Competing sexual-asexual generic names in Agaricomycotina (Basidiomycota) with recommendations for use

With the change to one scientific name for fungal taxa, generic names typified by species with sexual or asexual morph types are being evaluated to determine which names represent the same genus and thus compete for use. In this paper generic names of the Agaricomycotina (Basidiomycota) were evaluated to determine synonymy based on their type. Forty-seven sets of sexually and asexually typified names were determined to be congeneric and recommendations are made for which generic name to use. In most cases the principle of priority is followed. However, 16 generic names are recommended for use that do not have priority and thus need to be protected: Aleurocystis over Matula; Armillaria over Acurtis and Rhizomorpha; Asterophora over Ugola; Botryobasidium over Acladium, Allescheriella, Alysidium, Haplotrichum, Physospora, and Sporocephalium; Coprinellus over Ozonium; Coprinopsis over Rhacophyllus; Dendrocollybia over Sclerostilbum and Tilachlidiopsis; Diacanthodes over Bornetina; Echinoporia over Echinodia; Neolentinus over Digitellus; Postia over Ptychogaster; Riopa over Sporotrichum; Scytinostroma over Artocreas, Michenera, and Stereofomes; Tulasnella over Hormomyces; Typhula over Sclerotium; and Wolfiporia over Gemmularia and Pachyma. Nine species names are proposed for protection: Botryobasidium aureum, B. conspersum, B. croceum, B. simile, Pellicularia lembosporum (syn. B. lembosporum), Phanerochaete chrysosporium, Polyporus metamorphosus (syn. Riopa metamorphosa), Polyporus mylittae (syn. Laccocephalum mylittae), and Polyporus ptychogaster (syn. Postia ptychogaster). Two families are proposed for protection: Psathyrellaceae and Typhulaceae. Three new species names and 30 new combinations are established, and one lectotype is designated.


INTRODUCTION
With the change to one scientific name for fungal taxa in accordance with the International Code of Nomenclature for algae, fungi, and plants (McNeill et al. 2012;Turland et al. 2018), there is a need to determine which generic name should be applied when two or more generic names typified by types representing different morphs are congeneric. Formal recommendations about which generic name to use have been made by specialized Subcommissions or Working Groups (WG) of the International Commission for the Taxonomy of Fungi (ICTF) as discussed by May (2017). A number of publications have recommended generic names for use in major groups of Ascomycota, including Sordariomycetes such as Diaporthales (Rossman et al. 2015a), Hypocreales (Rossman et al. 2013;Quandt et al. 2014;Kepler et al. 2017), Magnaporthales (Zhang et al. 2016), Microascales and Ophiostomatales (De Beer et al. 2013), Xylariaceae (Stadler et al. 2013) and remaining Sordariomycetes (Réblová et al. 2016), as well as Dothideomycetes (Rossman et al. 2015b), Eurotiales (Samson et al. 2014;Visagie et al. 2014), Leotiomycetes including Erysiphales (Braun 2013;Johnston et al. 2014), Pezizomycetes (Healy et al. 2016), yeast fungi (Daniel et al. 2014), and overlooked generic names in the Ascomycota (Rossman et al. 2016a). Within the Basidiomycota a paper on the Pucciniomycotina and Ustilaginomycotina has been published (Aime et al. 2018). Where recommended names do not follow the principle of priority, such names need to be confirmed for protection by the Nomenclature Committee for Fungi (NCF) appointed by the International Mycological Congress and ultimately by the General Committee on Nomenclature appointed by the International Botanical Congress. Names approved so far by the NCF have been compiled by May (2017). Once approved, protected names appear in the on-line Appendix to the International Code of Nomenclature for algae, fungi, and plants (Wiersema et al. 2020).
Generic names of Agaricomycotina representing sexually and asexually typified genera that compete for use have been evaluated by the Homobasidiomycetes WG of the ICTF**. The original members of this group were assembled prior to compilation of the list of names needing assessment and once the list was prepared, additional mycologists who have an interest in the nomenclature of this group were involved, leading to the recommendations made herein about which generic name to use. The comprehensive list of sexual-asexual generic names by Wijayawardene et al. (2012) was used as the initial starting point for determining which generic names in the Agaricomycotina compete for use. Citations for generic names and their types are based on Index Fungorum (Kirk 2020). Each set of generic names was evaluated using the current literature about the phylogenetic placement of their types to determine if the names are congeneric. A recommendation for use is presented based on consideration of such factors as priority, number of species, required name changes, and frequency of citations in the literature based primarily on Google Scholar searches (GSS). Because there are relatively few competing generic names, they are listed in alphabetical order rather than by fungal order 1 .
Forty-seven sets of generic names were identified and evaluated. Details about each set of generic names and the basis for each decision are presented below with an S indicating a sexually typified name, an A indicating an asexually typified name, and A/S indicating either ambiguity or both. The citation for each generic name, their types, accepted name of type, and action required are listed in Table 1. Many generic names recommended for use have priority by date with relatively few or no name changes required. However, 16 generic names recommended for use do not have priority and are thus recommended for protection: Aleurocystis over Matula; Armillaria over Acurtis and Rhizomorpha; Asterophora over Ugola; Botryobasidium over Acladium, Allescheriella, Alysidium, Haplotrichum, Physospora, and Sporocephalium; Coprinellus over Ozonium; Coprinopsis over Rhacophyllus; Dendrocollybia over Sclerostilbum and Tilachlidiopsis; Diacanthodes over Bornetina; Echinoporia over Echinodia; Neolentinus over Digitellus; Postia over Ptychogaster; Riopa over Sporotrichum; Scytinostroma over Artocreas, Michenera, and Stereofomes; Tulasnella over Hormomyces; Typhula over Sclerotium; and Wolfiporia over Gemmularia and Pachyma. In addition, nine specific names are proposed for protection: Botryobasidium aureum, B. conspersum, B. croceum, B. simile, Pellicularia lembosporum (syn. B. lembosporum), Phanerochaete chrysosporium, Polyporus metamorphosus (Riopa metamorphosa), P. mylittae (Laccocephalum mylittae) and P. ptychogaster (Postia ptychogaster) as listed in Table 2. Two family names are proposed for protection: Psathyrellaceae over Zerovaemycetaceae and Typhulaceae over Sclerotiaceae as listed in Table 3. Three new species names and 30 new combinations are established and one lectotype is designated.

