Amanita griseoverrucosa Zhu L. Yang, Bibliotheca Mycologica 170: 155 (1997)

Hosen, Md. Iqbal, Mehmood, Tahir, Das, Kanad, Kudzma, Linas V. & Bhatt, R. P., 2018, Amanitatullossiana, a new species, and two new records of AmanitasectionLepidella from north-western Himalaya, India, MycoKeys 37, pp. 73-92 : 73

Amanita griseoverrucosa Zhu L. Yang, Bibliotheca Mycologica 170: 155 (1997) Figs 4a, b, 5a, b

Description.

Basidiomata medium-sized to large. Pileus 60-125 mm wide, initially hemispherical then convex to plano-convex, dry, slightly viscid when moist, whitish to greyish-white (1B1) to ash grey (1B2) to grey (1D1); context 6-11 mm thick, white (1A1), thinning evenly towards margin, unchanging when cut or bruised. Universal veil on pileus as felted to subconical to verrucose, brownish-grey (1D3), greyish-brown (5F3) to dark grey (1F1), soft, up to 4 mm thick, 5-8 mm wide, irregularly distributed; margin non-striate, appendiculate; Lamellae free to narrowly adnate, crowded, white (1A1), unchanging, 6-10 mm broad; lamellulae attenuate, plentiful, of several lengths, with 7-8 lamellae per cm at margin. Stipe 45-90 × 12-21 mm (excluding bulb), narrowing upwards, solid, lower part covered by light grey (1D1) fibrillose squamules, upper part covered by white farinose squamules; context white, unchanging on cutting or bruising. Bulb 32-62 × 19-32 mm, ventricose to clavate, white, covered with grey (1D1) to dark grey (1F1), universal veil remnants. Partial veil superior, soft, cottony, white, easily collapsed. Odour indistinct, taste not observed. Spore deposit white.

Basidiospores [80/4/2] (8-) 8.5 –10(– 11) × (5.5-)6 -6.5 (-7) µm, [L =9.05-9.17 µm, L' = 9.11 µm; W = 5.9-6.5 µm, W' = 6.2 µm; Q = (1.32 –)1.42–1.5(– 1.69), Q = 1.51-1.54, Q' = 1.53], ellipsoid, hyaline, thin walled, smooth, amyloid, apiculus sublateral, up to 1 µm. Basidia (34 –)45–50(– 53) × (9.5 –)10–12(– 14) µm, 2 to 4-spored, thin-walled, colourless, hyaline; sterigmata up to 4 µm long; basal clamp connections not observed in any tissue after extensive search. Lamellae edge sterile; composed of clavate or pyriform inflated cells 35-50 × 22-31 μm, thin walled, colourless, hyaline. Subhymenium 35-40 μm thick, wst-near = 30-40 μm, wst-far = 40-55 μm, basidia arising from subglobose to broadly ellipsoid cells (11-18 × 8-15 μm). Hymenophoral trama bilateral, divergent; wcs = 40-60 μm; well rehydrated, filamentous, undifferentiated hyphae 3-8 μm wide; inflated cells ellipsoid to elongated 55-90 × 12-19 μm, diverging at an angle of approximately 40°; vascular hyphae 11-14 μm wide, infrequent. Pileipellis 130-150 μm thick, subradially to densely arranged, filamentous, undifferentiated hyphae 2-7 μm wide; vascular hyphae 7-10 μm wide, infrequent. Universal veil on pileus disordered; filamentous, undifferentiated hyphae 2-7 μm wide, scattered, branched, thin walled; inflated cells dominantly globose to subglobose 40-70 × 30-65 µm, broadly ellipsoid to ellipsoid 40-60 × 10-13 μm, often in chain of 2-3 cells, thin walled, hyaline, often with yellowish-brown vascular pigment. Universal veil on base of stipe disordered; filamentous, undifferentiated hyphae 3-8 μm wide, scattered, thin walled, branched, with brownish vacuolar pigments; inflated cells dominantly globose to subglobose 30-65 × 26-58 µm, broadly ellipsoid to ellipsoid or pyriform 26-55 × 8-13 μm, thin-walled, hyaline, with brownish vacuolar pigment. Partial veil abundant inflated cells clavate to broadly clavate 76-130 × 13-25 µm, thin walled, colourless, hyaline or brownish vacuolar pigments; filamentous, undifferentiated hyphae 3-5 µm wide. Stipe context longitudinally acrophysalidic, filamentous, undifferentiated hyphae 5-7 µm wide; acrophysalides 220-270 × 33-45 µm, filamentous, undifferentiated hyphae 4-8 µm wide, hyaline, vascular hyphae not found. Clamp connections not observed in any tissue.

Habitat and distribution.

Solitary to gregarious, with plants of Fagaceae , Pinaceae and Ericaceae ( Rhododendron arboretum ).

Known distribution.

Currently known from China ( Yang 2004, 2015) and now India.

Specimens examined.

INDIA, Uttarakhand, Pauri district, Phedkhal, at 1900 m a.s.l., 30°09.728'N, 078°51.206'E, 29 July 2016, T. Mehmood, TM 16-1228 (GUH-M-27010); same location, 26 August 2015, T. Mehmood, TM-15-971 (GUH-M-27011), 1910 m a.s.l., 30°09.732'N, 078°51.214'E.

Commentary.

Morphologically, the Indian collections of A. griseoverrucosa are characterised by a whitish to greyish-white pileus covered with easily detachable greyish-brown to dark grey, felted to verrucose universal veil remnants, a ventricose to clavate stipe base, broadly ellipsoid to ellipsoid basidiospores, universal veil on the pileus with abundant inflated cells and scattered filamentous, undifferentiated hyphae and the absence of clamp connections at bases of basidia. The characteristic features and molecular data from the Indian collections match rather well with the original description of A. griseoverrucosa , reported from China ( Yang 2004).

The absence of clamp connections at the bases of basidia, ellipsoid to broadly ellipsoid basidiospores and abundant inflated cells with scattered hyphae in the universal veil placed this species in Amanita [sect. Lepidella subsect. Solitariae] stirps Cinereoconia ( Yang 2004). Phylogenetically, both Indian (TM 16-1228) and Chinese (HKAS 38459) collections of A. griseoverrucosa are closely related to A. cinereoconia and A. tullossiana (Fig. 1). Amanita cinereoconia has a white to greyish pileus covered with pulverulent to small warted universal veil remnants and elongate to cylindric basidiospores 8.5-11.5 × 5-6.5 µm ( Bas 1969, Jenkins 1986). Amanita griseoverrucosa is also distinguished from Amanita tullossiana (see above).