Amanita virgineoides Bas, Persoonia 5: 435 (1969)

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 virgineoides Bas, Persoonia 5: 435 (1969) Figs 4c, d, 5c, d

Description.

Basidiomata medium-sized to large. Pileus 50-140 mm wide, white to slightly yellowish-white (1A2) with age, ovoid at first, hemispherical when expanding, later convex to plano-convex to flat; slightly depressed, dry, shiny, densely covered with conical to subconcal warts; margin appendiculate, incurved; context 8-13 mm thick, thinning evenly towards margin, white, turning yellowish-white (1A2) when cut or bruised. Universal veil on pileus as conical, subconic to pyramidal warts, 5-10 mm thick, white, easily detachable when touched, sometimes washed away by rains, turning slightly yellowish-white (1A2) with age. Lamellae 12-15 mm thick, free, white (17A1) crowded, with 8-9 lamellae per cm at margin; lamellulae attenuate, of 4-5 lengths, plentiful, white to cream. Stipe 75-140 × 26-22 mm (excluding bulb), white (16A1), slightly tapering upwards, the upper part covered by flocculent squamules, the lower part covered by irregularly arranged, conical to sub-conical warts; context white, solid, turning light yellowish (1A3) when cut or bruised. Bulb 23-29 × 23-30 mm, subglobose, ovoid to napiform, white, slightly yellowish-white with age. Universal veil on stipe base as white conical to subconical warts. Partial veil superior, white, submembranous, thick, covered with white conical warts, fragile, easily detachable when touched. Odour unpleasant. Taste not recorded. Spore print white.

Basidiospores [180/9/4] (7.5 –)8–10.5(– 11) × (5.5 –)5.8– 7.5 µm, [L = 8-10 µm, L' = 9.05 µm; W = 6.0-6.7 µm, W' = 6.45 µm; Q = (1.22 –)1.33–1.55(– 1.66), Q = 1.33-1.46, Q' = 1.41], colourless, hyaline, thin walled, smooth, amyloid, broadly ellipsoid to ellipsoid; apiculus lateral to sublateral, up to 1 µm long; contents monoguttulate. Basidia (42 –)48–51(– 58) × (10 –)11–12(– 12.5) µm, 2 to 4-spored, thin-walled, colourless, hyaline; sterigmata up to 4 µm long; basal septa often clamped. Lamellar edge tissue sterile, with inflated cells; subglobose to pyriform 15-25 × 8-15) μm, thin walled, colourless, hyaline, clamps present. Subhymenium 30 µm thick, wst-near = 28-45 μm, wst-far= 35-50 μm, ramose, with inflated; ovoid to ellipsoid cells 12-18 × 8-14 μm; clamp present. Hymenophoral trama, bilateral, divergent; wcs= 40-65 μm; lateral stratum comprising of inflated intercalary segment 30-65 × 8-20 μm, common; filamentous, undifferentiated hyphae 3-9 μm wide, thin-walled, colourless, hyaline, vascular hyphae rare; clamp present. Pileipellis hardly differentiated; filamentous hyphae 2-7 μm wide, interwoven, non-gelatinised, thin walled, colourless, hyaline. Universal veil on the pileus with elements anticlinally arranged; filamentous, undifferentiated hyphae 4-8 μm wide, abundant, branched, colourless, hyaline; inflated cells dominantly subglobose to pyriform 16-46 × 14-32 μm, broadly ellipsoid to fusiform 30-66 × 10-21 μm; clamp present. Universal veil on the stipe base with elements anticlinally arranged; filamentous, undifferentiated hyphae 4-7 µm wide, scattered to abundant, colourless, thin walled, hyaline; inflated cells dominantly globose to subglobose 20-50 × 18- 48 µm, broadly ellipsoid to ellipsoid 45-65 × 15-20 µm, thin walled, hyaline, colourless, clamps present. Partial veil abundant inflated cells subglobose to ellipsoid 15-36 × 12-28 μm, thin walled, colourless, hyaline; filamentous, undifferentiated hyphae 3-8 µm wide, dominant, colourless, thin walled, clamps present. Stipe context longitudinally acrophysalidic; filamentous hyphae 2-13 μm wide, acrophysalides measuring 120 -181 × 20-30 μm, dominant, colourless, thin walled, hyaline, clamps present. Clamp connections common.

Macrochemical tests on fresh basidiomata.

Chemical reactions on pileus surface: 10% NH4OH - pinkish, 5% KOH - negative, 2% phenol - negative; and FeSO4 crystals - negative on pileus and stipe context.

Habitat and distribution.

Solitary to subgregarious in temperate mixed forest dominated by Quercus leucotrichophora and Cedrus deodara at 1850-2050 m a.s.l.

Known distribution: This species was originally described from Japan. It has also been reported from China ( Yang 1997), South Korea ( Kim et al. 1993), Thailand ( Sanmee et al. 2008) and now India.

Specimens examined.

INDIA, Uttarakhand, Pauri district, Phedkhal, 24 August 2014, T. Mehmood, TM 14-413 (RET 717-9); same location, 12 August 2015, T. Mehmood, TM 15-917 (GUH-M-27012); same location, 16 July 2016, T. Mehmood, TM 16-1098 (GUH-M-27013); same location, 24 July 2017, T. Mehmood, TM 17-1468 (GUH-M-27014).

Commentary.

An Indian collection (RET 717-9) is grouped phylogenetically with Chinese material of A. virgineoides (HKAS 79691, GenBank nrLSU: KJ466495 and HKAS 77278, GenBank nrLSU: KC429043), with pairwise genetic divergence between their nrLSU sequences = 0.35% (might be intragenomic heterogeneity present amongst collections as the sequence was not clean). It is worth mentioning that there is no genetic distance between rpb2 sequences derived from the Chinese (HKAS 79691, GenBank rpb2: KJ466663) and Indian (RET 717-9) collections. The evidence suggests that the two collections could be conspecific and exhibiting a minor intra-specific variability. In addition, the sample size is also small. For these reasons, we do not feel justified in erecting a new species or subspecies. Interestingly, another Chinese collection (HKAS 18394), labelled as A. virgineoides (GenBank nrLSU: AF024484, Weiß et al. 1998), is also grouped with the Indian collection, but the sequence derived from this collection is divergent from the two previously cited collections (Fig. 1). However, the habit and size of the basidiomata and basidiospores of the Indian collections match well with those characters in the descriptions of A. virgineoides provided by Bas (1969) and Yang (1997, 2015). Therefore, the Indian collection (RET 717-9) is being treated here as A. virgineoides - a new record for India.

Amanita virgineoides belongs to Amanita [sect. Lepidella subsect. Solitariae] stirps Virgineoides because of the presence of conical to subconical warts on the pileus surface which consist of inflated cells rather abundant hyphae, the presence of clamp connections at the bases of basidia and the broadly ellipsoid basidiospores ( Bas 1969, Yang 1997). In stirps Virgineoides , A. gracilior Bas & Honrubia and A. miculifera Bas & Hatanaka resemble A. virgineoides morphologically. Amanita gracilior , originally described from Spain, has a white pileus turning yellowish-brown with age, a rooting base and elongate basidiospores 10-11.5 × 5.5-6.5 µm, with a higher Q' value = 1.8 ( Bas 1969). Amanita miculifera , originally described from Japan, has a pearl grey pileus and a stipe with a notably radicating basal bulb ( Bas and Hatanaka 1984, Yang 1997). The white basidiomata of A. virgineoides also resembles the basidiomata of other of Bas’ stirpes. In creating these stirpes, Bas morphologically segregated these taxa from A. virgineoides ( Bas 1969).