GENERIC AND FAMILY NAMES RECOMMENDED FOR USE IN AGARICOMYCOTINA
Use Aegerita Pers. 1794 (A) rather than Crocysporium Corda 1837 or Bulbillomyces Jülich 1974 (S) The monotypic genus Bulbillomyces, typified by B. farinosus, was described as the sexual morph of A. candida (Jülich 1974), the type of Aegerita, thus these generic names are synonyms. Lyman (1907) had earlier demonstrated the link between the sexual and asexual morphs using cultures and transferred Aegerita candida to Peniophora as P. candida (Pers.) Lyman 1907. Although two species were originally included in the protologue of Aegerita, Donk (1962) explains the history and selection of A. candida as type by Brongniart (1824Brongniart ( , 1825, although Donk's interpretation of validation dates he used in 1962 must be adjusted by application of the current Shenzhen Code (Turland et al. 2018). Forty names have been described in Aegerita, although some of these have been found to belong outside of Aegerita in both Ascomycota and Basidiomycota (Kirk 2020). Within Aegerita only A. candida (as B. farinosus) has been sequenced. Recently Justo et al. (2017) showed that A. candida (as B. farinosus) was sister to the type of Hypochnicium, H. bombycinum. The name Aegerita candida is used about equally with B. farinosus (GSS A. candida = 131, B. farinosus = 105). Table 1 Recommended names of genera of Agaricomycotina among those that compete for use. The recommended accepted name is in bold; see text for the rationale for these decisions. For each name this list provides the author, its date and place of publication, type, its basionym, their dates of publication and the currently accepted name, if different. The action required is indicated in the last column, specifically approval by the Nomenclature Committee for Fungi (NCF) for those generic names that do not have priority and thus need protection   Aegerita candida is the name used by ecologists who have examined the extracellular enzymatic activity of this aeroaquatic fungus (Abdullah and Taj-Aldeen 1989). An obscure generic name, Crocysporium (GSS 32), is typified by C. aegerita, a name that is considered a synonym of Aegerita candida (Donk 1962), thus Crocysporium is a later synonym of Aegerita. Five other species names have been described in Crocysporium of which all but two are placed elsewhere and none have been widely used. Given its priority, the greater number of names, and use in ecological literature, we recommend the use of Aegerita.
Protect Aleurocystis Lloyd ex G. Cunn. 1956 (S) over Matula Massee 1888 (A) The sexual morph of the type of Aleurocystis, A. hakgallae (as Peniophora hakgallae), was connected to the asexual morph Matula poroniiforme, type of Matula, by Petch (1926) and later accepted by Martin (1940) and Giraldo et al. (2017), thus the generic names Aleurocystis and Matula are synonyms. When he validated the name Aleurocystis, Cunningham (1956) included the generic name Matula as a synonym, and also listed Artocreas poroniiforme [as poroniaeforme] as a synonym of the type, Aleurocystis hakgallae. Cunningham (1956) also corrected the orthography from "Aleurocystus" that had been attributed to "McGinty" by Lloyd (1921). Under Art. F.8.1 both generic names Aleurocytis and Matula are legitimate. The basionyms for these species, namely Corticium hakgallae and Artocreas poroniiforme, were published in the same article (Berkeley and Broome 1875) and thus had equal priority. Cunningham (1956) placed Artocreas poroniiforme in synonymy of Aleurocystis hakgallae, thereby establishing priority for the species epithet, hakgallae. The only additional species in Matula, M. rombellii, is considered a synonym of M. poroniiforme, thus is A. hakgallae (Martin 1942). The only additional species of Artocreas is its lectotype, A. micheneri, now considered a synonym of Scytinostroma artocreas [see below under Scytinostroma]. The genus Aleurocystis has been widely used, includes four names (Ryvarden 1998;Hjorstam and Ryvarden 2000;Rajchenberg and Robledo 2005), and requires no name changes, thus Aleurocystis is recommended for protection. One final note is that Massee (1888) published a new ordinal name, Matulales (as Matuleae), typified by Matula, skipping over description of a family. Fortunately, priority of names only extends to the level of family (Art. 11.1). Armillaria is a well-known genus of mushroomforming fungi lectotypified by A. mellea (Clements and Shear 1931), the honey fungus, which is now recognized in a restricted sense within a complex amalgam of segregate species (Pegler 2000). The lectotype of Rhizomorpha, R. fragilis, represents rhizomorphs of A. mellea (Donk 1962), thus Armillaria and Rhizomorpha are synonyms. Donk (1962) provides a lengthy discussion of the lectotypification of Rhizomorpha. Rhizomorpha was accepted at the rank of genus in Fries (1821) and therefore is sanctioned, whereas Agaricus [unranked "tribus"] Armillaria is sanctioned only as an infrageneric name. Therefore, at the generic rank, Armillaria requires protection over Rhizomorpha. Although 117 names exist in Rhizomorpha, this generic name has been applied to the sterile rhizomorphs produced by different kinds of fungi not related to the type. For example, Rhizomorpha hippotrichoides is Xylaria hippotrichoides and R. necatrix is Rosellinia necatrix, both in Ascomycota (Kirk 2020). The generic name Acurtis was based upon Clavaria gigantea, which itself was based upon structures now recognized as the so called carpophoroids of Entoloma abortivum. For many years these carpophoroids were considered to be aborted, parasitized basidiomes of the Entoloma (Donk 1962;Watling 1974), but it has been shown that they are aborted basidiomes of Armillaria (Lindner Czederpiltz et al. 2001;Fukuda et al. 2003). Instead of threatening the name Entoloma, this oft debated generic name threatens the name Armillaria. Because Armillaria is a clearly circumscribed and a well-known genus with species causing diseases of economic importance (Fox 2000), we recommend protection of the generic name Armillaria. The monotypic generic names Arthrosporella and Nothoclavulina were published for the sexual and asexual morphs of the same species in the same publication (Singer 1970), specifically A. ditopa and N. ditopa, thus they are synonyms having equal priority.
Here we designate A. ditopa as having priority. This species was re-described and discussed by Stalpers et al. (1991) and Baroni et al. (2007). Because Arthrosporella is more widely cited (GSS Arthrosporella = 24, Nothoclavulina = 11) and is typified by the mushroom-like sexual morph, we here designate Arthrosporella as having priority and recommend Arthrosporella for use.
Protect Asterophora Ditmar 1809 (S) over Ugola Adans. 1763 (A) and use rather than Nyctalis Fr. 1825 (S) The generic name Asterophora includes species that are parasitic on other mushrooms especially Lactarius and Russula (Russulaceae). Asexual morphs of species of Asterophora have been described in Ugola typified by U. physaroides, a synonym of Asterophora physaroides. Redhead and Seifert (2001a) unraveled and clarified the nomenclature of these generic names including Nyctalis as a synonym of Asterophora. They also proposed conservation of the name of the type of Asterophora as A. lycoperdoides over the earlier name A. agaricoides (Redhead and Seifert 2001b) and this was approved by the NCF (Gams 2004). Redhead and Seifert (2001a) recognized three species in Ugola, all of which have names in Asterophora. Redhead and Seifert (2001b) also recognized A. lycoperdoides and A. physaroides as the same species, thus Asterophora and Ugola are synonyms. Although Ugola has priority, this generic name is rarely used while Asterophora includes approximately 20 names and is widely used. For these reasons we recommend that Asterophora be protected over Ugola and be used instead of Nyctalis.
Use Athelia Pers. 1818 (S) rather than Fibularhizoctonia G.C. Adams & Kropp 1996 (A) The generic name Athelia, lectotypified by A. epiphylla by Donk (1949), includes about 40 species names and is widely used for saprobic, crustose, wood-inhabiting fungi as well as important plant pathogens (Jülich 1972). Fibularhizoctonia, typified by F. carotae, was described for the sclerotial-forming Rhizoctonia carotae (Rader 1948) and is recognized as the asexual morph of Athelia arachnoidea, a species that causes a cold-storage disease of carrots throughout temperate regions of the world (Adams and Kropp 1996). The two additional species of Fibularhizoctonia, sometimes misspelled 'Fibulorhizoctonia', are recognized in Athelia (De Vries et al. 2008;Kirk 2014). One species of Athelia, A. rolfsii (Curzi) C.C. Tu & Kimbr. 1978(syn. Sclerotium rolfsii Sacc. 1911) is the scientific name for a soilborne pathogen that causes blight stem and root rot diseases of crop and nursery plants throughout the world (Punja 1985). Athelia is used much more commonly than Fibularhizoctonia (GSS Athelia = 5280, Fibularhizoctonia = 54). Given its priority, greater number of species, and widespread use, the generic name Athelia is recommended for use.

