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Thelephora humicola Kõljalg, I. Saar & Svantesson 2024

Syn.:Tomentella terrestris (Berk. & Broome) M. J. Larsen 1974

Basidiome effused, adherent, encrusting, soft and tomentose to compact and felted or somewhat subceraceous, becoming slightly crustose, up to 0.5 (1) mm thick.
Hymenial surface finely porulose to granulose when young, soon becoming continuous, smooth, rather polished in well developed specimens, often deeply cracked and exposing context and subiculum in a peculiar way when dry, normally uniformly dark reddish brown to dark greyish brown when fresh (7.5–10 YR 4/2–3), greyish brown when dry (10 YR 5/3).
Subhymenium strongly thickening, up to 0.5 (0.8) mm, compact, homogeneous, dark brown to very dark greyish brown, (10YR 4–3/2–3), normally distinctly darker than fertile areas.
Subiculum scanty to developed, soft, becoming slightly fibrous, up to 0.1 mm thick, more or less concolour or slightly paler and slightly more yellowish brown to reddish brown than the subhymenium (7.5YR 4/4).
Margin fertile throughout, abrupt or narrow, shortly thinning out and sterile or almost so, concolour to paler than the fertile area (10YR 6/4), infrequently very pale greyish brown (10YR 7/2), soon becoming yellowish to brownish, pubescent to slightly fibrillose.
Rhizomorphs absent.

Hyphal system monomitic; all hyphae with mostly fibulate primary septa; scattered simple septa are present in subicular hyphae.
Subicular hyphae loosely arranged, regular (but some short-celled or somewhat irregular ones may be present), (3) 4–6 (8) µm wide, with thick wall (about 1 µm), light brown to slightly umbrinous, infrequently mixed with subhyaline hyphae, 3–4 µm wide with slightly thickening wall.
Subhymenial hyphae fibulate, (3) 4–9 µm diam, often short cylindrical and botryose, 8–12 µm diam, soon with thickening wall, englobing or starting from large vesicular cells (possibly undeveloped basidioles) 18–25 µm wide, subhyaline to pale brown to brownish.
Cystidia absent.
Basidia when young more or less cylindrical to somewhat obpyriform, soon enclosed in the thickening hymenium and becoming ventricose, up to 15 (20) µm wide; when mature slightly cylindrical and sinuous, utriform or ventricose, abruptly narrowed at the base and often shortly stipitate, 50–70 (80) µm long, 12–15 µm wide at the apex, 12–18 (20) µm in the lower middle, often with pale brown to light brownish content; 4 sterigmata up to 8 (10) µm long and 2–3 µm wide at the base.
Basidiospores regular to slightly irregular, echinulate, without crowns, normally with a large guttula, wall 0.4–0.8 µm thick, brownish, concolour to slightly darker than subhymenial elements in mass; (6.5) 7–9 (9.5) µm long; lateral face mostly ellipsoid with flattening adaxial side, (5.3) 5.5–7 (7.5) µm diam, Q = (1.1) 1.15–1.35 (1.4); frontal face subovoid to broadly ellipsoid, sometimes slightly elongated and ellipsoid, rarely becoming faintly lobed, (6) 6.5–8 (8.5) µm diam, Q = (0.95) 1–1.2 (1.3); in polar view globose to subglobose or transversally subglobose. Aculei up to 1.2 (1.5) µm long, 0.4–0.8 (1) µm wide at the base, slightly tapering, single or rarely paired at the base, unevenly distributed. Apiculus lateral near the base in side view, 1.2–1.8 µm across, inamyloid; hilum mostly indistinct. Macrospores infrequent, 10–11 x 8–10 µm.
Chlamydospores absent.

description: Elia Martini

drawings and photo: Elia Martini