Trichocybe puberula

Trichocybe puberula (Kuyper) Vizzini 2010, in Vizzini et al., Fungal Diversity, 42, 97-105 (2010)

Basionym: Clitocybe puberula Kuyper, Sydowia 36: 173 (1983).

Diagnosis: Pileus 10–45 mm broad, at first hemispherical, broadly conical-trapezoidal to convex, expanding with age to planoconvex, then nearly applanate, slightly depressed at centre to funnel-shaped when old; with involute, then straight margin, finally with irregularly undulate marginal zone, sometimes fimbriate, pubescent, membranaceous to thin-fleshed, translucently striate when moist; dry, hygrophanous, at first roughly pruinose-pubescent overall due to minute white squamulose flocci persisting towards margin; vinaceous-brown, with margin darker, dark brown to blackish brown, with vinaceous-violaceous tinges, pallescent when wet to cream-yellowish, whitish-cream. Lamellae L= 26–30, l=(1) 2–3(–4), up to 4–5 mm broad, moderately distant, sinuate to broadly adnate to slightly decurrent, often slightly intervenose, sometimes partially fused with the lamellulae and then forked, firm, flexible greasy to the touch, fairly thick, with entire concolorous edge; whitish-cream with lilac hues, then yellowish-ochre. Stipe 25–60×3–7 mm, central to clearly eccentric, rarely lateral, cylindrical or slightly broadened towards the base, often curved or flexuous, fistulose, with abundant white mycelium at base, dry, finely white fibrillose-granulose at apex, minutely whitish-striate downwards; cream-whitish, ochre-brown, concolorous with lamellae at apex, distinctly darkening towards the base. Rhizomorphs absent. Context rather firm, non-reviviscent, tough in the pileus, fibrous in the stipe, cream-whitish then ochre-brown, in the pileus 1.5–2.5 mm thick. Smell, strongly farinaceous, subrancid; taste mild, subfarinaceous, subrancid. Spore-print whitish. Spores [90, 6, 3] (5.0)6.5–8.5(–9)×(3.0) 3.5–4.8(–5.5) μm, on average 7.5×4.2 μm, Q=(1.3)1.6–1.9(–2.0), Qm= 1.75, smooth, hyaline, thin-walled, inamyloid, nondextrinoid, acyanophilous, only a small minority in tetrads, subellipsoid-subcilindric in side-view, oblongellipsoid in front-view. Basidia 22–30×6–7 μm, 4-spored, claviform to pear-shaped, clamped, with basal clamp connection, lacking siderophilous granules. Pileipellis a slightly gelatinized plagio trichoderm (sensu Clémençon 2004), i.e. a cutis of 3–11 μm wide, cylindrical to physaloid periclinal hyphae, which patchily has a tendency to form a trichoderm; the erect, repent elements rising from the cutis may be isolated, tufted into squamules or even coalesce into dense, 120–450 μm high, pyramidal or oblique bunches of yellow-pigmented hyphae. The hyphae may have 10–80 μm long lateral outgrowths. Subpellis made up of largely cylindrical to physaloid-vesiculose intercalary elements, 5–30 μm wide, sometimes sphaerocyte-like. Stipitipellis consisting of slightly gelatinized hyphae, (2.5)4–8(–10) μm wide, sometimes with a fine yellow pigment and with yellow, often minutely incrusted, walls, often diverticulate and with long outgrowths. Stipititrama composed of longitudinally running, thin-walled, up to 30 μm wide, cylindrical, unbranched, smooth, colourless, inamyloid hyphae. Cheilocystidia 35–60×3–5 μm, scattered, mostly cylindrical, sublageniform, often curved and flexuous, sometimes forked at apex, with branched apex, hyaline, thin-walled.

Index Fungorum Number: IF512689

Figure 1. Trichocybe puberula (TO-HG 1148, Musumeci 7092-08). a Basidiomes. b Basidiospores. c Cheilocystidia. Bars: a = 10 mm, b–c = 10 μm