Psathyrella subspadiceogrisea T. Bau & J.Q. Yan, 2017

Yan, Jun-Qing & Bau, Tolgor, 2017, New and newly recorded species of Psathyrella (Psathyrellaceae, Agaricales) from northeast China, Phytotaxa 321 (1), pp. 139-150 : 140-141

Psathyrella subspadiceogrisea T. Bau & J.Q. Yan sp. nov. Figs. 1a , 2

MycoBank MB 820210

Diagnosis:—Surface of pileus covered with scattered, small, white, superficial veil remnants. Veil not detached. Spores 6.8–7.8 × 3.9– 4.9 μm. Pleurocystidia fusiform to subutriform. Cheilocystidia resembling pleurocystidia, but much smaller, scanty. Caulocystidia absent.

Etymology:—Referring to its morphological similarity to Psathyrella spadiceogrisea .

Type:— CHINA. Jilin Province: Changbai Mountain, Erdaobaihe Town, Yanbian Korean Autonomous Prefecture, N42°24′10″, E128°05′53″, 15 June 2016, Tolgor Bau and Jun-Qing Yan HMJAU35992 (Holotype!).

Description:— Pileus 11—23 mm, hemispherical to paraboloid, hygrophanous, brown (7D6–7E6), darker at center (7E6–7E7), white (7A1) in periphery, striate up to 1/3, becoming dirty white to faint yellow (2A1–2A3) as pileus dries. Veil scanty, white (2A1), fibrillose, superficial. Context dirty white (2A1–2A2), very thin and fragile, about 2.0 mm at center. Lamellae about 3.0 mm broad, close, thin, adnate, grayish brown (7D5-7D7), edges white (7A1), even. Stipe 30–50 mm long, 2.5–3.0 mm thick, white (7A1), cylindrical, hollow, equal, fragile, surface covered with small white (7A1), evanescent fibrils. Odour and taste indistinctive. Spore print dark brown (8E7-8E8).

Spores (6.3)6.8–7.8 × 3.9–4.9 μm, Q=1.4–2.0, ellipsoid to elongated-ellipsoid, rarely oval, in profile flattened on one side, faint brown in 5% KOH, inamyloid, smooth, 1–2 guttulate, germ pore indistinct, 1.0–1.2 μm in diam. Basidia 17–22 × 7.3–9.8 μm, 4 or 2-spored, clavate. Pleurocystidia scattered, 37–59 × 9.8–15 μm, thin-walled and hyaline in 5% KOH, fusiform to subutriform, with obtuse apex, rarely forked. Marginal cells spheropedunculate cells 22–26 μm broad, abundant and very densely packed. Pleurocystidioid cheilocystidia scanty, 22–37 × 9.8–12 μm, fusiform, thin-walled, with obtuse apex. Trama of gills parallel hyphae, faint yellow. Pileipellis a 1–2 cells deep layer of subglobose or clavate hyphae, 22–27 μm broad. Veil composed of hyphae 5–7 μm broad, thin-walled, fawn in 5% KOH. Clamps only observed on hyphae of stipe.

Habit and habitat:—Scattered on rotten wood in mixed forests of larch and birch.

Known distribution:— Jilin Province, China.

Additional material examined:— CHINA. Jilin Province: Changbai Mountain, Erdaobaihe Town, Yanbian Korean Autonomous Prefecture, 16 June, 2016, Tolgor Bau and Jun-Qing Yan HMJAU 35996

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 2. Psathyrella subspadiceogrisea (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.