Compiled by Brian Coppins, with help from many colleagues.

The original intention of this synonym list was to supplement the Flora (Purvis et al. 1992), by filling the gap of listed synonyms between the Checklists of Hawksworth et al. (1980) and Cannon et al. (1984) and the Flora [and more latterly the Checklist of Coppins (2002)], and documenting any subsequent changes. It was not intended to duplicate the synonyms given in the aforementioned checklists, except where there had been subsequent changes in interpretation. However, by ‘popular demand’ the list has been extended to include many earlier synonymies, especially those appearing in publications subsequent to the second edition of Smith’s monograph (Smith 1918, 1926). The List now includes all lichenicolous fungi, greatly aided by David Hawksworth's checklist (Hawksworth 2003). The compilation as provided here is certainly not comprehensive and will be added to and amended as appropriate. Similarly, the List is unlikely to be devoid of mistakes, especially with regard to author citations!

The list includes not only synonyms in the strict sense, but also many misinterpretations and misapplications of names, and names of uncertain application. The mis-uses included are mainly those that have appeared in the published literature, but a few additional ones that are commonly met with in the study of herbarium material are also included. The study of herbarium material reveals many additional misidentifications, but it is unrealistic to account for all such eventualities.

In the strict sense, synonyms are of two types:

1. Nomenclatural synonyms, sometimes called homotypic synonyms. These are two or more names based on the same type; e.g. Anaptychia obscurata (Nyl.) Vain. and Heterodermia obscurata (Nyl.) Trevis. Here, a species is transferred from one genus to another, and its species epithet is unchanged. Sometimes there is a slight change in the spelling of the species epithet because the generic name is of a different gender; e.g. Cetraria aculeata [feminine], Lichen aculeatus [masculine] and Coelocaulon aculeatum [neuter].
   
   In some cases, the species epithet has to change completely for reasons of priority. For example, Stigmatidium dendriticum Leight. was considered by Peter James to belong to Arthonia. However, there already existed a different species with the name Arthonia dendritica, so an alternative name (a ‘nomen novum’) had to be coined. Hence, Stigmatidium dendriticum was published in Arthonia as Arthonia atlantica P. James.
   
   
2. Taxonomic synonyms, sometimes called heterotypic synonyms. This is where two or more names are based on different types but which are considered to belong to the same species. E.g. Collema fuscovirens (With.) J.R. Laundon and Collema tuniforme (Ach.) Ach.

If the updating of species lists was just a matter of converting old names to currently accepted names by their nomenclatural and taxonomic synonyms, the process could be done simply and mechanically. Unfortunately life is not so simple!

As a simple example, the type specimen of Lecidea prasinula has been shown to belong to Lecidella scabra. On the grounds of straight synonymy Lecidea prasinula and its nomenclatural synonym Lecidella prasinula are synonyms of Lecidella scabra. However, ‘prasinula’ had been used for decades for a different species, i.e. what we now call Lecidella meiococca. Most collections of prasinula, apart from the type collection, belong to L. meiococca. Hence:

• Lecidella prasinula (Wedd.) Hertel = Lecidella scabra
• Lecidella prasinula auct. = Lecidella meiococca

Many names have been partly misapplied because a broad concept was previously attributed to them. As examples, the ‘old’ Peltigera canina is now considered to comprise two species: P. canina and P. membranacea. The ‘old’ Peltigera polydactyla now comprises three species: P. polydactyla, P. hymenina and P. neckeri. The ‘old’ Physcia grisea now comprises Physconia grisea, P. enteroxantha and P. perisidiosa. The ‘old’ Peltigera aphthosa now comprises P. britannica and P. leucophlebia; there is a also a ‘true’ P. aphthosa, but that species has not been correctly reported from the British Isles.

How to interpret the outcome of such splits is best accomplished by the re-determination of voucher specimens, where such exist. Where they do not exist, some intelligent guesswork can be made by considerations of the location, habitat and date of the record in relation to the known distribution, ecology, taxonomy and nomenclatural history of the species concerned. For example, a record of Peltigera canina made prior to about 1982, and from mossy tree bases in woodland, or mossy siliceous boulders, or acid grassland or dunes, is almost certainly to be P. membranacea, which is also the much commoner of the two species. Similarly, a record of Peltigera 'polydactyla' from grassland in southern England is most likely to be P. hymenina, as P. polydactlyon is so far not known to occur in that region, whereas P. hymenina is widely distributed there. This does not always work, because if the record was on mossy rocks in the Pennines or Scotland, you may as well toss a coin!

