A new genus classification of the Thelotremataceae is presented. Myriotrema, Ocellularia and Thelotrema sensu HALE (1980, 1981) were found to be heterogeneously circumscribed and were segregated into more natural units. The following changes are made: Ampliotrema Kalb is validated, and Chapsa Massal., Leptotrema Mont., Leucodecton Massal. and Stegobolus Mont. are resurrected. The genera Acanthotrema A. Frisch, Gyrotrema A. Frisch, Melanotrema A. Frisch and Redingeria A. Frisch are described as new to science. 19 genera are accepted for the family: Acanthotrema, Ampliotrema, Chapsa, Chroodiscus, Diploschistes (not treated), Fibrillithecis, Gyrotrema (part II), Ingvariella (not treated), Leptotrema, Leucodecton, Melanotrema (part II), Myriotrema, Nadvornikia (not treated), Ocellularia, Redingeria (part II), Reimnitzia, Stegobolus (part II), Thelotrema and Topeliopsis. The Thelotrema glaucopallens- and the Ocellularia clandestina-group are of uncertain generic affiliation.

The first and major part is based on the PhD thesis of the first author of all 3 papers.

A new genus classification of the Thelotremataceae is presented which became necessary because Myriotrema, Ocellularia and Thelotrema (sensu Hale) were found to be heterogeneous. 19 genera are now accepted for the family including the resurrection of Chapsa A. Massal., Leptotrema Mont., Leucodecton A. Massal. and Stegobolus Mont., the validation of Ampliotrema Kalb and the newly described genera Acanthotrema A. Frisch, Gyrotrema A. Frisch, Melanotrema A. Frisch and Redingeria A. Frisch. Unfortunately two groups of uncertain generic affiliation remain, the Thelotrema glaucopallens- and the Ocellularia clandestina-group.

The revision is based on some 1300 collections by the author from Cameroon and Tanzania and about 120 additional specimens obtained from public herbaria. 38 of the formerly recorded 73 taxa from Africa are accepted as valid species, but some had to be excluded from the family. 17 species are described as new to science (in parts one and two) and a further 47 species are recorded for the first time from Africa. In all, 94 species are presently known from the continent. All these species are described and illustrated in detail and keys to genera and species are given. Checklists for Thelotremataceae in the African countries based on verified names and some reliable, more recent literature sources are presented in an appendix. This is an enormous step forward in the knowledge of African crustose lichens independent from the acceptance of all the taxonomic changes which can only be proofed by time and deeper knowledge. In the final paper of this collection, the authors reinforce their classical taxonomy with molecular methods, obtaining new sequence data for 46 species of Thelotremataceae, representing 13 out of the 19 accepted genera and the uncertain Thelotrema glaucopallens- and Ocellularia clandestina-groups. The results of the Bayesian analysis of mitochondrial 16S rDNA gene data are in fairly good congruence with the proposed new classification scheme.

The volume is concluded by a taxonomic index for all three contributions together. A minor criticism might be that not all authors are cited according to the widely accepted index of authors of fungal names (e.g. "Dodge" instead of "C. W. Dodge" or "Massal." instead of "A. Massal.") or that the names in appendix 2 "Excluded or dubious names" are not completely in alphabetical order, but these are rather unimportant points compared to the huge work presented with these contributions. Clearly, this book belongs in every taxonomic lichen library. It is the most important contribution to African lichenology since SWINSCOW & KROGs Macrolichens of East Africa published in 1988.

The Editor

International Lichenological Newsletter vol. 39 no. 1 (Sept. 2006), p.3-4

In the second part, the authors show that taxa with complex columella structures evolved independently and make sense of this by establishing three new genera, Gyrotrema, Melanotrema, and Redingeria, and reinstating the old name Stegobolus, while retaining a couple of species in Myriotrema and Ocellularia. Except for Redingeria, for which no sequences were available, and the apparently polyphyletic Stegobolus, the concept is confirmed by molecular data. However, one might have problems to distinguish Redingeria and Stegobolus. In the discussion of Redingeria, it is stated that Stegobolus is "... well distinguished ... in morphology and might be only distantly related." (p. 406), but the picture of Redingeria glyphica (Pl. 20) closely resembles Stegobolus species (e.g., Pl. 21, 23). According to the key, the diagnostic differences are the Redingeria-type ascospores and the inclusion of ascospore remnants in the excipulum, but it takes a while to find out what exactly Redingeria-type ascospores are. The difference in ornamentation, depicted in Fig. 121 (Redingeria) versus 129b (Stegobolus), does not appear significant, especially as the ascospore in Fig. 121 is fully turgescent, while the one in Fig. 129b appears collapsed. The structure of the ornamentation itself is similar and could even be interpreted as a synapomorphy. As for the inclusion of old ascospores in the excipulum and columella, the authors themselves state that this character is "... of limited taxonomic relevance." (p. 406). The remaining differences are the thick-walled ascospores (especially when young) with irregular lumina in Redingeria, but it remains to be tested whether these hold as diagnostic characters at genus level.

