Inocybe xanthomelas Boursier & Kühner, 1933

Esteve-Raventós, Fernando, Pancorbo, Fermín, Larsson, Ellen, Turégano, Yolanda, Moreno, Gabriel & Altés, Alberto, 2022, Inocybe vaurasii (Agaricales, Inocybaceae), a new species of the I. xanthomelas group and similar European species with asteriform spores, Phytotaxa 566 (2), pp. 171-188 : 183-184

Inocybe xanthomelas Boursier & Kühner in Kühner, Bulletin de la Société Mycologique de France 49: 84 (1933). Figs. 4b, e

Studied material: lectotype of I. xanthomelas invalidly designated by J . Vauras in 2007 (unpublished) and validated here by Vauras & Esteve-Raventós ( MBT: 10008763). Figs 5e, f :— FRANCE, Seine-et-Marne , Fontainebleau, Mail (1 ex), a terre ou dans les feuilles mortes des bois feuillus (hêtres) ou mêlés, 19 August 1931, R . Kühner, « Mail var. affinis » G00127626 ( G!), GenBank : ITS ON 227438 ; paratype of I. xanthomelas, Seine et Marne, Fontainebleau , près de Mail , 6 August 1930, R . Kühner, Herb. Kühner « Nedler » G00260857 , GenBank: ITS ON 227437 ; paratype of I. xanthomelas, Seine et Marne, Fontainebleau, Mail Henry IV , 19 August 1931, R . Kühner, Herb. Kühner « Mail-var. Amphi » G00260858 . GenBank: ITS ON 227439 .

Basidiospores star-shaped, ochraceous, provided with numerous knobs (8–15), 1.2–2.4 µm high, subisodiametric, (9.1–)9.4– 10.6 –11.9(–13.1) × (7.1–)7.5– 8.1 –8.8(–9) µm. Q = (1.16–)1.18– 1.3 –1.4(–1.5) (40 spores). Basidia hyaline, claviform, 4-spored. Gill edge more or less the same colour as the faces (due to brownish content). Cheilocystidia (46.4–)46.7– 49,3 –52(–52.3) × (13.2–)13.4– 14.6 –15.7(–15.8) µm. Q = (3.1–)3.1– 3.4 –3.7(–3.72) (10 cystidia), very frequent, well differentiated, hyaline or showing a brownish intracellular pigment, crystalliferous at apex, lageniform, with prominent neck; paracystidia clavate, hyalin. Pleurocystidia numerous, similar to cheilocystidia, (50–)50– 59 – 71.4(–78) × (14–)14.2– 16.9 –19.4(–20) µm. Q = (2.94–)2.97– 3.5 –4.26(–4.58) (12 cystidia), hyaline or showing a brownish intracellular pigment, thick-walled (2.3–2.5 µm), with very pale-yellow reaction to ammonia. Caulocystidia very abundant, lageniform with well delimited neck (41–)44.1– 54.2 –62.2(–63.4) × (14.7–)14.7– 15.5 –16.7(–16.9) µm. Q = (2.72–)2.81– 3.4 –4.1(–4.14) (7 cystidia), with dark brown content, crystalliferous, present from the apical part to the base of the stipe in tufts, with numerous hyaline clavate paracaulocystidia. Clamps present.

Additional collections examined of Inocybe xanthomelas :— SPAIN, Huesca, Bielsa, La Larri, in a Fagus sylvatica forest on calcareous soil, 42.681666, 0.078888, 1305 m asl., 25 August 2015, M.A. Ribes, J. Hernanz, F. EsteveRaventós, F. Pancorbo, AH 47646!, GenBank: ITS ON263161 -LSU ON276735 ; ibidem, 12 October 2018, F. Pancorbo, AH 48233! SWEDEN, Gotland, Fardhem, Fardhem prästänge, under Tilia and Corylus , 13 September 2017, E. Larsson 485-17 (GB!); Öland, Torslunda, Skogsby, Tveta hägnet, 29 August 2005, T. Knutsson 2005-024 (GB-0234342!).

Figures

FIGURE 4. Fresh basidiomata in situ. a, d. Inocybe humilis AH 56423. b, e. Inocybe xanthomelas AH 47646. c, f. Inocybe subrimosa AH 44474. Scale bar: 20 mm. Photos: F. Pancorbo.

FIGURE 5. Vouchers and SEM spores of types. a, b. Inocybe humilis J. Favre, G00126386, Z.S. 583. Holotype. c, d. Inocybe subrimosa (P. Karst.) Sacc. P.A.K. No. 3223 (H). Lectotype. e, f. Inocybe xanthomelas Boursier & Kühner, « Mail var. affinis » G00127626. Lectotype. Scale bar: 2 µm = b, d, f; 10 mm = a, c, e. Photos: G. Moreno.