Entoloma nigroflavescens Armada, Bellanger, Noordel. & Dima 2022, sp. nov.
Creators: name: Buyck, Bart
name: Eyssartier, Guillaume
name: Armada, François
name: Corrales, Adriana
name: Hembrom, Manoj Emanuel
name: Rossi, Walter
name: Bellanger, Jean-Michel
name: Das, Kanad
name: Dima, Bálint
name: Ghosh, Aniket
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Agaricomycetes
Agaricales
Entolomataceae
Entoloma
Entoloma nigroflavescens

description: 113. Entoloma nigroflavescens Armada, Bellanger, Noordel. & Dima, sp. nov.
(Figs 2; 5; 6)
DIAGNOSIS. — Entoloma nigroflavescens Armada, Bellanger, Noordel. & Dima, sp. nov. can be distinguished from E. turci, which frequently occurs in similar habitats, by the finely roughened, innately fibrillose stipe, the absence of red staining at stipe base, and the absence of cheilocystidia.
HOLOTYPE. — France. Savoie, Bourg-Saint-Maurice, Arc 2000, secteur du lac Marlou, 2500 m alt., leg. F. Armada, 21.VIII.2018, holo-, LY (FA 4277).
MYCOBANK. — MB 840118.
GENBANK. — MZ198884 (ITS holotype).
ETYMOLOGY. — Nigrus for black and flavescens for yellowing, referring to the colour and colour change of the pileus.
ADDITIONAL MATERIAL STUDIED. — France. Savoie, Peisey-Nancroix, secteur du col de la Chal, 2500 m alt., leg. F. & E. Armada, 17.VIII.2010, LY(FA 1726), ITS[MZ198883].
DESCRIPTION
Pileus
9-22 mm, convex to plano-convex, with slightly inflexed margin, very variably shaped, sometimes umbilicate, with a small central umbo, or with irregular, undulating margin, not hygrophanous, not translucently striate, entirely very dark blackish brown to sepia brown at first, later on more yellow brown at margin, finally most of the pileus yellow brown with dark brownishblack centre; entirely rugose-tomentose to rimulose-fibrillose at first, breaking up in appressed squamules all over with age.
Lamellae
Rather distant, adnate-emarginate, thin or somewhat thick, ventricose, up to 3.5 mm broad, frequently intervenose, sordid white to greyish white, then sordid pinkish brown with an entire, thickened, concolorous edge.
Stipe
16-38 × 1.5-3.5 mm, equal, cylindrical, straight or curved, early fistulose, almost white when young, then beige-yellowish to pale yellow brown, minutely pruinose/punctate when young, glabrescent, never strictly polished but with fine, innate fibrils, base attenuate or slightly enlarged, slightly white tomentose, no reddening observed.
Context
Very thin, fragile, concolorous with surface, white inside, not reddening.
Odour
Weak or vaguely farinaceous.
Taste
None.
Basidiospores
(9)10.5-12.5 × (6.7)7.0-8.5(9) µm, heterodiametrical, irregularly 7-8(9) angled, sometimes almost nodulose.
Basidia
36-45 × 11.5-13 µm, 4-spored.
Cheilocystidia
Absent, lamella edge fertile.
Pileipellis
A cutis with transitions to a trichoderm, with clavate terminal elements, 30-90 × 13-24 µm. Pigment brown, intracellular.
Clamp-connections
Absent.
Habitat
In alpine zone, on mossy soil amongst Salix herbacea, Polygonum viviparum, and Alchemilla pentaphyllea.
Distribution
Known from two different localities in the French Alps.
NOTES
Entoloma nigroflavescens sp. nov. is a remarkable species with its dark, blackish brown basidiomata, which develop yellow tinges when maturing, and the fertile lamella edge without cystidia. In the ITS phylogeny it is a sister species to E. perasprellum, a recently described new species from the Alps, with a blue, polished stipe, reminiscent of E. asprellum (Dima et al. 2021). Entoloma nigroflavescens sp. nov. can be distinguished from E. turci which frequently occurs in similar habitats, by the finely roughened, innately fibrillose stipe, the absence of red staining at stipe base, and the absence of cheilocystidia.
description: Published as part of 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, pp. 23-61 in Cryptogamie, Mycologie 20 (2) on pages 29-31, DOI: 10.5252/cryptogamie-mycologie2022v43a2, http://zenodo.org/record/7828891