Mycena brunnescens L. N. Liu, 2024

Zhang, Hong, Xiao, Ying Xin, Tan, Zhu Ming, Shen, Ai Rong, Shen, Bao Ming, Tan, Yun, Li, Sai Nan, Feng, Li Guo, Liu, Zhu Xiang & Liu, Li Na, 2024, Mycena brunnescens (Basidiomycota, Mycenaceae), a new species of Mycena sect. Pterigenae from China, Biodiversity Data Journal 12, pp. e 125570-e 125570 : e125570-

Mycena brunnescens L. N. Liu sp. nov.

Materials

Type status: Holotype. Occurrence: occurrenceID: 2723CE40-21C3-5048-93D7-89379C9BF8F0; Taxon: kingdom: Fungi; phylum: Basidiomycota; class: Agaricomycetes; order: Agaricales ; family: Mycenaceae ; genus: Mycena ; taxonRank: species; Location: country: China; stateProvince: Guangxi; county: Leye; verbatimLocality: Yachang Orchid National Nature Reserve; verbatimLatitude: 24 ◦ 29 ′ 04.62 ″ N; verbatimLongitude: 106 ◦ 22 ′ 35.40 ″ E; Identification: identifiedBy: Ying Xin Xiao; Event: eventDate: 30 June 2021; Record Level: institutionID: JIU; collectionID: JIU 125

Type status: Paratype. Occurrence: occurrenceID: 10688CAA-8D2B-56EE-86AD-CF320C05CC3E; Taxon: kingdom: Fungi; phylum: Basidiomycota; class: Agaricomycetes; order: Agaricales ; family: Mycenaceae ; genus: Mycena ; taxonRank: species; Location: country: China; stateProvince: Guangxi Zhuang Autonomous Region and Sichuan Province; county: Leye; verbatimLocality: Yachang Orchid National Nature Reserve; verbatimLatitude: 27 ° 23 ′ 40 ′′ N; verbatimLongitude: 106 ° 11 ′ 35 ′′ E; Identification: identifiedBy: Ying Xin Xiao; Event: eventDate: 30 June 2021; Record Level: institutionID: JIU; collectionID: JIU 126

Type status: Paratype. Occurrence: occurrenceID: 611F3C05-18F0-5409-A51F-6496001496C9; Taxon: kingdom: Fungi; phylum: Basidiomycota; class: Agaricomycetes; order: Agaricales ; family: Mycenaceae ; genus: Mycena ; taxonRank: species; Location: country: China; stateProvince: Sichuan province; Identification: identifiedBy: Ying Xin Xiao; Event: eventDate: 30 September 2023; Record Level: institutionID: JIU; collectionID: JIU 127

Description

Pileus 3–8 mm diam., hemispherical, plane-convex to nearly applanate, umbonate to deppresed to almost subumbilicate, first translucent-striate, then sulcate, glabrous, light orange (6 A 5) to orange (6 B 7) when young, becoming yellowish-brown (6 F 6) or dark brownish-grey (6 F 8) in the disc and in the grooves with age, margin concolorous or paler, pale yellowish-brown (5 D 8) to brown (6 D 7) or dark brown (6 F 4–6 F 8). Context thin, fragile, whitish. Lamellae decurrent, moderately distant (L = 15–20, I = 1–2), changing from whitish (1 A 1) to dark brown (6 F 7–6 F 8) when bruised, lamellae edges light orange to orange (6 A 5-6 B 7), light brown (6 D 4–6 D 8) to brown (6 E 8). Stipe 17–34 × 1–2 mm, cylindrical, hollow, surface smooth, yellowish-red (8 B 6) to reddish-brown (8 D 6) towards apex when young, becoming yellowish-brown (6 F 6–6 F 8) in age, the upper portion brownish-orange (6 C 6), light brown (6 D 4–6 D 8) or brown (6 E 4–6 E 8), equal and with a slightly bulbous base, covered with whitish fibrils (Fig. 1 ). Odour and taste not distinctive.

Basidiospores 5.9–7.3 (7.5) × (3.1) 3.2–3.8 μm, Q = 1.6–2.2, ellipsoid to oblong, few subcylindrical, smooth, hyaline, amyloid, thin-walled. Basidia 14–23 × 5–10 μm, short clavate or clavate, 4 – spored, thin walled. Cheilocystidia 20–42 × 6–12 μm, clavate or cylindrical, with branches excrescences at the apex, 3–10 × 1–3 μm, with yellowish- brown (5 D 8) contents. Pleurocystidia absent. Pileipellis a cutis, hyphae of the pileipellis 1.6–4 μm wide, hyaline, densely covered with cylindrical excrescences, 1–4 × 1–2 μm. Hyphae of the stipitipellis 1–7 μm wide, with cylindrical excrescences 1–4 × 1–2 μm, hyaline, thin-walled. Clamps present in all tissues (Fig. 2 ).

Diagnosis

Mycena brunnescens has a brown pileus, lamellae that change from whitish to brown when bruised, orange to brown lamellae edges, basidiospores ellipsoid to oblong, cheilocystidia clavate with yellowish-brown contents, pileipellis and stipitipellis covered with cylindrical excrescences. Differs from M. strobilinoidea by branched cheilocystidia and absent pleurocystidia.

Etymology

Referring to the colour of basidiomata.

Distribution

Only known from Guangxi Zhuang Autonomous Region and Sichuan Province.

Ecology

Scattered or gregarious on decayed leaves.

Figures

Figure 1. Basidiomata of Mycena brunnescens. Scale bar = 5 mm. Photos by Li Na Liu.

Figure 2. Morphological features of Mycena brunnescens. a basidiomata; b basidia; c basidiospores; d cheilocystidia; e pileipellis; f stipitipellis. Scale bars: a = 5 mm, b, c, d, e, f = 10 μm.