Lyophyllum deqinense Y.H. Ma, W.M. Chen & Y.C. Zhao, 2023

Ma, Yuanhao, Liu, Ping, Zhao, Ziyue, Chen, Weimin & Zhao, Yongchang, 2023, Lyophyllum deqinense (Lyophyllaceae, Agaricales), a new species from southwestern China, Phytotaxa 598 (3), pp. 219-228 : 223-226

Lyophyllum deqinense Y.H. Ma, W.M. Chen & Y.C. Zhao sp. nov.

( Figs. 2 , 3 )

MycoBank: MB 847556

Etymology:—the epithet “deqin” refers to Deqin County where the holotype was collected.

Diagnosis:—This species is characterized by its greyish orange to slightly desaturated orange pileus with a broad, low and obtuse central umbo, covered by minute and caducous fibrillose scales; subglobose to globose basidiospores (5.7–7.2 × 5.5–6.8 µm), clavate basidia (24–34 × 7–10 µm); occurrence in a pure evergreen bushland dominated by Quercus sp. , and cespitose and gregarious habit on the ground. L. pallidofumosum differs in the smaller basidiospores (4.5–5.6 × 4.3–5.4 µm), and solitary, gregarious or subcaespitose habit on the ground in a mixed forest dominated by Pinus yunnanensis , Pinus armandi , and Quercus fabrei .

Holotype:— CHINA. Yunnan Province, Deqin County, Hongpo Village , 28°17′37″ N, 98°55′25″ E, elev. 3341 m, 06 July 2022, 22hp0175 ( HKAS 127113 ).

Description:— Pileus 40–60 mm diameter, not very fleshy, convex or convex-paraboloid when young to applanate when older, with a broad, low and obtuse central umbo; surface dry, covered by minute fibrillose scales, frequently caducous; margin inrolled; initially light greyish orange (7C2) to dark greyish orange (7D–6), then greyish orange (7D3–6) or slightly desaturated orange (7C4) with a darker center and margin. Lamellae close, adnate or subdecurrent, whitish (7A1). Stipe 30–55 × 4–13 mm, cylindrical, central, solid, whitish (7A1), surface appressed fibrillose. Context thin, whitish (7A1), unchanging in color when injured. Smell faint, taste mild.

Basidiospores hyaline, subglobose to globose, smooth, some with a single oil drop and a small apiculus, (5.6–) 5.7–7.2 (–7.4) × (5.2–) 5.5–6.8 (–7.1) µm, (m/n/p=97/5/3), l m =6.4 ± 0.4 µm, w m =6.1 ± 0.4 µm, Q=1.0–1.1, Q m =1.1 ± 0.0. Basidia 4-spored, clavate, sometimes ventricose, (22.4–) 24.1–33.8 (–35.2) × (7.1–) 7.3–9.9 (–10.8) µm, l m =29.1 ± 2.5 µm, w m =8.6 ± 0.7 µm, Q= (2.5–) 2.8–4.1 (–4.6), Q m =3.4 ± 0.4. Cheilocystidia and pleurocystidia not observed. Lamella trama more or less regular, hyphae 4.9–16.1 (–24.5) µm wide, thin-walled with constricted septa, hyaline. Pileipellis a cutis, composed of parallel, cylindrical hyphae, not or slightly narrowed at septa, 2.9–6.7 µm wide, thickwalled, branched or non-branched. Stipitipellis consisting of parallel, cylindrical hyphae, 2.4–8.5 µm wide, thickwalled, non-branched. Clamp connections present in all tissues of the basidioma.

Habitat:—cespitose and gregarious on the ground in a pure evergreen bushland dominated by Quercus sp.

Additional specimens examined:— CHINA. Yunnan Province, Xuanwei County, Reshui Town, in a mixed forest, 25°58′17″ N, 103°44′50″ E, elev. 2344m, 24 July 2019, YAASM6138 ( HKAS 124189 ); ibid., 09 September 2021 , 21rs0242 (HKAS 124190); 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: YAASM6843 and YAASM6844 , isolated from the inner tissues of two basidiomata.

Ex-type sequences:—YAASM6843/HKAS127113 = LSU: OQ418112, ITS: OQ418117; YAASM6844/ HKAS127113 = LSU: OQ418111, ITS: OQ418116.

Figures

FIGURE 2. Lyophyllum deqinense. A–C. Whole basidiomata (HKAS 127113, Holotype). Scale bars: A–B = 50 mm, C = 10 mm. Photos by: Y. H. Ma.

FIGURE 3. Microscopic features of Lyophyllum deqinense (HKAS 127113, Holotype) in Congo Red. A. Basidiospores; B. Basidia; C. Lamella trama; D. Pileipellis; E. Stipitipellis. Scale bars: A–E = 20 μm. Photos by: Y. H. Ma.