Handbook of Ascomycota, Vol. 1a Bildband. Pyrenomycetes s.l.” and Handbook of Ascomycota, Vol. 1b Bildband. Preynomycetes s.l
Reviewed by: Dr. Amy Rossman
Wergen, Björn 2018 Handbook of Ascomycota, Vol. 1a Bildband. Pyrenomycetes s.l. Sordariomycetes, Dothideomycetes, Eurotiomycetes. Arten mit ein- bis zweizelligen Sporen. Funghiparadise Productions.
Wergen, Björn 2018 Handbook of Ascomycota, Vol. 1b Bildband. Preynomycetes s.l. Sordariomycetes, Dothideomycetes, Eurotiomycetes. Arten mit zweifach septierten bis mauerförmigen Sporen. Funghiparadise Productions.
Anyone who has ever tried to identify pyrenomycetes, those tiny little black spheres, knows that it’s really, really hard. Truly there are no books that cover all of them anywhere in the world. The two volumes reviewed here are amazing and should be purchased by those who wrestle with these fungi.
Each book is a compilation of color plates usually one for each species. Each plate consists of close-up macrophotos of the fruiting bodies, often including a cross-section plus asci and ascospores and conidia. All micrographs are of excellent quality with good contrast showing diagnostic characteristics such as ascal apices and ascospore septation. For some species the asexual morph is also presented with the sexual morph as for Calonectria lauri; however, for others in which the sexual morph is unknown or rarely seen, there is a section devoted solely to those only known in that morph. The plates are presented in numerical order starting in volume 1a up to number 0820 to give you an idea of how many species are included in these volumes.
Each volume starts with a simple pictorial key to ascospore morphology with headings in both German and English. This starts in the first volume with hyaline, non-septate (no. 0000-0064) and brown, non-septate (no. 0065-0197). Like I said, these fungi are difficult and even dividing them into these hopefully easy-to-recognize differences is not easy. For example, among dark, non-septate ascospores for nos. 0124-0128 are species of Eutypa with barely yellowing ascospores that one might consider hyaline. The next lead is for spores with one septation divided into hyaline, equally one-septate, versus bicolored, often unequally septate, and brown, one-septate. Here the septation on some of the hyaline, septate ascospores is difficult to discern even in these high-quality photographs, for example, nos. 0198-0200 species of Coronophora in which the septum is not visible.
The second volume includes the completed pictorial key of species with two-septate to muriform ascospores, another reason that both volumes should be purchased. Next is a second pictorial key to fruiting body characteristics separating each ascospore group into those with fruiting bodies that are black, coloured, or stromatic and then those that are smooth, with conidia, or hairy/setose. In both volumes the keys are followed by a series of plates illustrating these characteristics. For example, in the first volume there are two plates illustrating the diversity of hairy or setose fruiting bodies, one plate showing color variations in fruiting bodies, another with wall structures, three plates illustrating the variety of ascospore septations and color, several plates with various ascal apices showing a reaction to iodine or Congo red, and two plates showing the micromorphology of members of the Amphisphaeriales and Xylariales. A similar set of plates illustrates the diversity of morphology in fungi in the second volume.
One issue that the author apparently recognizes as indicated by his request for corrections is the use of outdated names, for example, Bionectria is now considered a synonym of Clonostachys, thus Bionectria ralfsii is Clonostachys ralfsii and all species of Hypocrea are now placed in Trichoderma, thus H. citrina should be T. citrinum. For some taxa a correct name simply does not exist; for example, Pleospora is now regarded as Stemphylium but no names exist for Pleospora alnicola or P. helvetica and others. However, the majority of names reflect the use of one scientific name for fungi.
Both volumes include an alphabetical listing of the species with each number. At the end of the second volume is an index listing the species by host genus for both volumes.
Those studying microfungi are extremely grateful to Björn Wergen for these excellent, well-illustrated accounts of such beautiful, but difficult, fungi.
Amy Rossman, Book Review Editor
Department of Botany and Plant Pathology
Oregon State University
Corvallis, Oregon, USA