Amauroderma preussii

Basidiome annual, corky, with distinctly contracted base at the center, becoming hard corky to woody hard when dry. Pileus single, 8–12 cm, up to 1 cm thick at the base, orbicular; upper 127 surface brown (6E4) to dark brown (6E5) alternating colour zones, near to margin, weakly laccate to non laccate, concentrically undulate, radially rugose; margin grey (6F1), wavy, inflexed; lower surface usually brown (6D7). Hymenophore up to 10 mm long, indistinctly stratose; pores initially brownish orange (5C4), bruising brown (6E8), pores circular or isodiametric, 2–4 per mm. Context 1 cm thick, triplex, not completely homogeneous in color; lower layer whitish-yellow (4A2) to yellow (4A3), corky; middle layer whitish-yellow (4A2) to yellow (4A3); fibrous/pithy, composed of coarse loose fibrils; upper layer yellowish-brown (6B3), woody.

Basidiospores (n = 25) (8.5)9.0–9.9–10.8(12.1) × (6.7)7.6–8.5–9.5(10.5) µm (Qm = 1.1, Q = 0.9–1.4, with myxosporium). (n = 25) (7.5)7.9–8.6–9.4(10.1) × (4.9)6.2–7.3–8.3(9.9) µm (Qm = 1.1, Q = 0.8–1.6, without myxosporium), subglobose, bitunicate, with a dark brown (6D8), eusporium bearing echinulae, overlaid by a hyaline myxosporium. Pileipellis a hymeniderm, pale yellow (4A3), streaks near the cutis, a closely-packed palisade, whitish-yellow (4A2), clavate terminal elements. Context trimitic; generative hyphae (n = 30) (0.3–0.9–1.6) µm in width, colorless, thin-walled; skeletal hyphae (n = 30) (1.9–2.4–3.1) µm in width, thick-walled, sometimes branched brown (6E4) to greyish brown (6E3); binding hyphae (n = 30) (0.4–1.4–2.3) µm in width, branched, with clamp-connections, brown (6E4) to greyish brown (6E3), frequently branched at apex, intertwined with the skeletal hyphae. Macrochemical reactions — KOH reaction positive, yellow. Schäffer’s reaction positive, reddish-orange on dry specimen.

Facesoffungi number. FoF 05185.

Habitat. Rotten conifer wood, on the soil near humus-rich soil with over heavily rotted litter on the ground, growing up from soil.

Material examined. Laos, Xiengkhouang Province, Phoukoud District, Yai village, evergreen forest, 19°58′N-103° 00′E, elev. 1120 m, collection date 27 July 2016, collector P. Phengsintham (GACP16072703, GACP16072833). China, Hainan Province, Jiangfengling Mountain, Coniferous rainforest, 18°44′N-108°51′E, elev. 550 m, collection date 21 October 2015, collector X.L Wu (GACP WXL15100201 ).