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Thelephora pilosa (Burt) Kõljalg, I. Saar & Svantesson 2024

Syn.: Tomentella pilosa (Burt) Bourd. & Galz. 1924

Basidiome effused, loosely adherent to separable, often detached from the substrate, araneose to pellicular, soft, up to 0.3 mm thick.
Hymenial surface mostly discontinuous, porulose to finely tufted, rarely becoming almost smooth or finely granulose, reddish brown, cinnamon, strong brown (7.5–10YR (5) 4 /4–6) rarely with slightly darker areas (10YR 3/3), often very finely dotted yellow, reddish yellow or reddish brown under the lens.
Subiculum as a thin, poorly developed layer inseparable from subhymenium, very loose and rhizomorphic near the substrate; when the basidiome is pellicular and can be turned upside-down, the subiculum is visible as a soft fibrous layer concolour or slightly more lighter than the fertile surface (5–10YR 5/6).
Margin indistinct to indefinitely thinning out, araneose to byssoid, concolour to distinctly more yellow or reddish yellow than the fertile surface (7.5–10YR 5/6).
Rhizomorphs common and easily seen in subiculum, at the margin, and in the substrate, up to 0.1 (0.2) mm thick but normally thinner and often fasciculate, rigid and smooth, becoming dark to very dark brown (10YR 3–2.5/2).

Hyphal system dimitic with skeletal binding hyphae associated with rhizomorphs; generative hyphae mostly with fibulate primary septa.
Subicular hyphae almost regular to slightly sinuous, 3–5 (6) µm wide, with thickening to thick wall, yellow to yellowish brown.
Subhymenial hyphae almost regular, relatively long-celled, 2.5–5 (8) µm wide, often branched from clamps, soon with thickening wall, subhyaline to yellow or light yellowish brown.
Rhizomorphs starting as thin strands of generative hyphae like the subicular ones, then becoming structured with a core of generative hyphae 3–5 (7) µm wide surrounded by hyphae becoming thinner, with thicker walls, with infrequent fibulate septa and progressively more branched, sinuous, often with elbow-like bends, 2–3 µm in diam., without primary septa, ending as richly branched, unseptated or with some simple secondary septa, 0.5–1.5 µm wide hyphae, building incomplete labyrithiform structures on the surface of rhizomorphs; cystidia sometimes present, narrowly clavate, 40–70 x 3.5–4.5 µm wide at apex.
Cystidia present, arising from subicular and subhymenial hyphae, clavate, subcapitate or capitate, with thin or more frequently thickening wall, normally with 1–3 fibulate septa along their length, 50–150 (200) µm long and (8) 10–16 (20) µm wide at the apex, enclosed to projecting, infrequently hyaline, normally becoming some shade of yellowish brown.
Basidia subclavate or subcylindrical, normally with a slight median compression, somewhat sinuous, 50–60 x 9–10 µm, hyaline to pale yellowish brown, sometimes with homogeneous ochre to brownish content; 4 sterigmata up to 5 (6) µm long, and up to 2 µm wide at the base.
Basidiospores with a distinctly lobed outline, in side view often 2-3 lobed, with wider base and a flattening adaxial side, often 3-lobed in frontal view, globose to somewhat 3-lobed in polar view, (7.5) 8–10.5 (11) x (5.5) 6–8 (8.5) x (7) 7.5–9.5 (10) µm, Q¹ = (1.1) 1.2–1.4 (1.5), Q² = (0.95) 1–1.2, aculeate, yellowish brown to dark golden brown; aculei up to 2.5 (3.5) µm long, 0.5–1 (1.2) µm wide at the base, single, tapering.
Chlamydospores absent.
Incrustation: yellow, golden yellow to yellow brown resinous matter frequent in hymenium and subhymenium especially in old basidiomes, often adhering to spores and not or only partly dissolving in KOH.
Chemical reactions: IKI: –. CB: thin-walled elements slightly to more or less distinctly cyanophilous, coloured elements acyanophilous. KOH: almost no reaction observed. description: Elia Martini

drawing: Elia Martini