Amanita annulata L.P. Tang & W.H. Zhang, 2021

Zhang, Wen-Hao, Huang, Ting, Huang, Hong-Yan & Tang, Li-Ping, 2021, Amanita annulata, a new species of Amanita section Vaginatae with an annulus from southwestern China, Phytotaxa 514 (3), pp. 261-274 : 264-267

Amanita annulata L.P. Tang & W.H. Zhang , sp. nov. ( Figs. 3–4 )

McoBank:— MB 840210

Etymology:— annulata , refers to this species having an annulus.

Diagnosis:—Characterized by its large white basidioma, yellowish white subpyramidal volval remnants on pileus surface and stipe base, white annulus, basal bulb absent; broadly ellipsoid to ellipsoid, non-amyloid basidiospores, and the absence of clamps in all parts of basidiome.

Holotype:— CHINA. Yunnan Province: Jianchuan Prefecture, Shibao Mountain , on the ground in an evergreen broad-leafed forest, 26°23′43.51”N, 99°50′43.35”E, elev. 2500 m, 18 August 2014, L.P. Tang 1671 ( MHKMU L. P. Tang 1671).

Gene sequences ex-holotype:— MZ005574 (ITS); MZ005570 (LSU).

Description:— Pileus 13−15 cm diam, convex-applanate to applanate, without an umbo or depression at centre, white to snow white (1A1), margin with short striations (0.1−0.13R), set with a few erect, firm, large volval remnants over centre, pyramidal to subpyramidal or subconical warts, 0.2−0.7 cm high, 0.4−1 cm diam at base, yellowish white (3A2 to 4A2) (usually brownish discoloration due to soil) at tips, nearly white (1A1) at base, easily breaking off or washed away by rain; context 0.5−1 cm thick in centre of pileus, firm, white (1A1), no color change when cut or bruise. Lamellae 1cm wide, free, very crowded, about 200 pieces of primaries with 1−2 tiers of nearly truncate lamellulae, thin, brittle, white (1A1), broad. Stipe 17−25 cm long, 1.7−1.9 cm diam at apex, 2−2.5 cm diam at base, almost cylindrical, slightly tapering upwards, straight or slightly curved, usually appressed concolorous fibrillose scales above annulus, usually smooth, sometimes lower part with some large recurved scales below annulus; context white, partially hollow; remnants of volva on base of stipe similar to those on pileus, but some larger, basal bulb absent. Annulus 0.8−1 cm wide, subapical, below apex of stipe, thick, mealy, white, faintly striate above, fugacious, or evanescent. Taste and odor faint, indistinct.

Basidiospores [160/4/3] (10−) 11−15 (−16.5) × (8−) 9−12 (−13) μm, Q = (1.00−) 1.15−1.5 (−1.67), Q m = 1.3 ± 0.09, mostly broadly ellipsoid to ellipsoid, occasionally subglobose, inamyloid, colorless and hyaline, thin-walled, smooth. Basidia 58–82 × 15–22 μm, usually tetrasporic, rarely bisporic; sterigmata 3–8 μm long. Subhymenium consisting of 1–4 layers of irregular subglobose cells 15–30 × 10–20 μm. Lamellar trama bilateral, consisting of abundant inflated cells 50–105 × 15–40 μm, cylindro-clavate, clavate, fusiform to subfusiform; mixed with abundant filamentous hyphae 2–7 μm wide, thin-walled, colorless and hyaline; vascular hyphae rare to absent. Volval remnants on pileus: the upper part of the wart composed of irregularly arranged, abundant to very abundant hyphae 2–6 μm wide, septate and branched, sometimes colorless and hyaline, usually yellowish brown to brown; mixed with rare to scattered inflated cells 20–30 × 18–25 μm, subglobose, ellipsoid to fusiform, single and terminal, sometimes colorless and hyaline, usually yellowish brown to brown; the lower part of the wart is similar to the upper. Volval remnants on stipe base structure similar to the structure of volval remnants on pileus. Pileipellis upper layer composed of quite abundant filamentous hyphae 2–8 μm wide, gelatinized, predominantly radially arranged, colorless and hyaline, non-septate, non-branched; lower layer composed of filamentous hyphae 5–8 μm wide, radially and compactly arranged. Annulus predominantly composed of abundant to very abundant inflated cells 35–163 × 10–35 μm, subglobose, ellipsoid to clavate; mixed with abundant filamentous hyphae 3–6 μm wide, colorless and hyaline, thin-walled; vascular hyphae rare. Stipe trama mainly composed of clavate terminal cells 90–250 × 25–40 μm, longitudinally arranged, mixed with scattered to abundant filamentous hyphae 2–10 μm wide. Clamps absent in all tissues.

Habit and habitat:—Scattered or in small groups in forests, appearing in rainy season (July to August).

Distribution:—Currently known only from Yunnan Province, southwestern China.

Other material examined:— CHINA. Yunnan Province: Jianchuan County, Shibao Mountain , on ground in an evergreen broad-leafed forest, 26°23′43.51”N, 99°50′43.35”E, elev. 2560 m, 20 August 2014, L.P. Tang 1730

(MHKMU L.P. Tang 1730, GenBank Acc. No.: nrLSU = MZ005571 , ITS = MZ005573 ); Shizong County, Junzi Mountain , 24°38′0″N, 104°9′3″E, elev. 2330 m, 22 July 2020, W.H. Zhang 232 ( MHKMU W.H. Zhang 232, GenBank Acc. No.: nrLSU = MZ 005569 , ITS = MZ 005572 ) .

Figures

FIGURE. 3 Basidioma of Amanita annulata. a: MHKMU W.H. Zhang 232; b–d, f, g: MHKMU L.P. Tang 1671 (holotype); e: MHKMU L.P. Tang 1730; (a, photo by W.H. Zhang; b–g, photos by L.P. Tang).

FIGURE 4. Microscopic features of Amanita annulata. a. Pileipellis. b. Lamellar trama. c. Basidiospores. d. Basidia. e. Hymenium and subhymenium. f. inflated cells of the annulus. Bars: a–b = 100 μm, c–f = 20 μm. (a–f, photos by: W.H. Zhang).