A world monograph of the genus Plectocarpon (Roccellaceae, Arthoniales)

Ed.: Damien Ertz; Claude Christnach; Mats Wedin; Paul Diederich

2005. 155 pages, 123 figures, 14x23cm, 330 g
Language: English

(Bibliotheca Lichenologica, Band 91)

ISBN 978-3-443-58070-4, paperback, price: 58.00 €

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PlectocarponRoccellaceaeArthonialeslichenincolous fungus


Synopsis top ↑

The lichenicolous genus Plectocarpon (Roccellaceae, Arthoniales) is mono— graphed. Thirty two species are accepted, of which fifteen are new to science (Pl. bunodophori sp. nova on Bunodophoron patagonicum, Pl. concentricum sp. nova on Pseudocyphellaria homoeophylla, Pl. coppinsii sp. nova on Ps. crocata, Pl. cristalliferum sp. nova on Sticta sp., Pl. latisporum sp. nova on PS. coriifolia, Pl. melanohaleae sp. nova on Melanohalea ushuaiensis, Pl. obtectum Sp. nova on Ps. encoensis, Pl. Opegraphoideum sp. nova on Ps. homoeophylla and Ps. multgfida, Pl. pseudoleuckertii sp. nova on Ps. coriifolia, Pl. serusiauxii sp. nova on Sticta sp., Pl. sticticola sp. nova on Sticta spp., Pl. tibellii sp. nova on Ps. rubella, Pi. triebeliae sp. nova on Lobaria quercizans, Pl. venustum sp. nova on Nephroma papillosum, and Pi. violaceum Sp. nova on Nephroma antarcticum), two are newly combined in the genus (Pl. gallowayi comb. nova, bas. Melaspilea gallowayi, and Pi. leuckertii comb. nova, bas. Opegrapha leuckertii), and one is left unnamed (Pl. sp. on Usnea). Seven species examined during the study are included in other genera: Arthonia sampaianae comb. nova (bas. Pl. sampaianae), Arthonia sp. (on Sticta leami), Enterographa epiphylla comb. nova (bas. Chiodecton epiphyllum), E. punctata sp. nova (on Lobaria sp.), Opegrapha phaeophysciae sp. nova (on Phaeophyscia hispidula), Perigrapha nitida sp. nova (on Ps. glabra), and Sigridea labyrinthica comb. nova (bas. Plectocarpon labyrinthicum). Lectotypes are designated for Celidium dubium and Lichenomyces parasiticus. A key is given to all known genera of Roccellaceae containing lichenicolous species, and another key to the species of Plectocarpon. Species of Plectocarpon are especially diverse on Lobariaceae and Nephromataceae: Pseudocyphellaria (at least 11 species), Lobaria (6 species), Sticta (3 species), Nephroma (3 species) and Lobarina (1 species), and most of them are confined to one or a few closely related host species. Regions with a high species diversity are Australia and New Zealand (7 species), southern South America (10 species), and the boreal region (8 species). Host-specificity of Pl. lambinonii and Pi. lichenum, together with morphological and molecular data suggest that Pseudocyphellaria anomala and Ps. anthraspis might belong to Lobaria s. str.

Review: Australasian Lichenology 58, January 2006, p. 40-42 top ↑

The genus Plectocarpon was established by the Strasbourg pteridologist, cryptogamist, Professor of Botany, and cleric Antoine Laurent Apollinaire Fée (1789-1874) In his celebrated Essai sur les cryptogames des écorces exotiques officinales (Fee 1825). However, Fée himself did not realise that it was a lichenicolous fungus, and another 159 years passed before its true identity was recognised and the generic name re-entered modern mycological systematics.

I still vividly remember my excitement in discovering Delise's splendidly preserved specimens of "Sticta" in the Lenormand Herbarium one golden October afternoon in 1982 in the Paris Herbarium (PC-LENORMAND) when sheet after sheet proved to be type material of names described by Delise in his monograph (Delise 1825a, 1825b) and long thought to be lost in World War II when the city of Caen, where they were originally lodged (see Degelius [1935]), was heavily bombed. One of those was the type of Sticta delisea (Delise 1825a), which is where the modern story of Plectocarpon begins. The type specimen (Hawksworth & Galloway 1984, Galloway & James 1986) is a collection of what is now known as Pseudocyphellaria glabra Infected with a lichenicolous fungus forming apothecia-like galls on its upper surface. When the Delise specimens which I had requested on loan arrived at length in London at the BM, I showed that intriguing specimen of P. glabra to David Hawksworth, and we agreed to collaborate on material that had implications for Plectocarpon Fée, for the Venus Lichenomyces Trevis. (Trevisan 1853), and also for the typification of Delise's Sticta Relish (Hawksworth & Galloway 1984). It is an interesting story.

