Rhodophana corylina Consiglio, Dima & Eyssart., 2021

Buyck, Bart, Eyssartier, Guillaume, Dima, Bálint, Consiglio, Giovanni, Noordeloos, Machiel Evert, Papp, Viktor, Bera, Ishika, Ghosh, Aniket, Rossi, Walter, Leonardi, Marco & Das, Kanad, 2021, Fungal Biodiversity Profiles 101 - 110, Cryptogamie, Mycologie 20 (5), pp. 63-89 : 76-78

107. Rhodophana corylina Consiglio, Dima & Eyssart. , sp. nov.

( Figs 13-15 )

Well-characterized by the combination of its ochraceous brown pileus, dark grey-brown stipe, very pale and contrasting gills, strong farinaceous odour, pink spore print, and subamygdaliform to ellipsoid, verrucose spores, as well as by produced ITS sequence data.

HOLOTYPE. — France. Dordogne, Razac-sur-l’Isle, regional nature reserve of Peyssac ( RNR 62); on a rich soil, under Prunus laurocerasus , with various Lepiota and other nitrophilic species, leg. G. Eyssartier, 29.X.2019, GE 19.017 (holotype PC [ PC 0142533]).

MYCOBANK. — MB 838804.

GENBANK. — MW604812 (ITS holotype),MW604813, MW604814 (ITS paratypes)

ETYMOLOGY. — Named after the dull ochraceous brown pileus, which evokes a little bit the color of some hazelnuts.

ADDITIONAL EXAMINED MATERIAL. — Italy. Riserva Naturale Bosco della Mesola (Ferrara), under Quercus ilex , leg. G. Consiglio, R. Bolletta, C. Orlandini & M. Panchetti, 12.XI.2004, Herbarium AMB no. 18726, GenBank MW604813; Roncosambaccio (Pesaro- Urbino), in a mixed forest of broadleaved trees, leg. M. Maletti, 16.XI.2009, Herbarium AMB no. 18727, GenBankMW604814.

DESCRIPTION

Pileus

Measuring (5) 10-15 (20) mm, quickly flat, with an often wavy margin, a little greasy to the touch or satiny, smooth or very finely wrinkled radially, of a fairly dull ochraceous brown, hazelnut to bistre, paler towards the margin which is clearly striate over nearly half the radius.

Gills

Shortly emarginate, moderately spaced, pale, whitish to very pale with greyish cream tinges, sometimes yellowish in places, forming a clear contrast with the stipe; entire edge concolorous.

Stipe

(15) 20-25 (30) × 1.5-2.5 (3) mm, equal or only slightly tapering towards the base, more or less wavy-irregular or sinuous, giving a somewhat “moire” effect to the otherwise finely fibrous surface, with fine white floccules at the top and sometimes up to mid-height, on a rather dark grey-brown surface, contrasting sharply with the pale tinge of the gills; mycelium white.

Flesh

Thin, pale brownish flesh.

Odour

Strong, of rancid flour or rancid oil.

Taste

Evoking odour and astringent or slightly bitter, unpleasant.

Spore print

Fresh with a beautiful bright pink color.

Spores

(4.3) 4.4-5-5.5 (5.9) × (3.2) 3.3-3.5-3.8 (4.5) µm, Q = (1.1) 1.3-1.4-1.5 (1.6), n = 80, subamygdaliform to ellipsoid, often with a deep suprahilar depression in side view, ellipsoid to ovoid in front view, distinctly warty when still attached to the basidia, then nodulose-verrucose to indistinctly nodulose when fully mature, sometimes also slightly polygonal, distinctly cyanophilic, inamyloid, with one to several oily drops and a hilar appendix rather showy, conical and refractive, up to 1 µm long.

Basidia

Tetrasporic, with fine sterigmata up to 6 µm long, slightly clavate, measuring 18-22 (30) × 5-5.5 (6.5) µm; sclerobasidia present.

Cystidia

Absent. Occasional long hairs present on the lamellar edge.

Lamellar trama

Regular, composed of parallel, cylindrical to enflated, smooth, hyaline or pale yellowish, hyphae, 5-15 (25) µm wide on average, often with fairly short elements, narrowing at the walls and then taking on a “sausage-like” appearance, tapering towards the subhymenium, colourless or almost so. Occasional trombopleurogenic hyphae with a grey-yellowish content present.

Stipitipellis

Composed of tightly packed hyphae (2) 5-15 µm wide, with a rather abundant ochraceous-brown intracellular and parietal pigment, the last finely encrusting, from which emerge here and there cylindrical, clavate or slightly irregular hyphae, tightly assembled and difficult to dissociate at least on exsiccata, reaching 10 (20) µm wide on average; these hyphae form the floccules visible on the surface of the stipe.

Pileipellis

Composed of a thin cutis of cylindrical hyphae, 3-5 (8) µm wide, the external hyphae slightly gelatinized with pale yellowish to brownish yellow parietal and cytoplasmatic contents; sparse fascicules of erected, agglutinate, cylindrical to subvesiculose, 6-12 µm wide hyphae present; occasional trombopleurogenic hyphae with a grey-yellowish content present; pseudoparenchymal-like hypoderm composed of hyaline, cylindrical to fusiform or enflated, smooth-walled elements easily reaching 20 µm wide; yellowish-brown parietal pigment, coating or finely encrusted.

Clamp-connections

Present throughout.

NOTES

The genus Rhodophana Kühner is still very little known and some groups of species are just beginning to reveal their complexity. As an example, the Rhodophana nitellina (Fr.) Kühner group is genetically composed of at least fifteen operational taxonomic units ( Dima et al. 2018, see also our Fig. 13 ). Our new species is obviously akin to Rhodocybe melleopallens P.D. Orton ( Orton 1960), but is distinguished by its slightly less dull colors, by its distinctly lighter gills, forming an evident contrast with the stipe, and by its slightly shorter spores. Rhodocybe leucophylla ad int., which also has very pale gills, is odourless and has significantly larger spores ( Corriol & Trichies 2013). The recently described Rhodophana griseobrunnea E. Musumeci is another brownish coloured species with strong farinaceous odour, but its spores are much larger and measure 7-11 (13) × 4.7-5.5 (6) µm ( Musumeci 2020).

Figures

FIG. 13. — Phylogram based on analysis of both published and still unpublished ITS sequence data (by B. Dima & V. Papp) showing the position of Rhodophana within Entolomataceae and the various operational taxonomic units that need to be named in Europe. Phylogenetic tree inferred from nrDNA ITS sequences using PhyML 3.1 (Guindon & Gascuel 2003) with the following settings: GTR+I+G model of evolution, gamma distribution of 10 rate categories, and tree topology search as SPR. Branch support was tested using the non-parametric, Shimodaira-Hasegawa version of the approximate likelihood-ratio test (SH-aLRT). PhyML SH-aLRT support values (>50) are indicated at the branches.Clades represented by at least one unpublished sequence are compressed.All published sequences from repositories are shown in brackets. Newly generated sequences for our new species are highlighted in boldface. Bar indicates 0.05 expected change per site per branch.

FIG. 14. – Rhodophana corylina Consiglio, Dima & Eyssart., sp. nov.: A, fresh basidiomata of the holotype; B, fresh basidiomata of collection AMB18727. Photos: G. Eyssartier & G. Consiglio.

FIG. 15. – Rhodophana corylina Consiglio,Dima & Eyssart., sp. nov.: A, hymenium with basidia and spores; B, spores;C, sclerobasidia;D, spores of the holotype. Photos: M. Marchetti. Drawings: G. Eyssartier. Scale bars: A-C, 10 μm; D, 5 μm.