Use Bjerkandera P. Karst. 1879 (S) over Geotrichopsis Tzean & Estey 1991 (A)
Geotrichopsis was introduced for G. mycoparasitica, a hyphomycete that produced thallic-arthric conidia and was isolated as a mycoparasite in a culture of an Arthrobotrys species. Because it had dolipore septa, it was considered to be the asexual state of a basidiomycete (Tzean and Estey 1991). It was described as new because it did not match the features in culture of various basidiomycetes known to produce asexual morphs, including Polyporus adustus (now Bjerkandera adusta). However, sequences of the ITS (MH862453) and LSU (MH874100) regions have been obtained from CBS 687.93, the ex-type culture of G. mycoparasitica (Vu et al. 2019), and the sequences have high BLAST Table 3 Family names proposed for protection with the names proposed for rejection. See text for the rationale about the proposed protected names. This list provides the names to be protected or rejected, author, their place and date of publication, and type. The names proposed for protection will be evaluated and recommended for approval by the Nomenclature Committee for Fungi  The generic name Botryobasidium is typified by B. subcoronatum, while the holotype of Haplotrichum is H. capitatum. Holubová-Jechová (1976) recognized the generic name Haplotrichum for the asexual morphs of Botryobasidium "as a result of the conservation of the generic name Oidium for conidial states of Erysiphe …" (Partridge et al. 2001a) and this was accepted in a monographic account of Botryobasidium (Langer 1994). Botryobasidium includes species with or without Haplotrichum asexual morphs, clamp connections, smooth or ornamented basidiospores, and chlamydospores or cystidia, but excludes morphologically similar species that produce secondary spores or outgrowing clamps (Langer 1994). Partridge et al. (2001aPartridge et al. ( , b, 2002 provided a comprehensive study of Haplotrichum in which H. capitatum is recognized as the asexual morph of B. candicans. Haplotrichum capitatum is based on Acladium capitatum, therefore, Rossman et al. (2016b) recombined this name as Botryobasidium capitatum. Botryobasidium candicans is now considered a synonym of B. capitatum. They also placed Sporotrichum rubiginosum in Botryobasidium as B. rubiginosum. The type of Physospora, P. rubiginosa, is also based on Sporotrichum rubiginosum, thus Physospora is a synonym of Botryobasidium. Donk (1962) reviewed the typification of Physospora concluding that Sumstine (1911) was the first to lectotypify this genus. The generic name Physospora was considered dubious by Donk (1962) and has been little used. Acladium, lectotypified by A. conspersum, now regarded as B. conspersum, is also congeneric with Botryobasidium and Haplotrichum as outlined by Holubová-Jechová (1976). Four species were originally included in Acladium. Both Clements and Shear (1931) and Hughes (1958) regarded A. conspersum as the type according to Donk (1962). The generic name Alysidium typified by A. fulvum has been considered a synonym of Haplotrichum (Holubová-Jechová 1980) as explained by Partridge et al. (2001a) who regarded A. fulvum as a synonym of the asexual morph of B. aureum. Sporocephalium was lectotypified with S. capitatum by Hughes (1958) who considered Sporocephalium a synonym of Acladium. Partridge et al. (2002) regarded Acladium to be a synonym of Haplotrichum with Sporocephalium capitatum as the asexual morph of B. candicans, now regarded as B. capitatum. Only four species of Sporocephalium, typified by S. capitatum, now B. capitatum, have been described, and this generic name is relatively obscure. Another generic name, Allescheriella is typified by A. uredinoides, now regarded as a synonym of B. croceum by Partridge et al. (2002), although Hughes (1951) recognized it as B. fulvum. Either way Allescheriella is a synonym of Botryobasidium. A recently described monotypic asexual morph generic name, Neoacladium, is here considered to be a synonym of Botryobasidium rather than sister to that genus (Hyde et al. 2019). Despite the lack of a known asexual morph of B. subcoronatum, type of Botryobasidium, this species is considered to be congeneric with Botryobasidium conspersum, as shown by Binder and Hibbett (2002) and Larsson (2007), in which H. conspersum, H. curtisii, and B. isabellinum constitute a monophyletic group. Based on a nuclear ribosomal DNA large subunit (nLSU) analysis, Moncalvo et al. (2006) demonstrated that Botryobasidium included species with asexual morphs and smooth basidiospores (e. g. B. candicans, B. conspersum, B. simile,), species without asexual morphs and smooth basidiospores (e. g. B. obtusisporum and B. vagum), and species without an asexual morph and ornamented basidiospores (e. g. B. isabellinum) as well as the type B. subcoronatum. These species formed a well-supported monophyletic group as previously demonstrated by micromorphological and ultrastructural characters (Langer 1994;Langer and Langer 1998). Thus, Botryobasidium, Acladium, and Haplotrichum, as well as the lesser known Alysidium, Sporocephalium, Physospora, Allescheriella, and Neoacladium, are all synonyms.
Five names in Botryobasidium are proposed for protection because they are widely used or already placed in Botrybasidium. In addition, 17 names described in Haplotrichum or other synonymous genera known to belong in Botryobasidium are re-combined in that genus here. Oidium biforme Linder, Lloydia 5: 188. 1942. The names listed above for the sexual morph have older names that could be applied to the asexual morph. Because use of the oldest epithet would require a new combination that would displace a familiar and commonly used name, the five names in Botryobasidium listed above are proposed for protection. This synonymy is based primarily on Partridge et al. (2001aPartridge et al. ( , b, 2002. Bulleromyces albus, type of the monotypic generic name Bulleromyces, was described as the sexual state of Bullera alba, type of the generic name Bullera (Boekhout et al. 1991), thus Bullera and Bulleromyces are synonyms. Bullera is used more widely than Bulleromyces (GSS Bullera = 1230, Bulleromyces = 129).
Given that Bullera has priority, currently includes over 60 species, and is widely used, we recommend the use of Bullera.
Use Chaetospermum Sacc. 1892 (A) rather than Efibulobasidium K. Wells 1975 (S) Chaetospermum, typified by C. chaetosporum, the name of the original illegitimate name C. tubercularioides (Smith and Ramsbottom 1914;Tangthirasunun et al. 2014), was placed in Sebacinales (Rungjindamai et al. 2008;Oberwinkler et al. 2014). A relationship of Chaetospermum to Efibulobasidium was shown by Wells and Bandoni (2001). Kirschner and Oberwinkler (2009) noted that conidia of C. gossypinum were associated with specimens of E. albescens, the type of Efibulobasidium, thus Chaetospermum and Efibulobasidium are most likely synonyms as accepted by Wells and Bandoni (2001) and Crous et al. (2014). In addition, Chaetospermum camelliae was studied by Kirschner et al. (2017) who placed its sexual morph in Efibulobasidium. Thirteen species have been accepted in Chaetospermum while only four names have been described in Ebifulobasidium, one of which has since been transferred to Globulisebacina (Oberwinkler et al. 2014) and two of which are invalid (Kirk 2020). Given its priority, the greater number of species, and more common usage (GSS Chaetospermum = 208, Efibulobasidium = 83), we recommend the use of Chaetospermum.

(A)
The generic name Coprinellus, lectotypified by C. deliquescens, was resurrected for a segregate group of approximately 50 species previously placed in   Coprinus ). Many authors consider Coprinellus domesticus to be the sexual morph of Ozonium auricomum, type of the sanctioned generic name Ozonium (Plowright 1901;Buller 1924;Watling 1979). However, Cáceres et al. (2006) state that "it will probably never be possible to decide to which teleomorph belongs the type species Ozonium auricomum" and suggest referring to the asexual morph as "the Ozonium stage". While one could determine the sexual morph of O. auricomum with an adequate holotype or lectotype and epitype with an ex-epitype culture, this is not necessary for the purpose of determining the synonymy of the genus Ozonium with Coprinellus. At the least O. auricomum is closely related to C. domesticus. Padamsee et al. (2008) demonstrated that C. deliquescens and C. domesticus are congeneric, thus Coprinellus and Ozonium are synonyms. Use of Ozonium for species now currently recognized as Coprinellus would not be tenable. Instead, the term "ozonium-like" should be used to describe the asexual morph of species of Coprinellus as suggested by Cáceres et al. (2006). In addition, the generic name Coprinellus is more widely used than Ozonium (GSS Coprinellus = 621, Ozonium = 98). Given the widespread use of Coprinellus and the many species placed in that genus, it is recommended that Coprinellus be protected. The generic name Ozonium has also been used for a fungus unrelated to O. auricomum, namely the nonsporulating morph of the ascomycete Phymatotrichopsis omnivora (Shear) Hennebert 1973, often listed in the literature as Ozonium omnivorum (Shear 1907). Now placed in Rhizinaceae (Pezizales), Phymatotrichopsis omnivora is an ubiquitous, economically important plant pathogen that causes root rot of alfalfa, cotton, peanut, and pecan as well as diseases of approximately 2000 species of dicotyledonous plants (Marek et al. 2009). The generic name Coprinopsis, lectotypified by C. friesii, is recognized for a group of species segregated from Coprinus and now includes over 100 species ). Redhead et al. (2000) discussed in detail the debate over whether Rhacophyllus was based on an asexual or sexual morph and the history of the application of the name. Maniotis (1964) demonstrated that two morphs, a 'Coprinus' and Rhacophyllus represented one taxon. He named the sexual form Coprinus clastophyllus. Based upon morphological similarities to phylogenetetically classified taxa,  considered C. clastophyllus and C. friesii to be congeneric and transferred Coprinus clastophyllus to Coprinopsis, thus Coprinopsis and Rhacophyllus are synonyms. While Coprinopsis is well known, Rhacophyllus has been rarely used (GSS Coprinopsis = 4530, Rhacophyllus = 45). The synonyms Rhacophyllus lilacinus and Coprinopsis clastophylla are currently both in use at a similar low frequency (GSS ca. 20 citations each, some of which are duplicates), and therefore there is no reason not to adopt the earlier name, which we do below. The generic name Hormographiella, typified by H. aspergillata, includes three species each isolated from animals or animal products, including humans (Guarro et al. 1992;Surmont et al. 2002). The relationship between the asexual morph H. aspergillata and the sexual morph Coprinus cinereus was determined by Gené et al. (1996) and C. cinereus was placed in Coprinopsis by . Although Coprinopsis friesii falls in sect. Alachuana and C. cinereus in the separate C. cinereus clade, both species are confirmed as members of the genus Coprinopsis (Nagy et al. 2013a, b), thus Coprinopsis and Hormographiella are synonyms. Coprinopsis includes over 100 species and is widely known while only three names have been placed in Hormographiella and it is less commonly used (GSS Hormographiella = 302). Zerovaemyces was described with a single species, Z. copriniformis, by Gorovij (1977). This species name is probably synonymous with Rhacophyllus lilacinus. Given that Coprinopsis is widely known and includes many species, we recommend protection of Coprinopsis over Rhacophyllus and use of Coprinopsis rather than Hormographiella and Zerovaemyces.

