CA Mushrooms
CA Mushrooms

Book Review

The Genus Mycena s.l.
Fungi of Northern Europe, Vol. 5

By Arne Aronsen & Thomas Læssøe
2016; The Danish Mycological Society
ISBN 978-87-983581-2-1
Hardcover, 373 pages
Publisher’s price: DKK 375 / 450 (DMS members / non-members;
European booksellers pricing range: €60–€90

I live in Seattle, a city which has long been a national leader in recycling, and so it seems natural that I should indulge in a little recycling of text from my review of Volume 4 (Tricholoma) in this series of monographic guides ... Most mushroom hunters who have a keen interest in identifying the different fungi they find are familiar with the six-volume series, Fungi of Switzerland, generally known as the “Swiss books.” I don’t know whether the Swiss mycologists are big baseball fans or not, but they “batted 1000” by producing 6 out of 6 excellent books. More recently, the Danish Mycological Society embarked on a series of books covering the mushrooms of northern Europe. Although very different from the Swiss books in their approach, with their latest effort, they are now 5 for 5, maintaining their own perfect batting average.

Volume 5 describes 115 of the 160 species of Mycena (in the broad sense) that have been reported to occur in northern Europe. Of the 115, 60 are described, and 10 others mentioned, in Alexander Smith’s North American Species of Mycena. Thus, the book should be useful to North American mushroom hunters. Although the authors acknowledge that the genus as traditionally circumscribed is in the process of being split up, largely in response to DNA sequencing, they sensibly chose to retain most species in a traditional broad concept of the genus, other than including one species each in Roridomyces and Resinomycena.

The attractive appearance and overall organization of this volume are much the same as in its four predecessors (covering Hygrocybe, Lactarius, Hebeloma, and Tricholoma). After the acknowledgments and two prefaces, the introduction summarizes the authors’ methodology, provides a lengthy description of Mycena (in the broad sense) covering both the macroscopic and microscopic features (well illustrated with excellent photographs and line drawings), and continues with brief summaries of ecology and habitat (illustrated with photographs of typical habitat sites and a characteristic species of Mycena found in each one), conservation aspects, season of fruiting, cytology and culture studies, bioluminescence, toxicity, fungus parasites of the genus, phylogeny, and their species concept and systematic arrangement of taxa within the genus. Species concepts and the classification scheme generally follow those of Maas Geesteranus and, thus, are based principally on morphological characters. However, the authors are careful to point out that the results of DNA sequencing will no doubt lead to changes in both.

Next comes a six-page summary of 27 genera that might be confused with mycenas. Each receives a brief paragraph highlighting distinguishing features, plus one or two photographs of a typical species. This is followed by the keys — an initial key to mycenoid genera (and selected species), then two groups of keys to the species of Mycena. The first group of species keys emphasizes macroscopic features and the second makes greater use of microscopic features. Although some species can be identified using only macro features, a larger number require consideration of microscopic features. The last section of the up-front material is a handy listing of species by habitat and substrate.

The main section of the book contains the descriptions. Each species receives at least two pages that include a comprehensive but succinct description, comments on ecology and distribution, and a discussion of the taxon in relation to possible lookalikes and other taxonomists’ concepts. Illustrations for each taxon include at least two high quality color photographs that are particularly effective for identification, and excellent line drawings of cap surface hyphae, spores, cheilocystidia, and stipe surface hyphae.

The book concludes with presentations of a variety of additional information — formal descriptions of the two species newly described in the book, a nomenclatural note concerning Mycena rosea, brief discussions of 46 taxa not treated in the main text, of 11 rejected names, and of 19 names the authors consider to be dubious, lists of taxa excluded either because they are presumed not to occur in northern Europe or because they have been transferred to other genera, a 14-page list of references, and a taxonomic index.

Congratulations to Aronsen and Læssøe, and the editors of the Fungi of Northern Europe series on another first-class effort. Beautiful, professionally presented, and just the right amount of information to help us get a handle on northern Mycena species.

— Review by Steve Trudell
— Originally published in Fungi