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Thelephora viridescens (Bres. & Torrend) Kõljalg, I. Saar & Svantesson 2024

Syn.: Tomentella viridescens (Bres. & Torrend) Bourdot & Galzin 1928

Basidiome effused, tufted to tomentose, fragile, adherent or separable in pieces, 0.2–0.5 µm thick.
Hymenial surface smooth, finely discontinuous, pruinose, tufted to pulverulent, becoming continuous, ochre yellow with an olivaceous tint (2.5Y–10YR 5–6/6).
Subiculum scanty to developed, hypochnoid, tomentose, olivaceous brown to brown (2.5Y–5YR 4–3/2).
Margin not differentiated, shortly thinning out, slightly discolour.
Rhizomorphs absent.

Hyphal system monomitic; all hyphae mostly with fibulate primary septa; scattered simple septa may be present in subicular hyphae.
Subicular hyphae regular, fibulate, (4) 4.5–7 (8) µm, often with projections and elbow-like bends with localized wall thickenings, rarely cross-branched and anastomosed, with thickening wall, yellowish brown.
Subhymenial hyphae regular, fibulate, (3.5) 4—7 (8) µm, soon with thickening wall (up to 1 µm), hyaline to yellowish.
Cystidia absent.
Basidia subcylindrical, frequently with a faint median compression, slightly utriform, somewhat sinuous, 40–60 x (8) 9–11 (12) µm (top) x 7–10 (12) µm (lower middle); 4 sterigmata 6–9 µm long and 1.5–2.5 (3) µm wide at the base.
Basidiospores with regular outline; lateral face subglobose to broadly ellipsoid with slightly flattening adaxial side; frontal face globose to subglobose or somewhat subovoid; polar view globose to subglobose, (8) 8.5–11.5 (12) x (7) 7.5–10 (10.5) x (8) 8.5–11 (11.5) µm, Q1 = 1.1–1.25 (1.3), Q2 = 1–1.2 (1.25), echinulate, thick-walled (0.5–1 µm), pale yellowish to ochraceous, paler than subicular hyphae. Aculei up to 0.6–1.5 (2) µm long and 0.5–0.8 (1) µm wide at the base, single, tapering. Apiculus 1.5–2.5 µm across.
Chlamydospores absent.
Incrustation: none.
Chemical reactions: IKI: apiculus of spores not amyloid; some localized thickening of walls of subicular hyphae sometimes amyloid. KOH: faint pH-related staining of hyphae, especially subicular ones, turning slightly darker but without colour reaction in presence of air. CB: most thin-walled elements more or less cyanophilous, many spores doubtfully cyanophilous, aculei mostly CB+.

description: Elia Martini

 ...https://www.aphyllo.net/app/imgs/01/20/73/em-7161_b.jpg...

drawings and photo: Elia Martini