The Synonym List tries to take account of such things, and can doubtless be much improved in this respect. However, the List can deal only with the more common and important misapplication of names - it cannot take account of every misidentification to be found in the literature or the major herbaria! The misapplications listed are also restricted to those made in the British Isles.

Author names and their abbreviations follow ‘Authors of Fungal Names’ by Kirk & Ansell which is available [here]

• auct. = auctorum; of authors, usually meaning those other than the original person or person who originally described the taxon
• auct. brit. = auctorum britannicum; of British authors.
• auct. europ. = auctorum europaeum; of European authors.
• comb. inval. = combination invalid; the name was not changed to a different genus according to the rules of nomenclature.
• nom. rej. = nomen rejiciendum; a name that has been formally rejected and is no longer available for use.
• p.p. = pro parte; in part
• p.max.p. = pro maxima parte; for the most part
• p.min.p. = pro minore parte; for the smaller part
• sensu = in the sense of [author(s) or collector(s)]
• s. lat. = sensu lato; in the broad sense of the name (i.e. including the nomenclatural type and other entities).
• s. str. = sensu stricto; in the strict sense of the name (i.e. including the nomenclatural type).
• sphalm. = sphalmate; by mistake. In other words, a lapsus or 'slip of the pen.'
• [CR] = chemical race
• {F} non-lichenized fungus, although many of these fungi are traditionally treated as ‘lichens’.
• {LF} lichenicolous fungi (but excluding lichenicolous lichens)
• % a name given here as a synonym, but which is likely to become adopted as the correct name in the future.
• # a name that is for a species that is adopted on the British list, but which has been misused in the past. This is indicated by expressions such as “auct.”, “auct. brit.”, “auct. brit. p.p.”, “auct. brit. p.max.p.” For example, most British records of Leptogium byssinum are referable to L. biatorinum, although one correctly identified collection of L. byssinum is known.

NB: The list of species “incorrectly reported from British Isles” is not complete - see the latest published checklist (Coppins 2002) for others.

NB: The Syn List is mostly compatible with the Checklist found on this web site, but as the two may not necessarily be updated at the same time, the user may find one or two discrepancies. Nevertheless, do not be afraid to report them (see below).

NB: The Syn List does not yet deal fully with lichenicolous fungi, but it will be updated to do so in the future.

Studies in the taxonomy and nomenclature of lichens continue, and name changes are inevitable. Furthermore, detailed studies of historical collections give us a better understanding of the past uses (and abuses) of names by different authors and over different periods of time. Please send any relevant information pertaining to the Syn List, including suggested additions and corrections, and any other comments as to how you think the List can be improved to B.Coppins@rbge.org.uk

• Cannon, P.F., Hawksworth, D.L and Sherwood-Pike, M.A. (1985) The British Ascomycotina. An annotated checklist, Slough: Commonwealth Agricultural Bureaux.
• Coppins, B.J. (2002) Checklist of Lichens of Great Britain and Ireland. London: British Lichen Society
• Hawksworth, D.L., Coppins, B.J. and James, P.W. (1980) Checklist of British Lichen-forming, lichenicolous and allied fungi. Lichenologist 12: 1–115.
• Kirk, P.M. & Ansell, A.E. (1992) Authors of Fungal Names. [Index of Fungi Supplement]. Wallingford: CAB International.
• Purvis, O.W., Coppins, B.J., Hawksworth, D.L., James, P.W. and Moore, D.M. (1992) The Lichen Flora of Great Britain and Ireland. London: Natural History Museum Publications & British Lichen Society.
• Purvis, O.W., Coppins, B.J. and James, P.W. (1993) Checklist of lichens of Great Britain and Ireland. British Lichen Society Bulletin 72 (Suppl.): 1–75. Purvis, O.W., Coppins, B.J. and James, P.W. (1994)
• Checklist of Lichens of Great Britain and Ireland. London: British Lichen Society. Smith, A.L. (1918)
• A Monograph of the British Lichens, Vol. 1, 2 edn. London: British Museum (Natural History). Smith, A.L. (1926)
• A Monograph of the British Lichens, Vol. 2, 2 edn. London: British Museum (Natural History).

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