Protect
A new family, Zerovaemycetaceae, was proposed by Gorovij (1977) and competes for use with Psathyrellaceae [see below under Psathyrellaceae for a discussion about this].
The advantages of using the generic name Coprinopsis over the earlier name Pselliophora P. Karst. 1879 were discussed by . Ultimately, a proposal to conserve Coprinopsis over Pselliophora was accepted by the NCF (Gams 2005 The generic name Filobasidiella was described by Kwon-Chung (1976) for the sexual morph of Cryptococcus neoformans, type of Cryptococcus, thus these generic names are synonyms. Cryptococcus neoformans and related species cause serious respiratory diseases of humans and animals that can be fatal for immunocompromised patients (May et al. 2016). More than 300 species had been placed in Cryptococcus but recently Liu et al. (2015) re-circumscribed Cryptococcus to include only ten species placing many names in other genera. All except one of the five names in Filobasidiella are now recognized in Cryptococcus (Kirk 2020;Liu et al. 2015). Given priority, its well-defined generic status, and widespread use especially for the medically important C. neoformans, we recommend the use of Cryptococcus. The generic name Ditiola Fr. 1822 was accepted over the pre-Friesian Ditiola P. Browne 1756, now regarded as Schizophyllum, as well as by Donk (1958) based on Nannfeldt (1947) and as accepted and explained by McNabb (1966). Ditiola radicata was designated as type of Ditiola by Brongniart (1824). This species was included in a study of Dacrymyces with Ditiola radicata grouping inside Dacrymyces (Shirouzu et al. 2013; Zamora and Ekman 2019), thus Ditiola is a synonym of Dacrymyces. The type specimen of the type of Pionnotes, P. capitata based on Fusarium capitatum, was re-examined by Seifert (2013) and determined to be Dacrymyces chrysospermus. Based on the phylogenetic trees presented by Shirouzu et al. (2007Shirouzu et al. ( , 2009Shirouzu et al. ( , 2013, D. chrysospermus is congeneric with the type of Dacrymyces, D. stillatus, thus Pionnotes is another synonym of Dacrymyces. Pionnotes has often been used in regard to species of Fusarium, while Dacrymyces includes over 100 names and is widely used. Phylogenetic studies of Dacrymycetes by Kirschner and Yang (2005), Shirouzu et al. (2009Shirouzu et al. ( , 2013, and Zamora and Ekman (2020) demonstrated that the type of the asexually typified Pseudohelicomyces albus, type of the monotypic generic name Pseudohelicomyces, was described for the asexual morph of Psilocybe merdaria (Valenzuela and Garnica 2000), now regarded as Deconica merdaria (Noordeloos 2009). Since then, the generic name Psilocybe has been proposed for conservation with a new type, P. semilanceata, in order to include species that produce psilocybin (Redhead et al. 2007); this proposal was accepted (Norvell 2010) and is included in Appendix III of the ICN (Wiersema et al. 2020). Thus, P. merdaria and other non-hallucinogenic species previously recognized in Psilocybe have been shown to fall outside of the group that includes the conserved type of Psilocybe (Moncalvo et al. 2002). Although the type of Deconica, D. bullacea, has not been sequenced, it is accepted that D. bullacea and D. merdaria are congeneric (Noordeloos 2009), thus Deconica and Pseudohelicomyces are synonyms. Deconica includes 59 names and is widely used (GSS = 400) while monotypic Pseudohelicomyces remains an obscure name (GSS = 21). Given these reasons and based on priority, we recommend the use of Deconica. The generic name Dendrocollybia is typified by D. racemosa, a species previously placed in Collybia (Hughes et al. 2001). The asexual morph of D. racemosa has been recognized in Tilachlidiopsis typified by T. racemosa of which Sclerostilbum septentrionale, the type of the monotypic generic name Sclerostilbum, was considered a synonym (Stalpers et al. 1991;Hughes et al. 2001). Thus, the types of the latter two generic names are synonyms of D. racemosa and these three generic names are synonyms. Tilachlidiopsis has included diverse species in the Ascomycota and Basidiomycota (Stalpers et al. 1991) and is rarely used for the latter. Hofstetter et al. (2014) showed that Dendrocollybia should be recognized as a distinct genus. Although Tilachlidiopsis has been used more than Dendrocollybia, many of those references are to names now placed in the ascomycete genus Ophiocordyceps (GSS Dendrocollybia = 85, D. racemosa = 61, Tilachlidiopsis = 89, T. racemosa = 23, Sclerostilbum = 45). Given the widespread use of Dendrocollybia and its distinct morphology, we recommend that Dendrocollybia be protected over Tilachlidiopsis and Sclerostilbum.

Protect Diacanthodes Singer 1962 (S) over Bornetina L. Mangin & Viala 1903 (A)
The genus Diacanthodes, typified by D. novoguineensis, includes six species with two varieties of tropical fungi . The asexual morph of D. novoguineensis was determined to be Bornetina corium in the monotypic genus Bornetina (Fidalgo 1962a, b), thus Diacanthodes and Bornetina are synonyms. Diacanthodes novoguineensis causes a root disease known as phthiriasis of coffee and other tropical hosts (Rajchenberg and Robledo 2013). Diacanthodes is used more frequently (GSS = 118) and includes more species than Bornetina (GSS = 70), thus we recommend Diacanthodes for protection.

(A)
The generic name Echinoporia, typified by E. hydnophora, was described as the sexual morph of Echinodia theobromae, the type of the monotypic genus Echinodia (Ryvarden and Johansen 1980;Ryvarden 1983), thus Echinoporia and Echinodia are synonyms. Echinoporia includes three species and is more commonly used than Echinodia (GSS Echinoporia = 66, Echinodia = 15). Because it has a greater number of species and has been used in the recent literature (Motato-Vasquez et al. 2015), we recommend the protection of Echinoporia.

Moore 1987 (A)
The genus Femsjonia is typified by F. luteoalba for which Exidia peziziformis provides an earlier epithet, thus this species is regarded as F. peziziformis (McNabb 1965). The putative asexual morph of F. peziziformis (as F. luteoalba) was named by de Hoog (1974) as Sporothrix luteoalba, and the connection was reiterated by Maekawa (1987) and Middlehoven et al. (2000). When Cerinosterus was described, it was typified by S. luteoalba, which was erroneously interpreted as the asexual morph of a Cerinomyces sp. (Moore 1987). We confirm the relationship of Cerinosterus luteoalbus with F. peziziformis based on the 100% match of a BLAST search of an ITS sequence (MH856312) from an exparatype strain of C. luteoalbus (CBS 208.48) with F. peziziformis. Thus, Cerinosterus and Femsjonia are synonyms. Femsjonia includes 12 names while only two names have been placed in Cerinosterus, one of which, C. cyanescens, is now placed in Quambalaria (de Beer et al. 2006). Shirouzu et al. (2009Shirouzu et al. ( , 2017 demonstrated that F. peziziformis groups outside of Dacrymyces and this was confirmed by Zamora and Ekman (2019) who placed Femsjonia in the Dacrymycetaceae. Given its priority, the greater number of names, and greater use (GSS Femsjonia = 175, Cerinosterus = 71), we recommend the use of Femsjonia.

Use Fistulina Bull. 1791 (S) rather than Confistulina Stalpers 1983 (A)
The asexual morph of Fistulina hepatica, type of Fistulina, was described in the monotypic genus Confistulina typified by C. hepatica (Stalpers and Vlug 1983), thus these generic names are synonyms. Fistulina currently includes 21 names and is widely used (GSS Fistulina = 2900, Confistulina = 23). Given its priority, greater number of species, and its widespread use, Fistulina is recommended for use.
Use Heteroacanthella Oberw. 1990 (S) rather than Acanthellorhiza P. Roberts 1999 (A) The monotypic generic name Acanthellorhiza is typified by A. globulifera, which is the asexual morph of Heteroacanthella acanthophysa (Roberts 1999). Heteroacanthella is typified by H. variabilis (Oberwinkler et al. 1990). Zamora et al. (2014) regarded H. acanthophysa and H. variabilis as congeneric and added a third species. Heteroacanthella is more widely used than Acanthellorhiza (GSS Heteroacanthella = 35, Acanthellorhiza = 4). Heteroacanthella has priority and includes three species, while Acanthellorhiza is monotypic and remains little known, thus we recommend the use of Heteroacanthella.

