Agaricales » Agaricales genera incertae sedis » Paralepistopsis

Paralepistopsis amoenolens

Paralepistopsis amoenolens (Malençon) Vizzini 2012, in Vizzini & Ercole, Mycotaxon, 120, 253-267 (2012)

Diagnosis: Pileus (2–)3.57(–8) cm diam., fleshy, sub-elastic, hemispherical to convex at first, becoming plano-convex and applanate, finally plano-concave, at times broadly umbonate; margin narrowly inrolled and decurved at first, remaining inrolled for a long time, then expanding to become somewhat wavy, shortly sulcate-striate or corrugated; not hygrophanous, occasionally appearing hygrophanous when water soaked; surface slightly viscid when moist, at first entirely whitely pruinose, then pubescent-pruinose only at margin, typically diffracted-scaly near the disc, sometimes corrugated, wrinkled and areolate, later subglabrous often with more or less concentrically arranged watery, drop like spots, especially near margin (as many Lepista species); at first cream-beige coloured (Capucine Buff, Pale Ochraceous-Salmon, Pale Ochraceous-Buff), then pinkish beige to rusty orange (Ochraceous-Buff, Zinc Orange) towards the centre. Lamellae crowded to close (L = 4048(–50), l = (0–)12(–3)), thick, interspersed with lamellulae, (2–)34(–5) mm broad, decurrent, easily separable from the pileus context, at times intervenose or forked towards the stipe, at first whitish then yellowish ochre (Ivory Yellow, Chamois) to pinkish beige (Pale Ochraceous-Salmon, Pale Ochraceous-Buff); edges even, entire, concolorous. Stipe (2.5–)33.5(–5) cm long, 0.71.3 cm thick, short, central or subexcentric, equal or with a somewhat enlarged base, straight or recurved, concolorous with the pileus or slightly paler, minutely white pruinose at apex, glabrous elsewhere, stuffed with white medulla, becoming hollow; the base often with copious whitish tomentum with adhering Pinaceae needles and woody debris. Context 411(–14) mm thick at disc, elastic, white in the pileus, whitish cream (Capucine Buff) in the stipe cortex, unchanging; taste mild, fungoid, subfarinaceous, slightly bitter-farinaceous after long mastication; odour strong, aromatic, floral, reminiscent of Inocybe corydalina, Tricholoma caligatum, Lepista irina, or Entoloma ameides. Spore print whitish to pale Basidiospores (3.8–)4.05.4(–5.6) × (2.3–)3.24.0(–4.3) μm (n = 120), on average 4.8 × 3.4 μm, Q = 1.31.7, Qm = 1.42, broadly ellipsoid, hyaline, thin-walled, smooth, slightly cyanophilous, inamyloid, non-dextrinoid, usually with only a single oil drop and a distinct truncated apiculus up to 0.7 μm long, mostly adhering together in tetrads in dried specimens. Basidia (25–)3037(–38) × 56(–7) μm, cylindro-clavate, usually four-spored, occasionally two-spored, sterigmata up to 5 μm long. Hymenophoral trama regular in young stages, but subirregular in mature basidiomata, consisting of hyaline, elongated, cylindrical hyphae 46(–8) μm broad. Pleurocystidia absent. Lamella edges fertile, with rare, scattered cells, not well differentiated from basidia, 1545(–60) × 2.55(–7) μm, cylindric to subfusiform or sublageniform, often curved and flexuous, sometimes forked at apex, hyaline, thin-walled. Pileipellis duplex: upper layer (suprapellis) a soon disappearing, slightly gelatinous thin cutis (1030 μm thick), of cylindrical hyphae, 13 μm broad; lower layer (subpellis) (150350 μm thick) composed of densely arranged parallel to slightly interwoven hyphae (46 μm in diam.), terminal elements scattered, erect and repent cylindrical to fusiform-lageniform, sometimes with short lateral outgrowths. Pileitrama consisting of cylindrical or slightly cream (Light Buff, Pale Pinkish Buff). inflated, smooth hyphae, (4–)59(–12) μm broad, irregularly arranged, and with aeriferous lacunae. Stipitipellis a cutis consisting of hyphae 34 μm broad; towards the stipe apex with numerous thin-walled, flexuous, cylindrical to subfusiform caulocystidioid elements, 2035 × 36 μm. Stipititrama formed by hyphae 67 μm broad. Thromboplerous hyphae (= oleiferous hyphae sensu Clémençon 2004) present especially in subpellis, pileus and hymenophoral trama. Pigment (yellowish) usually parietal and intracellular (cytoplasmatic) in the pileipellis; sometimes minutely incrusting or forming extracellular masses and granules. Clamp connections present at nearly all septa.

Index Fungorum Number: IF564341

Figure 1. Tricholomatoid clade. Bayesian phylogram obtained from the combined ITS-LSU sequence alignment. Support values for clades that are supported in either the Bayesian (Posterior Probabilities values BPP) or Maximum likelihood (ML Bootstrap percentage MLB) analyses are indicated. BPP > 0.70 and MLB > 50% are given above branches. Numbers (1, 2) refer to the Paralepistopsis and Paralepista collections.