Melanoleuca juliannae var. decolorans Antonín & Tomšovský, 2014

Antonín, Vladimír, Benedek, Imre Rimóczi Lajos, Papp, Viktor, Szarkándi, János Gergő, Dima, Bálint, Nagy, László G., Papp, Tamás, Ďuriška, Ondrej & Tomšovský, Michal, 2014, Melanoleuca juliannae (Basidiomycota, Tricholomataceae), a new species from subgen. Urticocystis, Phytotaxa 170 (1), pp. 13-23 : 19-21

Melanoleuca juliannae var. decolorans Antonín & Tomšovský , var. nov. ( FIGURES 5–8 )

MycoBank MB 808034

It differs from the typical variety by the absence of the blue-violaceous colour in the stipe base.

Holotype:— ITALY. Monti Sibillini National Park , Altino di Montemonaco, 20 November 2012, V. Antonín 10.438 (HOLOTYPE, BRNM 751960 ).

Etymology:—Lacking the blue colour in the stipe base.

Pileus 25–35 mm broad, plano-convex, with obtuse, conical, rather broad but ± distinct central umbo within sometimes depressed centre, margin reflexed and involute, hygrophanous, not translucently striate, smooth, glabrous, entirely dark brown (6F5) when young, pallescent to (grey-)brown (6D5-7E 5, 6E 4-5, 6-7D3) from margin. Lamellae moderately close, L = c. (30–)55–60, l = 3–4, shortly emarginate and attached with a short tooth, sinuate, cream coloured with beige reflex, with concolorous, finely pubescent edge. Stipe 28–45 × 3–6 mm, cylindrical, slightly broadened at apex, cylindrical to slightly clavate-bulbose (up to 7 mm) at base, longitudinally fibrillose, finely pruinose-floccose at apex, lustrous, dark grey-brown (6E3-6, 7E-F3), with brown (6D4) apex; basal tomentum white. Context watery offwhite, hollow in stipe, brown to dark brown in stipe base, in stipitipellis colour in stipe cortex, with indistinct or slight fungoid smell and mild taste.

Basidiospores (7.0–)8.0–10 × (5.0–)5.5–6.5 μm, average = 8.5 × 5.7 μm, E = 1.27–1.73, Q = 1.42–1.55, (broadly) ellipsoid, ovoid, verruculose with ridges, amyloid. Basidia 28–42 × 10.5–13 μm, 4-spored, clavate. Basidioles 15–45 × 4.0–12 μm, cylindrical, clavate. Cheilocystidia 35–50 × 4.5–12 μm, urticoid of two types, the brevipes - type more frequent than the exscissa - type, basal part (sub)cylindrical or fusoid, sometimes irregular, apical part 2.5–4.0 μm wide, almost cylindrical to subulate, thin-walled. Pleurocystidia not seen. Trama hyphae cylindrical to subinflated, thin-walled, smooth or minutely incrusted, non-dextrinoid, up to 20 μm wide. Pileipellis an ixocutis, transient to ± ixotrichoderm at centre, composed of ± interwoven, cylindrical, thin-walled, non-dextrinoid, up to 7.0(–9.0) μm wide hyphae; terminal cells adpressed to (sub)erect, cylindrical, (narrowly) clavate, subfusoid, obtuse, thin-walled, up to 9.0 μm wide. Stipitipellis a cutis of cylindrical, parallel, ± thin-walled, non-dextrinoid, up to 7.0 μm wide hyphae. Caulohymenium of (1) 25–55 × 8.0–9.0 μm, clavate, subcylindrical, thin-walled cells, and (2) 68–71 × 8.0 μm, urticoid cystidia similar to cheilocystidia, sometimes rare or absent(?). Clamp connections absent.

Habitat:—On xeric alcaline (calcareous and serpentinite) soils in a montane pasture with Juniperus communis and J. oxycedrus , in grass in a pasture, and in a grassy xerothermic steppe.

Material studied:— CZECH REPUBLIC. Hrubšice , Nad řekami Nature Reserve, elev. 240–260 m, 6 November 2010, V . Antonín 10.377 ( BRNM 751961 ). Brno-Slatina , Stránská skála National Nature Reserve, elev. 290 m, 4 December 2006, R . Schles ( BRNM 751962 ). ITALY, Monti Sibillini National Park, Altino di Montemonaco, elev. 1220–1320 m, 20 November 2012, V . Antonín 10.438 (holotype BRNM 751960 ) .

Remarks:— Melanoleuca juliannae var. decolorans is both macro- and microscopically similar to the type variety. The main differential character is the absence on the blue colour in the stipe base.

Figures

FIGURE 5. Melanoleuca juliannae var.decolorans (Holotype). Italy, Monti Sibillini National Park,Altino di Montemonaco, 20 November 2012. Photo V. Antonín.

FIGURE 6. Melanoleuca juliannae var. decolorans. SEM microphotographs of basidiospores (left: BRNM 751961, right: BRNM 751962). Photo L. Ilkovics.

FIGURE 7. Melanoleuca juliannae var. decolorans. SEM microphotographs of cheilocystidium (left, Holotype) and caulocystidium (right, BRNM 751962). Photo K. Bóka.

FIGURE 8. Melanoleuca juliannae var. decolorans. a. cheilocystidia, b. basidiospores, c. caulohymenium. Scale bar = 20 μm. Drawings V. Antonín.