The Northeast Chinese species of Psathyrella (Agaricales, Psathyrellaceae) Author Yan, Jun-Qing Author Bau, Tolgor text MycoKeys 2018 33 85 102 http://dx.doi.org/10.3897/mycokeys.33.24704 journal article http://dx.doi.org/10.3897/mycokeys.33.24704 1314-4049-33-85 Psathyrella subsingeri T. Bau & J.Q. Yan sp. nov. MycoBank: MB823855 Figs 2 g-i , 6 Diagnosis. Pileus 15-40 mm, paraboloid to conical. Lamellae 2.0-4.0 mm broad, close. Basidiospores 5.8 -7.8(- 8.8) x 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 umbonate 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 x magnifier. Stipe 35-50 x 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) x 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 x 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 x 9.8-15 μm , rarely, various, clavate, utriform, thin-walled, hyaline. Trama of gills irregular, up to 15 μm broad. Pileipellis consisting of 1-2 cells, deep layer of subglobose cell, 20-32 μm broad. Clamps present. Figure 6. Microscopic features of Psathyrella subsingeri (HMJAU 37913). a Basidiomata b Basidiospores c Basidia d Pileipellis e Cheilocystidia f Caulocystidia. Bar: 10 mm (a); 10 μm ( b-f ). Drawing by Jun-Qing Yana. Habit and habitat. Solitary to scattered on terrestrial or humus in mixed forests. Other specimens examined. Henan Province, Xinyang City, Boerdeng National Forest Park, 16 Jul 2017, HMJAU 37915; Xian Mountain, 15 Jul 2017, HMJAU 37931; Jilin Province, Changchun City, Jilin Agricultural University, 21 Jun 2016. HMJAU 37811; Jingyuetan National Scenic Area, 25 Jun 2017, HMJAU 37914; 7 Jul 2017, HMJAU 37849; Tonghua City, Qiupi Village, 6 Aug 2015, HMJAU 37812, HMJAU 37813; Yunnan Province, Yeya Lake, 7 Aug 2016, HMJAU 37814; 6 Aug 2017, HMJAU 37852; 23 Aug 2017, HMJAU 37962.