Vizzinia Ševčíková & Kolařík, gen. nov
Index Fungorum number: IF900586; MycoBank number: MB 900586; Facesoffungi number: FoF 14225
Etymology – in honor of the mycologist Alfredo Vizzini for his excellent contribution to mycology.
Diagnosis – Genus Vizzinia (see below) differs from Marasmiellomycena by basidiomata turning brownish on handling, distinctly squamulose pileus, floccose or floccosefibrillose stipe, weakly amyloid spores, and absence of cheilocystidia (Consiglio et al. 2022).
Basidiomata strongly omphalinoid to omphalinoid-clitocyboid-marasmioid. Pileus small, squamulose, translucently radially striate-furrowed. Lamellae often whitish, thick, distant, intervenose, adnate-decurrent to long-decurrent, with lamellulae of various length. Stipe cylindrical, fistulous, covered with floccose fibrils, often darker on the lower part, strigose at the lowest part of the base. Context thin, turning brownish on handling. Odour non-distinctive. Basidiospores colourless, thin-walled, smooth, congophilic, cyanophilic, weakly amyloid. Basidia slightly amyloid at apex. Hymenial cystidia absent. Subhymenium filamentous, consisting of intertwined short elements. Hymenophoral trama metachromatic. Pileipellis a cutis with frequent or rare pileocystidiod elements. Caulocystidia present. Thromboplerous hyphae and clamp connections present.
Type species – Vizzinia nigripes (Angelini, Vizzini, Consiglio & M. Marchetti) Ševčíková & Kolařík
Notes – The genus Vizzinia contains two species viz. V. dominingense and V. nigripes and it forms a well-supported lineage clearly represents a new genus. This genus matches optimal thresholds at the genus level according to Vu et al. (2018); which is 98.2% based on LSU barcodes and 94.3% based on ITS barcodes. The closest matches with NCBI were P. fimbriatum with 96.64–96.37% (Vizzinia nigripes type) and 97.59%–97.36% (V. domingense type) based on LSU; P. omphaliiforme reference species with 84.28% (V. nigripes type) and 90.19% (V. domingense type) based on ITS. Consiglio et al. (2022) mentioned that “these groups of species will probably be considered as independent genera, especially the P. albodescendens/P. omphaliiforme and P. domingense/P. nigripes pairs”. In spite of these claims, they preferred to describe these species as Porotheleum domingense and P. nigripes. We could not avoid solving this new genus, if we want to justify the existence of the genus Marasmiellomycena and we believe that our new species M. pseudoomphaliiformis makes clear enough the relationship between P. omphaliiforme and P. domingense/P. nigripes lineages.
Species