Psathyrella cladii-marisci Sicoli, N.G. Passal., De Giuseppe, Palermo, Pellegrino, D. Deschuyteneer & Voto is a species of Psathyrellaceae recently described from southern Italy and reported also from Belgium. This species was placed in the genus Psathyrella (Fr.) Quél. based on morphological characters including small-medium size, greyish and pale clay to deep brown, thin, fragile, non-deliquescent basidiomata with lamellae as hymenophore, smooth, truncated and dark basidiospores, and versiform hymenial cystidia intermingled with sphaeropedunculate and clavate cells along the gill edge.

However, the suite of characters cited by the authors to support this placement defines an overly broad and now-superseded concept of the genus. A recent work led to a refinement of the concept of Psathyrella on the basis of morphological and molecular evidence (Wächter and Melzer 2020). According to this study, Psathyrella s.l. was further divided into three genera (Britzelmayria D. Wächt. & A. Melzer, Candolleomyces D. Wächt. & A. Melzer and Olotia D. Wächt. & A. Melzer) and some of the species which had formerly been placed in the genus Psathyrella have been transferred to other new genera.

While reporting two new rare species of Candolleomyces from China, Yan (Bau & Yan 2021) proposed a new combination for Psathyrella cladii-marisci based on a molecular (ITS) analysis: Candolleomyces cladii-marisci (G. Sicoli, N.G. Passalacqua, A.B. De Giuseppe, A.M. Palermo & G. Pellegrino) J.Q. Yan comb. nov. Moreover, a new record of C. cladii-marisci was recently reported from Thailandia based on a morphological and molecular (ITS and LSU) identification (Bhunjun et al. 2022). However, the new combination was referred to the name P. cladium-mariscii Sicoli, N.G. Passal., De Giuseppe, Palermo & Pellegrino (Sicoli et al. 2019a), which was invalidly published because the protologue had not included the citation of the identifier issue for the name by a recognized repository (Turland et al. 2018: Art. F.5.1), thus rendering invalid the new combination, too. Recently, the name was validly published by Sicoli et al. (2022), also integrating the first invalid description with some corrections (Sicoli et al. 2019b), and including further details from the second new detection from Europe (Deschuyteneer et al. 2020).

Here, we transfer the validly published name to Candolleomyces and make the new combination.

Candolleomyces cladii-marisci (Sicoli, N.G. Passal., De Giuseppe, Palermo, Pellegrino, D. Deschuyteneer & Voto) N.G.Passal. & Sicoli, comb. nov.

Psathyrella cladii-marisci Sicoli, N.G. Passal., De Giuseppe, Palermo, Pellegrino, D. Deschuyteneer & Voto Mycological Observations 3: 44 (2022)[Basionym].

Type. Italy. Calabria, Cosenza, Rende, Orto Botanico Università della Calabria. 39°21'25.05"N, 16°13'44.57"E, 220 m a.s.l., marsh at the base of cut culms of a Cladium mariscus (L.) Pohl plant, transplanted from Lago dell’Aquila (Laureana di Borrello, Reggio Calabria, southern Italy) at the corner of a concrete tank maintained full of water, 10 April 2018, Antonio Biagio De Giuseppe & Giovanni Sicoli (holotype CLU F302).