One also wonders about the separation of Melanotrema versus the Ocellularia auberianoides group, including the common neotropical O. bahiana (formerly in Myriotrema). In the key (p. 378), the main difference is the carbonized versus pale to brown excipulum, but species with different excipular pigmentation are accepted in Ocellularia. The Ocellularia auberianoides group is said to have an excipulum with "... clearly radiating hyphae ..."; the corresponding character is not mentioned for Melanotrema, but in the discussion the latter genus is said to have an excipulum with "... clearly radiating hyphae ..." (p. 383). The phenocortex of Melanotrema is said to be "... loosely organised or cartilaginous ...", while the corresponding alternative for the Ocellularia auberianoides group is not given. In the descriptions, the phenocortex is given as formed from irregular hyphae for both groups. At the species level, some conclusions are difficult to follow. The African material of Acanthotrema brasilianum differs from neotropical populations by submuriform versus 3-septate ascospores and might warrant recognition at the species level. Specimens from Africa identified as Chapsa alborosella differ from neotropical material by the presence of stictic acid, but it is argued that the TLC results were contaminated by dead thalli of Graphis growing under the Chapsa specimens. It is highly unlikely that the two widely separated African collections from Tanzania and Réunion grew on dead thalli of Graphis species that both produced stictic acid, a substance which is comparatively rarer in Graphis than in Chapsa. Thelotrema platycarpoides is listed as synonym of Chapsa platycarpa and said to represent a juvenile form of the latter because of the small apothecia. However, the ascospores of the latter are mostly 5-septate, while typical C. platycarpa has 3-septate ascospores, which contradicts the hypothesis of the former being a juvenile form of the latter.

The genus keys work relatively well, but a good knowledge of the morphological concepts outlined throughout the book are required to use the keys, since terms such as Ocellularia-type excipulum or Redingeria-type ascospores are frequently used. A quick reference as to where these terms are defined, or perhaps a short, illustrated glossary, would have been helpful. The lengthy couples in the genus keys make it sometimes difficult to filter the characters that separate a genus from another; it might have been better to exclude most of the non-differential information. The species keys work well, although in some instances (e.g., Redingeria), they strongly rely on chemistry, and one is required to do TLC before even starting to work with the key, especially in cases where spot tests do not work.

The third part of the work is a first attempt to test the generic rearrangement with DNA data. The number of newly produced sequences is impressive and many of the genera are supported, such as Chapsa, Fibrillithecis, Leucodecton, and Melanotrema, while a few need further study. The inclusion of the molecular phylogeny in this work supports the systematic changes, but as a stand-alone paper, one would have wished for more rigorous analyses of the data, including maximum parsimony and alternative hypothesis testing. The placement of the figures as appendix is odd, and it also takes some time to realize that the four trees do not represent different analyses, but map different taxonomic groups and characters on the same tree. Otherwise, this analysis is an excellent base for further studies and identifies the problematic genera and species groups.

