Lyophyllum pallidofumosum Y. H. Ma, W. M. Chen & Y. C. Zhao, 2022

Ma, Yuanhao, Liu, Ping, Zhao, Ziyue, Chen, Weimin & Zhao, Yongchang, 2022, Lyophyllum pallidofumosum sp. nov. (Lyophyllaceae, Agaricales), from southwestern China, Phytotaxa 576 (2), pp. 173-183 : 178

Lyophyllum pallidofumosum Y. H. Ma, W. M. Chen & Y. C. Zhao sp. nov. ( Figs. 1A , 3 )

MycoBank: MB 844903

Etymology: — pallidofumosum , refers to the morphological similarity of the new species to L. fumosum .

Diagnosis:— Lyophyllum pallidofumosum differs from the other species of the L. decastes complex by a greyish orange pileus surface, margin with waves when old; globose to subglobose basidiospores (4.5–5.6 × 4.3–5.4 µm), clavate basidia (25–34 × 7–9 µm); occurring in a mixed forest dominated by Pinus yunnanensis , Pinus armandi , and Quercus fabrei ; and the highest growth rate on the YPD medium,.

Holotype:— CHINA, Yunnan Province, Xuanwei City, Reshui Town , in a mixed forest, 25°58′17″ N, 103°44′50″ E, elev. 2344m, 09 September 2021, Yuanhao Ma, Weimin Chen, Ping Liu, 21rs0242 (HKAS 124190)

Description:—pileus 20–60 mm in diam., Pileus shape convex and margin involute when young, applanate, margin waves when old. Pileus colour slightly desaturated orange (5B3–5), greyish orange (6B5), oak brown (5D5–6). Lamellae adnate or subdecurrent. Lamellae colour white (5A1) to light greyish orange (5B2). Context white to whitish. Stipe cylindrical slightly enlarged towards base, central, solid, tough in texture, 30–80 × 8–15 mm. Stipe colour white (5A1) to light greyish orange (5B2).

Basidiospores hyaline, globose to subglobose, smooth, with a single large oil-drop and a small apiculus, (4.26–) 4.55–5.54 (–5.76) × (4.15–) 4.30–5.36 (–5.57) µm, (m/n/p=113/6/2, l m =5.06 ± 0.31µm, w m =4.83 ±0.31µm), Q= (1.00–) 1.01–1.11 (–1.12), Q m =1.05 ±0.32. Basidia 4-spored, clavate, sometimes ventricose, (24.10–) 25.53–33.50 (–35.36) × (6.78–) 7.09–8.78 (–9.63) µm, l m =29.08 ± 2.31µm, w m =7.89 ±0.55µm, Q= (2.93–) 3.15–4.24 (–4.44), Q m =3.70 ±0.34; sterigmata 1.77–3.87 µm long. Some with clamp connections. Lamellae without cheilocystidia and pleurocystidia.

Colonies 43–45 mm radius after 24 d at 22℃ in the dark on YPD, white, downy to cottony with loose aerial hyphae; some with clamp connections.

Habitat:—solitary, gregarious or cespitose on the ground as saprobic in a mixed forest dominated by Pinus yunnanensis , Pinus armandi , and Quercus fabrei .

Additional specimens examined:— CHINA, Yunnan Province, Xuanwei City, Reshui Town , in a mixed forest, 25°58′17″ N, 103°44′50″ E, elev. 2344m, 24 July 2019, YAASM6138 (HKAS 124189, Paratype) ; ibid., Shangri-La County, 16 October 2020, YAASM6215 ; ibid., 26 July 2006, yang 4742 (HKAS 50539) ; ibid., Lanping County, Jinding Town , 15 October 2011, zhao 1334 (HKAS 74287) .

Ex-type: YAASM6628 and YAASM6629, isolated from the inner tissues of two basidiomata.

Ex-type sequences:— YAASM6628/HKAS124190a = LSU: ON834576 , ITS: ON680829 ; YAASM6629/ HKAS124190b = LSU: ON834577 , ITS: ON680830 .

Figures

FIGURE 1. Morphological properties of Lyophyllum cultures on YPD medium after 24 d in the dark in a 90 mm diam petri dish. A. L. pallidofumosum; B. L. decastes; C. L. fumosum; D. L. shimeji. Scale bars: A–D = 18 mm.

FIGURE 3. Lyophyllum pallidofumosum. A–B. Whole basidiomata (HKAS 124190, Holotype). Scale bars: A = 100 mm, B = 20 mm. C. Whole basidiomata (HKAS 124189, Paratype). Scale bars = 50 mm. D–F. Hymenium, Scale bars: D = 100 μm, E–F = 20 μm. G. Basidiospores. H. Basidia and basidioles. Scale bars: G–H = 20 μm.