Fruitbodies growing singly or in small groups. Pileus 3–25 mm, at first subglobose to conical-sub- globose with involute margin, then convex to plano-convex or broadly campanulate, mostly with a broad low umbo, surface mat, dry but rarely slightly hygrophanous, finely fibrillose-tomentose to distinctly tomentose, sometimes to-mentose-scaly, colour variable, pale ochre, ochre to brown- ochre (5D7) when dry, but dark brown to rusty brown (6D8) when moist, old fruitbodies with rusty brown to purplish or- ange tinge, fibrillose-tomentose surface being yellow to yel- low-brown, drying surface being yellow-rusty (5B7). Lamellae rather sparse, L = 24–35, l = 1–3, 2–3 mm high, ventricose, near the stipe with a small decurrent tooth, yel- low with orange tinge when young, then sordid ochre- brownish (5D8), at maturity brown (6DE6), rusty brown (6D8) to typically dark brown (7E7), edge concolorous. Stipe 10–35 × 0.15–0.4 mm, cylindrical or gradually thick- ened towards base, concolorous with pileus: beige-ochre, ochre-brown, ochre-rusty to rusty brown, surface distinctly fibrillose-tomentose, covering pale yellow to yellow.
Taste mild (without traces of bitterish taste). Smell indistinct.
Spores (4.0–)4.5–6.0(–6.4) × (3.2–)3.5–4.5(–4.8) μm, E = 1.1–1.4(–1.5), Q = 1.17–1.33 (variability measured in 4 spec- imens), mostly subglobose but also broadly ellipsoid to broad- ly obovoid in side view, without suprahilar depression, in front view subglobose, broadly ellipsoid to broadly lacrymoid; sometimes with a slightly polygonate outline, rusty ochre in KOH, wall rusty brown, medium thick, distinctly but not coarsely verrucose, normal spores acyanophilous, those with broken wall cyanophilous without any reaction in Melzer’s reagent or very slightly dextrinoid (with reddish brown hue on mature spores and spores with a broken wall). Basidia 20–30 × 5–7 μm, narrowly cylindrical to narrowly clavate, often with median constriction, 4(2-) spored, sterigmata long, thin, 4–6 μ m. Cheilocystidia long, 25–45 × 4–8(–10) μ m, forming a sterile band on the edge, tibiiform with narrowly la- geniform, cylindrical or narrowly fusiform basal part, long narrow neck (1.0–2.0 μm) and distinct globose head (3.5–5 μm), sometimes with slightly thickened and rusty brown wall, especially in the head (up to 1 μm), content some- times homogeneously yellow-brown; rarely with hyaline la- geniform cystidia non-capitate. Pleurocystidia absent. Lamellar trama regular, hyphae 4–10(–14) μm broad, near the subhymenium only 2–4 μm, cells cylindrical to slightly inflat- ed (somewhere almost barrel-shaped), with distinct yellow- brown membranal and incrusting pigment, subhymenium not gelatinous, of densely arranged interwoven hyphae. Pileus cu- ticle (section) a cutis, not gelatinised, 30–50 μm thick, formed by densely arranged parallel hyphae 4–12(–14) μm broad, cells cylindrical, with yellow membranal pigment and coarse rusty brown incrustations, under it a hypodermium of parallel to slightly flexuously interwoven hyphae 4–8 μm broad, with same type of pigmentation, in scalp visible as a loose net of in- terwoven hyphae, terminal cells sometimes slightly clavate, pileocystidia absent. Stipe cuticle 2-layered, lower layer a cutis of parallel, densely arranged, cylindrical hyphae 2–8 μm broad, with yellow-rusty membranal pigment and rusty brown incrustations, from which emerge nests of loosely arranged and interwoven hyphae 2–6 μm broad, cylindrical but with la- geniform-fusiform outgrowths or terminal elements and with numerous caulocystidia resembling cheilocystidia in shape and size but often narrower (with cylindrical body). Clamp connections present in all tissues.
Fructification: July – October (CR). The species produces fruitbodies already in summer.
Ecology: In the Czech Republic, G. josserandii is known from montane forests at an altitude of about 750 to 1150 m. The forests are stands of Fagus, Picea, Abies and Acer pseudoplatanus (so called mixed montane forest) or pure Picea forests (or with admixed Fagus). The species is mostly found in natural stands (e.g. the “Boubínský prales” virgin forest in the Šumava Mts. and “Žofínský prales” vir- gin forest in the Novohradské hory Mts.) or near-natural forests, but finds from man-made spruce forests are also known (see Holec 2001b). Gymnopilus josserandii prefers wood of Picea abies but it was also found on Abies alba. Records from broadleaved trees are also reported (e.g. Josserand 1948, but with a question mark). The species is typical of strongly decayed stumps of old trees, mostly cov- ered with mosses. I have never seen it on fallen trunks. However, Keller et Moser (2001) and Beran (personal com- munication) report that G. josserandii grows on decayed fallen trunks of conifers in Austria.
Distribution: Gymnopilus josserandii is relatively rare in the Czech Republic as it is known only from three re- gions – the Šumava Mts. and Novohradské hory Mts. in Bo- hemia and the Beskydy Mts. in Moravia (see Antonín et Škubla 2000, Holec 2001b and the collections studied). In all these regions the species is rare but regularly occurs in suitable habitats – natural, seminatural to man-made mixed or coniferous forests with presence of old and strongly de- cayed stumps (or trunks) of Picea or Abies.
- THE GENUS GYMNOPILUS (FUNGI, AGARICALES) IN THE CZECH REPUBLIC WITH RESPECT TO COLLECTIONS FROM OTHER EUROPEAN COUNTRIES