Thelephora spinosispora (Cížek) Kõljalg, I. Saar & Svantesson 2024

Syn.: Tomentella spinosispora Cížek 2004

Basidiome effused, adherent to separable in small pieces, soft tomentose, up to 0.3 (0.5) mm thick.
Hymenophore smooth, very finely tufted or porulose to almost continuous, dark reddish brown (7.5–10YR 4–3/3).
Subiculum scanty to well developed, arachnoid to soft tomentose and loose, concolour with the fertile area.
Margin fertile throughout, indistinct, indefinitely thinning out, finely tufted and mostly discontinuous.
Rhizomorphs absent.

Hyphal system monomitic; all hyphae with simple septa.
Subicular hyphae of two kinds: 1) 4–7 (8) µm wide, regular, thick-walled (walls 0.5–2 µm), brown; 2) 2–3 µm diam., infrequent or even lacking in most preparations, straight, infrequently branched, with rather thin or slightly thickening wall, pale brown.
Subhymenial hyphae (3) 4–7 (8) µm wide, almost regular, infrequently cross-branched, loosely arranged, with relatively short cells, often thick-walled, pale brown to brown.
Cystidia absent.
Basidia immature clavate to cylindrical then cylindrical to slightly utriform with a more or less evident median compression, 40–50 (60) µm long, 7–10 µm diam. at top, 8–11 µm wide in the lower half where they are often thick-walled, subhyaline to brownish; 4 sterigmata up to 10 µm long and 2–3 µm wide at the base.
Basidiospores with regular outline; subglobose to broadly ellipsoid in side view, adaxial side convex; globose to subglobose in frontal view; globose in polar view; 7–9 µm across or, more precisely, (7) 7.5–9 (9.5) x 7–8 x 7.5–8.5 (9) µm, Q¹ = 1.05–1.2, Q² = 1-1.1 (1.15), wall 0.4–0.8 µm thick, paler to concolour with basal hyphae, echinulate, often with a large guttula; aculei 1.5–3 (3.5) µm long and 0.7–1 (1.2) µm wide at the base, solid, tapering, single, regularly arranged.
Chlamydospores absent.
Incrustation absent.
Chemical reactions IKI— or with some elements in hymenial layer becoming very dark brown to dark bluish in some preparations . CB— or doubtful: thin-walled elements and aculei with a thin cyanophilous stratum, thickening to thick walls acyanophilous, content of basidia and hyphae cyanophilous. KOH: walls distinctly swelling in KOH, at first inwards and then outwards, slowly at 2%, almost immediately at higher concentrations.

description: Elia Martini

drawings: Elia Martini