(3014) Proposal to conserve the name Clitocybe (Basidiomycota) with a conserved type

(3014) Clitocybe (Fr.) Staude, Schwämme Mitteldeutschl.: xxviii, 122. 1857 ≡ Agaricus "trib." Clitocybe Fr., Syst. Mycol. 1: 9, 78. 1 Jan 1821, nom. sanct. (Fries, ibid.), nom. cons. prop. Typus: Agaricus phyllophilus Pers., nom. sanct. (C. phyllophila (Pers.) P. Kumm.), typ. cons. prop. Clitocybe (Fr.) Staude (Schwämme Mitteldeutschl.: xxviii, 122. 1857) is a genus of the family Clitocybaceae Vizzini 2. 1985). The genus exhibits a wide global distribution, and has also been extensively documented in various comprehensive monographs, journals or field guides from Africa (e.g., Pegler in Persoonia 4: 73–124. 1966), Asia (e.g., Li He the next typification of Clitocybe is therefore critical. It has been assumed that this was by Donk (in Bull. Jard. Bot. Buitenzorg, ser. 3, 18: 321–322. 1949), as, for example in Index nominum genericorum (Farr Ammirati Vizzini Alvarado Cooper, l.c.: 1–9). However, it has been overlooked that Clements He He Hughes whereas the second clade (erroneously named Clitocybe in He (2) it is present in the major and most species-rich subgenus of the genus referred to as Collybia for the present; (3) it produces the typical toxin muscarine, like other poisonous clitocybes; and (4) it has a large basidiome, similar to that of previously suggested lectotypes of Clitocybe (Agaricus nebularis and A. infundibuliformis), and is a common and widely distributed species accessible for scientific examination. The generic type change also presents several significant advantages: (1) the majority of the species described within this genus would remain classified under Clitocybe, thereby avoiding hundreds of taxonomic combinations; (2) most of the traditional Lepista species fall within that generic clade, and their combinations with this genus name already exist, as Bigelow (in Brittonia 21: 144–177. 1965; l.c. 1982) treated Lepista as a section of Clitocybe; and (3) the phylogeny would also clearly delineate the generic boundary between Clitocybe in the new sense and Lepista s.str., ensuring that taxonomic literature and synonyms of Clitocybe remain unaffected. The sole disadvantage of this proposal lies in its inevitable repercussion on a few species names in extensive use and the final extinction of Collybia. To the best of our knowledge, Collybia and Clitocybe have always been recognized as distinct genera and have not been taxonomically combined since their publication in 1857. Considering the current species numbers of the two genera, the name Clitocybe should be given precedence over the name Collybia. To establish this unequivocally, as provided in Art. 11.5, we publish here the new combination Clitocybe tuberosa (Bull.) Z.M. He & Zhu L. Yang, comb. nov. ≡ Agaricus tuberosus Bull. (Herb. France 6: t. 256. 1785–Feb 1786), nom. sanct. (Fries, Syst. Mycol. 1: 133. 1821) ≡ Collybia tuberosa (Bull.) P. Kumm. Mycobank: 852416. Collybia is conserved against Gymnopus (Pers.) Gray (Nat. Arr. Brit. Pl. 1: 604. 1821) (App. III B. Fungi in Wiersema & al., ICN Appendices I–VII, https://naturalhistory2.si.edu/botany/codes-proposals/), but the type of Gymnopus (G. purus (Pers.) Gray) is currently treated as Mycena pura (Pers.) P. Kumm. in the Myceaceae, belonging to a different suborder of the Agaricales from Clitocybaceae. Gymnopus does not, therefore, threaten Clitocybe and the latter need not be conserved against it. The necessary revisions are (1) to transfer the remaining three species of previous Collybia s.str. aforementioned, along with 17 newly discovered Chinese species that have recently been classified under Collybia by He & al. (l.c.), to Clitocybe, and (2) to establish a new genus for C. nebularis and its two allies. Accordingly, the transfer will entail a significantly reduced number of new combinations compared to the several hundred combinations, including the adoption of Clitocybe for the some 30 species of the only distantly related Infundibulicybe, required if the type of Clitocybe were not changed with the new type conserved, as proposed. The authors express their gratitude to Dr. Xiang-Hua Wang for providing valuable insights and suggestions and greatly appreciate Dr. John McNeill's insightful comments, invaluable suggestions, and meticulous linguistic revisions.