Pleuromyces Hungaricus Fungal Planet Description Sheets 311

310 Persoonia – Volume 40, 2018

Pleuromyces hungaricus Fungal Planet description sheets 311

Fungal Planet 744 – 13 July 2018 Pleuromyces Dima, P.-A. Moreau & V. Papp, gen. nov.

Etymology. Pleuromyces is a compound name, reflecting the morphologi- yellowish brown, ovate to ellipsoid, thick-walled, smooth. Ba cal similarity to Pleuroflammula and Phaeomyces. sidia 2- or 4-spored. Cheilocystidia slender or heteromorphous, Classiﬁcation — Tubariaceae, Agaricales, Agaricomycetes. not encrusted, thin-walled, hyalin. Pileipellis a thin trichocutis with coarsely incrusted slender hyphae, inflate at septa. Wood- Basidiomata pleurotoid with short central to eccentric stipe; inhabiting, saprobic. pileus small size (> 1 cm), yellowish brown, ﬁbrillose, not hygro Type species. Pleuromyces hungaricus V. Papp, Dima & P.-A. Moreau. phanus. Lamellae ventricose, yellowish to rusty brown. Spores MycoBank MB824585.

Pleuromyces hungaricus V. Papp, Dima & P.-A. Moreau, sp. nov. Etymology. Name reflects the country (Hungary) where the species was Notes — Based on a BLAST search of NCBIs GenBank collected. nucleotide databases, the closest hits using the LSU sequence Basidiocarp pleurotoid, pileus 5–8 mm diam, flabelliform, yel- are Romagnesiella clavus (as Pachylepyrium sp., GenBank lowish brown, densely covered with fibrillose squamules, turn- HQ832461; Identities = 1 333/1 361 (98 %), 2 gaps (0 %)), ing ferruginous with age, dry, not hygrophanous. Lamellae Phaeomarasmius fulvidulus (GenBank KF830080; Identities ventricose, yellowish when young, rusty brown on dry speci- = 1 330/1 361 (98 %), 5 gaps (0 %)), Agrocybe pediades (Gen mens, edge serrulate, slightly darker. Stipe short, up to 1.5 × Bank DQ110872; Identities = 1 339/1 372 (98 %), 4 gaps (0 %)) 3 mm, eccentric or lateral, concolorous with pileus or darker, and Galerina sp. (GenBank HQ827183; Identities = 1 341/1 374 flocculose-fibrillose, dry, solitary. Context yellow brown, spore (98 %), 8 gaps (0 %)). The closest hit by BLAST using the ITS deposit not noted. Basidiospores in side view (6.5–)7(–7.5) × sequence had highest similarity to an ‘uncultured fungus’ which (4–)4.5(–5) μm, Q = 1.4–1.8, mean 7.19 × 4.5 μm, Q = 1.6 was sequenced from soil in Illinois, USA (GenBank KX195359); (n = 30), ovoid to ellipsoid, somewhat amygdaliform in side the ITS2 of this environmental sample is very similar to Pleuro view, smooth, thick-walled, yellowish brown, often with one or myces hungaricus (Identities = 323/327 (99 %), 2 gaps (0 %)). two guttules, apex usually blunt and subpored. Basidia 23–26 The second closest hit using the ITS sequence is Tubaria sp. × 5–6 μm (excluding sterigma), subclavate, 2- or 4-spored. (GenBank KY462443; Identities = 475/556 (85 %), 29 gaps Cheilocystidia abundant, in clusters on lamella edge, variable in (5 %)), with low query cover (85 %). Based on a discontinuous shape (heteromorphous, from slender fusiform to ± lageniform), megablast search the closest hits by best query cover (100 %) not incrusted, thin-walled, hyaline, up to 85 μm long. Pleuro are Flammulaster cf. carpophilus (as Phaeomyces dubiosus, cystidia not observed. Hymenophoral trama regular, made of unconfirmed, P.-A. Moreau unpubl. data; GenBank KF830099; slender hyphae 2–4.5 μm wide, pale, mostly smooth. Pileipel Identities = 543/644 (84 %), 42 gaps (6 %)) and Crassispo lis a thin adpressed trichocutis made of 1–2 layers of hyphae rium carbonicola (as Pachylepyrium carbonicola; GenBank 2.5–5.5 μm wide, coarsely incrusted, with cylindrical elements LN714579; Identities = 541/645 (84 %), 39 gaps (6 %)). Pleu 35–60 μm long, mostly filled with oily droplets, terminal element romyces hungaricus forms a distinct clade in our phylograms, usually rounded to slightly inflated at apex, thick-walled and well separated from other genera of Tubariaceae. Microscopi- smooth at apex. Pileitrama made of cylindrical hyphae 2–4 μm cal observations (spores smooth, thick-walled and subpored; wide, pale, smooth or incrustate-zebrate, sometimes thickened pileipellis with coarsely incrusted hyphae) suggest closest and darker at septa. Clamp connections present at all septa. affinities with species of Phaeomarasmius and Flammulaster Habitat — On large Fagus sylvatica log, in a lowland old- pp. (F. muricatus/F. limulatus), but the weak differentiation of the growth beech forest (Vértes Mts, Hungary). So far only known pileipellis is a distinctive feature for species of these genera. The from the type locality. holotype of Phaeomyces dubiosus was not available for revision but its description shows strong affinities with P. hungaricus; Typus. Hungary, Fejér County, near Csákberény (Vértes Mts), Juhdöglö- however, distant lamellae and the pileipellis with branching and völgy Forest Reserve, N47°22.662' E18°19.485', 28 Oct. 2013. V. Papp erected terminal hyphae suggest that it represents a distinct (holotype LIP0001404, ITS and LSU sequences GenBank MH036002 and MH036003, MycoBank MB824586). species of still unclear systematic position.

Colour illustrations. Juhdöglő-völgy Forest Reserve (Vértes Mts, Hun- gary), substrate of the type material; basidiocarp; cheilocystidia and spores (all from holotype). Scale bars = 5 mm (basidiocarp), 10 μm (elements of hymenium).

Bálint Dima, Eötvös Loránd University, Department of Plant Anatomy, Budapest, Hungary; Department of Biosciences (Plant Biology), Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland; e-mail: [email protected], [email protected] Pierre-Arthur Moreau, Universite de Lille, EA4483 IMPECS, Lille, France; e-mail: [email protected] Viktor Papp, Szent István University, Department of Botany, Budapest, Hungary; e-mail: [email protected], [email protected]