The taxonomic index at the end of the book is a bit difficult to use since the epithets are listed under the genera in which they were described. In order to find an epithet, one has to know the original genus or scroll through the entire index. Alphabetical arrangement of epithets, with corresponding genera in brackets, would have been a more practical solution. A few other inconsistencies might also be mentioned. The concept of "phenocortex" does not conform to its original definition, according to which a phenocortex is a cortex-like structure formed by dead algal cells, hyphal fragments, and other materials. From the descriptions and illustrations (p. 37ff), it is obvious that Thelotremataceae largely feature a true cortex formed 552 by fungal hyphae (e.g., Pl. 1d). Naming the perfectly conical columella shape in Fig. 5c "truncated conical", while the shape that resembles a skittle (Fig. 5a) is termed "conical", will cause confusion. It probably stems from the notion that in German, skittles are named "Kegel" ("cones"), even if those "Kegel" are not conical in the technical sense. The species descriptions are reversed, mentioning ascospore characters before asci and paraphyses, which makes them more difficult to read. In some places, data on distributions are inconsistent. Chapsa indica is given as ´Africa and tropical Asia¡, while the pantropical Thelotrema pycnophragmium is listed as a synonym. On page 328, is is stated that Thelotrema glaucopallens "... might be rare or even absent in some areas for no obvious reasons ..." (citing Hale’s Sri Lanka paper from 1981), but it is difficult to understand how the absence of that species in East Africa "... can be explained by this ...". A few Latin epithets are incorrect. Chapsa cinchonara should read cinchonarum, as it represents the genitive plural of the tree genus Cinchona. Ocellularia polydisca should read polydiscus, the epithet being a noun. In the citations of Leucodecton subcompunctum (p. 163) and Reimnitzia santensis (p. 272), the term "lectoparatype" is used, suggested some time ago to denote those syntypes or paratypes remaining after lectotypification. However, it was argued (Vorster, Taxon 35: 316-317, 1986) that such a designation has no meaning, since syntypes and paratypes are not types and, with the selection of a lectotype, cease to have value for typification, except for the original protologue in which they continue to be syntypes or paratypes. Thus, there is no provision in the Code for the term "lectoparatype" and such material cannot be cited as type. The (≡) sign is applied against current usage to denote heterotypic taxonomic synonyms, for which the (=) sign should have been used instead.

Overall, the CONTRIBUTIONS TOWARDS A NEW SYSTEMATICS OF THE LICHEN FAMILY THELOTREMATACEAE is an important work, indispensable for colleagues and students dealing with tropical lichens. It represents an outstanding treatment of African Thelo-tremataceae and an important step towards a generic rearrangement of the family, including a wealth of data and new ideas which will stimulate many further studies in this diverse group of lichens. The book invites for comparison with Staiger’s DIE FLECHTENFAMILIE GRAPHIDACEAE, and while both have a similar underlying philosophy, the CONTRIBUTIONS TOWARDS A NEW SYSTEMATICS OF THE LICHEN FAMILY THELOTREMATACEAE has the advantage of being entirely in English and thus accessible for a wide audience. The taxonomic treatment, even if geographically restricted to Africa or taxonomically to the species with complex columella, is very useful for identifying species at the world level, especially as many non-African taxa are discussed in the first part. Students will be happy to see that, while Staiger’s Graphidaceae from 2002 is priced at 128,- (approx. $ 165,-), the 88,- ((approx. $ 113,-) for the present book are much more reasonable, especially considering that it has 40 pages more and twice as many photographic plates, all integrated in the text.

ROBERT LÜCKING, Chicago

Nova Hedwigia 84 3-4, p. 549-552

The first part excludes taxa with complex columella structures, which are dealt with in the second part, co-authored by Klaus Kalb. This revises taxa worldwide with a reticulate or fissured hymenium. Some 650 specimens, including pertinent types, have been examined and 42 species are accepted dispersed through five genera, three of which are newly described (viz. Gyrotrema, Melanotrema, and Redingeria). The largest is Stegobolus (26 spp.), a resurrected generic name introduced by Montagne in 1845 and hardly used since. The other genera are much smaller: Gyrotrema has one species, Melanotrema six, Ocellularia four, and Redingeria five.

In the final part, the authors combine with Martin Grube to test the robustness of the new systematic proposed by molecular methods using material of 46 species representing 13 of the now recognized genera. There was a “fairly good congruence” (p. 518); Fibrillithecis, Myriotrema, and Ocellularia formed a monophyletic clade, and the rest of the genera a polyphyletic looser Thelotrema cluster. However, Ampliotrema was not supported, and the family concept is brought into question by two Graphis species clustering with the Ocellularia clade. It would be interesting to see the results of an analysis including larger numbers of species, and especially representatives of genera currently placed in Graphidaceae.

The contrast of the generic classification proposed here with the three-genera system (viz. Myriotrema, Ocellularia, and Thelotrema) adopted by Mason E. Hale in the early 1980s, can only be described as staggering. The systematics of the thelotrematoid fungi is raised to a new level by this major work, and the generic placement of many Asian and Neotropical species lacking complex columella structures will now have to be revisited. It is an outstanding achievement.

Mycotaxon vol. 107, 2009 p. 520