Thelephora umbrinospora (M.J. Larsen) Kõljalg,
I. Saar & Svantesson 2024
Syn.: Tomentella umbrinospora M.J. Larsen 1968
Basidiome effused, loosely adherent to separable, hypochnoid to tomentose or pelliculose, soft, up to 0.5 (1) mm thick.
Hymenophore discontinuous to continuous, tufted to granulose, rarely
smooth, soon yellowish red, orange brown to dark reddish brown (2.5–5YR
4–3/4–6).
Subiculum scanty to well developed, araneose
to hypochnoid or byssoid, yellowish to yellowish
brown (10–5YR 6–5/8), paler than the fertile areas.
Margin sterile or fertile throughout, shortly to indefinitely thinning
out, araneose to byssoid, yellow, yellowish red,
yellowish brown, paler than the fertile areas, almost concolours
or slightly paler than the subiculum.
Rhizomorphs present, common in subiculum, at the margin and in the
substrate, up to 0.1 mm thick, yellow to golden yellow, rarely yellowish brown.
Hyphal system dimitic with skeletal hyphae associated with
rhizomorphs; generative hyphae mostly fibulate.
Subicular hyphae regular, 2.5–3 (4) µm wide, with thin to slightly
thickening wall, subhyaline to yellowish, rarely ochraceous.
Subhymenial hyphae regular, 2–3.5 (4.5) µm wide, thin-walled, subhyaline to pale yellowish or yellow, content sometimes ochraceous.
Rhizomorphs starting as thin strands of generative hyphae like the subicular ones, soon associated with some skeletal hyphae;
old rhizomorphs with a core of slightly wider hyphae up to 8 µm surrounded by
generative hyphae and coated by a surface layer of straight skeletal hyphae.
Individual generative hyphae with fibulate or sparse
simple septa, 2.5–4 µm wide, sometimes with closely spaced secondary septa, subhyaline to yellowish, thin-walled and infrequent
simple-septate hyphae 1–1.5 (2) µm wide, simulating skeletal hyphae,
thin-walled, hyaline to subhyaline; skeletal hyphae
straight, 0.8–1.5 µm wide, with thick to solid wall, with rare 'elbows' and
very rare branching, yellow to golden yellow.
Cystidia absent.
Basidia narrowly clavate to subcapitate, slightly sinuous, 30–50 (65) x (5.5) 6.5–8 (9)
µm, fibulate at the basal septum, subhyaline
to pale yellowish, often with yellowish to ochraceous
content; 4 sterigmata up to 7 long and 1–1.8 µm wide
at the base.
Basidiospores normally with somewhat irregular
to lobed outline; lateral face ellipsoid to broadly ellipsoid with regular to
sinuous outline, sometimes broadening toward the base; frontal face triangular
or slightly ovoid to more or less distinctly three-lobed; polar face globose to
irregularly globose, rarely somewhat lobed, (6.5) 7–8.5 (9) x (5) 5.5–6.5 (7.2)
x (6.5) 7–8 (8.5) µm, Q1 = 1.1—1.3 (1.4), Q2 = 0.9–1.15,
shortly echinulate, yellow-orange brown to yellowish brown or light brown;
apiculus lateral; aculei up to 0.8 (1.2) µm long,
normally blunt.
Chlamydospores absent.
Incrustation: in water with a lot of yellow, orange to reddish-yellow
resinous material that partially dissolve in KOH-mounts producing a yellowish
to yellowish brown diffusate. Better preparations to
study microscopic details are obtained with Hydrochloric acid pretreatment.
Chemical reactions: IKI–; CB– but some young spores cyanophilous;
KOH: without noticeable changes.
description: Elia Martini
drawings: Elia Martini