Use Heterobasidion Bref. 1888 (S) rather than Spiniger Stalpers 1974 (A)
The holotype of Heterobasidion, H. annosum, is the sexual morph of the type of Spiniger, S. meineckellus (Stalpers 1974), thus these generic names are synonyms. Heterobasidion annosum, often reported as its synonym Fomes annosus, is the cause of a serious tree disease resulting in root and butt rot of pine trees in Eurasia, although previously this name had been used to represent a species complex occurring in temperate coniferous forests throughout the world (Ostrosina and Garbelotto 2010;Pegler and Waterston 1968). A number of segregate species have now been described in Heterobasidion (Ostrosina and Garbelotto 2010).
Heterobasidion includes about 30 species, has priority, and is well known (GSS Heterobasidion = 14,200, Spiniger = 5700), while Spiniger includes only one additional species and remains relatively obscure, thus we recommend the use of Heterobasidion.
Use Hohenbuehelia Schultzer 1866 (S) rather than Nematoctonus Drechsler 1941 (A) The generic synonymy of Hohenbuehelia, typified by H. petaloides, and Nematoctonus, typified by N. tylosporus, was proven by Koziak et al. (2007) in which they showed that Hohenbuehelia-Nematoctonus including their types formed a monophyletic clade in Pleurotaceae. Donk (1962) was the first to designate N. tylosporus as the type of Nematoctonus stating that he chose this as the best species to represent the genus. Thorn (2013) made the nomenclatural changes consistent with the recognition of the use of Hohenbuehelia rather than Nematoctonus. Hohenbuehelia produces a mushroom-like sexual morph and is more widely used than the nematode-trapping asexual morph represented by Nematoctonus (GSS Hohenbuehelia = 1500, Nematoctonus = 564). Given that Hohenbuehelia has priority and includes 182 names while Nematoctonus includes only 16 names and in agreement with Thorn (2013), we recommend Hohenbuehelia for use.

Use Leucocoprinus Pat. 1888 (S) rather than Attamyces Kreisel 1972 (A)
The monotypic generic name Attamyces is typified by A. bromatificus, a bromatia-forming fungus associated with attine or leaf-cutter ant nests in the western hemisphere (Kreisel 1972). Attamyces bromatificus was considered to refer to an asexual morph of Leucoagaricus gongylophorus (Chapela et al. 1994;North et al. 1997). Ortiz et al. (2008) analyzed sequences from L. gongylophorus and discussed the taxon under Leucoagaricus, although much earlier the combination Leucocoprinus gongylophorus had been introduced by Heim (1957). Controversy exists over the use of Leucocoprinus and Leucoagaricus. The older name Leucocoprinus is lectotypified by L. cepistipes, while confusion had existed over the type of Leucoagaricus, first validly published by Singer (1948) because he suggested as type an invalid name while including two other validly published names. This dilemma was resolved by Redhead (2016) who lectotypified the generic name Leucoagaricus by L. rubrotinctus, thus overriding the classification of Leucocoprinus americanus as Leucoagaricus americanus by Vellinga (2000). Phylogenetic analyses of DNA sequence data place numerous species of Leucocoprinus and Leucoagaricus, including their types, in the same clade with an intermixing of species from each genus (Vellinga et al. 2011). Despite the evident synonymy of Leucoagaricus with Leucocoprinus, novel species continue to be described in both genera (Ge et al. 2015) pending a comprehensive treatment of the group. For the purpose of placing Attamyces, we treat Leucocoprinus and Leucoagaricus as synonyms with Leucocoprinus having priority. At present, Attamyces should be regarded as a synonym of Leucocoprinus. Given its greater number of names and widespread use, we recommend that Leucocoprinus be used rather than Attamyces.
Coccobotrys is another generic name that has been mentioned as a synonym of members of Agaricaceae such as Leucoagaricus. When introducing Coccobotrys, typified by C. xylophilus, Boudier and Patouillard (1900) noted that the specimen of the type from France differed in some respects from the characteristics of the original description of the basionym Cenococcum xylophilum Fr. 1829. Van Bambeke (1900) reported further material from Belgium, which he regarded as conspecific with the French specimen observed by Boudier and Patouillard (1900). Van Bambeke (1900) considered Coccobotrys xylophilus to be an asexual morph of Lepiota meleagris (now Leucoagaricus meleagris). According to Else C. Vellinga (pers. comm.), the material examined by Boudier and Patouillard (1900) and van Bambeke (1900) is not conspecific with the original collection of Cenococcum xylophilum from Russia. Therefore, the recognition of Coccobotrys as a lepiotaceous fungus is based on a misapplication. The identity of the type of Coccobotrys is unknown. A second species of Coccobotrys, C. chilensis, was transferred to Leucoagaricus by Ruiz and Molinari-Novoa (2016). Note also that Coccobotrys could be confused with the later homonym Coccobotrys R. Chodat 1913, a name applied to a group of algae.  -Nejhad et al. (2010) demonstrated that the species originally described as Laeticorticium quercinum falls within a clade also containing Marchandiomyces corallinus, an asexual morph that is the type of Marchandiomyces. They chose to place the two species in the same genus, but under the rules of nomenclature at the time, they could not take up Marchandiomyces for the basidiospore-producing L. quercinum. Therefore, they introduced Marchandiopsis, typified by L. quercinum. With the move to one fungus-one name, Hawksworth and Henrici (2015) argued that Marchandiopsis had rarely been used in comparison to Marchandiomyces and they proposed to take up the latter name. They made the necessary new combination, Marchandiomyces quercinus. Diederich et al. (2018) transferred three other species originally described in Marchandiomyces to Laetisaria, placed Marchandiomyces aurantiacus in Erythricium, and retained three species in Marchandiomyces, including M. quercinus and M. corallinus. Given current usage of Marchandiomyces (GSS Marchandiomyces = 404, Marchandiopsis = 9) and in agreement with recent authors, we recommend that Marchandiomyces be used.

Use Mycena (Pers.) Roussel (S) 1806 rather than Decapitatus Redhead & Seifert (A) 2000
The generic name Mycena, typified by M. galericulata, is used for over 2000 species of small mushrooms, while the monotypic Decapitatus, typified by D. flavidus based on Stilbum flavidum, was used for the asexual morph of Mycena citricolor (Seifert 1985;Redhead et al. 2000). Several authors have considered M. citricolor and M. galericulata to be congeneric (Bermudes et al. 1991;Desjardin et al. 2007), thus Mycena and Decapitatus are synonyms. Mycena is more widely used than Decapitatus (GSS Mycena = 11,400, Decapitatus = 243). Given the widespread use of Mycena, the high number of species, and its priority, we recommend Mycena for use when Mycena is adopted wth a broad concept.
Use Myxarium Wallr. 1833 (S) rather than Hyaloria Möller 1895 (S) or Helicomyxa R. Kirschner & Chee J. Chen 2004 (A) Myxarium nucleatum, the type of Myxarium, and M. mesonucleatum were shown to form a strongly supported clade with Hyaloria pilacre, type of the generic name Hyaloria, by Kirschner and Chen (2004), thus Myxarium and Hyaloria are synonyms. They also showed that the type of the monotypic generic name Helicomyxa, H. everhartioides, is closely related to Myxarium. The small conidiomata with conidia of M. tremelloides (as Exidia tremelloides) are similar to those of H. everhartioides suggesting that these names are synonyms or at least closely related. Thus, the available data suggest that Helicomyxa, Hyaloria, and Myxarium are synonyms. Given the greater number of species, greater use (GSS Myxarium = 213, Hyaloria = 53, Helicomyxa = 22), and priority, we recommend the use of Myxarium.  Rant (1911) connected Necator to an unnamed Corticium and later Rant (1912) connected it to Corticium javanicum and C. salmonicolor (Petch 1912). Most recently the fungus in all stages has been classified as Erythricium salmonicolor (e. g. Moraes et al. 2006) but also has been shown to be an independent sister taxon to Erythricium (Roux and Coetzee 2005;Ghobad-Nejhad et al. 2010;Diederich et al. 2011). In an overlooked publication, Harsojo-Tjokrosoedarmo (1992 proposed a new genus Upasia for E. salmonicolor. Recognized as a genus separate from Erythricium, Necator has priority and is here recommended for use. A new combination in Necator is required and proposed here. Erythricium, typified by E. laetum, is considered to be a separate genus that includes as a synonym Marchandiobasidium, typified by M. aurantiacum now recognized as Erythricium aurantiacum (Hawksworth and Henrici 2015;Diederich et al. 2018)). Erythricium and its synonym Marchandiobasidium are sexual morph names. Digitellus humanus, the lectotype of Digitellus, is presumed to be based upon the aborted basidiomes of Neolentinus, most probably N. lepideus (cf. Donk 1962;Redhead and Ginns 1985), which typically do not form expanded pilei but the sterile stipes often become multibranched in complete darkness, such as on supporting timbers in abandoned mine shafts (Vlasenko et al. 2017). Hence, the generic name and species epithet refer to a hand-like form, which have also been named Neolentinus lepideus f. ceratoides based upon Ramaria ceratoides. The validity of the Paulet names and the date of Paulet's 1793 publication have been questioned because of its production during the French revolution and conflicting accounts of its distribution. Presuming the name Digitellus published as genus XVI in his index is valid and noting its obscurity, when Neolentinus typified by N. kauffmanii includes N. lepideus, we recommend that the name Neolentinus should be protected. This is subject to resolution of a proposal to list Paulet's publication as a "Suppressed Work" (Parra et al. 2015).