Fée (1825) described the new genus Delisea (honouring his friend and fellow cryptogamist Dominic Francois Delise [1780-1814], a distinguished retired major of the French Army and Chevalier of the Legion d'Honneur), on lichen material collected from King Island in Bass Strait between Tasmania and Australia (the collection is discussed in detail in Galloway & James [1986]). It differed from any species of Dicta then known in the peculiar structure of what Fée considered to be its apothecia. For the specific epithet of his new genus, he chose pseudosticta (Fée 1825) and provided a colour illustration of it (Fée 1825). However, Delisea Fée is a later homonym of Delisea Lamouroux (Rhodophyta) published in 1819, so it had to be rejected. He realised that, and in the "Additions et Corrections" to the Essai (Fée 1825), he introduced Plectocarpon Fée as a replacement for Delisea Fée, again discussing in some detail the peculiar, apothecia-like structures. However, he did not combine the epithet pseudosticta with Plectocarpon until his account of Plectocarpon in the Dictionnaire Classique d'Histoire Naturelle (Fée 1828), an often overlooked compendium of cryptogamic information. David Hawksworth and I erred in attributing the taxon Plectocarpon pseudosticta (Fée) Fée to Fée's account in the Supplement to the Essai (Fée 1837), and furthermore, in our account the date of publication of the name Delisea pseudosticta Fée is erroneously given as 1925 instead of 1825! That error was subsequently rectified in Galloway & James (1986), but unfortunately the mistake is still perpetuated in the monograph reviewed here.

In the 20th century, the first accounts of a Plectocarpon-like fungus were as Lecanora parasitica (Keissler 1930) and Rolf Santesson's resurrection of Trevisan's genus Lichenomyces (Trevisan 1853) for a parasite on Lobaria pulmonaria, which he identified as Lichenomyces lichenum (Sommerf.) R. Sant. (Santesson 1960) in a paper which he wrote on lichenicolous fungi from northern Spain. Hawksworth and I realized that Lichenomyces and Plectocarpon were nonspecific, and mentioned that Santesson had earlier intimated that an undescribed species also occurred on Nephroma antarcticum from southern South America. That implicated Plectocarpon as a co-evolved parasite on Pseudocyphellaria, Lobaria, and Nephroma. Later, Galloway (1997) mentioned Sticta caliginosa as being ". . . commonly infected with Plectocarpon sp. ", underlining the association of Plectocarpon with taxa in the Peltigerineae, families Lobariaceae and Nephromataceae (Eriksson 2005). Santesson (1993) synonymised Epiphora Nyl. with Plectocarpon, making two new combinations in the Genus, bringing the known species to five, to which Diederich and Etayo (1994) added a further five species from Northern Hemisphere collections. Aptroot et al. (1997) described two new species from Papua New Guinea, Wedin & Hafellner (1998) transferred Arthonia linitae into Plectocarpon, and a new species was described from Canada and Russia (Ertz et al. 2003), one from North America (Hafellner et al. 2002), and one from Chile (Follmann & Werner 2003).

Today, 22 years after the modern resurrection of Plectocarpon as a name for a Genus of lichenicolous fungi, we have a world monograph of the genus authored by Damien Ertz, Claude Christnach, Mats Wedin, and Paul Diederich, who bring together for the first time a view of the genus expanded both taxonomically and geographically, with the great riches of recent collections from the Southern Hemisphere (where the genus is most speciose) at last adequately researched and documented. The monograph accepts 32 species in Plectocarpon, 15 of them newly described. The genus is well-represented and speciose in the cool temperate Southern Hemisphere, with 10 species recorded from southern South America and seven from Australasia. Flight species are known from northern parts of the Northern Hemisphere, four are reported from Papua New Guinea, and three are recorded from Macaronesia, continental Africa, and Réunion. Plectocarpon is not known from Antarctica, Greenland, the Pacific Ocean, Mexico, or Central America, nor from the whole of Asia except for Russia and Turkey.

