Psathyrella boreifasciculata Kytöv & Liimat. (2014: 238)

Yan, Jun-Qing & Bau, Tolgor, 2017, New and newly recorded species of Psathyrella (Psathyrellaceae, Agaricales) from northeast China, Phytotaxa 321 (1), pp. 139-150 : 141-144

Psathyrella boreifasciculata Kytöv & Liimat. (2014: 238) Figs. 1b , 3

Description:— Pileus 10–25 mm, hemispherical to conical, narrowly convex in center, dark brown (7E7–7E8), hygrophanous, becoming greyish brown (7D4–7D5) and subsulcate when drying. Veil with a thin coating of fibrils, evanescent. Context dirty white (7A1), very thin and fragile. Lamellae about 2.0 mm broad, close, thin, adnate, greyish white (8A1–8A2), becoming dark brown (8D8–8E7) as spores mature. Stipe 60–120 mm long, 1.5–3.0 mm thick, white (8A1), cylindrical, hollow, equal, fragile, the stipes intertwine or coalesce, which can form small to large bundles, with white rhizomycelia at base. Odour and taste indistinctive. Spore print not recorded.

Spores (7.3)8.5–9.8(12.0) × (4.4)4.6–5.1(5.4) μm, Q= (1.5)1.7–2.1(2.5), ellipsoid to elongated-ellipsoid, or rarely subcylindrical, dark yellow brown in 5% KOH inamyloid, smooth, 1–2 guttulate, germ pore distinct, 1.5 μm in diam. Basidia 17.1–23.3(24.0) × (7.3)7.6–9.8(11.2) μm, 4-spored, clavate. Pleurocystidia scanty, (34.6)36.2–44.1(45.3) × (9.8)11.2–14.3(17.2) μm, fusoid to utriform with obtuse to slightly broadly rounded apex. Cheilocystidia (19.0)24.6– 31.4(34.2) × (7.3)9.8–12.1(14.2) μm, fusoid to utriform, rarely ventricose with pointed to obtuse apex. Caulocystidia absent. Trama of gills irregular hyphae, hyaline. Pileipellis a 1–2 cells deep layer of vesiculose cell-like hyphae. Clamps present.

Habit and habitat:—Caespitose on humus in mixed forests of larch and birch.

Known distribution:— China, Finland ( von Bonsdorff et al. 2014), Norway ( von Bonsdorff et al. 2014) and Sweden ( von Bonsdorff et al. 2014).

Material examined:— CHINA. Heilongjiang Province: Nanwenghe National Nature Reserve, Huzhong District , 11 September, 2015, Jun-Qing Yan HMJAU27556 ; Shuanghe National Nature Reserve, Heihe City, 7 September , 2015, Jun-Qing Yan HMJAU35981 ( HMJAU!) .

Figures

FIGURE 1. a) Psathyrella subspadiceogrisea (HMJAU35992) b) Psathyrella boreifasciculata (HMJAU27556) c) Psathyrella gordonii (HMJAU35983) d) Psathyrella senex (HMJAU37306). Bars: a–d=10 mm. Photos a, b, d by Jun-Qing Yan; Photo c by Tolgor Bau.

FIGURE 3. Psathyrella boreifasciculata (HMJAU27556) a) Basidiomata b) Basidiospores c) Basidia d) Pileipellis e) Pleurocystidia f) Cheilocystidia. Bars: a=10 mm, b–f=10 μm. Illustration by Jun-Qing Yan.