Odontia fibrosa (Berk. & M.A. Curtis) Kõljalg 2014
Syn.: Tomentella
fibrosa (Berk. & M.A. Curtis) Kõljalg 1996
Basidiome effused, loosely adherent to separable, araneose to byssoid or loosely tomentose,
soft membranaceous, up to 0.5 (1) mm thick.
Hymenophore discontinuous to continuous, tufted, irregular, granulose,
becoming indistinctly hydnoid, ferrugineous brown
(5YR 4/6), rarely dark reddish brown (7.5YR 3/3–4).
Aculei conical, not well formed, often concrescent,
up to 0.1 (0.2) mm long, penicillate at the apex
because of the projecting cystidia-like hyphae.
Subiculum poorly to well developed, araneose to hypochnoid or soft
fibrous, light yellowish brown (10YR 6/4) to strong brown (10YR 4/3), normally
paler than the fertile surface.
Margin indistinct, almost fertile throughout or
indefinitely thinning out, araneose to byssoid,
yellowish to yellowish orange or brownish, distinctly paler to almost concolour with the subiculum.
Rhizomorphs frequent in subiculum and substrate if well decayed, obscure
or easily found at the margin, flexible, compact, slightly pilose
to almost smooth, up to 0.1 (0.2) mm in diam., light yellowish brown to ochraceous (10YR 6–5/4–6).
Hyphal system dimitic with skeletal hyphae in subiculum and
rhizomorphs; generative hyphae with simple septa.
Subicular hyphae of two kinds: 1) generative hyphae regular,
(1.5) 2–3.5 (4) µm in diam., with thin or slightly thickening wall, subhyaline to pale yellowish brown; 2) skeletal
hyphae regular, straight, 1–1.5 (2) µm in diam., infrequently with some
elbow-like bends, with solid wall, yellowish.
Subhymenial hyphae almost regular, 2.5–4 (5) µm wide,
thin-walled, subhyaline to pale yellowish brown.
Rhizomorphs starting as thin strands of generative like the subicular ones, soon associated with some skeletal hyphae;
old rhizomorphs developing a core of slightly wider hyphae up to 7 µm in diam.,
surrounded by compactly arranged generative hyphae like the subicular
ones; outer layer built up by numerous yellowish skeletal hyphae.
Cystidia absent, but with evident, differentiated hyphae projecting from
hymenium and more or less parallel-arranged in the core of aculei,
mostly arising from subicular and tramal
hyphae, cylindrical, with thick wall, up to 200 (250) µm long and 5–6 (8) µm
wide, with repetitive simple septa along their length, yellowish brown.
Basidia clavate to narrowly clavate, sometimes almost tubular, sinuous, (35) 45–70
(100) x (5) 6–9 (13) µm, hyaline to subhyaline, often
with ochraceous content; (2) 4 sterigmata
up to 5 µm long, and 1–2 µm wide at the base.
Basidiospores with regular to irregular or
slightly lobed outline, frontal face globose to more or less indistinctly
4–7-lobed, lateral and polar face mostly ellipsoid; dimensions strongly varying
between specimens: from (5.5) 6–7.5 x 4.5–6 x 6–7.5 µm or 6–7 µm across [e.g.
types of Z. fibrosus and K. bombycina] to 8–10 x 6.5–8 x 8.5–9.5 µm or 8–10 µm
across [e.g. em-9997], Q1 = 1.1–1.4 (1.5), Q2 = 0.9–1.1
(1.2), verrucose to bluntly echinulate, often with
bi- or trifurcate warts or small lobes, rarely with forked aculei,
with slightly thickening wall, yellowish brown to brownish; single aculei up to 0.5 (1) µm long, 0.3–0.6 (0.8) µm wide at the
base. Apiculus almost central in side view
Chlamydospores absent.
Incrustation: some segments of hyphae (and cystidia-like hyphae) with a
discontinuous sheath of yellowish brown resinous matter that partly dissolve in KOH-mounts producing a yellowish or ochraceous diffusate.
Chemical reactions: IKI–. CB–. KOH: faint
darkening of all elements with KOH; sometimes generative hyphae in rhizomorphs
assuming a pale grey to bluish tint.
description: Elia Martini
drawing: Elia Martini