Seven taxa are currently accepted from Australasia, with P. pseudosticta (the generitype) being known from Tasmania, New Zealand, and Chile, P. gallowayii (an Australasian species transferred from Melaspilea), and five newly described species namely P. bunodophori (on Bunodophoron patagonicum and known from New South Wales, Tasmania, and New Zealand), P. concentricum (on Pseudocyphellaria homceophylla and apparently endemic to New Zealand), P. opegraphoideum (on Pseudocyphellaria homoeophylla and P. multifida, and apparently endemic to New Zealand); P. sticticola (on Sticta caliginosa, S.filix, S. squamata, and S. subcaperata, and apparently endemic to New Zealand, although some years ago the late Geoff Bratt discovered galls on a Tasmanian collection of ''Dendriscocaulon'', leading him to write to me that he had "found fertile Dendriscocaulon!"), and P. tibellii (on Pseudocyphellaria rubella and also apparently endemic to New Zealand).

Plectocarpon as discussed in the monograph comprises lichenicolous, stromatic Roccellaceae (Arthoniales) with more or less carbonised, multilocular stromata, many of which produce apothecia-like galls. The generic delimitation, especially with respect to Opegrapha-like taxa, is still unclear and needs resolution. Many species of Plectocarpon are restricted to Peltigeralean hosts. Pseudocyphellaria is the host genus richest in species of Plectocarpon, with at least 11 species known, adding substantially to data on lichenicolous fungi (and associated chemical patterns) from Pseudocyphellaria recorded earlier by Kondratyuk & Galloway (1995). To set Plectocarpon in perspective, a key is given to lichenicolous genera of Roccellaceae, including Perigrapha (a new species is described from New Zealand), Opegrapha, Plectocarpon, Sigridea, Enterographa, Mazosia, and Lecanographa. Several species formerly included in Plectocarpon are transferred to other genera, namely Arthonia sampianae, Enterographa epiphylla, Sigridea labyrinthica, and three Plectocarpon-like taxa. Enterographa punctata (from Sri Lanka), Opegrapha phaeophysciae (from Russia), and Perigrapha nitida (from New Zealand) are newly de- scribed. A key to all accepted species of Plectocarpon is given, together with an account of the pigments, crystals, and pruina found in the stromatic tissue, which are useful in species separation. Two species of Celidium (C. bacidiosporum from Kenya and C. dubium from New Zealand) are excluded from Plectocarpon.

Although the monograph is comprehensive in scope and detail, one gets the impression that it is far from the final word, and in several places the authors hint at areas deserving further study, with fascinating vistas of speciation and co-evolution in both Plectocarpon and the Lobariaceae to be explored in the future. I hope that this excellent and timely compilation will be both a guide and a stimulant to such studies in the near future. It is a fine addition to the growing literature of lichenicolous fungi but more than that it offers some solid pointers to new research agendas, which I hope will be quickly taken up. From a Southern Hemisphere perspective, it is a solid achievement and a particularly welcome development. Congratulations to all concerned with its production.


