded to the Biodiversity Literature Repository (https://zenodo.org/ collection/user-biosyslit). This solution potentially makes all the treatments of all the taxa citable and the digital representation directly accessible, while not violating the copyright, if any, of the publication (Agosti and Egloff 2009; Patterson et al. 2014). BLR provides -as part of Zenodo/CERN -the long term digital repository. Digital Object Identifiers (DOI's) issued and maintained by DataCite (https://www.datacite.org/) allow the treatments to be easily cited and retrieved using a familiar, standard, and persistent identifier, and discoverable through search tools such as Refindit (http://refindit.org).
6. Field SYNONYMY (not mandatory): Synonymy is given once for every group of names based on the same type. The synonyms, chronologically arranged, appear either in the entry of the accepted name, or its basionym if it has one, or a replaced synonym if that is older. For each entry with one or more homotypic synonyms, a clickable cross-link to the entry including the synonymy is provided in the field BASIS, under "basionym" or "replaced synonym". Names appearing in a SYNONYMY field are cross-linked to their own entry. For technical reasons, heterotypic synonyms (if any) are not included in these synonymies; they can be found with the help of the taxonomic equivalences given in the ASSESSMENT field in square brackets, when appropriate. 7. Field BASIS (mandatory for validly published names): For names of new taxa, this field includes information on the nomenclatural type, or relevant for its establishment if it has not been designated so far. It starts with the indication of Original material, comprising the verbatim citation [from protologue] of any indication, in the protologue itself, relevant for establishing what elements have been used by the author of the validating description or diagnosis; when no original material is mentioned in the protologue, this citation is replaced by an explanatory statement. Thereafter, whenever possible, concrete type specimens (e.g., holotype, syntype, lectotype), or original specimens or illustrations, are enumerated, with their herbarium of deposit and accession number, followed by an asterisk (*) when a digital image of the specimen can be consulted online via the Internet. Whenever traced, places of lectotype designation are mentioned. -For new combinations, names at new rank and replacement names, the BASIS field mentions the basionym and/or replaced synonym, cross-linked to their own entry. -Names that are not validly published lack a nomenclatural basis.
8. Field COMMENTS (optional): Free text in which any particular circumstances related to the listed name are mentioned, e.g. those relevant for their status, adopted spelling and authorship, taxonomic assessment and typification, in particular in (but not limited to) those cases in which our conclusions differ from those currently prevailing in the literature and/or indexes.

Sources of information
As mentioned before, our main initial source of names was the International Plant Name Index (http://www.ipni.org). However, it soon appeared that IPNI is neither complete nor consistently accurate -which is not really a surprise but does not detract from the general usefulness and value of IPNI as a first-rate means of information on names and nomenclatural data. Yet, IPNI's shortcomings must be mentioned here as a positive fact, as they were our initial trigger. They encouraged us to embark on our self-set task: to complete and refine the inventory of names relevant in the taxonomic context of Cynoglossum sensu lato. Had we guessed beforehand the amount of work involved we might well have desisted, but when it dawned upon us it was too late to back out.
Our second-level sources can best be described as the entire botanical literature, both shelved and, increasingly, available online. Direct verification of the source works registered in IPNI led on to any number of further relevant publications, and through them, to a ramified and interconnected wealth of published data. Only when the snowball effect causing that avalanche started to subside and we discovered less and less new, unrecorded data did we feel that completion of our task (while never possible at 100 %) was in sight.
During the implementation of our plans, when tracking down every reference found within and outside the IPNI dataset, we were greatly assisted by the modern search mechanisms now available online. Literature directories such as WorldCat (http://www.worldcat.org) and the Karlsruhe Virtual Catalogue (KVK; http://www.ubka.uni-karlsruhe.de/kvk.html) for books, and for journals the German Zeitschriftendatenbank (ZDB; http:// dispatch.opac.dnb.de/DB=1.1), are invaluable tools, registering both physical publications with their location and virtual, digitised media with their access links. Other directories, concerned with online-accessible publications only, were also regularly consulted, in particular Biological Heritage Library (BHL, http://www.biodiversitylibrary.org), Botanicus ( The ever increasing presence in the Internet of digitised images of herbarium specimens, particularly types, has enabled us to add a feature to our data that would have been unthinkable a few years back: direct reference to type specimens and elements of the original material, usually with herbarium location and accession numbers, plus an indication by means of an asterisk (*) that an image has been consulted by us. The most complete and useful gateway to type specimen illustrations is JSTOR's Global Plants (htt p://plants.jstor.org), which unfortunately is not accessible for free. Other important (and free) sources of images are institute-based and must be accessed individually, as there is no global portal to that information yet. Many important herbarium holdings are presently accessible online, at least in part, including Virtual Herbaria (W, WU, JE, etc. Finally, mention must be made of Species 2000 and ITIS' Catalogue of Life (CoL; http:// www.catalogueoflife.org/col). While less complete than IPNI as an inventory of names, it has one quality that is absent from the latter: it advises on synonymy. During the last stage of editing our inventory, when we introduced taxonomic assessment of names into it, we have repeatedly consulted CoL's dynamic checklist and found it a useful and usually, though not invariably, accurate guide in matters of taxonomic synonymy. Especially when the correct identity of non-Cynoglossum names had to be assessed, we mostly found ourselves in full agreement with the choices in CoL.

