Wijayawardene et al. 2020
Classification of the kingdom Fungi has been updated continuously, with the frequent inclusion of data from DNA sequences in recent studies. Re-collecting historic taxa and neo- or epitypifying them by using both fresh material and cultures is also an increasingly common practice among mycologists, although yet not easily accomplished in some groups. Utilization of environmental sequences for recognizing taxa that are not observed directly and naming them with only a sequence as a holotype is a controversial topic that remains to be addressed (Hongsanan et al. 2018, Lücking & Hawksworth 2018, Lücking et al. 2018, Thines et al. 2018, Zamora et al. 2018).
Tedersoo et al. (2018) proposed a novel classification for the kingdom Fungi that was based on phylogenies and the divergence time of particular taxa. Using these criteria, they accepted 18 phyla: Aphelidiomycota, Ascomycota, Basidiobolomycota, Basidiomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota. This study was, however, based on only 111 taxa and it remains to be seen how widely it will be accepted and stand up as more taxa are analyzed. Outlines for the Ascomycota (and notes for genera in the Ascomycota) and the basal clades of fungi (Wijayawardene et al. 2017, 2018a, b) have been published, with the participation of experts in particular groups. Jaklitsch et al. (2016a) provided a synopsis of accepted Ascomycota families with descriptions and lists of included genera (and their synonyms), and Begerow et al. (2018) prepared a parallel treatment for the families of Basidiomycota and Entorrhizomycota, including brief diagnoses and indications of ecology and distributions for all genera (though without listing synonyms of genera and with some genera that are still debated). A separate outline, with notes and divergence times of Basidiomycota was also published by He et al. (2019).
Wijayawardene et al. 2022
The ‘Outline of Fungi and fungus-like taxa’ (Wijayawardene et al. 2020a) was the first attempt at compiling a classification of all taxa (from genera to higher levels) in the Kingdom Fungi, with the contribution and agreement of 155 authors. The Outline listed higher-level taxa (phyla, classes, orders, families and genera) in the higher fungi (i.e. Ascomycota, Basidiomycota), early-diverging lineages of fungi, fossil fungi and fungus-like taxa. Moreover, the estimated number of species based on the available data, for each genus, was included. During preparation of the manuscript, the authors recognized the necessity to continuously update such an important database, and thus www.outlineoffungi.org was developed (Wijayawardene et al. 2020b). One of the important features of the Outline of Fungi is providing a platform for different opinions on different taxa, mainly at higher ranks. As an example, Wijayawardene et al. (2020a) included two different classifications for Leotiomycetes and Glomeromycota. The aim of including these differing opinions was to make these aware to taxonomists and mycologists since it is vital to discuss divergent views broadly, rather than ignoring or excluding them without rational arguments. It is widely accepted that only ca. 150,000 (5-10%) species of fungi (Species Fungorum 2021) are currently recognized, thus classification conclusions will be subjective. Nevertheless, publishing such controversial opinions in a single peer reviewed article is challenging; hence, the series of Outline of Fungi and its web page (https://www.outlineoffungi.org/) aim to provide an opportunity for this.