Aptroot, A; Diederich, P; Sérusiaux, E; Sipman, HJM (1997): Lichens and lichenicolous fungi from Nerv Guinea. Bibliotheca Lichenologica 64. Regelaus, G (1935): Das ozeanische Element der Strauch- und Laubflechtenflora von Skandinavien. Acta Phytogeographica Suecica 7. Delise, DF (1825a)["1822"]: H~stoire des lichens. Genre Sticta. Mémoires de la Société Linnéene de Calvados (Normandie) 2, 1-167. Delise, DF (1825b): Dernièadition au genre Sticta. Mémoires de la Société Linnéenne de Calvados (Normandie) 2, 598-600. Diederich, P; Etayo, J (1994): Taxonomic notes on the genus Plectocarpon Lichenicolous AscomycotinaJ. Nordic Journal of Botany 14, 589-600. Eriksson, OE (2005): Outline of Ascomycota - 2005. Myconet 11, 1-113. Ertz, D; Zhurbenko, M; Diederich, P; Miadlikowska, J (2003): A new species of Plectocarpon Lichenicolous Roccellaceae, Ascomycota) on Peltigera. Biologist 106, 465-467. Fée, ALA (1824-1825, 1837): Essai sur les crypogames des écorces exotiques officinales. Firmin Didot Père et Fils, Paris, F.G. Levrault, Paris, Strasbourg. Fée, ALA (1828): Plectocarpon. Bot. Crypt. (Lichens). Dictionnaire Classique d'Histoire Naturelle 14, 45. Follmann, G; Werner, CB (2003): Lichenicolous fungi occurring on Roccellaceae (Arthoniales) I. New species from South America. Journal of the Hattori Botanical Laboratory 94, 261-292. Galloway, DJ (1997): Studies on the lichen genus Sticta (Schreber) Ach. IV. New Zealand species. Lichenologist 29, 105-168. Galloway, DJ; James, PW (1986): Species of Pseudocyphellaria Vainio (Lichenes), recorded in Delise's "Histoire des Lichens: Genre Sticta". Nova Hedwigia 42, 423-490. Hafellner, J; Triebel, D; Ryan, BD; Nash III, TH (2002): On lichenicolous fungi from North America. II. Mycotaxon 84, 293-329. Hawksworth, DL; Galloway, DJ (1984): The identity of Plectocarpon Fée, and its impli- cations for Lichenomyces pseudocyphellaria and the typification of Sticta delisea. Lichenologist 16, 85-89. Keisler, K (1930): Die Flechtenparasiten. Dr L. Rabenhorst's Kryptogamen-Flora von Deutsch- land, Österreich und der Schweiz 8. Kondratyuk, SY; Galloway, DJ (1995): Lichenicolous fungi and chemical patterns in Pseudocyphellaria. Bibliotheca Lichenologica 57, 327-245. Santesson, R (1960): Lichenicolous fungi from northern Spain. Svensk Botanisk Tidskrifit 54, 499-522. Santesson, R (1993): The Lichens and Lichenicolous Fungi of Sweden and Norway. SBT-förlaget, Lund. Santesson, R; Moberg, R, Nordin, A, Tonsberg, T, Vitikainen, O (2004): Lichen-forming and lichenicolous fungi of Fennoscandia. Museum of Evolution, Uppsala University, Uppsala. Trevisan, V (1853): Spighe e Paglie, scritti botionici varj. Tip. Sicca, Padova. Wedin, M; Hafellner, (1998): Lichenicolous species of Arthonia on Lobariaceae with notes on excluded taxa. Lichenologist 30, 59-91.

David J. Galloway

Australasian Lichenology 58, January 2006

Review: International Lichenological Newsletter vol. 38 nr. 2, Feb. 2006, p.5 top ↑

Plectocarpon one of the earliest described (by Fée 1825) and most conspicuous genera of lichenicolous fungi is monographed. Plectocarpon species are often gall-forming, the galls sometimes at first glance being similar to the apothecia of the lichen host. Despite being a well established genus, only about half of the species had been recognized before the present monograph describes 32 species (plus an undescribed one on Usnea) of which 15 are new to science and two are new combinations. Seven further species are described in other genera (Arthonia, Enterographa, Opegrapha, Perigrapha and Sigridea) which have been previously included in Plectocarpon or have some similarities with it; these include three new described species and two new combinations.

Plectocarpon is considered as commensalistic with the host lichen rather than parasitic on it as there is no damage to the host visible other than gall-induction. Most species grow on hosts of the Lobariaceae (esp. Pseudocyphellaria) and the authors discuss the possibilities of co-evolution in special chapters. They also suggest some explanations for obvious differences in the distribution of the hosts and the lichenicolous fungi growing on them.

The monographic treatment starts with two keys, one for the species of Plectocarpon and the other for the genera of Roccellaceae with lichenicolous species. Every accepted species is described in detail and accompanied by instructive illustrations (photographs and/or drawings) and the distribution maps of all species are provided. Authors and publishers are to be congratulated for production of a monograph of such high standard.