Additional information
The nomenclatural database for Cynoglossum sensu lato comprises 1338 entries: 209 (in grey) of names not validly published in the place cited (these include isonym entries for names previously validated elsewhere); 268 (in orange) of names of which the types do not belong to our core or target group but have been nomenclaturally or taxonomically associated with it in the past, in some way or other; and 861 (in green) that do really pertain. The statistical digest in Table 1 is limited to names in the green group, as this is the only one for which coverage is supposed to be complete.  From the very beginning, one of our self-set targets was a comparison of the information found by us with what is currently in the IPNI database. We wanted, for one, to get an idea of how reliable IPNI is and to which extent, and in which respect, it might be inaccurate and/or incomplete. Also, we had and keep the hope that, subsequent to their publication, our data will be of use for updating the IPNI record, as we know and appreciate the hard work of the IPNI staff, both at Kew and Harvard, to continually improve their entries.
We will not dwell on minor errors, including wrong numbers, some of which may well go back to weaknesses of the optical character recognition (OCR) software used when the original Index Kewensis volumes were scanned; nor on the failure to adopt IPNI's own standards in many of the old entries, as we know that standardising them is among the ongoing concerns of the IPNI staff. Apart from such minor, trivial aspects, we found that IPNI currently has shortcomings principally in three fields.
1. Missing names. These are in their great majority found in ranks between genus and species and below species, which is explained by the fact that Index Kewensis, from which the bulk of IPNI entries originates, did not cover these ranks (contrary to the Gray Card Index). Only in recent years have infraspecific names and those of subdivisions of genera been registered consistently, and if it is judged worth while to fill that gap retroactively, this will constitute a gigantic task that will take decades to complete. Currently, for infraspecific names in particular, information in IPNI is fragmentary only. On the other hand, at the level of genera (94.4 %) and species (95.8 %) the coverage is reasonably good.
2. Inclusion of non-names. In a nomenclatural database, designations that are not validly published (some of which do not appear at all in the indicated place) should be either eliminated or -if maintained to avoid loss of information -prominently flagged. Current IPNI policy is to record them when they are intended as a nomenclatural novelty, but the author fails to comply with the conditions for valid publication, a fact that is then duly noted. But of old, such "names" were accepted at face value, and if and when validation finally occurred no note was taken. Worse, the early volumes of Index Kewensis are full of records of what appear to be junior homonyms, but are in fact mere misapplications of earlier names -a distinction that, while nomenclaturally relevant now, was not made at that time. This ballast, of what in terms of current nomenclature are junior isonyms without standing, lost whatever relevance it may once have had when it was decided to eliminate from the IPNI database the original reason of being of such entries: the sense in which the names had been misapplied, carefully recorded in Index Kewensis. As they are listed now, devoid of their rationale, all these isonyms are just only confusing, and a real nuisance. We hope that sooner or later they will be thrown over board.
3. Wrong assessment of the status of names, wrong author citations. For newly added names, IPNI is careful to distinguish legitimate from illegitimate ones, and new combinations or replacement names are referred to their basionym or replaced synonymadditionally, with increasing frequence, they are linked to outside sources available online. Old entries, however, have been updated only in part. The early volumes of Index Kewensis did not cite basionyms nor mention parenthetical authors, and illegitimacy at that time was an unheard-of concept. Updating such imperfect information is a big, demanding task for the future, requiring verification of the original source if it is to be properly done; we hope that the present inventory will be used for that purpose. Verification of author citations is a particular aspect of status assessment and is also necessary for former entries, because the relevant rules have changed substantially after the Tokyo Congress in 1993.
The problems just highlighted with respect to IPNI, the main existing nomenclatural data source for vascular plants, strengthen our belief in the usefulness of improved nomenclatural inventories such as the present one. We are conscious of the fact that no such list will ever be perfect, but we also believe that, beyond a certain point, aiming at an ever greater level of reliability becomes a futile exercise, an investment of time and money for little if any useful return. Once an inventory of this kind exists, it should be possible to confer official sanction to its basic contents, meaning certain parameters of the listed names (such as status, authorship, date and place of publication, spelling, etc.). We strongly advocate the creation of such a stabilising option under the rules governing nomenclature.

Conclusions
As stated in the introduction, the authors of this paper are divided as to their preferred generic concept for Cynoglossum sensu lato. This is no disadvantage. On the contrary, it permits us to present our readers with a dual approach, allowing them to choose between alternative classifications.
The problem with narrowly defined genera, the option endorsed by HHH, is that it would be premature to present them in a firm classificatory frame. Traditional generic definitions, based mainly on fruit morphology, are clearly unnatural in some cases. A reassessment leading to the establishment of natural segregate units requires further in-depth morphological and expanded molecular studies. The solution presented here -the best that is currently feasible -is to declare as acceptable, or potentially correct, names that exist under any of the currently adopted genera. This does not of course preclude the treatment of some names as synonyms when they belong to a taxon (species or subspecies) for which an older name exists, but for the time being it prevents the validation of new, potentially correct combinations in cases when they are likely needed under the segregate-genera concept.
The option of treating Cynoglossum sensu lato as a single genus, favoured by WG and VS, is less prone to future change. It is certainly possible, indeed likely, that some species currently assigned to that genus will have to be excluded from it in the future, but in general terms the unit that has emerged as monophyletic (Selvi et al. 2011, Weigend et al. 2013 is