Amanita orientalis

Amanita orientalis Q. Cai, Y.Y. Cui and Zhu L. Yang

Fungal Namber: FN 571586.

Basidioma small, medium-sized to large. Pileus 3–11 cm diam., plano-convex to applanate, surface gray-brown (2C2–4), brown (3E3–5) to yellow-brown (4C4–6), often darker at center; volval remnants on pileus verrucose to felted, dark gray (1E1–3) to gray (1C1–3), often dirty white (1B1) at apical part; margin striate (0.3–0.6 R), non-appendiculate; trama white (1A1) to dirty white (1B1), unchanging. Lamellae free, crowded, white (1A1) to dirty white (1B1), sometimes with brownish (3B2–3) tinge; lamellar edges gray (1B1), gray-brown (1B2) to brown (3B2–4); lamellulae truncate, plentiful. Stipe 10–17 cm long × 0.5–1.5 cm diam., slender, subcylindric, slightly tapering upwards, with apex slightly expanded, grayish (1B1), brownish (1B2) to gray-brown (2D2–4), covered with concolor squamules; context white (1A1) to dirty white (1B1), hollow in center; basal bulb absent; volval remnants on stipe base tomentose, arranged in incomplete rings, gray (1C1–3) to gray-brown (1B2). Annulus absent. Odor indistinct.

Lamellar trama bilateral. Mediostratum 20–30 μm wide, composed of abundant, clavate inflated cells (50–80 × 10–20 μm); filamentous hyphae abundant, 2–8 μm wide; vascular hyphae scarce. Lateral stratum composed of abundant, ellipsoid to fusiform inflated cells (20–40 × 10–20 μm), diverging at an angle of ca. 30° to 60° to mediostratum; filamentous hyphae abundant and 2–8 μm wide. Subhymenium 30–50 μm thick, with 2–3 layers of ellipsoid to fusiform or irregularly arranged cells, 10–30 × 8–20 μm. Basidia 40–60 × 13–18 μm, clavate, 4-spored; sterigmata 5–8 μm long; basal septa lacking clamps. Basidiospores [40/2/2] (9.5–) 10–12 (–12.5) × (9–) 9.5–11 (–11.5) μm, Q = 1–1.13 (–1.15), Qm = 1.06 ± 0.03, globose to subglobose, inamyloid, colorless, thin-walled, smooth; apiculus small. Lamellar edge appearing as a sterile strip, composed of subglobose, ellipsoid to clavate inflated cells (10–45 × 10–30 μm), single and terminal or in chains of 2–3, thin-walled, colorless; filamentous hyphae abundant, 2–8 μm wide, irregularly arranged or ± running parallel to lamellar edge. Pileipellis 50–100 μm thick; upper layer (30–50 μm thick) gelatinized, composed of radially arranged to interwoven, thin-walled, colorless filamentous hyphae 2–5 μm wide; lower layer (40–50 μm thick) composed of radially arranged filamentous hyphae 4–7 μm wide, colorless; vascular hyphae scarce. Volval remnants on pileus composed of more or less vertically arranged elements: inflated cells very abundant to dominant, globose, subglobose, ellipsoid to fusiform, 10–60 × 10–50 μm, brown to brownish or colorless, thin-walled, mostly terminal or sometimes in chains of 2–3; filamentous hyphae rare, 3–7 μm wide, brown to brownish or colorless, thin-walled, branching, anastomosing. Volval remnants on stipe base composed of longitudinally arranged elements, becoming horizontally arranged towards upper parts: inflated cells very abundant to nearly dominant, globose, subglobose, ellipsoid, fusiform to clavate, 20–80 × 10–50 μm, brown to brownish or colorless, thin-walled, mostly terminal or sometimes in chains of 2–3; filamentous hyphae rare to fairly abundant, 2–8 μm wide, brown to brownish or colorless, thin-walled, branching, anastomosing. Stipe trama composed of longitudinally arranged, clavate terminal cells, 100–400 × 15–40 μm; filamentous hyphae scattered to abundant, 2–10 μm wide; vascular hyphae scarce. Clamps absent in all parts of basidioma.

Habitat: Solitary to scattered on soil in subtropical broad-leaved forests dominated with Fagaceae, sometimes in mixed forests with fagaceous and Pinus plants.

Distribution: Known from eastern China.

Additional specimens examined: CHINA. ANHUI PROVINCE: Huangshan, in a forest dominated with Fagaceae, altitude 1300 m, 13 July 2018, Ting Guo 1018 (HKAS 127631); same location, in a forest dominated with Fagaceae, altitude 670 m, 13 July 2018, Rui-Heng Yang 73 (HKAS 127632); same location, in a forest with Fagaceae and Pinaceae, altitude 940 m, 15 July 2018, Rui-Heng Yang 123 (HKAS 127633); same location, in a forest dominated with Fagaceae, altitude 760 m, 15 July 2018, Rui-Heng Yang 127 (HKAS 127634); same location, in a forest dominated with Fagaceae, altitude 1220 m, 17 July 2018, Rui-Heng Yang 184 (HKAS 127635); same location, in a forest dominated with Fagaceae, altitude 1200 m, 17 July 2018, Rui-Heng Yang 186 (HKAS 127636); same location, in a forest dominated with Fagaceae, altitude 940 m, 15 July 2018, Hong-Yu Chen 77 (HKAS 127637).

Notes: Based on molecular phylogenetic analysis, A. multicingulata is closely related to A. liquii, but the latter species has shorter striations on pileal margin (0.1–0.3 R), larger basidiospores (11.5–15 × 11–14.5 μm) and occurs in subalpine forests dominated by trees of Picea and Abies. In addition, A. liquii has white to grayish lamellae that turn dark gray to dark brown when dried. Amanita cinctipes Corner and Bas, A. griseofolia and A. neocinctipes Zhu L. Yang et al. of A. sect. Vaginatae with a nonsaccate volva were also reported from China. Smaller basidiospores (9–10.5 × 8–9.5 μm) and shorter striations on the pileal margin (0.3–0.4 R) distinguish A. cinctipes from A. multicingulata [2,29]. Amanita griseofolia differs from A. multicingulata by its more grayish pileus and slightly larger basidiospores (10–13.5 × 9.5–13 μm). White lamellae and subglobose to broadly ellipsoid basidiospores (8.0–10.5 × 7.0–9.0 μm, Q = 1.09–1.29, Qm = 1.19 ± 0.07) in A. neocinctipes set it apart from A. multicingulata.

Fig. 1 Phylogenetic tree of Amanita sect. Vaginatae inferred from maximum likelihood analyses based on the combined dataset (nrLSU, tef1-α and rpb2). Bootstrap values over 50% and Bayesian posterior probabilities over 0.90 are shown along the branches. Sequences from type collections are indicated with (T), and new species are in boldface.