The Editor

International Lichenological Newsletter vol. 38, nr. 2 Feb. 2006, p.5

Review: Nova Hedwigia Vol. 84/1-2, 2007 top ↑

Lichenicolous fungi were for a long time neglected and poorly known. Mycologists were often not studying lichens as a substrate and lichenologists were too often happy to ignore them. This situation has changed dramatically since the 1970s after the pioneer works by David Hawksworth, who was followed by several others working with these kind of ecologically specialized fungi. Paul Diederich and Mats Wedin are amongst those and have been publishing in recent years on these fungi. They contributed much to our knowledge of these previously neglected organisms. One breathtaking blast in our knowledge was the discovery of numerous basidiomycetes, chiefly belonging to the genus Tremella, among lichenicolous fungi. Diederich (1996) treated 54 species of which he described 41 as new to science at the time. In a less spectacular manner, the world monograph of Plectocarpon represents another huge step forward in our knowledge of lichenicolous fungi. I am impressed by this superb piece of work. 32 species are accepted by the authors, of which 15 are newly described. The species are well illustrated and described, including concise and helpful comments on the characterization of the taxa. The distribution maps give overviews on the known distribution of some species, but undoubtedly, the distribution of most of the species will change with addition of collecting and the recognition this treatment allows. The general part of the monograph is rather short, but includes numerous interesting observations. The separation from other genera, including Opegrapha, is discussed. Here it would have been helpful to have a more thorough discussion of the differences and the different groups within Opegrapha that are only vaguely mentioned. How data on lichenicolous fungi can be employed to infer conclusions on the taxonomy of the hosts is illustrated in two examples by the authors: I) they provide convincing evidence that Lobaria pulmonaria on the Canary Islands consists of two species, only one attacked by Plectocarpon macaronesiae. II) Plectocarpon species support molecular results suggesting that Pseudocyphellaria anomala and P. anthraspis may in fact belong to Lobaria. Most exciting, however, is the find that almost all taxa seem to be species-specific or almost species-specific. It will be a fascinating project to study co-evolutionary processes in Plectocarpon and peltigeralean fungi using molecular techniques. To conclude, this is a well-done monograph of a previously neglected group of fungi that evokes numerous ideas for further research on the biology and evolution of these organisms. (DIEDERICH, P. (1996): The lichenicolous Heterobasidiomycetes. - Bibl. Lichenol. 61: 1-198.)

H .T. LUMBSCH, Chicago

Nova Hedwigia Vol. 84/1-2, 2007

Review: Mycotaxon vol. 96 (April-June 2006), p. 348-349 top ↑

It has been evident since the study of Diederich & Etayo (1994) that the lichenicolous genus Plectocarpon was more speciose than the 1-2 species traditionally assumed when the generic name was resurrected (Hawksworth & Galloway 1984). This monograph makes the point as a result of extensive collections made in recent years: 32 species are accepted here of which 15 are new to science and two are newly combined into the genus. Most species occur on members of Peltigerales, especially Southern Hemisphere species of Lobaria (6 species), Nephroma (3), Pseudocyphellaria (11+), and Sticta (3). The species are all described in detail with full discussions of the nomenclature and well-illustrated by half-tones (many of which have not reproduced as well as I would have hoped) and line-drawings of asci and ascospores. All seem to be well-separated microscopically and this is clearly a pivotal work in studies of these fungi. I have used the key to identify some material hiding in my drawers for too many years successfully.

The placements and typifications of various other taxa examined during the study are discussed in detail, and as a result several are either described in or combined into the genera Arthonia, Enterographa, Opegrapha, Perigrapha, and Sigridea.

I was especially pleased by the discussions of host-specificity and biogeography (which include world distribution maps for several species) and intrigued by the suggestion that the host lichens Pseudocyphellaria anomala and P. anthraspis might be better placed in Lobaria as recent molecular studies have indicated this are not monophyletic with Pseudocyphellaria s. str.

This is a most carefully executed monograph, on which the authors are to be congratulated, and will be required by all workers on lichenicolous fungi.

Mycotaxon vol. 96, April-June 2006, p. 348-349

Review: Bibl. of Systematic Mycology and Index of Fungi top ↑

The genus Plectocarpon Fée was largely neglected from its illegitimate inception in 1825 until some 20 years ago, since when 16 species have been added. Continuing this trend, the present work accepts 32 species.

Phylogenectically, Plectocarpon is closely related to Opegrapha within the Roccellaceae (Arthoniales), although delimination between the two genera requires further study, and indeed several species of Opegrapha are probably closer to Plectocarpon than to the type of Opegrapha. Other anatomically similar genera include the lichenized chiodecton, Dichosporidium and Streimannia. Details of stromatic pigments, so far as they have been characterised, as well as pruina and crystals, are provided. Biogeography, endemism, host specificity and co-evolution and co-distribution with their hosts are discussed at some length, although these are working hypotheses that need to be tested phylogenetically. Species diversity is notable on Lobariaceae and Nephromataceae, as indicated above, and fairly host-specific. Keys are provided to all species and, in addition, to all known lichenicolous genera of Roccellaceae.

Alphabetical treatment of species constitutes the bulk of the work, accompanied by acceptable black and white photographs of macromorphology and (for new taxa only) clear drawings of asci and ascospores, plus distribution maps, combined for several species. Fifteen species are newly described (on host genera Bunodophoron (1), Lobaria (1), Melanohalea (1), Nephroma (2), Pseudocyphellaria (7) and Sticta (3)), and two new combinations transferred from Melaspilea and Opegrapha; one remains unnamed. Three species of Plectocarpon are combined into Arthonia, Enterographa, and Sigridea, and a further three taxa are described as new species in Enterographa, Opegrapha and Perigrapha. The work is completed by a list of references, and indexes to hosts and lichenicolous taxa.

