These two German lichen books appeared simultaneously and share the same first author. The books have more in common: they are both richly illustrated with colour pictures, some of which are in fact shared, they are both intended for use in the whole of Central Europe, and the taxonomy and nomenclature is virtually the same.
Die Flechten Deutschlands is an adapted and enlarged version of the famous Die Flechten Baden-Württembergs (Wirth Reference Wirth1995). Its basic structure, with elaborate keys and abbreviated data about ecology and distribution, but without descriptions, is essentially the same, except that no distribution maps are given. The book now covers all species reported from the whole of Germany. It thus contains more taxa, and many additional photographs, often of species that are rarely illustrated. Some of the previous photographs have been replaced, especially in cases where the identification has been reported as wrong, like that of Cladonia foliacea. The illustrations are among the best lichen photographs in the world, and the book is carefully printed. Only in a few cases are the pictures unsatisfactory: Pertusaria coccodes and P. flavida, on opposite pages, are printed in the same colour, while they are markedly different in the field; the two Flavoparmelia species on opposite pages do not show the colour difference nor the distinction in the soredia; and the red of the red Cladonia species is a bit too bright. The only possibly incorrect identification that struck the eye is that of Lopadium pezizoideum, which seems to be L. disciforme.
The expansion to cover the whole of Germany is mainly by the addition of distribution and ecology data from Northern Germany, and the addition of some coastal or even maritime species. This has been done quite thoroughly by various collaborators from these regions. Obviously, some specialties of Northern Germany (as compared to the South) have still been overlooked. Examples of missed distributions among the macrolichens are Arctoparmelia incurva, which is still occurring on several places in the western lowlands in Lower Saxony (cited as extinct there already before 1950) and Cladonia callosa (not cited from this region at all). Examples of ecologies that were missed out are the saxicolous occurrences of Fellhanera bouteillei, F. subtilis, F. viridisorediata, Fellhaneropsis myrtillicola, and Lecanora horiza, all of which are rather common on rock in the area, the first four on siliceous rock, specifically roof tiles, the last one on vertical limestone of grave stones and rock outcrops. Some species are added awkwardly or with wrong characters into the old keys: for instance, Opegrapha areniseda is keyed out on the sole character that it occurs on sand, which is not the case in Germany and not the normal substratum of this species anywhere.
Another challenge of the expansion was the need to treat some species that are incompletely known, and of which only the type exists. This applies especially to genera like Staurothele, Thelidium and Verrucaria, and the much expanded keys to these and other genera contain (very welcome) information on some dubious taxa. This original information makes the book a must for all specialists. The keys are mainly written by the authors; only one key, that of Caloplaca, gives Vondrak and Wirth as authorship. It is not the best key in the book, and partly keys out to entities marked as s. lat. or group or sometimes two species, while the corresponding entries are not given ecological or distributional notes, only the individual species. In some places it is unclear if these notes are included under the name-giving species or also partly elsewhere.
A very modern classification has been adopted throughout the book. Since 1995, there have been a lot of name changes, mostly generic fragmentation due to phylogenetic reconstructions, but also newly unearthed epithets and cases of changed opinions on taxon delimitation. It is in itself laudable that virtually all proposed changes have been followed, and the book can be used for some time as an updated checklist. There are however drawbacks: some of the proposed changes will not last, and this is awkwardly demonstrated here. During the final stage of the preparation of this book a new classification for Xanthoria s. lat. was (again) proposed, and this will render this the only book ever in which the genera Gallowayella, Massjukiella, Oxneria, and Rusavskia are accepted. The adoption of novel taxonomy has also led in some cases to somewhat inconsistent treatments. Species like the above-mentioned Opegrapha areniseda and O. rupestris probably belong to one of the other genera where former Opegrapha species are now classified. Buellia splits-offs like the monotypic Monerolechia and Tetramelas are accepted, but Hafellia is not, making the remaining genus quite polyphyletic. Also, although lichenicolous non-lichenized ascomycetes are in principle not treated, there are here and there some included in generic keys if they are belonging to genera which also include lichens, like Arthonia, Arthrorhaphis and Opegrapha. However, the fragmentation of genera means that now some species in genera like Placographa and Placothecium are keyed out. They are only in the key because they were once Opegrapha species. The treatment of these taxa is somewhat inconsistent in any case: ecology and distribution is given for all Arthrorhaphis species, but for only one of the lichenicolous Opegrapha species (O. rupestris), and for none of the lichenicolous Arthonia species. They are all keyed out though, but two common lichenized Arthonia species (A. atra and A. calcarea) are not keyed out in the Arthonia key. Another source of inconsistency is introduced by the occasional inclusion of extra-territorial species in the keys, such as some Scandinavian Biatora species. These do not make the book significantly more complete but make the Biatora key even more complex.
Very few subspecific taxa are accepted. There are a few notable cases in Cladonia, where C. chlorophaea is treated as a single entity and C. pocillum and C. pyxidata are still united under one species, and where C. verticillata is treated as a subspecific taxon of C. cervicornis, while C. pulvinata is accepted. Somewhat surprisingly, Haematomma ochroleucum and H. porphyrium are treated as separate species, just as it was until the seventies of the last century. The rationale is not given and the most recent paper mentioned is the monograph by Staiger & Kalb (Reference Staiger and Kalb1995), who do not accept H. porphyrium, not even at subspecific rank, and only refer to it as a variety in a note. Similar cases where variation exists in cortical pigmentation without correllation to morphology or ecology, such as Evernia herinii and E. prunastri and Lecanora flotoviana and L. xanthostoma (now both in L. semipallida), are not treated at species level.
Flechten einfach bestimmen is a very practical guide. It is small enough to take to the field and has 11 concise keys to groups like “Flechten überall auf Bäumen”. These keys generally lead you to one or two pages in the book, on which one or more similar species are treated with a full description, all of them illustrated in colour. As with the other book, the nomenclature is very modern, the only difference being that newer names are used for the Xanthoria species, which are here partly in Xanthoria, partly in Polycaulionia. A bonus is that German names are given for all species treated.
A very good feature of the book is that when a species is compared with another species, for example, Amandinea punctata, Buellia griseovirens and Cladonia coniocraea, another picture is given. This way, many species are illustrated twice, which will greatly help understanding the variation. Altogether, about 400 species are treated. The pictures are mostly good and the selection of species treated and the attribution to the various ecological groups is sensible. It is to be expected that many people will be able to identify the majority of the lichens with this book, even without previously attending specialised excursions. A few minor comments: Peltigera will be a problem area, as no lower surfaces or rhizines are illustrated. Also, I disliked seeing Cladonia coniocraea treated as a terricolous lichen. It is really an epiphyte or lignicolous, and faulty vegetation relevés from dunes and heathlands can for instance be weeded out on the sole purported presence of this species on bare soil.
When new books are published, one is always confronted with the dilemma: buy it or not? This is especially acute when books are adaptations or new editions of previous books already in one's possession. In this case, I would heartily advise every lichenologist, even those who already have a copy of Die Flechten Baden-Württembergs, to buy Die Flechten Deutschlands, as it contains much novel information, in the keys, the text and in the illustrations. Similarly, I would suggest at least everybody who is active with lichen excursions in Central Europe to obtain a copy of Flechten einfach bestimmen. The claim that you can identify most of the common lichens in Central Europe with it is not far-fetched, as long as you don't pay too much attention to little green crusts or get to very rich localities in the Alps!