Roberts 1998 (A)
The generic name Oliveonia, typified by O. fibrillosa, was established to replace the later homonym Heteromyces Olive 1957 non Müll. Arg. 1889 (Donk 1958). Although regarded as related to Ceratobasidium, Oliveonia has been shown to be distinct including five species (Kotiranta and Saarenoksa 2005). Oliveorhiza anapauxilla, the type and only species of Oliveorhiza, was described for the asexual morph of Oliveonia pauxilla (Roberts 1998). Oliveonia fibrillosa and O. pauxilla are congeneric (Kotiranta and Saarenoksa 2005;Roberts 1998), thus Oliveonia and Oliveorhiza are synonyms. Oliveonia has been more widely used than Oliveorhiza (GSS Oliveonia = 107, Oliveorhiza = 6). Given its priority, greater number of species, and widespread use, we recommend the use of Oliveonia.
Use Pleurotus (Fr.) P. Kumm. 1871 (S) rather than Antromycopsis Pat. & Trab. 1897 (A) The generic name Pleurotus is applied to a number of mushroom-forming fungi including the type, P. ostreatus, the oyster mushroom, one of the most commonly cultivated edible fungi in the world, and P. eryngii (DC.) Quél. 1872, the widely consumed king oyster mushroom (Zervakis et al. 2004). Species of Pleurotus are also used industrially to break down aromatic hydrocarbons (Adenipekun et al. 2015); in addition, they can produce toxic compounds that paralyze nematodes. The generic name Pleurotus has already been conserved over six earlier generic names (Wiersema et al. 2020). Miller Jr. (1969 described P. cystidiosus for the sexual morph of Antromycopsis broussonetiae, type of the generic name Antromycopsis. Pleurotus ostreatus and P. cystidiosus were shown to be congeneric by Gonzalez and Labarère (2000), thus Pleurotus and Antromycopsis are synonyms. The genus Pleurotus includes over 500 species names; of these, a few dozen have been wellstudied and are nematophagous (Thorn and Barron 1984;Barron and Thorn 1987), whereas the name Antromycopsis is rarely used and includes only 19 names (GSS Pleurotus = 132,000, Antromycopsis = 175). Considering the widespread use of Pleurotus, its numerous species, its economic importance, and its priority, we recommended the use of Pleurotus.
Use Polyporus P. Micheli ex Adans. 1763 (S) rather than Mycelithe Gasp. 1841 (A) The monotypic generic name Mycelithe, typified by M. fungifera, accommodates sclerotia of Polyporus tuberaster, lectotype of Polyporus. Donk (1962) provides one of the few references to the obscure generic name Mycelithe. Based on the original well-illustrated publication, Gasparrini (1842) concluded that M. fungifera refers to sclerotia of a species in Polyporus, thus these two generic names are synonyms. Polyporus is a widely used name with over 3000 names described in this genus while the monotypic Mycelithe is uncommonly used (GSS Polyporus = 30,100, Mycelithe = 7). Given its widespread use and priority as well as the numerous described species, we recommend the use of Polyporus.
Controversy exists regarding the typification of the sanctioned name Polyporus. The earliest non-mechanical lectotypification was by Clements and Shear (1931) who selected P. brumalis for "Polyporus (Mich.) Fr. Epicr. 427 1838". However, Fries (1838) considered the generic name to link back to Fries (1821) and consequently Donk (1933) selected P. tuberaster as lectotype from species included by Fries (1821). For the moment, we follow Donk (1933) and current usage by indicating P. tuberaster as type of Polyporus, but we note that formal conservation with a conserved type may be required.

Protect Postia Fr. 1874 (S) over Ptychogaster Corda 1838 (A)
Postia, lectotypified by P. lactea, is a well-defined genus as recently circumscribed by Pildain and Rajchenberg (2013) and Shen et al. (2015Shen et al. ( , 2019. Walker (1996) provided an extensive discussion of the validity of the publication of the generic name Postia. The type of Ptychogaster, P. albus, was placed in Postia as P. ptychogaster by Knudsen and Hansen (1996) and is widely reported (Shen et al. 2015;Vampola et al. 2014;Vizzini and Zotti 2008). Given that Postia lactea and P. ptychogaster are congeneric, as demonstrated by Shen et al. (2015), then Postia and Ptychogaster are synonyms. Most names in Ptychogaster are now recognized in Postia or other related genera (Stalpers 2000). Postia is the most widely used of these two names (GSS Postia = 7950, Ptychogaster = 617), thus we recommend protection and use of the generic name Postia.
Lectotype: See Table 2. Zerovaemyces is regarded as a synonym of Coprinopsis with the type of Zerovaemyces, Z. copriniformis, considered a synonym of Rhacophyllus lilacinus, now Coprinopsis lilacina as discussed above under Coprinopsis. Gorovij (1979) published a new class name, Loculomycetes. Redhead et al. (2000) argued that Zerovaemyces and Zerovaemycetaceae, the latter introduced by Gorovij (1979), were asexual morphs and using the Code in force in  elevated Coprinaceae subfam. Psathyrelloideae Singer to family level with priority based upon the date 2001. Coprinopsis (syn. Zerovaemyces) is classified in the Psathyrellaceae in modern phylogenetic analyses, thus Zerovaemycetaceae is a synonym of Psathyrellaceae. Psathyrellaceae appears in over 1500 GS records while Zerovaemycetaceae appears in 3 GS hits, two of which are Redhead et al. (2000. The name Psathyrellaceae is adopted in modern phylogenetic analyses and in mushroom books. It would be disruptive to switch to a family name used so infrequently and based upon synonymized taxon names, thus we propose the name Psathyrellaceae for protection.

Use Rhizoctonia DC. 1815 (A) rather than Thanatephorus Donk 1956 (S)
The generic name Rhizoctonia has been conserved with R. solani as the conserved type and R. solani is formally conserved against R. napaeae (Stalpers et al. 1998;Wiersema et al. 2020). Rhizoctonia includes many species, especially ones causing plant diseases (Ajayi-Oyetunde and Bradley 2018; Oberwinkler et al. 2013). Some names in Rhizoctonia have been shown to be ascomycetous fungi and removed to Ascorhizoctonia and other genera (Yang and Korf 1985) while others have been transferred to Waitea. By far the most important species is the ubiquitous type R. solani, which has been divided into anastomosis groups and causes diseases such as root rot, damping off in seedlings, and leaf and fruit rot of many plant hosts (Gonzales et al. 2016). The sexual morph of R. solani was described as Thanatephorus cucumeris, type of the genus Thanatephorus (Roberts 1999), thus Rhizoctonia and Thanatephorus are synonyms. The decision to use Rhizoctonia or Thanatephorus is a difficult one; however, Rhizoctonia is used more commonly albeit in a broad sense and has priority (GSS Rhizoctonia = 22,400, Thanatephorus = 1930), thus we recommend the use of Rhizoctonia.
See below in regard to species of Rhizoctonia that belong to Waitea.

