Psathyrella amygdalinospora T. Bau & J.Q. Yan, 2021

Bau, Tolgor & Yan, Jun-Qing, 2021, A new genus and four new species in the / Psathyrella s. l. clade from China, MycoKeys 80, pp. 115-131 : 115

Psathyrella amygdalinospora T. Bau & J.Q. Yan sp. nov. Figs 2d-f , 4

Etymology.

Referring to the spore shape.

Type.

China. Scenic Spot of Kangding Love Song (Mugecuo), Kangding City, Tibetan Autonomous Prefecture of Garze , Sichuan Province, 30°08'49.19"N, 101°51'39.18"E, 3790 m, 21 August 2017, Jun-Qing Yan, Herbarium of Mycology , Jilin Agricultural University (HMJAU37952) .

Diagnosis.

Differs from P. obtusata by its spores, ovoid in front view, amygdaliform in profile and dark brown and gradually becoming black-brown in 5% KOH.

Pileus 15-25 mm broad, paraboloid, hygrophanous, chestnut (8F6-8F7), becoming dirty white (8A1-8B1) as pileus dries. Veil not observed. Context approximately 2.0 mm at the centre, fragile, concolorous with pileus. Lamellae 4.0 mm, light brown (8D3-8D5), edges white (8A1), even. Stipes 45-60 mm long, 2.5-3.0 mm thick, fragile, hollow, cylindrical, equal or slightly expanded at base, dirty white (8A1-8B1). Odour and taste indistinctive.

Spores 8.8-9.7 × 4.9-5.8 μm, Q = 1.5-1.9, ovoid in front view, amygdaliform in profile, reddish brown in water, dark brown and gradually becoming black-brown in 5% KOH, inamyloid, smooth, germ pore absent. Basidia 17-20 × 7.3-9.8 μm, clavate, hyaline, 4-spored. Pleurocystidia abundant, 44-68 × 9.8-13 μm, fusiform to narrowly utriform, thin-walled, apex obtuse to subacute, rarely subcapitate. Pleurocystidioid cheilocystidia abundant, 22-32 × 7.3-12 μm, fusiform to utriform, short mucronate or obtuse at apex, rarely mixed with pyriform cells. Trama of gills irregular. Pileipellis consisting of a 1-2-cell-deep layer of subglobose cells that were 30-40 μm broad. Clamps present.

Habit and habitat.

Scattered on mosses in mixed forests of Cunninghamia spp., Pinus spp. and Quercus semecarpifolia .

Other specimens examined.

China. Scenic Spot of Kangding Love Song (Mugecuo), Kangding City, Tibetan Autonomous Prefecture of Garze , Sichuan Province, 22 August 2017, Jun-Qing Yan, HMJAU57044 .

Figures

Figure 2. Basidiomata a-c Heteropsathyrella macrocystidia (HMJAU 37802) d-f Psathyrella amygdalinospora (HMJAU 37952) g, h P. piluliformoides (HMJAU 37923) i P. truncatisporoides (HMJAU 37947). Scale bars: 10 mm (a-i).

Figure 4. Psathyrella amygdalinospora (HMJAU 37952) a basidiomata b basidiospores c basidia d pileipellis e pleurocystidia f cheilocystidia. Scale bars: 10 mm (a); 10 μm (b-f).