back

Thelephora eucinerascens Kõljalg, I. Saar & Svantesson 2024

Syn.: Tomentella cinerascens (P. Karst.) Hoehn. & Litsch. 1906

Basidiome effused, araneose to soft membranaceous, adherent to separable, sometimes pellicular, fragile when dry, up to 0.2 (0.3) mm thick.
Hymenophore at first discontinuous, furfuraceous or tufted, then continuous, smooth to strongly granulose, becoming colliculose.
Colliculi rounded, 0.1–0.2 (0.3) mm in diam., 3–7 (10)/mm, sparse to crowded, easily separable from subiculum when well developed.
Hymenial surface mostly continuous or finely tufted under a strong lens, light brownish grey, brownish, dark greyish brown (7.5–10YR 6–4/2–3).
Subiculum poorly developed and araneose to rather thick, hypochnoid to fibrous, distinctly paler than the fertile area, white to very pale brown (10YR 8–7/2–3).
Margin abrupt or indefinitely thinning out, araneose to byssoid, sometimes well developed and sterile, distinctly rhizomorphic, white to very pale brown (10YR 8–7/2–3), paler to concolour with the subiculum.
Rhizomorphs often present in subiculum, at the margin and in cracks of the substratum, up to 0.1 (0.3) mm thick, irregularly branched, smooth, becoming relatively hard and rigid, white or whitish.

Hyphal system monomitic; hyphae with fibulate primary septa.
Subicular hyphae regular, 2–4 (5) µm, mostly branched at some distance or at the opposite side of clamps, often with simple anastomoses, thin-walled, rarely with slightly thickening walls, hyaline or subhyaline.
Subhymenial hyphae regular, short-celled, 2.5–4 (5) µm, compactly arranged in colliculi, thin-walled, hyaline or with some pale brown content in old specimens.
Rhizomorphs simple or poorly differentiated, built up by regular generative hyphae (1) 2–4 µm in diam., often with simple anastomoses, mostly thin-walled, hyaline; well developed and thicker rhizomorphs normally have a core of wider hyphae, up to 15 (25) µm in diam.
Cystidia absent; some subfusoid elements with rather obtuse apex may be present in hymenium, 30–50 x 4–6 µm. Differentiated "arboriform" hyphae sometimes present in hymenium or in the core of colliculi, sometimes also on the surface of rhizomorphs; these are intricately branched and aseptate gloeoplerous-like structures with homogeneous and non-oily content, 4–6 (8) µm in diam., wider than other hyphae and with slightly thickening wall (0.3–0.4 µm), sometimes collapsed and very difficult to find, subhyaline to very pale brown.
Basidia subclavate, often with a median compression to utriform, (25) 30–55 (70) x (5.5) 6–8 µm, rarely with a transverse simple septum, hyaline to subhyaline; (2) 4 sterigmata up to 5 (7) µm long and 1–2 µm wide at the base.
Basidiospores with regular to slightly sinuous-irregular outline, rarely more or less distinctly lobed; in frontal view subovoidal to slightly pyriform; in side view ellipsoid to broadly ellipsoid with a flattening adaxial side, rarely slightly lobed; in polar view mostly globose to subglobose, (5) 5.5–7.2 (7.8) x (4.2) 4.5–5.5 (6) x (4.7) 5–6.5 (6.8) µm, Q¹ = (1.1) 1.2–1.4 (1.5), Q² = 1.05–1.2 (1.3), echinulate, light yellowish brown to brownish, distinctly darker than the other elements; aculei up to 1 (1.2) µm long.
Chlamydospores absent.
Incrustation: all hyphae and hymenial elements strongly encrusted by small hyaline granules (up to 0.5 µm in diam.), visible in water mounts but immediately dissolved in KOH and other dyes.
Chemical reactions: IKI–. SA–. CB: hyphae acyanophilous; at least some spores more or less distinctly cyanophilous.

description: Elia Martini

drawing: H, Maser photo: Elia Martini