Protect Riopa D.A. Reid 1969 (S) over Sporotrichum Link 1809 (A)
The generic name Riopa, previously considered a synonym of Ceriporia, is typified by R. davidii, which is regarded as a synonym of the older name R. metamorphosa by Miettinen et al. (2016). Based on the concept of Miettinen et al. (2016), the genus includes one additional species R. pudens. The typification of Sporotrichum is complicated. Sporotrichum has been cited as having various types over time, and the type accepted by recent authors, S. aureum Link 1809 (Hughes 1958;Donk 1962;Stalpers 1984;Miettinen et al. 2016), is a homonym of the sanctioned name S. aureum (Pers.) Fr. 1832 and thus not available without conservation. Stalpers (1984) and Miettinen et al. (2016) considered S. aureum Link 1809 synonymous with S. aurantiacum Fr., which is the asexual morph of R. metamorphosa. Although more than 300 names have been placed in Sporotrichum, the majority of these names belong in Ascomycotina. Stalpers (1984) accepted three species in Sporotrichum, each of which has been shown to be phylogenetically distinct, i. e. not congeneric (Miettinen et al. 2016), thus Sporotrichum now includes only the type, S. aurantiacum Fr. 1832, a sanctioned, legitimate, later homonym of S. aurantiacum Grev. 1822 based on Mucor aurantius Bull. 1791. We follow Miettinen et al. (2016) and recommend Riopa for protection over Sporotrichum; in addition, we recommend the protection of R. metamorphosa over S. aurantiacum Fr.
Type: see Table 2. The sexual morph of Michenera, typified by M. artocreas, was described as Licrostroma, typified by L. subgiganteum, by Lemke (1964). Lyman (1907) had earlier demonstrated that cultures derived from the basidiospores of what he called Corticium subgiganteum, the basionym of L. subgiganteum, produced what he called Michenera spores, but he was unable to induce the cultures to form hymenia and basidiospores. Molecular data place L. subgiganteum with Scytinostroma aluta and S. portentosum, the type of Scytinostroma (Giraldo et al. 2017;K-H Larsson pers. comm. 2017) and with S. caudisporum (Leal-Dutra et al. 2020). Thus, Scytinostroma, Michenera, and Licrostroma are synonyms. Giraldo et al. (2017) recognized the synonymy of Licrostroma with Michenera but chose to use Licrostroma despite the priority of Michenera. Conversely, Liu et al. (2019) recognized Michenera including a new species; their phylogeny placed both the type and the new species of Michenera in a clade with the type of Scytinostroma, S. portentosum. Although the genus is not monophyletic (Larsson 2007), Scytinostroma currently includes 25 names, one of which was added by Wang et al. (2020). The type of the genus and other species of Scytinostroma with globose basidiospores were placed in "group 1" by Boidin and Lanquetin (1987). To this group these authors also refer Stereofomes nodulosus, the lectotype of Stereofomes selected by Donk (1956), because it was the only species that included a description as later discussed and accepted by Boidin and Lanquetin (1987). They recognized the synonymy of Scytinostroma with Stereofomes and suggested that Scytinostroma should be conserved over Stereofomes, although this was never formally done. Among the 12 names placed in Stereofomes, only four remain in that genus. Of these four synonymous generic names, Scytinostroma is the most well-known (GSS Scytinostroma = 612, Licrostroma = 30, Stereofomes = 13, Michenera = ca 50, but confused with other meanings of the word). Despite its polyphyletic nature, it seems least disruptive to protect the generic name Scytinostroma for the type S. portentosum and its relatives.
A final note is that Artocreas, lectotypified by Artocreas micheneri by Massee (1888), was based on the same find as Michenera artocreas, and may have been an unintentional flipping of the two binomial parts (cf. Donk 1962) but are clearly valid names. Considerable confusion was sown by Berkeley throughout the publication history of Artocreas by one lapsus calami after another. Berkeley in Berkeley and Curtis (1869) first published the name Michenera artocreas. Then he published Artocreas with Artocreas micheneri and A. poriniiforme (Berkeley and Broome 1875). This was followed by an admission of error (Berkeley and Broome 1876) that introduced more errors, namely that Artocreas is the same as Michenera, but he spelled Artocreas in two different ways with two different author citations, namely "Artocreas, B. & Br." and "Artrocreas, B. & C.". Massee (1888) further clarified and then muddied the waters by first lectotypifying Artocreas by A. micheneri, then declaring after a long discussion on Artocreas poroniiforme, "Under the circumstances it has been considered advisable to propose the genus Artocreas as the type of a new order, occupying a position exactly intermediate between the Nidulariaceae and the Hymenogastreae". He then proceeds to name a new order Matulales (as Matuleae) with a new genus Matula, typified by Matula poroniiforme, and not by Artocreas. In sanctioning Sistotrema, Fries (1821) included only S. confluens Pers. 1794, although listing Hydnum sublamellosum Bull. 1787 as a synonym. Persoon (1794) had previously described Sistotrema including S. confluens with Hydnum sublamellosum as a synonym as well as S. cinereum and Boletus unicolor. Sistotrema hamatum was described as the sexual morph of Ingoldiella hamatum, the type of Ingoldiella, according to Nawawi and Webster (1982) who obtained both morphs in pure culture from partially submerged decaying leaves collected in a stream in Malaysia. Although S. hamatum has not been sequenced, it has been widely accepted in Sistotrema, as congeneric with Sistotrema confluens, thus Sistotrema and Ingoldiella are synonyms. The large genus Sistotrema is classified in Hydnaceae, Cantharellales, with close relationships to Clavulina, Hydnum, and Membranomyces. It is considered polyphyletic (Moncalvo et al. 2006;Bernicchia and Gorjón 2010) or paraphyletic (Larsson 2007). Zhou and Qin (2013) determined that a monophyletic Sistotrema can be divided into subclades that include the type plus 13 members of the genus as well as other genera, however, S. hamatum was not included in this study. Sistotrema is more commonly used than Ingoldiella (GSS Sistotrema = 1250, Ingoldiella = 91) and includes over 200 names while Ingoldiella includes only three names. Given the widespread use of Sistotrema, the greater number of names, and its priority, we recommend the use of Sistotrema.
Use Sterigmatosporidium polymorphus, the type and only species in Sterigmatosporidium, was described for a species later determined to be the asexual morph of Cuniculitrema polymorpha, the type and only species of Cuniculitrema (Kirschner et al. 2001), thus these generic names are synonyms. Sterigmatosporidium was initially considered to be related to Sterigmatomyces (Kraepelin and Schulze 1982), the latter genus typified by S. halophilus, and now shown to belong in Pucciniomycotina (Aime et al. 2006(Aime et al. , 2018. Liu et al. (2015) included Sterigmatosporidium polymorphus (as Cuniculitrema polymorpha) in their molecular study of Tremellomycetes and placed this species near Fellomyces in Agaricomycotina. Sterigmatosporidium is used more extensively than Cuniculitrema (GSS Sterigmatosporidium = 186, Cuniculitrema = 60). Given that both genera are monotypic but Sterigmatosporidium has priority and is more widely used, we recommend the use of Sterigmatosporidium.
Use Subulicystidium Parmasto 1968 (S) rather than Aegeritina Jülich 1984 (A) The monotypic Aegeritina is typified by A. tortuosa, now considered a synonym of Subulicystidium longisporum, the type of Subulicystidium , thus these generic names are synonyms. Because it has priority, includes 11 names, and is widely used (GSS Subulicystidium = 248, Aegeritina = 19), we recommend the use of Subulicystidium.
Use Tomophagus Murrill 1905 (S) rather than Thermophymatospora Udagawa, Awao & Abdullah 1986 (A) The generic name Tomophagus, typified by T. colossus, was established for an unusual species often referred to as Ganoderma colossus (Fr.) C.F. Baker 1920. Hong and Jung (2004) were the first to show that G. colossus fell outside Ganoderma. Le et al. (2012) recognized this species in Tomophagus and described a second species of Tomophagus, T. cattienensis. The monotypic Thermophymatospora, typified by T. fibuligera, was described for an asexual basidiomycete, which was later determined to be the asexual morph of Tomophagus colossus as G. colossus (Adaskaveg and Gilbertson 1989), thus Tomophagus and Thermophymatospora are synonyms. Given its priority, the greater number of names, widespread use (GSS Tomophagus = 115, Thermophymatospora = 19), and recent study, we recommend the use of Tomophagus.
Use Trechispora P. Karst. 1890 (S) rather than Osteomorpha Watling & W.B. Kendr. 1979 (A) The type of Trechispora, T. onusta, is now regarded as a synonym of T. hymenocystis (Larsson 1994). When Watling and Kendrick (1979) validated the name Osteomorpha, typified by O. fragilis, they noted its association with Trechispora farinacea, a species name used at that time in a broad sense (Liberta 1973 In studying Trimorphomyces typified by T. papilionaceus, Kirschner and Chen (2008) concluded that the type of the monotypic genus Anastomyces, A. microsporus, was the asexual morph of T. papilionaceus, thus Trimorphomyces and Anastomyces are synonyms. Although both generic names include only one species name, Trimorphomyces is used more frequently (GS = 82) than Anastomyces (GS = 13). Given its priority and more common use, we recommend the use of Trimorphomyces. The generic name Tulasnella is typified by T. lilacina, regarded as a synonym of T. violea by Donk (1966), but not by Roberts (1994a, b), and includes 91 names. Hormomyces is typified by H. aurantiacus and includes seven names. The latter was often considered The type genus of Sclerotiaceae is Sclerotium Tode. Sclerotiaceae was first spelled 'Sclerotaceae' and correctly spelled by Link (1826). The name Sclerotiaceae has fallen out of use as a generalized family name for any sclerotial-based genera whereas the name Typhulaceae is useful for this phylogenetically defined group. The genus Waitea, typified by W. circinata (Warcup and Talbot 1962), mainly includes pathogens that cause diseases of monocotyledonous plants such as brown ring patch of turfgrasses, sclerotial rot and ear rot of corn, sheath spot of rice, and damping off and root rot of cereals and grasses, which typically occur in temperate regions (Gutierrez et al. 2007;Toda et al. 2007). The monotypic name Chrysorhiza was introduced for Rhizoctonia zeae, the asexual form of Waitea circinata (Stalpers and Andersen 1996) Several studies have shown that Rhizoctonia zeae should be placed in Waitea as a species distinct from W. circinata (Chang and Lee 2016;de la Cerda et al. 2007;Gürkanli et al. 2016;Toda et al. 2005Toda et al. , 2007Vojvodić et al. 2020); the new combination is therefore made here. An unidentified Rhizoctonia sp. was found causing a destructive new disease affecting Agrostis stolonifera and Poa pratensis turfgrasses in Japan; the disease is referred to as Waitea reddish-brown patch disease (Toda et al. 2007). Later authors referred to this Rhizoctonia sp. as "Waitea circinata var. agrostis" but the name was not validly published (Kammerer et al. 2011). Phylogenetic relationships based on DNA sequences show that this fungus is a member of the genus Waitea as a species distinct from W. circinata and other species in the genus (Kammerer et al. 2011;Toda et al. 2007), thus this new species is described here. Isolates utilized by Toda et al. (2007) could not be located, therefore an illustration is designated as the type and a reference sequence is selected from those obtained by Toda et al. (2007). Rhizoctonia oryzae and W. circinata var. oryzae are invalid names used by plant pathologists to refer to the causal agent of leaf and sheath spots of grasses and cereals. Although neither of these two names were validly published, there is no doubt that this fungus is congeneric with W. circinata and distinct from other species in the genus (Chang and Lee 2016;de la Cerda et al. 2007;Gürkanli et al. 2016;Kammerer et al. 2011;Leiner and Carling 1994;Ryker and Gooch 1938;Sharon et al. 2006;Toda et al. 2005Toda et al. , 2007. Therefore, the new species W. oryzae is formally established here. The original collection made by Ryker and Gooch (1938) held by BPI has been chosen as the type specimen. In the absence of a sequence from the type, one of the five sequences included by Toda et al. (2007) under R. circinata var. oryzae is indicated as a reference sequence. Diagnosis: Yellow-pink colony on PDA differs from pale yellow colony of W. agrostidis, dark brown colony of W. circinata, white-salmon pink colony of W. oryzae, and orange colony of W. zeae. Irregular to spherical, salmon to yellowish salmon sclerotia differ from irregular, dark brown sclerotia of W. agrostidis, pinkish or orange sclerotia of W. circinata, irregular, salmon pink to orange sclerotia of W. oryzae, and subspheroid, orange sclerotia of W. zeae.

