Diagnosis. Pileus 15–40 mm, paraboloid to conical. Lamellae 2.0–4.0 mm broad, close. Basidiospores 5.8–7.8(–8.8) × 3.9–4.4(–5.0) μm, very pale, nearly hyaline or slightly yellow in water and 5% KOH. Germ pore absent. Pleurocystidia absent. Cheilocystidia utriform to predominantly spheropedunculate.
Holotype. CHINA. Jilin Province, Changchun City, Jingyuetan National Scenic Area, 43°47’38"N, 125°26’55"E, 200 m alt., 25 Jun 2017, HMJAU 37913.
Etymology. Name refers to its microscopic characteristics similar to P. singeri.
Description. Pileus 15–40 mm, paraboloid to conical, obtuse or slightly um- bonate at disc, hygrophanous, dark reddish-brown (8E7–8F8) or faint yellowish-brown (5C5–5C4), becoming yellowish-brown (6D5–6D6) as pileus dries, striate indistinct. Veil present in early stage, thin, white (6A1), fibrillose, evanescent. Context white (6A1), thin and very fragile, about 2.5 mm thick at stipe centre. Lamellae 2.0–4.0 mm broad, close, adnate, pale brown (6C4–6C5), edges white (6A1), saw-toothed under 20× magnifier. Stipe 35–50 × 3.0–4.5 mm, cylindrical, hollow, equal, fragile, covered with slight white (6A1) fibrils, which fall off easily. Spore print chocolate (7E7–7E8). Odour and taste indistinctive.
Basidiospores 5.8–7.8(–8.8) × 3.9–4.4(–5.0) μm, Q=1.4–2.0, ellipsoid to oblong- ellipsoid, in profile flattened on one side, very pale, nearly hyaline or slightly yellow in water and 5% KOH, inamyloid, smooth. Germ pore absent. Basidia 15–22 × 7.3– 9.8 μm, 4- or 2-spored, clavate, hyaline. Pleurocystidia absent. Cheilocystidia utriform to spheropedunculate, rarely clavate to fusiform with an obtuse to broadly obtuse apex, thin-walled, hyaline. Caulocystidia 26–37 × 9.8–15 μm, rarely, various, clavate, utri- form, thin-walled, hyaline. Trama of gills irregular, up to 15 μm broad. Pileipellis con- sisting of 1–2 cells, deep layer of subglobose cell, 20–32 μm broad. Clamps present.
Habit and habitat. Solitary to scattered on terrestrial or humus in mixed forests.
Jun-Qing Yan & Tolgor Bau / MycoKeys 33: 85–102 (2018)