Book Review of Ascomycota Syllabus of Plant Families 1/2

Submitted by Tina on 5 May 2017.

Ascomycota 1/2

Syllabus of Plant families (2016)

Wolfgang Frey (Editor)

Review by Trond Schumacher, University of Oslo


While fungi are no longer part of the Plant Kingdom, they were formally included within the classic ‘Syllabus der Pflanzenfamilien’ which comprised families of blue green algae, algae, fungi, lichens, ferns, gymnosperms and flowering plants. When time has come to a new volume (13th edition) of this classic book series, a book dealing with the Ascomycota, i.e. volume 1/2 Ascomycota (2015), is also hidden behind the misleading title.  This time also with an English edition adjusted to young international students who is not familiar with the German language

The book is highly welcome, because, as we read in the Introduction to the volume:  “The last two and a half decades have provided revolutionary new insights into the phylogeny and diversity of organisms on earth. This is particularly true of the Fungi, where phylogenetic revisions have revolutionized the systematic classification of taxa from phylum to species level and a new understanding of fungal evolution and species delimitation has emerged. These new insights are here treated in an integrated context of morphological and molecular data, providing an up- to date synopsis of this phylum while acknowledging that the systematic classification of this diverse group of Fungi is not yet fully settled.  . . . this synthesis includes a complete phylogenetic synopsis of all taxa down to genus level together with detailed descriptions for all families, and complete listings of genera per family, with estimates of species numbers at the family or genus level, integrating classical anatomical-morphological characters with modern molecular data, combined with numerous new discoveries made during the last ten years”.

Ascomycota is the largest phylum of fungi comprising ca 6100 genera, and the total number of species approx. 57000. The systematics of this group of fungi has changed dramatically from textbook classifications published until a decade ago. This is mainly a result of the outcome of the ‘Deep Hypha’ project launched at the IMC 7 in Oslo in 2002, and concluding in a separate volume of the journal Mycologia in 2006 titled: ‘A phylogeny for kingdom Fungi – Deep Hypha issue’.  The phylum now contains three subphyla, the Saccharomycotina, the Taphrinomycotina, and the Pezizomycotina, and the three subphyla contain 18 formally recognized classes, by far most of them (13) in the Pezizomycotina.

In this volume of the Syllabus, classes and subclasses are arranged in systematic order and within each class or subclass, orders, suborders, and families in alphabetical order, with the families in some cases divided into subfamilies. The total number of families of Ascomycota is 406, plus an additional 10 lineages that might represent separate families but have not yet been formally named. Nearly 4000 genera of Ascomycota are explicitly listed in the volume, many of them with reference to recent monographs when available,

A closer look at the Pezizomycotina, which comprises 90 % of the species of Ascomycota and 50 % of Fungi, gives the impression of a thorough updating of familial and generic affiliation of species based on recent taxonomic revisions. A good example is found in the order Leotiales, where the two morphologically similar genera Sarcoleotia and Microglossum are accommodated and referred to the family Geoglossaceae and the Leotiaceae, respectively. This is where they rightly belong, as first demonstrated in the work by Sandnes (2006), which represent the first molecular work on a broad sampling of the morphologically similar and dissimilar ‘earth tongues’ of the order Helotiales, inclusive of the family Geoglossaceae ss. lato. She inferred three major clades in this group of fungi, one clade constituting the genera Geoglossum Pers., Trichoglossum Boud., and Sarcoleotia Ito and Imai, referred to the family Geoglossaceae ss. str., a second clade of Leotia Pers. and Microglossum Gillet and sister to the family Geoglossaceae, and a much diverging third clade of Cudonia and Spathularia spp. These separate lineages of the Helotiales fully support the disposition in the Syllabus, i.e. in placing them in different families and orders, i.e. the Geoglossaceae and Leotiaceae of the order Leotiales, and the family Cudoniaceae of the order Rhytismatales. These three lineages and families are now segregated from the earlier much too broadly defined Helotiales. The unwillingness by the authors of Syllabus to accept a separate class, Geoglossomycetes, for the Geoglossaceae ss. str., such as proposed and maintained in the work by Hustad et al. (2013), is understandable. When opposing the disposition on supra- and infrageneric classifications proposed in this latter work, it would have been at place to refer to the circumscription of generic and evolutionary lineages outlined in Sandnes (2006). However, this latter work seems to have escaped the recognition by the present authors of the Ascomycota volume, probably because of the undercommunication of Sandnes’ conclusions in the reference work by Hustad et al. (2013). I fully agree with the authors of the Syllabus that to resurrect the order Leotiales Carpenter to accommodate the two families Geoglossaceae and Leotiaceae is a better solution than establishing a new class Geoglossomycetes for the Geoglossaceae ss. stricto, such as proposed by Schoch et al. (2009) and Hustad et al. (2013).


Another reason to welcome this volume of the Syllabus is the extensive use of excellent and always sharp and correctly determined photographs of representatives of the various larger ascomycete groups. This will be much appreciated by the students who want to get an overview of present day classification of the Ascomycota. Masters and students of mycology and biology will need to ensure this volume for their private library. At a university library, this volume, and probably the whole book series, will be sought after and consequently is a ‘must have’.       


Trond Schumacher