Entoloma aurantioalpinum, Armada, Vila, Bellanger, Noordel., Krisai & Dima, 2022

Buyck, Bart, Eyssartier, Guillaume, Armada, François, Corrales, Adriana, Hembrom, Manoj Emanuel, Rossi, Walter, Bellanger, Jean-Michel, Das, Kanad, Dima, Bálint & Ghosh, Aniket, 2022, Fungal biodiversity profiles 111 - 120, Cryptogamie, Mycologie 20 (2), pp. 23-61 : 26-29

112. Entoloma aurantioalpinum Armada, Vila, Bellanger, Noordel., Krisai & Dima, sp. nov.

( Figs 2-4 )

DIAGNOSIS. — Macromorphologically similar to Entoloma formosum and E. xanthochroum , two widespread, not strictly alpine species in Europe that occur in lowlands and montane regions, and differ from this E. aurantioalpinum sp. nov. by their more distinctly translucently striate pileus, and furthermore, E. xanthochroum has a coloured lamella edge.

HOLOTYPE. — France. Savoie , Peisey-Nancroix, GR5 route du lac de la Plagne, 2050 m. alt., leg. F. Armada, 25.VIII.2018, holo-, LY ( FA 4336 ).

MYCOBANK. — MB 840117.

GENBANK. — MZ198885 (ITS holotype).

ETYMOLOGY. — From aureus (golden) referring to the color of the pileus, and alpinus for growing in an alpine environment.

ADDITIONAL MATERIAL STUDIED. — France. Savoie, Peisey-Nancroix, GR5 route du lac de la Plagne, 2050 m alt, leg. F. Armada, 23.VIII.2018, LY(FA 4334), ITS[ MZ198882 ].

Italy. Busa de Tasca (Dolomiti), leg. E. Bizio, 23.VIII.2009, Bizio-23082009i2 L [L-0607578], ITS [ MZ 468144 ]; Trentino-Alto Adige, Passo dello Stelvio/Stilfser Joch, near Berghotel Franzenshöhe, alpine grassland with Dryas and Salix spp., 2200 m alt., leg. B. Dima, 30.VII.2018, ELTE ( DB 2018-07- 30-4), ITS [ MZ 468145 ].

Austria. Kärnten, Völkermarkt, Eisenkappel: Vellacher Kotschna, 46°22’30”N, 14°32’30”E, mapping grid square 9653/1, alpine grassland, Caricetum firmae, Salix reticulata , calcareous soil, 1500 m s.m., leg. A. Hausknecht, M. E. Noordeloos, M. Meusers, I. Krisai-Greilhuber, and members of the Austrian Mycological Society, 9.IX.1998, WU-Mykol 18644, ITS [ MZ 467302 ] — Niederösterreich, Lilienfeld, St. Aegyd am Neuwalde: Krumbach, Krumbachsattel, 47°48’33.66”N, 15°25’54.85”E, mapping grid square, 8158/4d, altitude 1200 m s.m., alpine grassland, calcareous soil, leg. A. Hausknecht, 6.IX.2006, WU-Mykol 0026678, ITS [ MZ 467303 ].

DESCRIPTION

Pileus

15-25 mm, conico-convex, often truncate or with slight umbilicus, with involute then more or less straight margin, at first uniformly orange-yellow to yellow orange towards margin, not or only weakly translucently striate, finely granulose to subsquamulose all over, particularly at center, glabrescent with age.

Lamellae

Rather crowded, adnate, thin, ventricose, up to 4 mm broad, sometimes a few forked, white then pink, with entire, concolorous edge.

Stipe

29-43 × 2.5-4 mm, slender, cylindrical or with longitudinal groove, very brittle, with subbulbous base, pale orange, contrasting with pileus, polished or with a few longitudinal innate fibrils, with white basal mycelium.

Context

Very thin and brittle, concolorous with surface.

Odour

Indistinct.

Taste

Mild.

Basidiospores

9.5-12 × (6.5)7.3-8.0(8.5) µm, average 10.3-10.8 × 8.0- 8.3 µm, Q = 1.2-1.7, Qav = 1.45, 6-7 angled in side view.

Lamella edge

Heterogeneous to almost sterile, made up of dense clusters of cheilocystidia.

Cheilocystidia

40-65 × 10-14 µm, subcylindrical to clavate or broadly clavate.

Pileipellis

A cutis with transitions to a trichoderm at centre, made up of clavate terminal elements, 10-25 µm wide, with brownish yellow, intracellular pigment.

Clamp-connections

Absent.

Habitat

Terrestrial in alpine heaths amongst either Dryas octopetala or Salix species ( S. retusa , S. hastata , S. reticulata ), and herbs like Polygonum viviparum , and Alchemilla pentaphyllea , on calcareous bedrock.

Distribution

Rare, but probably widespread in the Alps in Austria, France, and Italy.

NOTES

Entoloma aurantioalpinum sp. nov. belongs to the diversified E. sarcitulum clade ( Fig. 2 ), and clusters with two other so far unnamed alpine species. The macromorphologically similar Entoloma formosum and E. xanthochroum are widespread species in Europe, occurring in lowlands and montane regions, but not strictly alpine. Both differ from E. aurantioalpinum sp. nov. by the more distinctly translucently striate pileus, and furthermore, E. xanthochroum has a coloured lamella edge.

The holotype of E. aurantioalpinum sp. nov. has, in addition to the intracellular pigment, also some slightly incrusted hyphae, but this has not been observed in the other collections of this species. Incrusting pigments are exceptional in Cyanula.

Figures

FIG. 2. — Phylogenetic tree depicting the relationship of Entoloma aurantioalpinum Armada, Vila, Bellanger, Noordel., Krisai & Dima, sp. nov. and Entoloma nigroflavescens Armada, Bellanger, Noordel. & Dima, sp. nov. within subgen. Cyanula, clades /Sarcitulum and /Atrocoeruleum, respectively. The new species are highlighted in color rectangles. Newly generated sequences are in boldface. The analysis was inferred from nrDNA ITS sequences using PhyML 3.1 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. Main clades within the subgenus are compressed. Clitopilus was chosen as outgroup. Bar indicates 0.05 expected change per site per branch.

FIG. 3. — Entoloma aurantioalpinum, Armada, Vila, Bellanger, Noordel., Krisai & Dima, sp. nov., habit in situ (from holotype). Photo: F. Armada.

FIG. 4. — Microstructures of Entoloma aurantioalpinum Armada, Vila, Bellanger, Noordel., Krisai & Dima, sp. nov.: A, spores; B, lamella edge with cheilocystidia; C, D, elements of pileipellis. Photos: F. Armada. Scale bars: A, B, 10 µm; C, D, 20 µm.