K. Hudson

Bibliography of Systematic Mycology and Index of Fungi

Table of contents top ↑

Introduction 6
Material and methods 7
Key to the genera of Roccellaceae with lichenicolous species 7
The genus Plectocarpon 8
Plectocarpon Fee 8
Phylogenetical position, generic delimitation and infrageneric groupings
of Plectocarpon 9
Pigments, crystals and pruina in Plectocarpon 12
The ecogeographical species-richness of Plectocarpon 14
The hosts of Plectocarpon macaronesiae 15
The phylogenetic position of Pseudocyphellaria anomala and Ps.
anthraspis 16
Host-range and specificity in Plectocarpon suggest that speciation took
place through co-evolution with their hosts 17
Species occurring only in a part of the distribution area of their hosts 18
Key to the species of Plectocarpon 19
Plectocarpon arthonioides Diederich 23
Plectocarpon bunodophori Wedin, Ertz & Diederich sp. nova 25
Plectocarpon cladoniae R. Sant 31
Plectocarpon concentricum Ertz, Diederich & Wedin sp. nova 34
Plectocarpon coppinsii Ertz & Diederich sp. nova 36
Plectocarpon cristalliferum Christnach, Ertz & Diederich sp. nova 40
Plectocarpon encausticum (Nyl.) R. Sant 43
Plectocarpon gallowayi (S. Kondratyuk) Ertz & Diederich comb. nova 47
Plectocarpon lambinonii Diederich & Etayo 50
Plectocarpon latisporum Ertz, Diederich & Wedin sp. nova 52
Plectocarpon leuckertii (S. Kondratyuk & D.J. Galloway) Ertz &
Diederich comb. nova 58
Plectocarpon lichenum (Sommerf.) D. Hawksw 61
Plectocarpon linitue (R. Sant.) Wedin & Hafellner 65
Plectocarpon macaronesiae Diederich, Etayo & Serusiaux 68
Plectocarpon melanohaleae Christnach, Ertz & Diederich sp. nova 71
Plectocarpon nashii Hafellner 73
Plectocarpon nephromeum (Norman) R. Sant 76
Plectocarpon obtectum Ertz & Diederich sp. nova 79
Plectocarpon opegraphoideum Christnach, Ertz, Diederich & Wedin sp. nova 81
Plectocarpon peltigerae Zhurb., Ertz, Diederich & Miadl 86
Plectocarpon pseudocyphellariae Diederich 88
Plectocarpon pseudoleuckertii Diederich, Ertz & Wedin sp. nova 89
Plectocarpon pseudosicta Fee 92
Plectocarpon aff. pseudosticta Fee 94
Plectocarpon scrobiculatoe Diederich & Etayo 96
Plectocarpon serusiouxii Ertz & Diederich sp. nova 99
Plectocarpon sticticola Ertz, Wedin & Diederich sp. nova 102
Plectocarpon tibellii Ertz & Diederich sp. nova 106
Plectocarpon triebeliae Diederich & Ertz sp. nova l O9
Plectocarpon usrneae Diederich & Etayo 112
Plectocarpon venustum Ertz, Coppins & Diederich sp. nova 114
Plectocarpon violaccum Ertz, R. Sant., Diederich & Wedin sp. nova 116
Plectocarpon sp. (on Usnea) 120

Species to be included in other genera 122
Arthonia Ach 123
Arthonia sampaianae (Diedarich & Etayo) Ertz & Diederich comb. nova 123
Arthonia sp. 124
Enterographa Fee 125
Enterographa epiphylla (Sews.) Ertz, Diederich & Sparrius comb. nova. 126
Enterographa punctata Ertz & Diederich sp. nova 128
Opegrapha anomea group 131
Opegrapha phaeophysicae R. Sant., Diederich, Ertz & Christnach sp. nova 132
Perigrapha Hafellner 135
Perigrapha nitida Ertz, Diederich, Christnach & Wedin sp. nova 136
Sigridea Tehler 138
Sigridea labyrinthica (Follmann) Ertz & Diederich comb. nova l 39

Doubtful species 143
Celidium bacidiosporum Steiner 143
Celidium dubium Linds 146
Acknowledgements 147

References 147
Index 152
Index of hosts 152
Index of lichenicolous fungi 153