Use
Description Waitea circinata var. prodiga was proposed as the name of a novel fungal pathogen responsible for a basal rot disease first identified from Paspalum vaginatum (Kammerer et al. 2011). The name was not validly published, but the phylogenetic relationship of this organism with other species of Waitea and distinctive morphological characters support the separation of W. prodiga from other species in the genus. Therefore, Waitea prodiga is here formally established as a new species. Isolates used by Kammerer et al. (2011) were not lodged in a reference collection, therefore an illustration is designated as the type, and a reference sequence is selected from those obtained by Kammerer et al. (2011). The generic name Wolfiporia, typified by W. cocos, was established for the fungus known as tuckahoe or Poria cocos, common throughout North America and regarded as the fungus used medicinally in Asia (Wang et al. 2013). A sclerotial morph of this fungus was described as Sclerotium cocos and placed in Pachyma as P. cocos, type of that genus, as typified and explained by Donk (1962). Although he chose the first species listed, he supports this decision citing that it was based on "a statement by Fries himself … under Pachyma …" . Wolfiporia was typified by Poria cocos F.A. Wolf, a now conserved name with a conserved type. Had it not been conserved, Poria cocos would, under Art. F. 8, be typified by the type of Sclerotium cocos. An earlier epithet for the sexual morph was discovered for this species, namely W. extensa (Ginns and Lowe 1983); however, prior to changes in the Code permitting one name for each fungus, Redhead and Ginns (2006) proposed to conserve the commonly used name Poria cocos. This was recommended for approval (Norvell 2008) and is now conserved (Wiersema et al. 2020). Wolfiporia itself is not conserved and is a later synonym of the sanctioned names Gemmularia and Pachyma. Wu et al. (2020) resurrected the generic name Pachyma, placing into synonymy the name Wolfiporia. They also distinguished between the commercially important eastern Asian cultivated fungus, formerly classified as Poria cocos or Wolfiporia cocos, and the North American fungi under those names. Wu et al. (2020) adopted the sanctioned name Pachyma hoelen Fr. for the commercial fungus in Asia. However, because they used a secondary source using an older Code, they overlooked the fact that the also sanctioned generic name Gemmularia predates Pachyma. They listed it as "Gemmularia Raf. per Steud." dating from 1824 taken from Donk (1962) who was using a Code recognizing a starting date of 1821 for most fungi. In that same publication, Donk (1962) lectotypified Gemmularia with G. rugosa Raf. The latter species was said to be the tuckahoe of North America (Rafinesque 1819). Donk (1962) questioned whether Gemmularia was accepted taxonomically by Fries (1823, 1832), which would mean the name is not sanctioned, but this argument is not currently accepted. Additionally, Fries (1832), while having the name Gemmularia typeset in smaller letters, nonetheless gave a direct reference to the page of his 1823 volume, which he did not do for other generic names he did not recognize. We conclude that Gemmularia like Pachyma is sanctioned. Rafinesque (1830) published yet another generic name, Tucahus, citing Gemmularia and the two species that he included in Gemmularia, but only describing T. rugosus.

Protect
While seven names have been placed in Wolfiporia, Lindner and Banik (2008) demonstrated that W. dilatohypha is not congeneric with W. cocos with the former species placed basal to Laetiporus. Only five names have been introduced in Pachyma, of which three (P. cocos, P. hoelen and P. pseudococos) relate to currently accepted species, while Pachyma tuber-regium is the sclerotial state of Pleurotus tuber-regium and Pachyma woermannii was introduced for the sclerotium of Lentinus woermannii, which is considered by Pegler (1983) to be a synonym of Pleurotus tuber-regium (as Lentinus tuber-regium). Wolfiporia is more widely used than Pachyma (GSS Wolfiporia = 2040, Pachyma = 479, Gemmularia = 8, Tucahus = 3) and the other names remain obscure. More recently, the entire genome of Wolfiporia cocos was sequenced and all sequences deposited under this name (Lee et al. 2019). Given its greater use and greater number of names, we recommend Wolfiporia for protection. Type: See Table 2. Phanerochaete chrysosporium is widely known for its industrial use as a white rot fungus that breaks down the aromatic polymer lignin and thus is important in the degradation of wood products (Kersten and Cullen 2007;Matityahu et al. 2015). Recently, Phanerochaete chrysosporium was confirmed as a member of the genus Phanerochaete s. str. (Floudas and Hibbett 2015). The older names Sporotrichum pruinosum and S. pulverulentum have been regarded as the asexual morph of this species either as one or two species (Burdsall Jr and Eslyn 1974;Burdsall Jr 1985). James et al. (2011) concluded that S. pulverulentum was distinct from S. pruinosum with the later linked to and providing an earlier name for P. chrysosporium. Given its widespread use and importance to applied microbiology, the name P. chrysosporium is proposed for protection.
The genus Mylitta Fr. 1825 is of uncertain application, but has been used for various growths, at least some of which were fungal sclerotia. Mylitta australis was introduced by Berkeley (1839) for the large sclerotia produced by a polypore later described from sporophores as Polyporus mylittae (Cooke 1892). The connection was explicitly made in the protologue of the latter where it was stated that the sporophores of P. mylittae were 'growing on Mylitta australis' (Cooke 1892). All subsequent authors including Cunningham (1965) have accepted M. australis as synonymous with P. mylittae. Núñez and Ryvarden (1995) (Grey and Grey 2005). In Polyporus, the epithet australis is pre-occupied by Polyporus australis Fr. 1828, now Ganoderma australe (Fr.) Pat., but there is no such obstacle to the transfer of M. australis to Laccocephalum. However, the name M. australis has only ever been applied to the sclerotium, and little used since the discovery of the sporophores more than a century ago. Therefore, P. mylittae is proposed for protection over M. australis to allow the continued use of L. mylittae.