Amanita pallidoverruca Yang-Yang Cui, Qing Cai & Zhu L. Yang, 2022

Cui, Yang-Yang, Yang, Zhu L. & Cai, Qing, 2022, Amanita pallidoverruca, a new species of Amanita section Validae from the Hengduan Mountains, southwestern China, Phytotaxa 542 (1), pp. 73-82 : 76-79

Amanita pallidoverruca Yang-Yang Cui, Qing Cai & Zhu L. Yang , sp. nov. Figs. 2–3

MycoBank: MB842861

Etymology: — pallidoverruca refers to the dirty white to greyish warts on the pileus.

Diagnosis:— Amanita pallidoverruca is closely related and similar to A. excelsa , but differs from the latter by its more robust basidioma, dirty white to greyish volval remnants on the pileus, and the greyish yellow to olivaceous edge of the annulus.

Holotype: — CHINA. Sichuan Province: Garzê Tibetan Autonomous Prefecture, Batang County, Cuopugou National Forest Park , elevation 4250 m, in a subalpine forest with trees of Picea , 6 August 2016, Bang Feng 2055 ( HKAS99345 !).

Description: —Basidioma ( Fig. 2 ) large. Pileus 9–13 cm diam., at first convex, later plano-convex to applanate, without umbo or depression at center, greyish white (1B1, 3B1, 4B1), greyish brown (4C2–4, 5C3–6) to greybrown (4D2–5, 5D2–4), densely covered with dirty white (4A2) to greyish (1B1–3) warts; margin non-striate and non-appendiculate; trama white (1A1), unchanging when cut. Lamellae free, crowded, white (1A1) to cream (1A2); lamellulae attenuate, plentiful. Stipe 10–15 cm long × 1.5–3 cm diam., subcylindric or slightly tapering upwards, with apex slightly expanded, white (1A1) to dirty white (4A2) above annulus, dirty white (4A2), grey (2B1, 2C1) to greyish brown (4B2–3, 4C2–3, 4D2–3) and decorated with grey (2B1, 2C1), grey-brown (4B2–3, 4C2–3, 4D2–3) to dark grey (3E1–3) squamules below annulus; context white (1A1); stipe base slightly inflated, fusiform, 2–4 cm diam., white (1A1) to dirty white (4A2), upper part covered with indistinct whitish warty volval remnants. Annulus present, subapical, pendent from attachment 2–4 cm below apex of stipe, white (1A1) at upper surface, greyish (1B1–3) to grey (1C1–3, 1D1–3) at lower surface, with greyish yellow (2B3–6) to olivaceous (2C3–5, 1C4–6) appendages at edge. Odor slightly pungent.

Lamellar trama bilateral. Mediostratum 30–40 μm wide, composed of abundant ellipsoid to clavate inflated cells (15–50 × 10–20 μm); filamentous hyphae abundant, 4–8 μm wide; vascular hyphae scarce. Lateral stratum composed of abundant subfusiform to ellipsoid inflated cells (15–40 × 10–20 μm), diverging at an angle of ca. 30–60 ° to mediostratum; filamentous hyphae abundant and 2–8 μm wide. Subhymenium ( Fig. 3a ) 20–50 μm thick, with 2–3 layers of subglobose to ellipsoid or irregular cells, 8–20 × 6–12 μm. Basidia ( Fig. 3a ) 40–70 × 10–12 μm, clavate, 4- spored; sterigmata 3–5 μm long; basal septa without clamps. Basidiospores ( Fig. 3b ) [40/2/2] 8–10 (–11) × (5.5–) 6–7 (–8) μm, Q = (1.27–) 1.33–1.58 (–1.75), Qm = 1.46 ± 0.12, predominantly ellipsoid, occasionally broadly ellipsoid or elongate, amyloid, colorless, thin-walled, smooth; apiculus small. Lamellar edge appearing as a sterile strip, composed of subglobose to ellipsoid to fusiform inflated cells (20–60 × 10–35 μm), single and terminal or in chains of 2–3, thinwalled, colorless; filamentous hyphae abundant, 2–8 μm wide, irregularly arranged or ± running parallel to lamellar edge. Pileipellis 60–150 μm thick; upper layer (30–50 μm thick) gelatinized, composed of subradially to somewhat interwoven, thin-walled, colorless filamentous hyphae 2–5 μm wide; lower layer (40–100 μm thick) composed of radially and compactly arranged filamentous hyphae 4–8 μm wide, colorless; vascular hyphae scarce. Volval remnants on pileus ( Fig. 3c ) composed of irregularly to vertically arranged elements: filamentous hyphae abundant, 2–10 μm wide, colorless, yellowish to brownish, thin-walled, branching, anastomosing; inflated cells very abundant, subglobose, fusiform to ellipsoid, 15–90 × 15–80 μm, colorless, yellowish to brownish, thin-walled, terminal or in chains of 2–3; vascular hyphae scarce. Annulus predominantly composed of two parts intergrading into each other. Upper part dominantly composed of radially to interwoven elements: filamentous hyphae scarce to abundant, 2–8 μm wide, brownish to brown, thin-walled; inflated cells very abundant to nearly dominant, subglobose, ellipsoid to fusiform, 25–80 × 10–70 μm, brownish to brown, thin-walled; vascular hyphae scarce. Lower part composed of radially arranged elements: filamentous hyphae very abundant to nearly dominant, 2–6 μm wide, brownish to brown, thin-walled; inflated cells scarce, clavate to long clavate, 30–60 × 10–30 μm, brownish to brown, thin-walled; vascular hyphae scarce. Clamps absent in all parts of basidioma.

Habit, habitat and distribution:—Solitary to scattered on soil in subalpine forests with Picea ; known from southwestern China.

Additional specimen examined:— CHINA. Sichuan Province: Garzê Tibetan Autonomous Prefecture, Batang County, Cuopugou National Forest Park , elevation 4220 m, in a subalpine forest with trees of Picea , 7 August 2014, Kuan Zhao 707 ( HKAS89638 ) .

Figures

FIGURE 2. Basidiomata of Amanita pallidoverruca. a. HKAS89638; b. HKAS99345 (holotype). Bars = 2 cm. Photos by Kuan Zhao (a) and Bang Feng (b).

FIGURE 3.Microscopical featuresofAmanitapallidoverruca(HKAS99345,holotype).a.Hymenium andsubhymenium;b.Basidiospores; c. Volval remnants on the pileus. Bars a–b = 10 μm, c = 20 μm.